Researcher basic information

• Ph.D, 米国Montana州立大学

• https://researchmap.jp/read0118371?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200901068708757596
• http://wqc-ue.eng.hokudai.ac.jp/~JOUSUI/

• 10253816

• 200901068708757596

• 光電気化学的有価物合成
• 微生物燃料電池(MFC)
• 嫌気性アンモニア酸化（anammox)
• 分子生物学
• 環境微生物生態学
• 糞便汚染
• 病原微生物
• 水質保全
• 水の安全性評価
• 浄水処理
• 廃水処理
• Molecular microbiology
• Environmental Microbiology
• fecal pollution
• pathogenic bacteria
• Water pollution contorl
• Water safety assessment
• Water Treatment
• Wastewater Treatment

• Life Science, Ecology and environment
• Environmental Science/Agriculture Science, Environmental materials and recycle technology
• Environmental Science/Agriculture Science, Environmental load reduction and remediation
• Social Infrastructure (Civil Engineering, Architecture, Disaster Prevention), Environmental systems for civil engineering

• Bachelor's degree program, School of Engineering
• Master's degree program, Graduate School of Engineering
• Doctoral (PhD) degree program, Graduate School of Engineering

Research activity information

• Jun. 2025, Research.com, 2025 - Research.com Microbiology in Japan Leader Award
• Sep. 2023, International Water Association (IWA), The Ardern-Lockett Award 2023
  Satoshi Okabe
• Jun. 2023, 公益社団法人 日本水環境学会, 学術賞
  窒素除去にかかわる複合微生物生態系の構造と機能の解析
  岡部 聡
• Mar. 2018, 北海道大学, 北海道大学教育研究総長表彰（研究部門）
  岡部 聡
• Mar. 2017, 北海道大学, 北海道大学教育研究総長表彰（教育部門）
  岡部 聡
• 2016, International Water Association, IWA Fellow
  OKABE Satoshi
• Apr. 2014, Nagase Science and Technology Foundation, Nagase Foundation Award
  OKABE Satoshi
• 2009, 日本水環境学会論文賞
  Japan
• 2008, 日本学術振興会賞
  Japan
• 2008, JSPS prize
• 2006, The best poster award at The 6th International Conference on Biofilm Systems
• 2005, 土木学会環境工学フォーラム優秀ポスター発表賞
  Japan
• 2003, 環境工学フォーラム論文賞
  Japan
• 2001, 月刊「水」論文賞
• 1999, 日本水道協会論文有効賞
  Japan
• 1999, 日本水環境学会論文奨励賞（廣瀬賞）
  Japan
• 1999, 平成10年度土木学会年次学術講演会優秀講演者賞
  Japan
• 1998, 平成9年度土木学会年次学術講演会優秀講演者賞
  Japan

• In Situ Biogas Upgrading Performance, Microbial Community Structures, and Metabolic Potentials during Biomethanation in a Thermophilic Anaerobic Membrane Bioreactor Treating Sewage Sludge
  Akira Hafuka; Mamoru Oshiki; Sota Fujino; Kohei Takahashi; Satoshi Okabe; Ryusei Ito; Shiho Mizuno; Kazuyuki Oshita; Katsuki Kimura
  ACS ES&T Water, American Chemical Society (ACS), 06 Oct. 2025
  Scientific journal
• Residual ammonia shapes nitrite-oxidizing activity and microbial spatial dynamics in gel-immobilized anammox biomass under mainstream conditions
  Hyungmin Choi; Jihun Park; Danbee Kim; Mamoru Oshiki; Satoshi Okabe; Changsoo Lee
  Chemical Engineering Journal, 519, 165408, 165408, Elsevier BV, Sep. 2025
  Scientific journal
• Oxygen isotope fractionation during anaerobic ammonium oxidation by the marine representative Candidatus Scalindua sp.
  Kanae Kobayashi; Kazuya Nishina; Keitaro Fukushima; Yuji Onishi; Akiko Makabe; Mamoru Oshiki; Keisuke Koba; Satoshi Okabe
  The ISME journal, 02 Jun. 2025, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, Analyzing the nitrogen (15ε) and oxygen (18ε) isotope effects of anaerobic ammonium oxidation (anammox) is essential for accurately assessing its potential contribution to fixed-N losses in the ocean, yet the 18ε of anammox remains unexplored. Here, we determined the previously unexplored 18ε of anammox using a highly enriched culture of the marine anammox species "Ca. Scalindua sp". Because Scalindua significantly accelerated oxygen isotope exchange between NO2- and H2O, we introduced a new rate constant for anammox-mediated oxygen isotope exchange (keq, AMX = 8.44 ~ 13.56 ×10-2 h-1), which is substantially faster than abiotic oxygen isotope exchange (keq, abio = 1.13 ×10-2 h-1), into a numerical model to estimate the 18ε during anammox. Based on our experimental results, we successfully determined the 18ε associated with: (1) conversion of NO2- to N2 (18εNO2-→N2 = 10.6 ~ 16.1‰), (2) NO2- oxidation to NO3- (18εNO2-→NO3- = -2.9 ~ -11.0‰, inverse fractionation), (3) incorporation of oxygen from water during NO2- oxidation to NO3- (18εH2O = 16.4 ~ 19.2‰). Our study underscores the possibility that unique anammox oxygen isotope signals may be masked due to substantial anammox-mediated oxygen isotope exchange between NO2- and H2O. Therefore, careful consideration is required when utilizing δ18ONO3- and δ18ONO2- as geochemical markers to assess the potential contribution of anammox to fixed-N losses in the ocean.
• Interspecific competition and adaptation of anammox bacteria at different salinities: Experimental validation of the Monod growth model with salinity inhibition
  Satoshi Okabe; Akimichi Kamizono; Seiya Kawasaki; Kanae Kobayashi; Mamoru Oshiki
  Water Research, 271, 122883, 122883, Elsevier BV, Mar. 2025, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Microbial photoelectrochemical cell using hybrid CuO/ZnO/CuO and Shewanella oneidensis MR-1 anode for hydrogen production
  Ryosuke Matsuo; Seiichi Watanabe; Satoshi Okabe
  Chemical Engineering Journal, 505, 159093, 159093, Elsevier BV, Feb. 2025, [Peer-reviewed], [Last author, Corresponding author]
  English, Scientific journal
• Microbial Community Structure of Mesophilic and Low-temperature Partial Nitrification-anammox Reactors: Distribution and Functional Roles of the Core Microbiome.
  Mamoru Oshiki; Kohei Takahashi; Seiya Kawasaki; Hyungmin Choi; Jihye Park; Kwiyong Kim; Hyokwan Bae; Satoshi Okabe; Changsoo Lee
  Microbes and environments, 40, 2, 2025, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, Microbial community structures in mesophilic and low-temperature anammox and partial nitrification-anammox reactors were exami-ned by a 16S rRNA-gene amplicon sequencing ana-lysis. The anammox bacterium, Jettenia sp., was dominant, and nitrifying bacteria, including Nitrosomonas sp. (aerobic ammonia-oxidizing bacterium) and Nitrospira sp., (nitrite-oxidizing bacterium) coexisted in the bioreactors. Core coexisting bacteria, such as Sulfurisoma sp. and Zeimonas sp., showed oxygen-scavenging and NO3- reduction potentials. Sulfurisoma-related bacteria are distributed across wastewater treatment plants worldwide, particularly in denitrification systems. These results underscore the ecological and functional importance of microbial consortia in enhancing nitrogen removal efficiency.
• Quantitative association of SARS-CoV-2 in wastewater and clinically confirmed cases in different areas of the Tokyo 2020 Olympic and Paralympic Village
  Masaaki Kitajima; Michio Murakami; Hiroki Ando; Syun-suke Kadoya; Ryo Iwamoto; Tomohiro Kuroita; Kiyoshi Yamaguchi; Hiroyuki Kobayashi; Satoshi Okabe; Hiroyuki Katayama; Seiya Imoto
  Science of The Total Environment, 960, 178209, 178209, Elsevier BV, Jan. 2025, [Peer-reviewed]
  English, Scientific journal
• Corrigendum to "The Efficient and Practical virus Identification System with ENhanced Sensitivity for Solids (EPISENS-S): A rapid and cost-effective SARS-CoV-2 RNA detection method for routine wastewater surveillance" [Sci. Total Environ. 843 (2022) 157101 (15 October)].
  Hiroki Ando; Ryo Iwamoto; Hiroyuki Kobayashi; Satoshi Okabe; Masaaki Kitajima
  The Science of the total environment, 954, 176606, 176606, 01 Dec. 2024, [International Magazine]
  English
• Salinity Tolerance and Osmoadaptation Strategies in Four Genera of Anammox Bacteria: Brocadia, Jettenia, Kuenenia, and Scalindua
  Satoshi Okabe; Akimichi Kamizono; Lei Zhang; Seiya Kawasaki; Kanae Kobayashi; Mamoru Oshiki
  Environmental Science & Technology, 58, 12, 5357, 5371, American Chemical Society (ACS), 16 Mar. 2024, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Quantitative analysis of SARS-CoV-2 RNA in wastewater and evaluation of sampling frequency during the downward period of a COVID-19 wave in Japan.
  Tomohiro Kuroita; Akimasa Yoshimura; Ryo Iwamoto; Hiroki Ando; Satoshi Okabe; Masaaki Kitajima
  The Science of the total environment, 906, 166526, 166526, 01 Jan. 2024, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Wastewater-based epidemiology (WBE) is a practical approach for detecting the presence of SARS-CoV-2 infections and assessing the epidemic trend of the coronavirus disease 2019 (COVID-19). The purpose of this study was to evaluate the minimum sampling frequency required to properly identify the COVID-19 trend during the downward epidemic period when using a highly sensitive RNA detection method. WBE was conducted using the Efficient and Practical virus Identification System with ENhanced Sensitivity for Solids (EPISENS-S), a highly sensitive SARS-CoV-2 RNA detection method, at nine neighboring wastewater treatment plants (WWTPs). These WWTPs were in the same prefecture in Japan, and they had different sewer types, sampling methods, and sampling frequencies. The overall detection rate of SARS-CoV-2 RNA was 97.8 % during the entire study period when the geometric means of new COVID-19 cases per 100,000 inhabitants were between 3.3 and 7.7 in each WWTP. The maximum SARS-CoV-2 RNA concentration in wastewater was 2.14 × 104 copies/L, which corresponded to pepper mild mottle virus (PMMoV)-normalized concentrations of 6.54 × 10-3. We evaluated the effect of sampling frequencies on the probability of a significant correlation with the number of newly reported COVID-19 cases by hypothetically reducing the sampling frequency in the same dataset. When the wastewater sampling frequency occurred 5, 3, 2, and 1 times per week, these results exhibited significant correlations of 100 % (5/5), 89 % (8/9), 85 % (23/27), and 48 % (13/27), respectively. To achieve significant correlation with a high probability of over 85 %, a minimum sampling frequency of twice per week is required, even if sampling methods and sewer types are different. WBE using the EPISENS-S method and a sampling frequency of more than twice a week can be used to properly monitor COVID-19 wave epidemic trends, even during downward periods.
• Collaborative metabolisms of urea and cyanate degradation in marine anammox bacterial culture
  Mamoru Oshiki; Emi Morimoto; Kanae Kobayashi; Hisashi Satoh; Satoshi Okabe
  ISME Communications, 4, 1, Oxford University Press (OUP), 01 Jan. 2024, [Peer-reviewed], [Last author, Corresponding author]
  English, Scientific journal, Abstract
  
  Anammox process greatly contributes to nitrogen loss occurring in oceanic oxygen minimum zones (OMZs), where the availability of NH4+ is scarce as compared with NO2−. Remineralization of organic nitrogen compounds including urea and cyanate (OCN−) into NH4+ has been believed as an NH4+ source of the anammox process in oxygen minimum zones. However, urea- or OCN−- dependent anammox has not been well examined due to the lack of marine anammox bacterial culture. In the present study, urea and OCN− degradation in a marine anammox bacterial consortium were investigated based on 15N-tracer experiments and metagenomic analysis. Although a marine anammox bacterium, Candidatus Scalindua sp., itself was incapable of urea and OCN− degradation, urea was anoxically decomposed to NH4+ by the coexisting ureolytic bacteria (Rhizobiaceae, Nitrosomonadaceae, and/or Thalassopiraceae bacteria), whereas OCN− was abiotically degraded to NH4+. The produced NH4+ was subsequently utilized in the anammox process. The activity of the urea degradation increased under microaerobic condition (ca. 32–42 μM dissolved O2, DO), and the contribution of the anammox process to the total nitrogen loss also increased up to 33.3% at 32 μM DO. Urea-dependent anammox activities were further examined in a fluid thioglycolate media with a vertical gradient of O2 concentration, and the active collaborative metabolism of the urea degradation and anammox was detected at the lower oxycline (21 μM DO).
• Tracking the effects of the COVID-19 pandemic on viral gastroenteritis through wastewater-based retrospective analyses.
  Hiroki Ando; Warish Ahmed; Satoshi Okabe; Masaaki Kitajima
  The Science of the total environment, 905, 166557, 166557, 20 Dec. 2023, [Peer-reviewed], [International Magazine]
  English, Scientific journal, The COVID-19 pandemic possibly disrupted the circulation and seasonality of gastroenteritis viruses (e.g., Norovirus (NoV), Sapovirus (SaV), group A rotavirus (ARoV), and Aichivirus (AiV)). Despite the growing application of wastewater-based epidemiology (WBE), there remains a lack of sufficient investigations into the actual impact of the COVID-19 pandemic on the prevalence of gastroenteritis viruses. In this study, we measured NoV GI and GII, SaV, ARoV, and AiV RNA concentrations in 296 influent wastewater samples collected from three wastewater treatment plants (WWTPs) in Sapporo, Japan between October 28, 2018 and January 12, 2023 using the highly sensitive EPISENS™ method. The detection ratios of SaV and ARoV after May 2020 (SaV: 49.8 % (134/269), ARoV: 57.4 % (151/263)) were significantly lower than those before April 2020 (SaV: 93.9 % (31/33), ARoV: 97.0 % (32/33); SaV: p < 3.5×10-7, ARoV: p < 1.5×10-6). Furthermore, despite comparable detection ratios before (88.5 %, 23/26) and during (66.7 %, 80/120) the COVID-19 pandemic (p = 0.032), the concentrations of NoV GII revealed a significant decrease after the onset of the pandemic (p < 1.5×10-7, Cliff's delta = 0.72). NoV GI RNA were sporadically detected (24.7 %, 8/33) before April 2020 and after May 2020 (6.5 %, 17/263), whereas AiV was consistently (100 %, 33/33) detected from wastewater throughout the study period (95.8 %, 252/263). The WBE results demonstrated the significant influence of COVID-19 countermeasures on the circulation of gastroenteritis viruses, with variations observed in the magnitude of their impact across different types of viruses. These epidemiological findings highlight that the hygiene practices implemented to prevent COVID-19 infections may also be effective for controlling the prevalence of gastroenteritis viruses, providing invaluable insights for public health units and the development of effective disease management guidelines.
• Fabrication of ZnO/CuO nanoforests and their applicability to microbial photoelectrochemical cells
  Ryosuke Matsuo; Yuki Takahashi; Seiichi Watanabe; Satoshi Okabe
  Applied Catalysis B: Environmental, 339, 123097, 123097, Elsevier BV, Dec. 2023, [Peer-reviewed], [Last author, Corresponding author]
  English, Scientific journal
• Growth of the Nitrosomonas europaea cells in the biofilm and planktonic growth mode: Responses of extracellular polymeric substances production and transcriptome
  Mamoru Oshiki; Takahiro Saito; Yuki Nakaya; Hisashi Satoh; Satoshi Okabe
  Journal of Bioscience and Bioengineering, Elsevier BV, Nov. 2023, [Peer-reviewed], [Last author, Corresponding author]
  English, Scientific journal
• Identification of SARS-CoV-2 variants in wastewater using targeted amplicon sequencing during a low COVID-19 prevalence period in Japan.
  Ryo Iwamoto; Kiyoshi Yamaguchi; Kotoe Katayama; Hiroki Ando; Ken-Ichi Setsukinai; Hiroyuki Kobayashi; Satoshi Okabe; Seiya Imoto; Masaaki Kitajima
  The Science of the total environment, 887, 163706, 163706, 20 Aug. 2023, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Wastewater-based epidemiology is expected to be able to identify SARS-CoV-2 variants at an early stage via next-generation sequencing. In the present study, we developed a highly sensitive amplicon sequencing method targeting the spike gene of SARS-CoV-2, which allows for sequencing viral genomes from wastewater containing a low amount of virus. Primers were designed to amplify a relatively long region (599 bp) around the receptor-binding domain in the SARS-CoV-2 spike gene, which could distinguish initial major variants of concern. To validate the methodology, we retrospectively analyzed wastewater samples collected from a septic tank installed in a COVID-19 quarantine facility between October and December 2020. The relative abundance of D614G mutant in SARS-CoV-2 genomes in the facility wastewater increased from 47.5 % to 83.1 % during the study period. The N501Y mutant, which is the characteristic mutation of the Alpha-like strain, was detected from wastewater collected on December 24, 2020, which agreed with the fact that a patient infected with the Alpha-like strain was quarantined in the facility on this date. We then analyzed archived municipal wastewater samples collected between November 2020 and January 2021 that contained low SARS-CoV-2 concentrations ranging from 0.23 to 0.43 copies/qPCR reaction (corresponding to 3.30 to 4.15 log10 copies/L). The targeted amplicon sequencing revealed that the Alpha-like variant with D614G and N501Y mutations was present in municipal wastewater collected on December 4, 2020 and later, suggesting that the variant had already spread in the community before its first clinical confirmation in Japan on December 25, 2020. These results demonstrate that targeted amplicon sequencing of wastewater samples is a powerful surveillance tool applicable to low COVID-19 prevalence periods and may contribute to the early detection of emerging variants.
• Impact of the COVID-19 pandemic on the prevalence of influenza A and respiratory syncytial viruses elucidated by wastewater-based epidemiology.
  Hiroki Ando; Warish Ahmed; Ryo Iwamoto; Yoshinori Ando; Satoshi Okabe; Masaaki Kitajima
  The Science of the total environment, 880, 162694, 162694, 01 Jul. 2023, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Since the COVID-19 pandemic, a decrease in the prevalence of Influenza A virus (IAV) and respiratory syncytial virus (RSV) has been suggested by clinical surveillance. However, there may be potential biases in obtaining an accurate overview of infectious diseases in a community. To elucidate the impact of the COVID-19 on the prevalence of IAV and RSV, we quantified IAV and RSV RNA in wastewater collected from three wastewater treatment plants (WWTPs) in Sapporo, Japan, between October 2018 and January 2023, using highly sensitive EPISENS™ method. From October 2018 to April 2020, the IAV M gene concentrations were positively correlated with the confirmed cases in the corresponding area (Spearman's r = 0.61). Subtype-specific HA genes of IAV were also detected, and their concentrations showed trends that were consistent with clinically reported cases. RSV A and B serotypes were also detected in wastewater, and their concentrations were positively correlated with the confirmed clinical cases (Spearman's r = 0.36-0.52). The detection ratios of IAV and RSV in wastewater decreased from 66.7 % (22/33) and 42.4 % (14/33) to 4.56 % (12/263) and 32.7 % (86/263), respectively in the city after the COVID-19 prevalence. The present study demonstrates the potential usefulness of wastewater-based epidemiology combined with the preservation of wastewater (wastewater banking) as a tool for better management of respiratory viral diseases.
• Oxygen tolerance and detoxification mechanisms of highly enriched planktonic anaerobic ammonium-oxidizing (anammox) bacteria
  Satoshi Okabe; Shaoyu Ye; Xi Lan; Keishi Nukada; Haozhe Zhang; Kanae Kobayashi; Mamoru Oshiki
  ISME Communications, 3, 1, Springer Science and Business Media LLC, 03 May 2023, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal, Abstract
  
  Oxygen is a key regulatory factor of anaerobic ammonium oxidation (anammox). Although the inhibitory effect of oxygen is evident, a wide range of oxygen sensitivities of anammox bacteria have been reported so far, which makes it difficult to model the marine nitrogen loss and design anammox-based technologies. Here, oxygen tolerance and detoxification mechanisms of four genera of anammox bacteria; one marine species (“Ca. Scalindua sp.”) and four freshwater anammox species (“Ca. Brocadia sinica”, “Ca. Brocadia sapporoensis”, “Ca. Jettenia caeni”, and “Ca. Kuenenia stuttgartiensis”) were determined and then related to the activities of anti-oxidative enzymes. Highly enriched planktonic anammox cells were exposed to various levels of oxygen, and oxygen inhibition kinetics (50% inhibitory concentration (IC₅₀) and upper O₂ limits (DO_max) of anammox activity) were quantitatively determined. A marine anammox species, “Ca. Scalindua sp.”, exhibited much higher oxygen tolerance capability (IC₅₀ = 18.0 µM and DO_max = 51.6 µM) than freshwater species (IC₅₀ = 2.7–4.2 µM and DO_max = 10.9–26.6 µM). The upper DO limit of “Ca. Scalindua sp.” was much higher than the values reported so far (~20 µM). Furthermore, the oxygen inhibition was reversible even after exposed to ambient air for 12–24 h. The comparative genome analysis confirmed that all anammox species commonly possess the genes considered to function for reduction of O₂, superoxide anion (O₂^•-), and H₂O₂. However, the superoxide reductase (Sor)-peroxidase dependent detoxification system alone may not be sufficient for cell survival under microaerobic conditions. Despite the fact that anaerobes normally possess no or little superoxide dismutase (Sod) or catalase (Cat), only Scalindua exhibited high Sod activity of 22.6 ± 1.9 U/mg-protein with moderate Cat activity of 1.6 ± 0.7 U/mg-protein, which was consistent with the genome sequence analysis. This Sod-Cat dependent detoxification system could be responsible for the higher O₂ tolerance of Scalindua than other freshwater anammox species lacking the Sod activity.
• Wastewater-based prediction of COVID-19 cases using a highly sensitive SARS-CoV-2 RNA detection method combined with mathematical modeling.
  Hiroki Ando; Michio Murakami; Warish Ahmed; Ryo Iwamoto; Satoshi Okabe; Masaaki Kitajima
  Environment international, 173, 107743, 107743, Mar. 2023, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Wastewater-based epidemiology (WBE) has the potential to predict COVID-19 cases; however, reliable methods for tracking SARS-CoV-2 RNA concentrations (CRNA) in wastewater are lacking. In the present study, we developed a highly sensitive method (EPISENS-M) employing adsorption-extraction, followed by one-step RT-Preamp and qPCR. The EPISENS-M allowed SARS-CoV-2 RNA detection from wastewater at 50 % detection rate when newly reported COVID-19 cases exceed 0.69/100,000 inhabitants in a sewer catchment. Using the EPISENS-M, a longitudinal WBE study was conducted between 28 May 2020 and 16 June 2022 in Sapporo City, Japan, revealing a strong correlation (Pearson's r = 0.94) between CRNA and the newly COVID-19 cases reported by intensive clinical surveillance. Based on this dataset, a mathematical model was developed based on viral shedding dynamics to estimate the newly reported cases using CRNA data and recent clinical data prior to sampling day. This developed model succeeded in predicting the cumulative number of newly reported cases after 5 days of sampling day within a factor of √2 and 2 with a precision of 36 % (16/44) and 64 % (28/44), respectively. By applying this model framework, another estimation mode was developed without the recent clinical data, which successfully predicted the number of COVID-19 cases for the succeeding 5 days within a factor of √2 and 2 with a precision of 39 % (17/44) and 66 % (29/44), respectively. These results demonstrated that the EPISENS-M method combined with the mathematical model can be a powerful tool for predicting COVID-19 cases, especially in the absence of intensive clinical surveillance.
• The detectability and removal efficiency of SARS-CoV-2 in a large-scale septic tank of a COVID-19 quarantine facility in Japan.
  Ryo Iwamoto; Kiyoshi Yamaguchi; Chisato Arakawa; Hiroki Ando; Eiji Haramoto; Ken-Ichi Setsukinai; Kotoe Katayama; Takuya Yamagishi; Sumire Sorano; Michio Murakami; Shigeru Kyuwa; Hiroyuki Kobayashi; Satoshi Okabe; Seiya Imoto; Masaaki Kitajima
  The Science of the total environment, 849, 157869, 157869, 25 Nov. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to be present in sewage, and wastewater-based epidemiology has attracted much attention. However, the physical partitioning of SARS-CoV-2 in wastewater and the removal efficiency of treatment systems require further investigation. This study aimed to investigate the detectability and physical partitioning of SARS-CoV-2 in wastewater and assess its removal in a large-scale septic tank employing anaerobic, anoxic, and oxic processes in a sequential batch reactor, which was installed in a coronavirus disease 2019 (COVID-19) quarantine facility. The amount of SARS-CoV-2 RNA in wastewater was determined with polyethylene glycol (PEG) precipitation followed by quantitative polymerase chain reaction (qPCR), and the association of SARS-CoV-2 with wastewater solids was evaluated by the effect of filtration prior to PEG precipitation (pre-filtration). The amount of SARS-CoV-2 RNA detected from pre-filtered samples was substantially lower than that of samples without pre-filtration. These results suggest that most SARS-CoV-2 particles in wastewater are associated with the suspended solids excluded by pre-filtration. The removal efficiency of SARS-CoV-2 in the septic tank was evaluated based on the SARS-CoV-2 RNA concentrations in untreated and treated wastewater, which was determined by the detection method optimized in this study. Escherichia coli and pepper mild mottle virus (PMMoV) were also quantified to validate the wastewater treatment system's performance. The mean log10 reduction values of SARS-CoV-2, E. coli, and PMMoV were 2.47 (range, 2.25-2.68), 2.81 (range, 2.45-3.18), and 0.66 (range, 0.61-0.70), respectively, demonstrating that SARS-CoV-2 removal by the wastewater treatment system was comparable to or better than the removal of fecal indicators. These results suggest that SARS-CoV-2 can be readily removed by the septic tank. This is the first study to determine the removal efficiency of SARS-CoV-2 in a facility-level sequencing batch activated sludge system.
• The Efficient and Practical virus Identification System with ENhanced Sensitivity for Solids (EPISENS-S): A rapid and cost-effective SARS-CoV-2 RNA detection method for routine wastewater surveillance.
  Hiroki Ando; Ryo Iwamoto; Hiroyuki Kobayashi; Satoshi Okabe; Masaaki Kitajima
  The Science of the total environment, 843, 157101, 157101, 15 Oct. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Wastewater-based epidemiology has attracted attention as a COVID-19 surveillance tool. Here, we developed a practical method for detecting SARS-CoV-2 RNA in wastewater (the EPISENS-S method), which employs direct RNA extraction from wastewater pellets formed via low-speed centrifugation. The subsequent multiplex one-step RT-preamplification reaction with forward and reverse primers for SARS-CoV-2 and a reverse primer only for pepper mild mottle virus (PMMoV) allowed for qPCR quantification of the targets with different abundances in wastewater from the RT-preamplification product. The detection sensitivity of the method was evaluated using wastewater samples seeded with heat-inactivated SARS-CoV-2 in concentrations of 2.11 × 103 to 2.11 × 106 copies/L. The results demonstrated that the sensitivity of the EPISENS-S method was two orders of magnitude higher than that of the conventional method (PEG precipitation, followed by regular RT-qPCR; PEG-QVR-qPCR). A total of 37 untreated wastewater samples collected from two wastewater treatment plants in Sapporo, Japan when 1.6 to 18 new daily reported cases per 100,000 people were reported in the city (March 4 to July 8, 2021), were examined using the EPISENS-S method to confirm its applicability to municipal wastewater. SARS-CoV-2 RNA was quantified in 92 % (34/37) of the samples via the EPISENS-S method, whereas none of the samples (0/37) was quantifiable via the PEG-QVR-qPCR method. The PMMoV concentrations measured by the EPISENS-S method ranged from 2.60 × 106 to 1.90 × 108 copies/L, and the SARS-CoV-2 RNA concentrations normalized by PMMoV ranged from 5.71 × 10-6 to 9.51 × 10-4 . The long-term trend of normalized SARS-CoV-2 RNA concentration in wastewater was consistent with that of confirmed COVID-19 cases in the city. These results demonstrate that the EPISENS-S method is highly sensitive and suitable for routine COVID-19 wastewater surveillance.
• High electrical energy harvesting performance of an integrated microbial fuel cell and low voltage booster-rectifier system treating domestic wastewater.
  N'Dah Joel Koffi; Satoshi Okabe
  Bioresource technology, 359, 127455, 127455, Sep. 2022, [International Magazine]
  English, Scientific journal, To harvest directly usable electrical energy from real domestic wastewater, a new power management system (PMS), transistor-based low voltage boosters followed by a voltage rectifier (LVBR), was developed and tested for its energy harvesting performance. Three air-cathode MFCs were individually linked with LVBs, which were electrically stacked in parallel and then connected with a single voltage rectifier (MFC-LVBR). The MFC-LVBR system could increase VMFCto 11.9 ± 0.6 V without voltage reversal, which was capable of charging a lithium-ion batteryand supercapacitor-based power banks. When the integrated MFC-LVBR system was linked with a lithium-ion battery, the highest normalized energy recovery (NERCOD) of 0.76 kWh/kg-COD (NERvolumeof 0.22 kWh/m3) was achieved with a minimal energy loss of 14.4%, whichwas much higher than those previously reported values.Furthermore, the electrical energy charged in the lithium-ion battery successfully powered a DC peristaltic pump requiring a minimum operating power of 0.46 W.
• Growth of nitrite-oxidizing Nitrospira and ammonia-oxidizing Nitrosomonas in marine recirculating trickling biofilter reactors.
  Mamoru Oshiki; Hirotoshi Netsu; Kyohei Kuroda; Takashi Narihiro; Naoki Fujii; Tomonori Kindaichi; Yoshiyuki Suzuki; Takahiro Watari; Masashi Hatamoto; Takashi Yamaguchi; Nobuo Araki; Satoshi Okabe
  Environmental microbiology, 24, 8, 3735, 3750, 07 Jun. 2022, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, Aerobic ammonia and nitrite oxidation reactions are fundamental biogeochemical reactions contributing to the global nitrogen cycle. Although aerobic nitrite oxidation yields 4.8-folds less Gibbs free energy (∆Gr ) than aerobic ammonia oxidation in the NH4 + -feeding marine recirculating trickling biofilter reactors operated in the present study, nitrite-oxidizing and not ammonia-oxidizing Nitrospira (sublineage IV) outnumbered ammonia-oxidizing Nitrosomonas (relative abundance; 53.8% and 7.59% respectively). CO2 assimilation efficiencies during ammonia or nitrite oxidation were 0.077 μmol-14 CO2 /μmol-NH3 and 0.053-0.054 μmol-14 CO2 /μmol-NO2 - respectively, and the difference between ammonia and nitrite oxidation was much smaller than the difference of ∆Gr . Free-energy efficiency of nitrite oxidation was higher than ammonia oxidation (31%-32% and 13% respectively), and high CO2 assimilation and free-energy efficiencies were a determinant for the dominance of Nitrospira over Nitrosomonas. Washout of Nitrospira and Nitrosomonas from the trickling biofilter reactors was also examined by quantitative PCR assay. Normalized copy numbers of Nitrosomonas amoA were 1.5- to 1.7-folds greater than Nitrospira nxrB and 16S rRNA gene in the reactor effluents. Nitrosomonas was more susceptible for washout than Nitrospira in the trickling biofilter reactors, which was another determinant for the dominance of Nitrospira in the trickling biofilter reactors.
• Correction for Oshiki et al., "Determination of 15N/14N of Ammonium, Nitrite, Nitrate, Hydroxylamine, and Hydrazine Using Colorimetric Reagents and Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS)".
  Mamoru Oshiki; Komei Nagai; Satoshi Ishii; Yoshiyuki Suzuki; Nobuo Saito; Takashi Yamaguchi; Nobuo Araki; Satoshi Okabe
  Applied and environmental microbiology, 88, 9, e0052522, 20 Apr. 2022, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal
• Determination of 15N/14N of Ammonium, Nitrite, Nitrate, Hydroxylamine, and Hydrazine Using Colorimetric Reagents and Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS).
  Mamoru Oshiki; Komei Nagai; Satoshi Ishii; Yoshiyuki Suzuki; Nobuo Saito; Takashi Yamaguchi; Nobuo Araki; Satoshi Okabe
  Applied and environmental microbiology, 88, 7, e0241621, 12 Apr. 2022, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, In the nitrogen (N) cycle, nitrogenous compounds are chemically and biologically converted to various aqueous and gaseous N species. The 15N-labeling approach is a powerful culture-dependent technique to obtain insights into the complex nitrogen transformation reactions that occur in cultures. In the 15N-labeling approach, the fates of supplemented 15N- and/or unlabeled gaseous and aqueous compounds are tracked by mass spectrometry (MS) analysis, whereas MS analysis of aqueous N species requires laborious sample preparation steps and is performed using isotope-ratio mass spectrometry, which requires an expensive mass spectrometer. We developed a simple and high-throughput MS method for determining the 15N atoms percent of NH4+, NO2-, NO3-, NH2OH, and N2H4, where liquid samples (<0.5 mL) were mixed with colorimetric reagents (naphthylethylenediamine for NO2-, indophenol for NH4+, and p-aminobenzaldehyde for N2H4), and the mass spectra of the formed N complex dyes were obtained by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) MS. NH2OH and NO3- were chemically converted to NO2- by iodine oxidation and copper/hydrazine reduction reaction, respectively, prior to the above colorimetric reaction. The intensity of the isotope peak (M + 1 or M + 2) increased when the N complex dye was formed by coupling with a 15N-labeled compound, and a linear relationship was found between the determined 15N/14N peak ratio and 15N atom% for the tested N species. The developed method was applied to bacterial cultures to examine their N-transformation reactions, enabling us to observe the occurrence of NO2- oxidation and NO3- reduction in a hypoxic Nitrobacter winogradskyi culture. IMPORTANCE 15N/14N analysis for aqueous N species is a powerful tool for obtaining insights into the global N cycle, but the procedure is cumbersome and laborious. The combined use of colorimetric reagents and MALDI-TOF MS, designated color MALDI-TOF MS, enabled us to determine the 15N atom% of common aqueous N species without laborious sample preparation and chromatographic separation steps; for instance, the 15N atom% of NO2- can be determined from >1,000 liquid samples daily at <$1 (U.S.) per 384 samples for routine analysis. This convenient MS method is a powerful tool that will advance our ability to explore the N-transformation reactions that occur in various environments and biological samples.
• Temporal dynamics of Campylobacter and Arcobacter in a freshwater lake that receives fecal inputs from migratory geese.
  Mayumi Kobayashi; Qian Zhang; Takahiro Segawa; Mitsuto Maeda; Reiko Hirano; Satoshi Okabe; Satoshi Ishii
  Water research, 217, 118397, 118397, 04 Apr. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Migratory geese could influence the microbiological water quality; however, their impacts on pathogen dynamics remain largely unknown. In this study, we analyzed the population dynamics of Campylobacter and Arcobacter group bacteria (AGB) in a freshwater lake in Japan over two years. The bacteria were quantified by using both culture-dependent and -independent methods. The potential sources of these bacteria were examined by a high-throughput flaA sequencing approach. Campylobacter was abundantly detected both by culture-dependent and -independent methods in the lake, especially when migratory geese were present in the lake. High-throughput flaA sequencing suggests that geese were the likely source of Campylobacter in the lake. The viable population of Campylobacter exceeds the concentrations that can potentially cause 10-4 infections per person per year when water is used to grow fresh vegetables. The occurrence of AGB, on the other hand, was not directly related to the population of migratory geese. AGB were not detected in geese fecal samples. Diverse AGB flaA genotypes occurred in the lake over multiple seasons. Our results suggest that AGB likely comprise a part of the indigenous microbial population of the lake and grow in response to high nutrient, warm temperature, and low dissolved oxygen concentrations in the lake. Geese therefore can indirectly impact the AGB population by providing nutrients to cause eutrophication and lower the dissolved oxygen concentration. Since geese travel long-distance and disperse their fecal microbiota and nutrients to wide areas, they may have significant impacts on water quality and public health.
• Effect of poised cathodic potential on anodic ammonium nitrogen removal from domestic wastewater by air-cathode microbial fuel cells.
  N'dah Joel Koffi; Satoshi Okabe
  Bioresource technology, 348, 126807, 126807, Mar. 2022, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, Performances of anodic ammonia oxidation have been investigated for various bioelectrochemical systems at a wide range of poised anodic potentials in the literature. The effect of poised cathodic potential on ammonium nitrogen (NH4+-N) and total nitrogen (TN, sum of NH4+-N, NO2--N, and NO3--N) removal from domestic wastewater by single chamber air-cathode microbial fuel cells (MFCs) was investigated. Poising the air-cathode potential at +0.7 V vs. SHE significantly increased current generation (from 11 ± 1 mA to 22.8 ± 5 mA) and oxygen permeation into the MFC through the air-cathode (from 75.4 ± 1.2 g-O2/m3/d to 151 ± 3.7 g-O2/m3/d), which consequently resulted in a high NH4+-N removal rate of 150 ± 13 g-NH4+-N/m3/d and TN removal rate of 63 ± 16 g-TN/m3/d. These high NH4+-N and TN removal rates could be attributed to the enhancement of dual respiratory pathways: the electrode-assisted anodic and aerobic NH4+ oxidation.
• Wastewater-based Epidemiology for Understanding COVID-19 Prevalence and Early Detection of Variants
  安藤宏紀; 岡部聡; 北島正章
  Journal of Environmental Biotechnology (Web), 22, 1, 2022, [Peer-reviewed]
  English
• The Intrapopulation Genetic Diversity of RNA Virus May Influence the Sensitivity of Chlorine Disinfection.
  Syun-Suke Kadoya; Syun-Ichi Urayama; Takuro Nunoura; Miho Hirai; Yoshihiro Takaki; Masaaki Kitajima; Toyoko Nakagomi; Osamu Nakagomi; Satoshi Okabe; Osamu Nishimura; Daisuke Sano
  Frontiers in microbiology, 13, 839513, 839513, 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, RNA virus populations are not clonal; rather, they comprise a mutant swarm in which sequences are slightly different from the master sequence. Genetic diversity within a population (intrapopulation genetic diversity) is critical for RNA viruses to survive under environmental stresses. Disinfection has become an important practice in the control of pathogenic viruses; however, the impact of intrapopulation genetic diversity on the sensitivity of disinfection, defined as -log10 (postdisinfected infectious titer/predisinfected titer), has not been elucidated. In this study, we serially passaged populations of rhesus rotavirus. We demonstrated that populations with reduced chlorine sensitivity emerged at random and independently of chlorine exposure. Sequencing analysis revealed that compared with sensitive populations, less-sensitive ones had higher non-synonymous genetic diversity of the outer capsid protein gene, suggesting that changes in the amino acid sequences of the outer capsid protein were the main factors influencing chlorine sensitivity. No common mutations were found among less-sensitive populations, indicating that rather than specific mutations, the diversity of the outer capsid protein itself was associated with the disinfection sensitivity and that the disinfection sensitivity changed stochastically. Simulation results suggest that the disinfection sensitivity of a genetically diverse population is destabilized if cooperative viral clusters including multiple sequences are formed. These results advocate that any prevention measures leading to low intrapopulation genetic diversity are important to prevent the spread and evolution of pathogenic RNA viruses in society.
• Metagenomic Analysis of Five Phylogenetically Distant Anammox Bacterial Enrichment Cultures
  Mamoru Oshiki; Yoshihiro Takaki; Miho Hirai; Takuro Nunoura; Atsushi Kamigaito; Satoshi Okabe
  Microbes and Environments, 37, 3, n/a, n/a, Japanese Society of Microbial Ecology, 2022, [Peer-reviewed], [Corresponding author]
  Scientific journal
• NH2OH Disproportionation Mediated by Anaerobic Ammonium-oxidizing (Anammox) Bacteria.
  Mamoru Oshiki; Lin Gao; Lei Zhang; Satoshi Okabe
  Microbes and environments, 37, 2, 2022, [Peer-reviewed], [Last author, Corresponding author], [Domestic magazines]
  English, Scientific journal, Anammox bacteria produce N2 gas by oxidizing NH4+ with NO2-, and hydroxylamine (NH2OH) is a potential intermediate of the anammox process. N2 gas production occurs when anammox bacteria are incubated with NH2OH only, indicating their capacity for NH2OH disproportionation with NH2OH serving as both the electron donor and acceptor. Limited information is currently available on NH2OH disproportionation by anammox bacteria; therefore, the stoichiometry of anammox bacterial NH2OH disproportionation was examined in the present study using 15N-tracing techniques. The anammox bacteria, Brocadia sinica, Jettenia caeni, and Scalindua sp. were incubated with the addition of 15NH2OH, and the production of 15N-labeled nitrogenous compounds was assessed. The anammox bacteria tested performed NH2OH disproportionation and produced 15-15N2 gas and NH4+ as reaction products. The addition of acetylene, an inhibitor of the anammox process, reduced the activity of NH2OH disproportionation, but not completely. The growth of B. sinica by NH2OH disproportionation (-240.3‍ ‍kJ mol NH2OH-1 under standard conditions) was also tested in 3 up-flow column anammox reactors fed with 1) 0.7‍ ‍mM NH2OH only, 2) 0.7‍ ‍mM NH2OH and 0.5‍ ‍mM NH4+, and 3) 0.7‍ ‍mM NH2OH and 0.5‍ ‍mM NO2-. NH2OH consumption activities were markedly reduced after 7‍ ‍d of operation, indicating that B. sinica was unable to maintain its activity or biomass by NH2OH disproportionation.
• Transcriptomic response of HepG2 cells exposed to three common anti-inflammatory drugs: Ketoprofen, mefenamic acid, and diclofenac in domestic wastewater effluents.
  Hiroe Hara-Yamamura; Koji Nakashima; Toshikazu Fukushima; Satoshi Okabe
  Chemosphere, 286, Pt 2, 131715, 131715, 05 Aug. 2021, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, The biological impacts of residual pharmaceuticals in the complex wastewater effluents have not been fully understood. Here, we investigated changes in the transcriptomic responses of hepatobrastoma (HepG2) cells exposed to a single or partially combined three common non-steroidal anti-inflammatory drugs (NSAIDs); ketoprofen (KPF), mefenamic acid (MFA) and diclofenac (DCF), in domestic wastewater effluents. After 48 h sub-lethal exposure to single compounds, the DNA microarray analysis identified 57-184 differently expressed genes (DEGs). The hierarchical clustering analysis and GO enrichment of the DEGs showed that gene expression profiles of the NSAIDs were distinct from each other although they are classified into the same therapeutic category. Four maker genes (i.e., EGR1, AQP3, SQSTM1, and NAG1) were further selected from the common DEGs, and their expressions were quantified by qPCR assay in a dose-dependent manner (ranging from μg/L to mg/L). The results revealed the insignificant induction of the marker genes at 1 μg/L of KPF, MFA, and DCF, suggesting negligible biological impacts of the NSAIDs on gene expression (early cellular responses) of HepG2 at typical concentration levels found in the actual wastewater effluents. Based on the quantitative expression analysis of the selected marker genes, the present study indicated that the presence of wastewater effluent matrix may mitigate the potentially adverse cellular impacts of the NSAIDs.
• Bioelectrochemical anoxic ammonium nitrogen removal by an MFC driven single chamber microbial electrolysis cell.
  N'Dah Joel Koffi; Satoshi Okabe
  Chemosphere, 274, 129715, 129715, Jul. 2021, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, Nitrogen removal from wastewater is an indispensable but highly energy-demanding process, and thus more energy-saving treatment processes are required. Here, we investigated the performance of bioelectrochemical ammonium nitrogen (NH4+-N) removal from real domestic wastewater without energy-intensive aeration by a single chamber microbial electrolysis cell (MEC) that was electrically powered by a double chamber microbial fuel cell (MFC). Anoxic NH4+-N oxidation and total nitrogen (TN) removal rates were determined at various applied voltages (0-1.2 V), provided by the MFC. The MEC achieved a NH4+-N oxidation rate of 151 ± 42 g NH4+-N m-3 d-1 and TN removal rate of 95 ± 42 g-TN m-3 d-1 without aeration at the applied voltage of 0.8 V (the anode potential Eanode = +0.633 ± 0.218 V vs. SHE). These removal rates were much higher than the previously reported values and conventional biological nitrogen removal processes. Open and closed-circuit MEC batch experiments confirmed that anoxic NH4+-N oxidation was an electrochemically mediated biological process (that is, an anode acted as an electron acceptor) and denitrification occurred simultaneously without NO2- and NO3- accumulation. Moreover, ex-situ15N tracer experiment and microbial community analysis revealed that anammox and heterotrophic denitrification mainly contributed to the TN removal. Thus, the bioelectrochemical anodic NH4+-N oxidation was coupled with anammox and denitrification in this MFC-assisted MEC system. Taken together, our MFC-driven single chamber MEC could be a high rate energy-saving nitrogen removal process without external carbon and energy input and high energy-demanding aeration.
• Maintenance power requirements of anammox bacteria "Candidatus Brocadia sinica" and "Candidatus Scalindua sp."
  Satoshi Okabe; Atsushi Kamigaito; Kanae Kobayashi
  The ISME journal, 15, 12, 3566, 3575, 18 Jun. 2021, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal, Little is known about the cell physiology of anammox bacteria growing at extremely low growth rates. Here, "Candidatus Brocadia sinica" and "Candidatus Scalindua sp." were grown in continuous anaerobic membrane bioreactors (MBRs) with complete biomass retention to determine maintenance energy (i.e., power) requirements at near-zero growth rates. After prolonged retentostat cultivations, the specific growth rates (μ) of "Ca. B. sinica" and "Ca. Scalindua sp." decreased to 0.000023 h-1 (doubling time of 1255 days) and 0.000157 h-1 (184 days), respectively. Under these near-zero growth conditions, substrate was continuously utilized to meet maintenance energy demands (me) of 6.7 ± 0.7 and 4.3 ± 0.7 kJ mole of biomass-C-1 h-1 for "Ca. B. sinica" and "Ca. Scalindua sp.", which accorded with the theoretically predicted values of all anaerobic microorganisms (9.7 and 4.4 kJ mole of biomass-C-1 h-1at 37 °C and 28 °C, respectively). These me values correspond to 13.4 × 10-15 and 8.6 × 10-15 watts cell-1 for "Ca. B. sinica" and "Ca. Scalindua sp.", which were five orders of magnitude higher than the basal power limit for natural settings (1.9 × 10-19 watts cells-1). Furthermore, the minimum substrate concentrations required for growth (Smin) were calculated to be 3.69 ± 0.21 and 0.09 ± 0.05 μM NO2- for "Ca. B. sinica" and "Ca. Scalindua sp.", respectively. These results match the evidence that "Ca. Scalindua sp." with lower maintenance power requirement and Smin are better adapted to energy-limited natural environments than "Ca. B. sinica", suggesting the importance of these parameters on ecological niche differentiation in natural environments.
• Glycogen metabolism of the anammox bacterium "Candidatus Brocadia sinica".
  Satoshi Okabe; Amrini Amalia Shafdar; Kanae Kobayashi; Lei Zhang; Mamoru Oshiki
  The ISME journal, 15, 5, 1287, 1301, May 2021, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal, Presence of glycogen granules in anaerobic ammonium-oxidizing (anammox) bacteria has been reported so far. However, very little is known about their glycogen metabolism and the exact roles. Here, we studied the glycogen metabolism in "Ca. Brocadia sinica" growing in continuous retentostat cultures with bicarbonate as a carbon source. The effect of the culture growth phase was investigated. During the growing phase, intracellular glycogen content increased up to 32.6 mg-glucose (g-biomass dry wt)-1 while the specific growth rate and ATP/ADP ratio decreased. The accumulated glycogen begun to decrease at the onset of entering the near-zero growth phase and was consumed rapidly when substrates were depleted. This clearly indicates that glycogen was synthesized and utilized as an energy storage. The proteomic analysis revealed that "Ca. B. sinica" synthesized glycogen via three known glycogen biosynthesis pathways and simultaneously degraded during the progress of active anammox, implying that glycogen is being continuously recycled. When cells were starved, a part of stored glycogen was converted to trehalose, a potential stress protectant. This suggests that glycogen serves at least as a primary carbon source of trehalose synthesis for survival. This study provides the first physiological evidence of glycogen metabolism in anammox bacteria and its significance in survival under natural substrate-limited habitat.
• Viral Interference as a Factor of False-Negative in the Infectious Adenovirus Detection Using Integrated Cell Culture-PCR with a BGM Cell Line.
  Daisuke Sano; Ryosuke Watanabe; Wakana Oishi; Mohan Amarasiri; Masaaki Kitajima; Satoshi Okabe
  Food and environmental virology, 13, 1, 84, 92, Mar. 2021, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal, This study investigated the influence of viral interference on the detection of enteric viruses using the integrated cell culture (ICC)-PCR with a BGM cell line. It was possible to detect 102 plaque-forming units (PFU)/flask of enterovirus 71 (EV71) in spite of the presence of 104 PFU/flask of adenovirus 40 (AdV40). Meanwhile, 104 PFU/flask of AdV40 was not detected in the presence of 102 PFU/flask of EV71. This inhibition of AdV40 detection using ICC-PCR was attributable to the growth of EV71, because the addition of a growth inhibitor of EV71 (rupintrivir) neutralized the detection inhibition of AdV40. The growth inhibition of AdV40 under co-infection with EV71 is probably caused by the immune responses of EV71-infected cells. AdV is frequently used as a fecal contamination indicator of environmental water, but this study demonstrated that false-negative detection of infectious AdV using ICC-PCR could be caused by the co-existence of infectious EV in a water sample. The addition of rupintrivir could prevent false-negative detection of AdV using ICC-PCR. This study, therefore, emphasizes the importance of confirming the presence of multiple enteric viruses in a sample derived from environmental water prior to the application of ICC-PCR because the viral interference phenomenon may lead to the false-negative detection of target viruses.
• Simple assay for colorimetric quantification of unamplified bacterial 16S rRNA in activated sludge using gold nanoprobes.
  Meri Nakajima; Reiko Hirano; Satoshi Okabe; Hisashi Satoh
  Chemosphere, 263, 128331, 128331, Jan. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Domestic and industrial wastewater treatment systems are vital in the protection of natural ecosystems and human health. Identification of microbial communities in the systems is essential to stable treatment performance. However, the current tools of microbial community analysis are labor intensive and time consuming, and require expensive equipment. Therefore, we developed a simple assay for colorimetric quantification of bacterial 16S rRNA extracted from environmental samples. The assay is based on RNA extraction with commercial kits, mixing the unamplified RNA sample with Au-nanoprobes and NaCl, and analyzing the absorbance spectra. Our experimental results confirmed that the assay format was valid. By analyzing the synthesized DNA, we optimized the operational parameters affecting the assay. We achieved adequate capture DNA density by setting the capture DNA probe concentration at 10 μM during the functionalization step. The required incubation time after NaCl addition was 30 min. The binding site of the target had negligible effect on DNA detection. Under the optimized condition, a calibration curve was created using 16S rRNA extracted from activated sludge. The curve was linear above 5.0 × 107 copies/μL of bacterial 16S rRNA concentration, and the limit of detection was 1.17 × 108 copies/μL. Using the calibration curve, the bacterial 16S rRNA concentration in activated sludge samples could be quantified with deviations between 48% and 208% against those determined by RT-qPCR. The findings of our study introduce an innovative tool for the quantification of 16S rRNA concentration as the activity of key bacteria in wastewater treatment processes, achieving stable treatment performance.
• High voltage generation from wastewater by microbial fuel cells equipped with a newly designed low voltage booster multiplier (LVBM).
  N'Dah Joel Koffi; Satoshi Okabe
  Scientific reports, 10, 1, 18985, 18985, 04 Nov. 2020, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, Although microbial fuel cells (MFCs) can produce renewable energy from wastewater, the generated power is practically unusable. To extract usable power from an MFC fed with wastewater, we newly developed a low voltage booster multiplier (LVBM), which is composed of a self-oscillating LVB and multistage voltage multiplier circuits (VMCs). The low output MFC voltage (ca. 0.4 V) was successfully boosted up to 99 ± 2 V, which was the highest voltage that has been ever reported, without voltage reversal by connecting an LVB with 20-stage VMCs. Moreover, the boosted voltage (81 ± 1 V) was stably maintained for > 40 h even after disconnecting the LVBM from the MFC. The energy harvesting efficiency of LVBM was > 80% when an LVB with 4-stage VMCs was charged to 9.3 V. These results clearly suggest that the proposed LVBM system is an efficient and self-starting energy harvester and storage for low-power generating MFCs.
• Influence of δ18 O of water on measurements of δ18 O of nitrite and nitrate.
  Kanae Kobayashi; Keitaro Fukushima; Yuji Onishi; Kazuya Nishina; Akiko Makabe; Midori Yano; Scott D Wankel; Keisuke Koba; Satoshi Okabe
  Rapid communications in mass spectrometry : RCM, 35, 2, e8979, 14 Oct. 2020, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, RATIONALE: Oxygen isotope ratio measurements of NO2- and NO3- by the azide method and denitrifier method are sensitive to the δ18 O of sample water. However, the influence of δ18 OH2O on those measurements has not been quantitatively evaluated and documented so far. Therefore, we investigated the influence of δ18 OH2O of sample on the δ18 O analysis of NO2- and NO3- . METHODS: We prepared NO2- and NO3- standards (with known δ18 ONO2- and δ18 ONO3- values) dissolved in waters having different δ18 OH2O values (δ18 OH2O = -12.6, 25.9, 56.7, and 110.1‰). Nitrite and nitrate were converted to N2 O using the azide method and the denitrifier method, respectively. The isotope ratios of the generated N2 O were measured with a Sercon PT-GC/IRMS system. The measured δ18 O values of the produced N2 O were plotted against known δ18 ONO2- and δ18 ONO3- values to evaluate the influence of exchange of an oxygen atom with H2 O during the conversion of NO2- to N2 O and NO3- to N2 O, respectively. RESULTS: The degree of O isotope exchange was 10.8 ± 0.3% in the azide method and 5.5 ± 1.0 % in the denitrifier method, indicating that the azide method is more susceptible to artifacts arising from differences in the δ18 OH2O value of water than the denitrifier method. Thus, the intercept of the standard calibration curve must be corrected to account for differences in δ18 OH2O . Abiotic NO2 - H2 O equilibrium isotope effect experiments yielded a rate constant of (1.13 ± 007) × 10-2 (h-1 ) and an equilibrium isotope effect of 11.9 ± 0.1‰ under the condition of pH=7.5, 30°C, and 2.5% salinity. CONCLUSIONS: Oxygen isotope ratio measurements of NO2- by the azide method are highly sensitive to δ18 OH2O as a result of significant oxygen isotope exchange between NO2- and H2 O. Therefore, to obtain the most accurate measurements the same δ18 OH2O value as that of the sample must be used to make the NO2- and NO3- standards.
• The Effect of GD1a Ganglioside-Expressing Bacterial Strains on Murine Norovirus Infectivity.
  Yifan Zhu; Hiroki Kawai; Satoshi Hashiba; Mohan Amarasiri; Masaaki Kitajima; Satoshi Okabe; Daisuke Sano
  Molecules (Basel, Switzerland), 25, 18, 07 Sep. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, In this study, we investigated the impact of GD1a-expressing bacterial strains on the infectivity of murine norovirus (MNV). Eligible bacterial strains were screened from a sewage sample using flow cytometry, and their genetic sequences of 16S rRNA were determined. The enzyme-linked immunosorbent assay (ELISA) was employed to analyze the binding between bacteria and MNV particles, and the plaque assay was used to assess the effects of GD1a-positive and negative strains on MNV infectivity. The result from ELISA shows that MNV particles are able to bind to both GD1a-positive and negative bacterial strains, but the binding to the GD1a-positive strain is more significant. The infectivity assay result further shows that the MNV infectious titer declined with an increasing concentration of GD1a-positive bacteria. The addition of anti-GD1a antibody in the infectivity assay led to the recovery of the MNV infectious titer, further confirming that the binding between MNV particles and bacterial GD1a ganglioside compromises MNV infectivity. Our findings highlight the role indigenous bacteria may play in the lifecycle of waterborne enteric viruses as well as the potential of exploiting them for virus transmission intervention and water safety improvement.
• N2O production using native nos-deficient denitrifying bacterial strains screened by a genome mining approach
  Mamoru Oshiki; Miho Ishimaru; Masashi Hatamoto; Takashi Yamaguchi; Nobuo Araki; Satoshi Okabe
  Bioresource Technology Reports, 11, Sep. 2020, [Peer-reviewed], [Last author, Corresponding author]
  English, Scientific journal
• Simultaneous removal of nitrate and heavy metals in a continuous flow nitrate-dependent ferrous iron oxidation (NDFO) bioreactor.
  Kazuki Jokai; Tomomi Nakamura; Satoshi Okabe; Satoshi Ishii
  Chemosphere, 262, 127838, 127838, 01 Aug. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Nitrogen and heavy metals can co-occur in various industrial wastewaters such as coke-oven wastewater. Removal of these contaminants is important, but cost-efficient removal technology is limited. In this study, we examined the usefulness of nitrate-dependent ferrous iron oxidation (NDFO) for the simultaneous removal of nitrate and heavy metals (iron and zinc), by using an NDFO strain Pseudogulbenkiania sp. NH8B. Based on the batch culture assays, nitrate, Fe, and Zn were successfully removed from a basal medium as well as coke-oven wastewater containing 5 mM nitrate, 10 mM Fe(II), and 10 mg/L Zn. Zinc in the water was most likely co-precipitated with Fe(III) oxides produced during the NDFO reaction. Simultaneous removal of nitrate, Fe, and Zn was also achieved in a continuous-flow reactor fed with a basal medium containing 10 mM nitrate, 5 mM Fe(II), 4 mM acetate, and 10 mg/L Zn. However, when the reactor is fed with coke-oven wastewater supplemented with 10 mM nitrate, 5 mM Fe(II), 4 mM acetate, and 10 mg/L ZnCl2, the reactor performance significantly decreased, most likely due to the inhibition of bacterial growth by thiocyanate or organic contaminants present in the coke-oven wastewater. Use of mixed culture of NDFO bacteria and thiocyanate/organic-degrading denitrifiers should help improve the reactor performance.
• Improvement of Electrochemical Conditions for Detecting Redox Reaction of K₃[Fe(CN)₆] toward the Application in Norovirus Aptasensor
  Seiya HIRANO; Junki SAITO; Tomoki YUKAWA; Daisuke SANO; Akihiro OKAMOTO; Satoshi OKABE; Masaaki KITAJIMA
  Electrochemistry, 88, 3, 205, 209, The Electrochemical Society of Japan, 05 May 2020, [Peer-reviewed]
  Scientific journal
• Bottleneck Size-Dependent Changes in the Genetic Diversity and Specific Growth Rate of a Rotavirus A Strain.
  Syun-Suke Kadoya; Syun-Ichi Urayama; Takuro Nunoura; Miho Hirai; Yoshihiro Takaki; Masaaki Kitajima; Toyoko Nakagomi; Osamu Nakagomi; Satoshi Okabe; Osamu Nishimura; Daisuke Sano
  Journal of virology, 94, 10, 04 May 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, RNA viruses form a dynamic distribution of mutant swarms (termed "quasispecies") due to the accumulation of mutations in the viral genome. The genetic diversity of a viral population is affected by several factors, including a bottleneck effect. Human-to-human transmission exemplifies a bottleneck effect, in that only part of a viral population can reach the next susceptible hosts. In the present study, two lineages of the rhesus rotavirus (RRV) strain of rotavirus A were serially passaged five times at a multiplicity of infection (MOI) of 0.1 or 0.001, and three phenotypes (infectious titer, cell binding ability, and specific growth rate) were used to evaluate the impact of a bottleneck effect on the RRV population. The specific growth rate values of lineages passaged under the stronger bottleneck (MOI of 0.001) were higher after five passages. The nucleotide diversity also increased, which indicated that the mutant swarms of the lineages under the stronger bottleneck effect were expanded through the serial passages. The random distribution of synonymous and nonsynonymous substitutions on rotavirus genome segments indicated that almost all mutations were selectively neutral. Simple simulations revealed that the presence of minor mutants could influence the specific growth rate of a population in a mutant frequency-dependent manner. These results indicate a stronger bottleneck effect can create more sequence spaces for minor sequences.IMPORTANCE In this study, we investigated a bottleneck effect on an RRV population that may drastically affect the viral population structure. RRV populations were serially passaged under two levels of a bottleneck effect, which exemplified human-to-human transmission. As a result, the genetic diversity and specific growth rate of RRV populations increased under the stronger bottleneck effect, which implied that a bottleneck created a new space in a population for minor mutants originally existing in a hidden layer, which includes minor mutations that cannot be distinguished from a sequencing error. The results of this study suggest that the genetic drift caused by a bottleneck in human-to-human transmission explains the random appearance of new genetic lineages causing viral outbreaks, which can be expected according to molecular epidemiology using next-generation sequencing in which the viral genetic diversity within a viral population is investigated.
• Simple and reliable enumeration of Escherichia coli concentrations in wastewater samples by measuring β-d-glucuronidase (GUS) activities via a microplate reader.
  Hisashi Satoh; Kai Kikuchi; Yutaka Katayose; Shu Tsuda; Reiko Hirano; Yuga Hirakata; Masaaki Kitajima; Satoshi Ishii; Mamoru Oshiki; Masashi Hatamoto; Masahiro Takahashi; Satoshi Okabe
  The Science of the total environment, 715, 136928, 136928, 01 May 2020, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal
• Ecological niche differentiation among anammox bacteria.
  Lei Zhang; Satoshi Okabe
  Water research, 171, 115468, 115468, 15 Mar. 2020, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, Anaerobic ammonium oxidizing (anammox) bacteria can directly convert ammonium and nitrite to nitrogen gas anaerobically and were responsible for a substantial part of the fixed nitrogen loss and re-oxidation of nitrite to nitrate in freshwater and marine ecosystems. Although a wide variety of studies have been undertaken to investigate the abundance and biodiversity of anammox bacteria so far, ecological niche differentiation of anammox bacteria is still not fully understood. To assess their growth behavior and consequent population dynamics at a given environment, the Monod model is often used. Here, we summarize the Monod kinetic parameters such as the maximum specific growth rate (μmax) and the half-saturation constant for nitrite (KNO2-) and ammonium (KNH4+) of five known candidatus genera of anammox bacteria. We also discuss potential pivotal environmental factors and metabolic flexibility that influence the community compositions of anammox bacteria. Particularly biodiversity of the genus "Scalindua" might have been largely underestimated. Several anammox bacteria have been successfully enriched from various source of biomass. We reevaluate their enrichment methods and culture medium compositions to gain a clue of niche differentiation of anammox bacteria. Furthermore, we formulate the current issues that must be addressed. Overall this review re-emphasizes the importance of enrichment cultures (preferably pure cultures), physiological characterization and direct microbial competition studies using enrichment cultures in laboratories.
• Required Chlorination Doses to Fulfill the Credit Value for Disinfection of Enteric Viruses in Water: A Critical Review.
  Andri Taruna Rachmadi; Masaaki Kitajima; Tsuyoshi Kato; Hiroyuki Kato; Satoshi Okabe; Daisuke Sano
  Environmental science & technology, 54, 4, 2068, 2077, 18 Feb. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, A credit value of virus inactivation has been assigned to the disinfection step in international and domestic guidelines for wastewater reclamation and reuse. To fulfill the credit value for water disinfection, water engineers need to apply an appropriate disinfection strength, expressed as a CT value (mg × min/L), which is a product of disinfectant concentration and contact time, against enteric viruses in wastewater. In the present study, we extracted published experimental data on enteric virus inactivation using free chlorine and monochloramine and applied the Tobit analysis and simple linear regression analysis to calculate the range of CT values (mg × min/L) needed for 4-log10 inactivation. Data were selected from peer-reviewed papers containing kinetics data of virus infectivity and chlorine residual in water. Coxsackie B virus and echovirus require higher CT values (lower susceptibility) for 4-log10 inactivation than adenovirus and a human norovirus surrogate (murine norovirus) with free chlorine. On the other hand, adenovirus has lower susceptibility to monochloramine compared to murine norovirus, coxsackievirus, and echovirus. The factors that influence the required CT value are virus type, pH, water temperature, and water matrix. This systematic review demonstrates that enteroviruses and adenovirus are appropriate representative enteric viruses to evaluate water disinfection using free chlorine and monochloramine, respectively.
• Transcriptomic analysis of HepG2 cells exposed to fractionated wastewater effluents suggested humic substances as potential inducer of whole effluent toxicity.
  Hiroe Hara-Yamamura; Toshikazu Fukushima; Lea Chua Tan; Satoshi Okabe
  Chemosphere, 240, 124894, 124894, Feb. 2020, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, We performed a transcriptome-based bioassay (TSB assay) using human hepatoma HepG2 cells to evaluate the potential toxicity of whole wastewater effluents from two membrane bioreactors (MBRs) and a conventional activated sludge process (AS). The biologically active agent(s) in the wastewater effluents were characterized based on expression of the marker genes (i.e., CYP1A1, AKR1B10, GCLM and GPX2) selected by DNA microarray analysis, after the wastewater effluent samples were concentrated by a reverse osmosis (RO) membrane and further fractionated by various manipulations. The qPCR assay of marker genes demonstrated that the induction of CYP1A1 and GPX2 was mitigated after passing through C18 and chelate columns. In addition, clear induction of CYP1A1 was observed in the smallest size fraction with 1 k Da or smaller organic molecules in all the tested effluents. These results together with the water quality data of the fractionated samples suggested that responsible constituents for potentially adverse and abnormal transcriptomic responses in HepG2 could have hydrophobic nature and act with metal-dissolved organic matter (DOM) complexes in 1 k Da or smaller size fraction. Although DOM is known to play two contradictory roles as a protector and an inducer of toxicants, our present study indicated the DOM in wastewater effluent, particularly humic substances with acidic nature, functioned as a toxicity inducer of residual chemicals in the effluents. This study provided a new insight into the nature of "toxic unknowns" in the wastewater effluents, which should be monitored whole through the reclamation process and prioritized for removal.
• Mixture toxicity of the combinations of silver nanoparticles and environmental pollutants.
  Toshikazu Fukushima; Wongta Jintana; Satoshi Okabe
  Environmental science and pollution research international, 27, 6, 6326, 6337, Feb. 2020, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, Although toxicity of silver nanoparticles (AgNPs) has been well studied, the mixture toxicity of the combination of AgNPs and other environmental pollutants is still largely unknown. Here, we investigated the mixture toxicity of the combinations of AgNPs and common environmental pollutants such as arsenic (As), cadmium (Cd), and chromium (Cr) on human hepatoma cell line (HepG2) at noncytotoxic concentrations based on analyses of cytotoxicity, genotoxicity, reactive oxygen species (ROS) generation, and modes of cell death. In addition, DNA microarray analysis was performed to understand the cellular responses at a molecular level. AgNPs-As and AgNPs-Cd combinations exhibited synergistic effect on cytotoxicity while AgNPs-Cr showed additive effect. The AgNPs-Cd combination caused much stronger synergism than AgNPs-As combination. Based on cellular and molecular level analyses, the synergistic effect could be explained by overproduction of reactive oxygen species (ROS), which induced DNA damage and consequently apoptotic cell death. On the other hand, the additive effect caused by AgNPs-Cr could be attributed to reduction of the mixture toxicity by precipitation of Cr ions. Taken together, our results clearly demonstrated that the mixture toxicity of AgNPs with As, Cd, or Cr at noncytotoxic concentrations had different toxicity effects. Particularly, toxicogenomic approach using DNA microarray was useful to assess the mechanisms of the mixture toxicity.
• Domestic wastewater treatment and energy harvesting by serpentine up-flow MFCs equipped with PVDF-based activated carbon air-cathodes and a low voltage booster
  N'Dah Joel Koffi; Satoshi Okabe
  Chemical Engineering Journal, 380, 15 Jan. 2020, [Peer-reviewed], [Last author, Corresponding author]
  English
• Candidal Prosthetic Hip Infection in a Patient with Previous Candidal Sepsis - A Case Report.
  Yoichi Murata; Satoshi Okabe; Shogo Tamagawa; Hideo Ohnishi; Akinori Sakai
  Journal of UOEH, 42, 4, 327, 330, 2020, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, A 60 year-old woman with hip dysplasia battled with duodenal cancer that was complicated with Candida tropicalis sepsis. Two years later, the patient underwent a total hip arthroplasty (THA). She complained of a persisting low-grade fever and local heat on the THA scar. Arthrocentesis of the hip was performed and the Candida tropicalis was detected. Debridement and polyethylene liner/modular head exchange were performed 28 days after the primary THA. Fluconazole was administrated for one year. The patient reported no symptoms five years later. It was found that periprosthetic infection could be prevented by implant preservation surgery.
• Cell Density-dependent Anammox Activity of Candidatus Brocadia sinica Regulated by N-acyl Homoserine Lactone-mediated Quorum Sensing.
  Mamoru Oshiki; Haruna Hiraizumi; Hisashi Satoh; Satoshi Okabe
  Microbes and environments, 35, 4, 2020, [Peer-reviewed], [Last author, Corresponding author], [Domestic magazines]
  English, Scientific journal, The activity of anaerobic ammonia-oxidizing (anammox) bacteria is considered to depend on cell density; however, this has not yet been confirmed due to the fastidious nature of anammox bacteria (e.g., slow growth, oxygen sensitivity, and rigid aggregate formation). In the present study, the cell density-dependent occurrence of anammox activity (14-15N2 gas production rate) was investigated using planktonic enrichment cultures of Candidatus Brocadia sinica. This activity was detectable when the density of cells was higher than 107‍ ‍cells‍ ‍mL-1 and became stronger with increases in cell density. At the cell densities, the transcription of the BROSI_A1042 and BROSI_A3652 genes, which are potentially involved in the biosynthesis and reception of N-acyl homoserine lactone (AHL), was detectable in Brocadia sinica cells. The presence of AHL molecules in the MBR culture of B. sinica was confirmed by an AHL reporter assay and gas chromatography mass spectrometry analysis. The exogenous addition of the MBR culture extract and AHL molecules (a cocktail of C6, C8, C10, and C12-homoserine lactones) increased the specific 14-15N2 production rate of B. sinica. These results suggest that the specific anammox activity of B. sinica is regulated by AHL-mediated quorum sensing.
• Dual nitrogen and oxygen isotope fractionation during anaerobic ammonium oxidation by anammox bacteria.
  Kanae Kobayashi; Akiko Makabe; Midori Yano; Mamoru Oshiki; Tomonori Kindaichi; Karen L Casciotti; Satoshi Okabe
  The ISME journal, 13, 10, 2426, 2436, Springer Science and Business Media LLC, Oct. 2019, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, Natural abundance of stable nitrogen (N) and oxygen (O) isotopes are invaluable biogeochemical tracers for assessing the N transformations in the environment. To fully exploit these tracers, the N and O isotope effects (15ε and 18ε) associated with the respective nitrogen transformation processes must be known. However, the N and O isotope effects of anaerobic ammonium oxidation (anammox), one of the major fixed N sinks and NO3- producers, are not well known. Here, we report the dual N and O isotope effects associated with anammox by three different anammox bacteria including "Ca. Scalindua japonica", a putative marine species, which were measured in continuous enrichment culture experiments. All three anammox species yielded similar N isotope effects of NH4+ oxidation to N2 (15εNH4→N2) ranging from 30.9‰ to 32.7‰ and inverse kinetic isotope effects of NO2- oxidation to NO3- (15εNO2→NO3 = -45.3‰ to -30.1‰). In contrast, 15εNO2→N2 (NO2- reduction to N2) were significantly different among three species, which is probably because individual anammox bacteria species might possess different types of nitrite reductase. We also report the combined O isotope effects for NO2- oxidation (18ENO2→NO3) by anammox bacteria. These obtained dual N and O isotopic effects could provide significant insights into the contribution of anammox bacteria to the fixed N loss and NO2- reoxidation (N recycling) in various natural environments.
• Fecal Source Tracking in A Wastewater Treatment and Reclamation System Using Multiple Waterborne Gastroenteritis Viruses.
  Zheng Ji; Xiaochang C Wang; Limei Xu; Chongmiao Zhang; Cheng Rong; Andri Taruna Rachmadi; Mohan Amarasiri; Satoshi Okabe; Naoyuki Funamizu; Daisuke Sano
  Pathogens (Basel, Switzerland), 8, 4, 170, 170, {MDPI} {AG}, 30 Sep. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Gastroenteritis viruses in wastewater reclamation systems can pose a major threat to public health. In this study, multiple gastroenteritis viruses were detected from wastewater to estimate the viral contamination sources in a wastewater treatment and reclamation system installed in a suburb of Xi'an city, China. Reverse transcription plus nested or semi-nested PCR, followed by sequencing and phylogenetic analysis, were used for detection and genotyping of noroviruses and rotaviruses. As a result, 91.7% (22/24) of raw sewage samples, 70.8% (17/24) of the wastewater samples treated by anaerobic/anoxic/oxic (A2O) process and 62.5% (15/24) of lake water samples were positive for at least one of target gastroenteritis viruses while all samples collected from membrane bioreactor effluent after free chlorine disinfection were negative. Sequence analyses of the PCR products revealed that epidemiologically minor strains of norovirus GI (GI/14) and GII (GII/13) were frequently detected in the system. Considering virus concentration in the disinfected MBR effluent which is used as the source of lake water is below the detection limit, these results indicate that artificial lake may be contaminated from sources other than the wastewater reclamation system, which may include aerosols, and there is a possible norovirus infection risk by exposure through reclaimed water usage and by onshore winds transporting aerosols containing norovirus.
• Complete Genome Sequence of a Novel Myoviridae Phage, SfΦ01, Infecting Shigella spp.
  Masaaki Kitajima; Satoshi Ishii; Tatsuma Takagi; Satoshi Okabe
  Microbiology resource announcements, 8, 23, 06 Jun. 2019, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal
• Sign-constrained linear regression for prediction of microbe concentration based on water quality datasets.
  Tsuyoshi Kato; Ayano Kobayashi; Wakana Oishi; Syun-Suke Kadoya; Satoshi Okabe; Naoya Ohta; Mohan Amarasiri; Daisuke Sano
  Journal of water and health, 17, 3, 404, 415, Jun. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Development of a simple analytical method to determine arsenite using a DNA aptamer and gold nanoparticles.
  Koji Matsunaga; Yu Okuyama; Reiko Hirano; Satoshi Okabe; Masahiro Takahashi; Hisashi Satoh
  Chemosphere, 224, 538, 543, Jun. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Membrane fouling potentials of an exoelectrogenic fouling-causing bacterium cultured with different external electron acceptors
  So Ishizaki; Rimana Islam Papry; Hiroshi Miyake; Yoko Narita; Satoshi Okabe
  Frontiers in Microbiology, 9, 3284, 3284, Dec. 2018, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Aggregation ability of three phylogenetically distant anammox bacterial species.
  Muhammad Ali; Dario Rangel Shaw; Lei Zhang; Mohamed Fauzi Haroon; Yuko Narita; Abdul-Hamid Emwas; Pascal E Saikaly; Satoshi Okabe
  Water research, 143, 10, 18, 15 Oct. 2018, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Anammox biomass carrying efficiency of polyethylene non-woven sheets as a carrier material.
  Sunja Cho; Minki Jung; Dongjin Ju; Young-Hee Lee; Kuk Cho; Satoshi Okabe
  Environmental technology, 39, 19, 2503, 2510, Oct. 2018, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Free-Chlorine Disinfection as a Selection Pressure on Norovirus.
  Andri Taruna Rachmadi; Masaaki Kitajima; Kozo Watanabe; Sakiko Yaegashi; Joeselle Serrana; Arata Nakamura; Toyoko Nakagomi; Osamu Nakagomi; Kazuhiko Katayama; Satoshi Okabe; Daisuke Sano
  Applied and environmental microbiology, 84, 13, 01 Jul. 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Complete Genome Sequence of Klebsiella quasipneumoniae Strain S05, a Fouling-Causing Bacterium Isolated from a Membrane Bioreactor.
  Masaaki Kitajima; So Ishizaki; Jeonghwan Jang; Satoshi Ishii; Satoshi Okabe
  Genome announcements, 6, 23, e00471-18, American Society for Microbiology, 07 Jun. 2018, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• 3-[Bis(pyridin-2-ylmethyl)amino]-5-(4-carboxyphenyl)-BODIPY as Ratiometric Fluorescent Sensor for Cu2.
  Akira Hafuka; Hisashi Satoh; Koji Yamada; Masahiro Takahashi; Satoshi Okabe
  Materials (Basel, Switzerland), 11, 5, 16 May 2018, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal
• Experimental Evidence for in Situ Nitric Oxide Production in Anaerobic Ammonia-Oxidizing Bacterial Granules.
  Rathnayake M L D Rathnayake; Mamoru Oshiki; Satoshi Ishii; Takahiro Segawa; Hisashi Satoh; Satoshi Okabe
  Environmental science & technology, 52, 10, 5744, 5752, 15 May 2018, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Selection of cellular genetic markers for the detection of infectious poliovirus
  D. Sano; M. Tazawa; M. Inaba; S. Kadoya; R. Watanabe; T. Miura; M. Kitajima; S. Okabe
  Journal of Applied Microbiology, 124, 4, 1001, 1007, Blackwell Publishing Ltd, 01 Apr. 2018, [Peer-reviewed], [Last author]
  English, Scientific journal
• Reverse transcription-quantitative PCR assays for genotype-specific detection of human noroviruses in clinical and environmental samples.
  Mohan Amarasiri; Masaaki Kitajima; Akiho Miyamura; Ricardo Santos; Silvia Monteiro; Takayuki Miura; Shinobu Kazama; Satoshi Okabe; Daisuke Sano
  International journal of hygiene and environmental health, 221, 3, 578, 585, Apr. 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Disinfection as a Selection Pressure on RNA Virus Evolution.
  Andri Taruna Rachmadi; Masaaki Kitajima; Kozo Watanabe; Satoshi Okabe; Daisuke Sano
  Environmental science & technology, 52, 5, 2434, 2435, 06 Mar. 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Electricity generation potential of poultry droppings wastewater in microbial fuel cell using rice husk charcoal electrodes
  Godwin E. Oyiwona; James Chukwuma Ogbonna; Chukwudi Anyanwu; Satoshi Okabe
  Bioresources and Bioprocessing, 5, 13, 1, 6, Mar. 2018, [Peer-reviewed], [Last author, Corresponding author]
• Insights into the roles of anammox bacteria in post-treatment of anaerobically-treated sewage
  Qian Wang; Giin-Yu Amy Tan; Mohammad Azari; Xiaowu Huang; Martin Denecke; Yujie Men; Jin-Young Jung; Satoshi Okabe; Muhammad Ali; Yu-Tzu Huang; Zhuoying Wu; Wai-hung Lo; Ji-Dong Gu; J. G. Lin; Po-Heng (Henry) Lee
  Critical Reviews in Environmental Science and Technology, 48, 6, 655, 684, Mar. 2018, [Peer-reviewed]
  English
• Microbial Community Analysis Revisited : Transition and Prospect
  伊藤 司; 金田一 智則; 押木 守; 岡部 聡
  EICA : journal of EICA : 環境システム計測制御学会誌, 22, 4, 21, 26, 環境システム計測制御学会, 2018, [Peer-reviewed], [Last author, Corresponding author]
  Japanese
• High-Throughput flaA Short Variable Region Sequencing to Assess Campylobacter Diversity in Fecal Samples From Birds.
  Qian Zhang; Gabriel A Al-Ghalith; Mayumi Kobayashi; Takahiro Segawa; Mitsuto Maeda; Satoshi Okabe; Dan Knights; Satoshi Ishii
  Frontiers in microbiology, 9, 2201, 2201, 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Current approach to identify sources of human pathogens is largely dependent on the cultivation and isolation of target bacteria. For rapid pathogen source identification, culture-independent strain typing method is necessary. In this study, we designed new primer set that broadly covers flaA short variable region (SVR) of various Campylobacter species, and applied the flaA SVR sequencing method to examine the diversity of Campylobacter spp. in geese fecal samples (n = 16) with and without bacteria cultivation. Twenty-three Campylobacter strains isolated from the 16 geese fecal samples were grouped similarly by conventional flaA restriction fragment length polymorphism (RFLP) method and by the flaA SVR sequencing method, but higher discriminant power was observed in the flaA SVR sequencing approach. For culture-independent flaA SVR sequencing analysis, we developed and optimized the sequence data analysis pipeline to identify as many genotypes as possible, while minimizing the detection of genotypes generated by sequencing errors. By using this pipeline, 51,629 high-quality flaA sequence reads were clustered into 16 operational taxonomic units (=genotypes) by using 98% sequence similarity and >50 sequence duplicates. Almost all flaA genotypes obtained by culture-dependent method were also identified by culture-independent flaA SVR MiSeq sequencing method. In addition, more flaA genotypes were identified probably due to high throughput nature of the MiSeq sequencing. These results suggest that the flaA SVR sequencing could be used to analyze the diversity of Campylobacter spp. without bacteria isolation. This method is promising to rapidly identify potential sources of Campylobacter pathogens.
• Rapid cultivation of free-living planktonic anammox cells.
  Lei Zhang; Satoshi Okabe
  Water research, 127, 204, 210, 15 Dec. 2017, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Multiple-endpoints gene alteration-based (MEGA) assay: A toxicogenomics approach for water quality assessment of wastewater effluents.
  Toshikazu Fukushima; Hiroe Hara-Yamamura; Koji Nakashima; Lea Chua Tan; Satoshi Okabe
  Chemosphere, 188, 312, 319, Dec. 2017, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Microbial competition among anammox bacteria in nitrite-limited bioreactors.
  Lei Zhang; Yuko Narita; Lin Gao; Muhammad Ali; Mamoru Oshiki; Satoshi Ishii; Satoshi Okabe
  Water research, 125, 249, 258, 15 Nov. 2017, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Target virus log10 reduction values determined for two reclaimed wastewater irrigation scenarios in Japan based on tolerable annual disease burden.
  Toshihiro Ito; Masaaki Kitajima; Tsuyoshi Kato; Satoshi Ishii; Takahiro Segawa; Satoshi Okabe; Daisuke Sano
  Water research, 125, 438, 448, 15 Nov. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Enhancement of organic matter degradation and methane gas production of anaerobic granular sludge by degasification of dissolved hydrogen gas.
  Hisashi Satoh; Wasala M K R T W Bandara; Manabu Sasakawa; Yoshihito Nakahara; Masahiro Takahashi; Satoshi Okabe
  Bioresource technology, 244, Pt 1, 768, 775, Nov. 2017, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal
• Determination of Cadmium in Brown Rice Samples by Fluorescence Spectroscopy Using a Fluoroionophore after Purification of Cadmium by Anion Exchange Resin.
  Akira Hafuka; Akiyoshi Takitani; Hiroko Suzuki; Takuya Iwabuchi; Masahiro Takahashi; Satoshi Okabe; Hisashi Satoh
  Sensors (Basel, Switzerland), 17, 10, 2291, 2291, 09 Oct. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Genetic diversity of marine anaerobic ammonium-oxidizing bacteria as revealed by genomic and proteomic analyses of 'Candidatus Scalindua japonica'.
  Mamoru Oshiki; Keisuke Mizuto; Zen-Ichiro Kimura; Tomonori Kindaichi; Hisashi Satoh; Satoshi Okabe
  Environmental microbiology reports, 9, 5, 550, 561, Oct. 2017, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Enrichment and physiological characterization of an anaerobic ammonium-oxidizing bacterium 'Candidatus Brocadia sapporoensis'.
  Yuko Narita; Lei Zhang; Zen-Ichiro Kimura; Muhammad Ali; Takao Fujii; Satoshi Okabe
  Systematic and applied microbiology, 40, 7, 448, 457, Oct. 2017, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Bacteriophage removal efficiency as a validation and operational monitoring tool for virus reduction in wastewater reclamation: Review.
  Mohan Amarasiri; Masaaki Kitajima; Thanh H Nguyen; Satoshi Okabe; Daisuke Sano
  Water research, 121, 258, 269, 15 Sep. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Membrane fouling induced by AHL-mediated soluble microbial product (SMP) formation by fouling-causing bacteria co-cultured with fouling-enhancing bacteria.
  So Ishizaki; Ryoichi Sugiyama; Satoshi Okabe
  Scientific reports, 7, 1, 8482, 8482, 16 Aug. 2017, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Maximum specific growth rate of anammox bacteria revisited.
  Lei Zhang; Yuko Narita; Lin Gao; Muhammad Ali; Mamoru Oshiki; Satoshi Okabe
  Water research, 116, 296, 303, 01 Jun. 2017, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Formation of CuO nano-flowered surfaces via submerged photo-synthesis of crystallites and their antimicrobial activity.
  Fumika Nishino; Melbert Jeem; Lihua Zhang; Kazumasa Okamoto; Satoshi Okabe; Seiichi Watanabe
  Scientific reports, 7, 1, 1063, 1063, 21 Apr. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Generation of Small Colony Variants in Biofilms by Escherichia coli Harboring a Conjugative F Plasmid.
  Yosuke Tashiro; Hiroaki Eida; Satoshi Ishii; Hiroyuki Futamata; Satoshi Okabe
  Microbes and environments, 32, 1, 40, 46, 31 Mar. 2017, [Peer-reviewed], [Last author, Corresponding author], [Domestic magazines]
  English, Scientific journal
• Oxidation of glucose by syntrophic association between Geobacter and hydrogenotrophic methanogens in microbial fuel cell.
  Godwin E Oyiwona; James Ogbonna; Chukwudi Uzoma Anyanwu; So Ishizaki; Zen-Ichiro Kimura; Satoshi Okabe
  Biotechnology letters, 39, 2, 253, 259, Feb. 2017, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Improvement of a Phosphate Ion-selective Microsensor Using Bis(dibromophenylstannyl)methane as a Carrier.
  Hisashi Satoh; Yuji Miyazaki; Shou Taniuchi; Mamoru Oshiki; Rathnayake M L D Rathnayake; Masahiro Takahashi; Satoshi Okabe
  Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 33, 7, 825, 830, 2017, [Peer-reviewed], [Last author], [Domestic magazines]
  English, Scientific journal
• Draft Genome Sequence of the Anaerobic Ammonium-Oxidizing Bacterium "Candidatus Brocadia sp. 40".
  Muhammad Ali; Mohamed Fauzi Haroon; Yuko Narita; Lei Zhang; Dario Rangel Shaw; Satoshi Okabe; Pascal E Saikaly
  Genome announcements, 4, 6, e01377-16, American Society for Microbiology, 08 Dec. 2016, [Peer-reviewed], [Corresponding author], [International Magazine]
  English, Scientific journal
• Evaluation of virus reduction efficiency in wastewater treatment unit processes as a credit value in the multiple-barrier system for wastewater reclamation and reuse.
  Toshihiro Ito; Tsuyoshi Kato; Makoto Hasegawa; Hiroyuki Katayama; Satoshi Ishii; Satoshi Okabe; Daisuke Sano
  Journal of water and health, 14, 6, 879, 889, Dec. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Source identification of nitrous oxide emission pathways from a single-stage nitritation-anammox granular reactor.
  Muhammad Ali; Rathnayake M L D Rathnayake; Lei Zhang; Satoshi Ishii; Tomonori Kindaichi; Hisashi Satoh; Sakae Toyoda; Naohiro Yoshida; Satoshi Okabe
  Water research, 102, 147, 157, 01 Oct. 2016, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Bactericidal and virucidal mechanisms in the alkaline disinfection of compost using calcium lime and ash.
  Nowaki Hijikata; Rui Tezuka; Shinobu Kazama; Masahiro Otaki; Ken Ushijima; Ryusei Ito; Satoshi Okabe; Daisuke Sano; Naoyuki Funamizu
  Journal of environmental management, 181, 721, 727, 01 Oct. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Impact of Anodic Respiration on Biopolymer Production and Consequent Membrane Fouling.
  So Ishizaki; Kotaro Terada; Hiroshi Miyake; Satoshi Okabe
  Environmental science & technology, 50, 17, 9515, 23, 06 Sep. 2016, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Membrane fouling potentials and cellular properties of bacteria isolated from fouled membranes in a MBR treating municipal wastewater.
  So Ishizaki; Toshikazu Fukushima; Satoshi Ishii; Satoshi Okabe
  Water research, 100, 448, 457, 01 Sep. 2016, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Ecology and physiology of anaerobic ammonium oxidizing bacteria.
  Mamoru Oshiki; Hisashi Satoh; Satoshi Okabe
  Environmental microbiology, 18, 9, 2784, 96, Sep. 2016, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Hydroxylamine-dependent anaerobic ammonium oxidation (anammox) by "Candidatus Brocadia sinica".
  Mamoru Oshiki; Muhammad Ali; Kaori Shinyako-Hata; Hisashi Satoh; Satoshi Okabe
  Environmental microbiology, 18, 9, 3133, 43, Sep. 2016, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Denitrification and Nitrate-Dependent Fe(II) Oxidation in Various Pseudogulbenkiania Strains
  Satoshi Ishii; Kazuki Joikai; Shigeto Otsuka; Keishi Senoo; Satoshi Okabe
  MICROBES AND ENVIRONMENTS, 31, 3, 293, 298, Sep. 2016, [Peer-reviewed], [Corresponding author]
  English, Scientific journal
• Genome Sequence of Enterobacter cloacae Strain SENG-6, a Bacterium Producing Histo-Blood Group Antigen-Like Substances That Can Bind with Human Noroviruses.
  Satoshi Ishii; Mohan Amarasiri; Satoshi Hashiba; Peiyi Yang; Satoshi Okabe; Daisuke Sano
  Genome announcements, 4, 4, e00893, 16, American Society for Microbiology, 25 Aug. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Enterobacter sp. strain SENG-6, isolated from healthy human feces, produces histo-blood group antigen (HBGA)-like substances that can bind with human noroviruses. Based on the genome sequence analysis, strain SENG-6 belongs to the species Enterobacter cloacae The genome sequence of this strain should help identify genes associated with the production of HBGA-like substances.
• Specific Single-Cell Isolation of Escherichia coli O157 from Environmental Water Samples by Using Flow Cytometry and Fluorescence-Activated Cell Sorting.
  Shuji Ozawa; Satoshi Okabe; Satoshi Ishii
  Foodborne pathogens and disease, 13, 8, 456, 61, Aug. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• 下水再生処理におけるヒト腸管系ウイルスの目標除去効率の算定法
  伊藤寿宏; 押木守; 小林直央; 加藤毅; 瀬川高弘; 幡本将史; 山口隆司; 原田秀樹; 北島正章; 岡部聡; 佐野大輔
  土木学会論文集, 72, 7, 305, 313, Jul. 2016, [Peer-reviewed]
• Bacterial histo-blood group antigens contributing to genotype-dependent removal of human noroviruses with a microfiltration membrane.
  Mohan Amarasiri; Satoshi Hashiba; Takayuki Miura; Toyoko Nakagomi; Osamu Nakagomi; Satoshi Ishii; Satoshi Okabe; Daisuke Sano
  Water research, 95, 383, 91, 15 May 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• EVIDENCE-BASED DETERMINATION OF THE HYGIENE STANDARD VALUE IN ENVIRONMENTAL WATER
  KOBAYASHI Ayano; SANO Daisuke; KATO Tsuyoshi; ITO Toshihiro; MIYAMURA Akiho; MIURA Takayuki; ISHII Satoshi; OKABE Satoshi
  Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 72, 3, 40, 49, Japan Society of Civil Engineers, Mar. 2016, [Peer-reviewed], [Last author]
  Japanese,  The present study proposes an approach for obtaining a candidate value of a water hygiene standard using water quality monitoring datasets and acceptable infection risks of waterborne pathogenic microbes. In the proposed approach, posterior predictive distributions of the concentration of an indicator microorganism and a pathogen-derived gene are estimated separately based on monitoring datasets, and then the probabilistic distribution of concentration ratio between the indicator microorganism and the pathogen-derived gene is obtained. In addition to it, an acceptable concentration of a pathogen-derived gene in water is derived from an acceptable infection risk (10^-4 infections per person per year) by quantitative microbial risk assessment (QMRA). The candidate value of water hygiene standard is determined by collating the calculated acceptable concentration of a pathogen-derived gene and the estimated distribution of concentration ratio. When a safety factor value is set at 10, 150 most probable number/ 100mL of Escherichia coli was obtained as a candidate value of water hygiene standard for river water that is used as a drinking water source. Although this study identified research areas that have to be investigated further, such as the validation of QMRA assumptions, the proposed approach makes it possible to determine water hygiene standard values based on the scientific basis, including accumulated datasets of environmental water monitoring.
• Estimation of concentration ratio of indicator to pathogen-related gene in environmental water based on left-censored data.
  Tsuyoshi Kato; Ayano Kobayashi; Toshihiro Ito; Takayuki Miura; Satoshi Ishii; Satoshi Okabe; Daisuke Sano
  Journal of water and health, 14, 1, 14, 25, Feb. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Effects of dissolved oxygen and pH on nitrous oxide production rates in autotrophic partial nitrification granules.
  Rathnayake M L D Rathnayake; Mamoru Oshiki; Satoshi Ishii; Takahiro Segawa; Hisashi Satoh; Satoshi Okabe
  Bioresource technology, 197, 15, 22, Dec. 2015, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Anammox-based technologies for nitrogen removal: Advances in process start-up and remaining issues.
  Muhammad Ali; Satoshi Okabe
  Chemosphere, 141, 144, 53, Dec. 2015, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Bayesian modeling of virus removal efficiency in wastewater treatment processes
  T. Ito; T. Kato; K. Takagishi; S. Okabe; D. Sano
  WATER SCIENCE AND TECHNOLOGY, 72, 10, 1789, 1795, Nov. 2015, [Peer-reviewed]
  English, Scientific journal
• Rapid and successful start-up of anammox process by immobilizing the minimal quantity of biomass in PVA-SA gel beads.
  Muhammad Ali; Mamoru Oshiki; Lashitha Rathnayake; Satoshi Ishii; Hisashi Satoh; Satoshi Okabe
  Water research, 79, 147, 57, 01 Aug. 2015, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Impacts of hydrophilic colanic acid on bacterial attachment to microfiltration membranes and subsequent membrane biofouling.
  Keitaro Yoshida; Yosuke Tashiro; Thithiwat May; Satoshi Okabe
  Water research, 76, 33, 42, 01 Jun. 2015, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Physiological characterization of anaerobic ammonium oxidizing bacterium 'Candidatus Jettenia caeni'.
  Muhammad Ali; Mamoru Oshiki; Takanori Awata; Kazuo Isobe; Zenichiro Kimura; Hiroaki Yoshikawa; Daisuke Hira; Tomonori Kindaichi; Hisashi Satoh; Takao Fujii; Satoshi Okabe
  Environmental microbiology, 17, 6, 2172, 89, Jun. 2015, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Removal properties of human enteric viruses in a pilot-scale membrane bioreactor (MBR) process.
  Takayuki Miura; Satoshi Okabe; Yoshihito Nakahara; Daisuke Sano
  Water research, 75, 282, 91, 15 May 2015, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Draft Genome Sequence of an Anaerobic Ammonium-Oxidizing Bacterium, "Candidatus Brocadia sinica".
  Mamoru Oshiki; Kaori Shinyako-Hata; Hisashi Satoh; Satoshi Okabe
  Genome announcements, 3, 2, 16 Apr. 2015, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Culture-independent evaluation of nonenveloped-virus infectivity reduced by free-chlorine disinfection.
  Daisuke Sano; Takatomo Ohta; Arata Nakamura; Toyoko Nakagomi; Osamu Nakagomi; Satoshi Okabe
  Applied and environmental microbiology, 81, 8, 2819, 26, Apr. 2015, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal
• Substituent Effects at the 5-Position of 3-[Bis(pyridine-2-ylmethyl)amino]-BODIPY Cation Sensor Used for Ratiometric Quantification of Cu2+
  Akira Hafuka; Ryosuke Kando; Kohei Ohya; Koji Yamada; Satoshi Okabe; Hisashi Satoh
  BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 88, 3, 447, 454, Mar. 2015, [Peer-reviewed]
  English, Scientific journal
• Microfluidic quantitative PCR for simultaneous quantification of multiple viruses in environmental water samples.
  Satoshi Ishii; Gaku Kitamura; Takahiro Segawa; Ayano Kobayashi; Takayuki Miura; Daisuke Sano; Satoshi Okabe
  Applied and environmental microbiology, 80, 24, 7505, 11, Dec. 2014, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal
• External CO2 and water supplies for enhancing electrical power generation of air-cathode microbial fuel cells.
  So Ishizaki; Itto Fujiki; Daisuke Sano; Satoshi Okabe
  Environmental science & technology, 48, 19, 11204, 10, 07 Oct. 2014, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Efficient Nitrogen Removal by Anaerobic Ammonium Oxidation (anammox) Process
  押木 守; 佐藤 久; 岡部 聡
  Journal of environmental biotechnology, 14, 1, 21, 29, 環境バイオテクノロジー学会, Oct. 2014, [Peer-reviewed], [Last author, Corresponding author]
  Japanese
• Identification of key nitrous oxide production pathways in aerobic partial nitrifying granules.
  Satoshi Ishii; Yanjun Song; Lashitha Rathnayake; Azzaya Tumendelger; Hisashi Satoh; Sakae Toyoda; Naohiro Yoshida; Satoshi Okabe
  Environmental microbiology, 16, 10, 3168, 80, Oct. 2014, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Simple, rapid and effective preservation and reactivation of anaerobic ammonium oxidizing bacterium "Candidatus Brocadia sinica".
  Muhammad Ali; Mamoru Oshiki; Satoshi Okabe
  Water research, 57, 215, 22, 15 Jun. 2014, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Estimation of Contamination Sources of Human Enteroviruses in a Wastewater Treatment and Reclamation System by PCR-DGGE
  Zheng Ji; Xiaochang C. Wang; Limei Xu; Chongmiao Zhang; Naoyuki Funamizu; Satoshi Okabe; Daisuke Sano
  FOOD AND ENVIRONMENTAL VIROLOGY, 6, 2, 99, 109, Jun. 2014, [Peer-reviewed]
  English, Scientific journal
• Water quality monitoring and risk assessment by simultaneous multipathogen quantification.
  Satoshi Ishii; Takamitsu Nakamura; Shuji Ozawa; Ayano Kobayashi; Daisuke Sano; Satoshi Okabe
  Environmental science & technology, 48, 9, 4744, 9, 06 May 2014, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal
• Application of fluorescence spectroscopy using a novel fluoroionophore for quantification of zinc in urban runoff.
  Akira Hafuka; Hiroaki Yoshikawa; Koji Yamada; Tsuyoshi Kato; Masahiro Takahashi; Satoshi Okabe; Hisashi Satoh
  Water research, 54, 12, 20, 01 May 2014, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Raoultella electrica sp. nov., isolated from anodic biofilms of a glucose-fed microbial fuel cell.
  Zen-Ichiro Kimura; Kyung Mi Chung; Hiroaki Itoh; Akira Hiraishi; Satoshi Okabe
  International journal of systematic and evolutionary microbiology, 64, Pt 4, 1384, 1388, Apr. 2014, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• Toxicity assessment of chlorinated wastewater effluents by using transcriptome-based bioassays and Fourier transform mass spectrometry (FT-MS) analysis.
  Toshikazu Fukushima; Hiroe Hara-Yamamura; Makoto Urai; Ikuro Kasuga; Futoshi Kurisu; Taro Miyoshi; Katsuki Kimura; Yoshimasa Watanabe; Satoshi Okabe
  Water research, 52, 73, 82, 01 Apr. 2014, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal
• 培養できないウイルスの感染性の評価法
  佐野大輔; 岡部聡
  感染と消毒, 21, 2, 24, 27, 2014, [Invited], [Last author]
  Japanese, Research society
• Bayesian Modeling of Enteric Virus Density in Wastewater Using Left-Censored Data
  Tsuyoshi Kato; Takayuki Miura; Satoshi Okabe; Daisuke Sano
  FOOD AND ENVIRONMENTAL VIROLOGY, 5, 4, 185, 193, Dec. 2013, [Peer-reviewed]
  English, Scientific journal
• Environmental Detection of Genogroup I, II, and IV Noroviruses by Using a Generic Real-Time Reverse Transcription-PCR Assay
  Takayuki Miura; Sylvain Parnaudeau; Marco Grodzki; Satoshi Okabe; Robert L. Atmar; Francoise S. Le Guyader
  APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 79, 21, 6585, 6592, Nov. 2013, [Peer-reviewed]
  English, Scientific journal
• Determination of Zn²⁺ in industrial wastewater by fluorescence spectroscopy with fluoroionophore
  HAFUKA Akira; YOSHIKAWA Hiroaki; OHYA Kohei; YAMADA Koji; TAKAHASHI Masahiro; OKABE Satoshi; SATOH Hisashi
  PROCEEDINGS OF ENVIRONMENTAL AND SANITARY ENGINEERING RESEARCH, 50, 3, 275, 280, Japan Society of Civil Engineers, Nov. 2013, [Peer-reviewed]
  Japanese, We applied a novel fluorescent indicator (i.e., fluoroionophore) for industrial wastewater to determine Zn²⁺ by using fluorescence spectroscopy. The fluoroionophore showed red-shifted fluorescence upon Zn²⁺ binding. The indicator exhibited ratiometric fluorescence spectral change with increase of Zn²⁺ concentrations. Zn²⁺ was successfully determined in real industrial wastewater matrix by using the fluoroionophore. In this research, we could demonstrate the potential application of fluorescence spectroscopy with the fluoroionophore to determine heavy metal ions in real wastewater.
• Use of a genetically-engineered Escherichia coli strain as a sample process control for quantification of the host-specific bacterial genetic markers.
  Ayano Kobayashi; Daisuke Sano; Asami Taniuchi; Satoshi Ishii; Satoshi Okabe
  Applied microbiology and biotechnology, 97, 20, 9165, 73, Oct. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Histo-blood group antigen-like substances of human enteric bacteria as specific adsorbents for human noroviruses.
  Takayuki Miura; Daisuke Sano; Atsushi Suenaga; Takeshi Yoshimura; Miyu Fuzawa; Toyoko Nakagomi; Osamu Nakagomi; Satoshi Okabe
  Journal of virology, 87, 17, 9441, 51, Sep. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Chicken- and duck-associated Bacteroides-Prevotella genetic markers for detecting fecal contamination in environmental water.
  Ayano Kobayashi; Daisuke Sano; Jun Hatori; Satoshi Ishii; Satoshi Okabe
  Applied microbiology and biotechnology, 97, 16, 7427, 37, Aug. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Acetate oxidation by syntrophic association between Geobacter sulfurreducens and a hydrogen-utilizing exoelectrogen.
  Zen-ichiro Kimura; Satoshi Okabe
  The ISME journal, 7, 8, 1472, 82, Aug. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Physiological Characterization of an Anaerobic Ammonium-Oxidizing Bacterium Belonging to the "Candidatus Scalindua" Group
  Takanori Awata; Mamoru Oshiki; Tomonori Kindaichi; Noriatsu Ozaki; Akiyoshi Ohashi; Satoshi Okabe
  APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 79, 13, 4145, 4148, Jul. 2013, [Peer-reviewed]
  English, Scientific journal
• Development and characterization of the partial nitrification aerobic granules in a sequencing batch airlift reactor.
  Yanjun Song; Satoshi Ishii; Lashitha Rathnayake; Tsukasa Ito; Hisashi Satoh; Satoshi Okabe
  Bioresource technology, 139, 285, 91, Jul. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Nitrate-dependent ferrous iron oxidation by anaerobic ammonium oxidation (anammox) bacteria
  M. Oshiki; S. Ishii; K. Yoshida; N. Fujii; M. Ishiguro; Hisashi Satoh; S. Okabe
  Applied and Environmental Microbiology, 79, 13, 4087, 4093, Jul. 2013, [Peer-reviewed]
  English, Scientific journal
• Physiological characterization of an anaerobic ammonium-oxidizing bacterium enriched from coastal sediments,Hiroshima,Japan
  Takanori Awata; Mamoru Oshiki; Tomonori Kindaichi; Noriatsu Ozaki; Akiyoshi Ohashi; Satoshi Okabe
  The 2nd International Anammox Symposium, pp.67, The 2nd International Anammox Symposium, Jun. 2013, [Peer-reviewed]
  Scientific journal, The effect of salinity on organic removal and ammonium oxidation in a down-flow hanging sponge reactor was investigated by conducting a long-term continuous experiment over a period of 800 days. The DHS reactor, constructed by connecting three identical units, was fed with artificial wastewater containing 500 mg-N/L of ammonium nitrogen and 1400 mg-COD/L of phenol. Salinity of the influent was controlled by the addition of 8.0 to 25 g-Cl-/L of NaCl. The DHS reactor was operated at a hydraulic retention time of 12 h in a temperature controlled room at 25 degrees C. No significant inhibition of organic removal and ammonium oxidation was observed at salinities of up to 20 g-Cl-/L, at which levels ammonium oxidation and COD removal both exceeded 90%, respectively. However, at a salinity of 25 g-Cl-/L, organic removal and ammonium oxidation were both severely inhibited. In addition, the ratio of effluent nitrite nitrogen to influent ammonium nitrogen increased from 3.4% at salinities of 8.0 g-Cl-/L to 33% at salinities of 20 g-Cl-/L.
• Evaluation of whole wastewater effluent impacts on HepG2 using DNA microarray-based transcriptome analysis.
  Hiroe Hara-Yamamura; Koji Nakashima; Asiful Hoque; Taro Miyoshi; Katsuki Kimura; Yoshimasa Watanabe; Satoshi Okabe
  Environmental science & technology, 47, 10, 5425, 32, 21 May 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Simultaneous quantification of multiple food- and waterborne pathogens by use of microfluidic quantitative PCR.
  Satoshi Ishii; Takahiro Segawa; Satoshi Okabe
  Applied and environmental microbiology, 79, 9, 2891, 8, May 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Introduction of a Degassing Membrane Technology into Anaerobic Wastewater Treatment
  W. M. K. R. T. W. Bandara; M. Ikeda; H. Satoh; M. Sasakawa; Y. Nakahara; M. Takahashi; S. Okabe
  WATER ENVIRONMENT RESEARCH, 85, 5, 387, 390, May 2013, [Peer-reviewed]
  English
• Effects of temperature and predator on the persistence of host-specific Bacteroides-Prevotella genetic markers in water.
  Ayano Kobayashi; Daisuke Sano; Satoshi Okabe
  Water science and technology : a journal of the International Association on Water Pollution Research, 67, 4, 838, 45, 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Spatial and temporal oxygen dynamics in macrofaunal burrows in sediments: a review of analytical tools and observational evidence.
  Hisashi Satoh; Satoshi Okabe
  Microbes and environments, 28, 2, 166, 79, 2013, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• A new approach for evaluating the infectivity of noncultivatable enteric viruses without cell culture.
  Kazuki Tojo; Daisuke Sano; Takayuki Miura; Toyoko Nakagomi; Osamu Nakagomi; Satoshi Okabe
  Water science and technology : a journal of the International Association on Water Pollution Research, 67, 10, 2236, 40, 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• BODIPY-Based Ratiometric Fluoroionophores with Bidirectional Spectral Shifts for the Selective Recognition of Heavy Metal Ions
  Akira Hafuka; Hiroki Taniyama; Sang-Hyun Son; Koji Yamada; Masahiro Takahashi; Satoshi Okabe; Hisashi Satoh
  BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 86, 1, 37, 44, Jan. 2013, [Peer-reviewed]
  English, Scientific journal
• Hydrogenophaga electricum sp. nov., isolated from anodic biofilms of an acetate-fed microbial fuel cell.
  Zen-ichiro Kimura; Satoshi Okabe
  The Journal of general and applied microbiology, 59, 4, 261, 6, 2013, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Cultivation of planktonic anaerobic ammonium oxidation (anammox) bacteria using membrane bioreactor.
  Mamoru Oshiki; Takanori Awata; Tomonori Kindaichi; Hisashi Satoh; Satoshi Okabe
  Microbes and environments, 28, 4, 436, 43, 2013, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Anaerobic treatment of municipal wastewater at ambient temperature: Analysis of archaeal community structure and recovery of dissolved methane.
  Wasala M K R T W Bandara; Tomonori Kindaichi; Hisashi Satoh; Manabu Sasakawa; Yoshihito Nakahara; Masahiro Takahashi; Satoshi Okabe
  Water research, 46, 17, 5756, 5764, 01 Nov. 2012, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Identification and quantification of key microbial trophic groups of methanogenic glucose degradation in an anaerobic digester sludge
  Tsukasa Ito; Kazumi Yoshiguchi; Herto Dwi Ariesyady; Satoshi Okabe
  BIORESOURCE TECHNOLOGY, 123, 599, 607, Nov. 2012, [Peer-reviewed]
  English, Scientific journal
• Occurrence of Hand-Foot-and-Mouth Disease Pathogens in Domestic Sewage and Secondary Effluent in Xi'an, China
  Zheng Ji; Xiaochang Wang; Chongmiao Zhang; Takayuki Miura; Daisuke Sano; Naoyuki Funamizu; Satoshi Okabe
  MICROBES AND ENVIRONMENTS, 27, 3, 288, 292, Sep. 2012, [Peer-reviewed]
  English, Scientific journal
• Physiological characteristics of marine anammox bacteria enriched from sea sediments,Hiroshima,Japan.
  Takanori Awata; Tomonori Kindaichi; Noriatsu Ozaki; Akiyoshi Ohashi; Mamoru Oshiki; Satoshi Okabe
  14th International Symposium on Microbial Ecology(isme14), PS09.457A, PS09.457A, 14th International Symposium on Microbial Ecology(isme14), 19 Aug. 2012, [Peer-reviewed]
  Scientific journal
• For a Great Leap in Biofilm Researches ; form Control to Coexistence
  OKABE Satoshi
  Technical Report on Salt Science, 66, 4, 191, 197, The Society of Sea Water Science, Japan, 01 Aug. 2012
  Japanese
• RelE-mediated dormancy is enhanced at high cell density in Escherichia coli.
  Yosuke Tashiro; Koji Kawata; Asami Taniuchi; Kenji Kakinuma; Thithiwat May; Satoshi Okabe
  Journal of bacteriology, 194, 5, 1169, 76, Mar. 2012, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Community structure and in situ activity of nitrifying bacteria in Phragmites root-associated biofilms.
  Satoshi Okabe; Yoshiyuki Nakamura; Hisashi Satoh
  Microbes and environments, 27, 3, 242, 9, 2012, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge
  Tsukasa Ito; Kazumi Yoshiguchi; Herto Dwi Ariesyady; Satoshi Okabe
  ISME JOURNAL, 5, 12, 1844, 1856, Dec. 2011, [Peer-reviewed]
  English, Scientific journal
• Enterobactin is required for biofilm development in reduced-genome Escherichia coli.
  Thithiwat May; Satoshi Okabe
  Environmental microbiology, 13, 12, 3149, 62, 12, Dec. 2011, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• N2O emission from a partial nitrification-anammox process and identification of a key biological process of N2O emission from anammox granules.
  Satoshi Okabe; Mamoru Oshiki; Yoshitaka Takahashi; Hisashi Satoh
  Water research, 45, 19, 6461, 70, 01 Dec. 2011, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Adsorption characteristics of an enteric virus-binding protein to norovirus, rotavirus and poliovirus
  Takahiro Imai; Daisuke Sano; Takayuki Miura; Satoshi Okabe; Keishi Wada; Yoshifumi Masago; Tatsuo Omura
  BMC BIOTECHNOLOGY, 11, 123, Dec. 2011, [Peer-reviewed]
  English, Scientific journal
• Development of long-term stable partial nitrification and subsequent anammox process.
  Satoshi Okabe; Mamoru Oshiki; Yoshitaka Takahashi; Hisashi Satoh
  Bioresource technology, 102, 13, 6801, 7, Jul. 2011, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Physiological characteristics of the anaerobic ammonium-oxidizing bacterium 'Candidatus Brocadia sinica'.
  Mamoru Oshiki; Masaki Shimokawa; Naoki Fujii; Hisashi Satoh; Satoshi Okabe
  Microbiology (Reading, England), 157, Pt 6, 1706, 1713, Jun. 2011, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Removal of residual dissolved methane gas in an upflow anaerobic sludge blanket reactor treating low-strength wastewater at low temperature with degassing membrane.
  Wasala M K R T W Bandara; Hisashi Satoh; Manabu Sasakawa; Yoshihito Nakahara; Masahiro Takahashi; Satoshi Okabe
  Water research, 45, 11, 3533, 40, May 2011, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• 微生物の多様性―「遺伝子の多様性」/「細胞の多様性」から見た生物多様性 バイオフィルム
  押木守; 岡部聡
  生物の科学 遺伝, 65, 3, 48, 54, エヌ・ティー・エス, 01 May 2011
  Japanese
• Exposure of conjugative plasmid carrying Escherichia coli biofilms to male-specific bacteriophages.
  Thithiwat May; Kenji Tsuruta; Satoshi Okabe
  The ISME journal, 5, 4, 771, 5, Apr. 2011, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Ecophysiology of Uncultured Filamentous Anaerobes Belonging to the Phylum KSB3 That Cause Bulking in Methanogenic Granular Sludge
  Takeshi Yamada; Kae Kikuchi; Toshihiro Yamauchi; Koji Shiraishi; Tsukasa Ito; Satoshi Okabe; Akira Hiraishi; Akiyoshi Ohashi; Hideki Harada; Yoichi Kamagata; Kazunori Nakamura; Yuji Sekiguchi
  APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 77, 6, 2081, 2087, Mar. 2011, [Peer-reviewed]
  English, Scientific journal
• Effect of feeding regimens on polyhydroxybutyrate production from food wastes by Cupriavidus necator
  Akira Hafuka; Kenji Sakaida; Hisashi Satoh; Masahiro Takahashi; Yoshimasa Watanabe; Satoshi Okabe
  Bioresource Technology, 102, 3, 3551, 3553, 3, Feb. 2011, [Peer-reviewed]
  English, Scientific journal
• Quantification and Genotyping of Human Sapoviruses in the Llobregat River Catchment, Spain
  Daisuke Sano; Unai Perez-Sautu; Susana Guix; Rosa Maria Pinto; Takayuki Miura; Satoshi Okabe; Albert Bosch
  APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 77, 3, 1111, 1114, Feb. 2011, [Peer-reviewed]
  English, Scientific journal
• Effect of feeding regimens on polyhydroxybutyrate production from food wastes by Cupriavidus necator.
  Akira Hafuka; Kenji Sakaida; Hisashi Satoh; Masahiro Takahashi; Yoshimasa Watanabe; Satoshi Okabe
  Bioresource technology, 102, 3, 3551, 3, Feb. 2011, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Development of a simultaneous partial nitrification and anaerobic ammonia oxidation process in a single reactor
  Sunja Cho; Naoki Fujii; Taeho Lee; Satoshi Okabe
  BIORESOURCE TECHNOLOGY, 102, 2, 652, 659, Jan. 2011, [Peer-reviewed]
  English, Scientific journal
• Effect of formation of biofilms and chemical scale on the cathode electrode on the performance of a continuous two-chamber microbial fuel cell.
  Kyungmi Chung; Itto Fujiki; Satoshi Okabe
  Bioresource technology, 102, 1, 355, 60, Jan. 2011, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• A polyphasic approach to study ecophysiology of complex multispecies nitrifying biofilms.
  Satoshi Okabe; Hisashi Satoh; Tomonori Kindaichi
  Methods in enzymology, 496, 163, 84, 2011, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• A Great Leap forward in Microbial Ecology
  Satoshi Okabe; Mamoru Oshiki; Yoichi Kamagata; Nobuyasu Yamaguchi; Masanori Toyofuku; Yutaka Yawata; Yosuke Tashiro; Nobuhiko Nomura; Hiroyuki Ohta; Moriya Ohkuma; Akira Hiraishi; Kiwamu Minamisawa
  MICROBES AND ENVIRONMENTS, 25, 4, 230, 240, Dec. 2010, [Peer-reviewed]
  English
• Characterization and global gene expression of F- phenocopies during Escherichia coli biofilm formation.
  Thithiwat May; Akinobu Ito; Satoshi Okabe
  Molecular genetics and genomics : MGG, 284, 5, 333, 42, Nov. 2010, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Thermodynamic Properties of N-Isopropylacrylamide in Water: Solubility Transition, Phase Separation of Supersaturated Solution, and Glass Formation
  Shigeo Sasaki; Satoshi Okabe; Yuji Miyahara
  JOURNAL OF PHYSICAL CHEMISTRY B, 114, 46, 14995, 15002, Nov. 2010, [Peer-reviewed]
  English, Scientific journal
• Nitrogen removal performance and microbial community analysis of an anaerobic up-flow granular bed anammox reactor
  Sunja Cho; Yoshitaka Takahashi; Naoki Fujii; Yohei Yamada; Hisashi Satoh; Satoshi Okabe
  CHEMOSPHERE, 78, 9, 1129, 1135, Feb. 2010, [Peer-reviewed]
  English, Scientific journal
• Microbial community structures and in situ sulfate-reducing and sulfur-oxidizing activities in biofilms developed on mortar specimens in a corroded sewer system.
  Hisashi Satoh; Mitsunori Odagiri; Tsukasa Ito; Satoshi Okabe
  Water research, 43, 18, 4729, 39, Oct. 2009, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Localized expression profiles of rpoS in Escherichia coli biofilms.
  Akinobu Ito; Thithiwat May; Asami Taniuchi; Koji Kawata; Satoshi Okabe
  Biotechnology and bioengineering, 103, 5, 975, 83, 01 Aug. 2009, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• In vitro toxicity of silver nanoparticles at noncytotoxic doses to HepG2 human hepatoma cells.
  Koji Kawata; Masato Osawa; Satoshi Okabe
  Environmental science & technology, 43, 15, 6046, 51, 01 Aug. 2009, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Continuous power generation and microbial community structure of the anode biofilms in a three-stage microbial fuel cell system.
  Kyungmi Chung; Satoshi Okabe
  Applied microbiology and biotechnology, 83, 5, 965, 77, Jul. 2009, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• A biofilm model for prediction of pollutant transformation in sewers
  Feng Jiang; Derek Hoi-wai Leung; Shiyu Li; Guang-Hao Chen; Satoshi Okabe; Mark C. M. van Loosdrecht
  WATER RESEARCH, 43, 13, 3187, 3198, Jul. 2009, [Peer-reviewed]
  English, Scientific journal
• Increased antibiotic resistance of Escherichia coli in mature biofilms.
  Akinobu Ito; Asami Taniuchi; Thithiwat May; Koji Kawata; Satoshi Okabe
  Applied and environmental microbiology, 75, 12, 4093, 100, Jun. 2009, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Comparison of gene expression profiles in HepG2 cells exposed to arsenic, cadmium, nickel, and three model carcinogens for investigating the mechanisms of metal carcinogenesis.
  Koji Kawata; Ryuhei Shimazaki; Satoshi Okabe
  Environmental and molecular mutagenesis, 50, 1, 46, 59, Jan. 2009, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• The Response of Pseudomonas aeruginosa PAO1 Efflux Pump-Defective Mutants to N-Octanoyl-L-Homoserine Lactone
  Yutaka Yawata; Hideaki Maseda; Satoshi Okabe; Akinobu Ito; Isao Sawada; Hiroaki Kurashima; Hiroo Uchiyama; Nobuhiko Nomura
  MICROBES AND ENVIRONMENTS, 24, 4, 338, 342, 2009, [Peer-reviewed]
  English, Scientific journal
• Colorectal carcinoma: Local tumor staging and assessment of lymph node metastasis by high-resolution MR imaging in surgical specimens
  Ichiro Yamada; Norio Yoshino; Akemi Tetsumura; Satoshi Okabe; Masayuki Enomoto; Kenichi Sugihara; Jiro Kumagai; Hitoshi Shibuya
  International Journal of Biomedical Imaging, 2009, 659836, 2009, [Peer-reviewed]
  English, Scientific journal
• Escherichia coli harboring a natural IncF conjugative F plasmid develops complex mature biofilms by stimulating synthesis of colanic acid and Curli.
  Thithiwat May; Satoshi Okabe
  Journal of bacteriology, 190, 22, 7479, 90, Nov. 2008, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Quantification of cell specific uptake activity of microbial products by uncultured Chloroflexi by microautoradiography combined with fluorescence in situ hybridization.
  Yuki Miura; Satoshi Okabe
  Environmental science & technology, 42, 19, 7380, 6, 01 Oct. 2008, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Community structure and function of candidate division TM7 in a wastewater treatment plant.
  Tomonori Kindaichi; Hiroshi Kajihara; Takashi Yamamoto; Noriatsu Ozaki; Akiyoshi Ohashi; Satoshi Okabe
  12th International Symposium on Microbial Ecology (isme12), Aug. 2008, [Peer-reviewed]
  Scientific journal
• Significance of rpoS during maturation of Escherichia coli biofilms.
  Akinobu Ito; Thithiwat May; Koji Kawata; Satoshi Okabe
  Biotechnology and bioengineering, 99, 6, 1462, 71, 15 Apr. 2008, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Comparative studies on the conformational change and aggregation behavior of irradiated carrageenans and agar by dynamic light scattering
  Lucille Abad; Satoshi Okabe; Nlitsuhiro Shibayama; Hisaaki Kudo; Seiichi Saiki; Charito Aranilla; Lorna Relleve; Alumanda de la Rosa
  INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES, 42, 1, 55, 61, Jan. 2008, [Peer-reviewed]
  English, Scientific journal
• Significance of Chloroflexi in performance of submerged membrane bioreactors (MBR) treating municipal wastewater.
  Yuki Miura; Yoshimasa Watanabe; Satoshi Okabe
  Environmental science & technology, 41, 22, 7787, 94, 15 Nov. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Layered structure of bacterial and archaeal communities and their in situ activities in anaerobic granules.
  Hisashi Satoh; Yuki Miura; Ikuo Tsushima; Satoshi Okabe
  Applied and environmental microbiology, 73, 22, 7300, 7, Nov. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Layered structure of bacterial and archaeal communities and their in situ activities in anaerobic granules
  Hisashi Satoh; Yuki Miura; Ikuo Tsushima; Satoshi Okabe
  Applied and Environmental Microbiology, 73, 22, 7300, 7307, Nov. 2007
  English, Scientific journal
• Electrostatic self-assembly of neutral and polyelectrolyte block copolymers and oppositely charged surfactant
  Masahiko Annaka; Kanae Morishita; Satoshi Okabe
  JOURNAL OF PHYSICAL CHEMISTRY B, 111, 40, 11700, 11707, Oct. 2007, [Peer-reviewed]
  English, Scientific journal
• Persistence of host-specific Bacteroides-Prevotella 16S rRNA genetic markers in environmental waters: effects of temperature and salinity.
  Satoshi Okabe; Yoko Shimazu
  Applied microbiology and biotechnology, 76, 4, 935, 44, Sep. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• In situ activity and spatial organization of anaerobic ammonium-oxidizing (anammox) bacteria in biofilms
  Tomonori Kindaichi; Ikuo Tsushima; Yuji Ogasawara; Masaki Shimokawa; Noriatsu Ozaki; Hisashi Satoh; Satoshi Okabe
  APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 73, 15, 4931, 4939, Aug. 2007, [Peer-reviewed]
  English, Scientific journal
• Relationships between Bacteroides 16S rRNA genetic markers and presence of bacterial enteric pathogens and conventional fecal indicators.
  Olga Savichtcheva; Noriko Okayama; Satoshi Okabe
  Water research, 41, 16, 3615, 28, Aug. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Phylogenetic and functional diversity of propionate-oxidizing bacteria in an anaerobic digester sludge.
  Herto Dwi Ariesyady; Tsukasa Ito; Kazumi Yoshiguchi; Satoshi Okabe
  Applied microbiology and biotechnology, 75, 3, 673, 83, Jun. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Classification of heavy-metal toxicity by human DNA microarray analysis.
  Koji Kawata; Hiroyuki Yokoo; Ryuhei Shimazaki; Satoshi Okabe
  Environmental science & technology, 41, 10, 3769, 74, 15 May 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Development of high-rate anaerobic ammonium-oxidizing (anammox) biofilm reactors.
  Ikuo Tsushima; Yuji Ogasawara; Tomonori Kindaichi; Hisashi Satoh; Satoshi Okabe
  Water research, 41, 8, 1623, 34, Apr. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Quantification of host-specific Bacteroides-Prevotella 16S rRNA genetic markers for assessment of fecal pollution in freshwater.
  Satoshi Okabe; Noriko Okayama; Olga Savichtcheva; Tsukasa Ito
  Applied microbiology and biotechnology, 74, 4, 890, 901, Mar. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Succession of sulfur-oxidizing bacteria in the microbial community on corroding concrete in sewer systems.
  Satoshi Okabe; Mitsunori Odagiri; Tsukasa Ito; Hisashi Satoh
  Applied and environmental microbiology, 73, 3, 971, 80, Feb. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Bacterial community structures in MBRs treating municipal wastewater: relationship between community stability and reactor performance.
  Yuki Miura; Mirian Noriko Hiraiwa; Tsukasa Ito; Takanori Itonaga; Yoshimasa Watanabe; Satoshi Okabe
  Water research, 41, 3, 627, 37, Feb. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Influences of infaunal burrows on the community structure and activity of ammonia-oxidizing bacteria in intertidal sediments.
  Hisashi Satoh; Yoshiyuki Nakamura; Satoshi Okabe
  Applied and environmental microbiology, 73, 4, 1341, 8, Feb. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Quantification of anaerobic ammonium-oxidizing bacteria in enrichment cultures by real-time PCR
  Ikuo Tsushima; Tomonori Kindaichi; Satoshi Okabe
  Water Research, 41, 4, 785, 794, 4, Feb. 2007, [Peer-reviewed]
  English, Scientific journal
• Quantification of anaerobic ammonium-oxidizing bacteria in enrichment cultures by real-time PCR.
  Ikuo Tsushima; Tomonori Kindaichi; Satoshi Okabe
  Water research, 41, 4, 785, 94, Feb. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Influences of infaunal burrows on the community structure and activity of ammonia-oxidizing bacteria in intertidal sediments
  Hisashi Satoh; Yoshiyuki Nakamura; Satoshi Okabe
  Applied and Environmental Microbiology, 73, 4, 1341, 1348, Feb. 2007
  English, Scientific journal
• Membrane biofouling in pilot-scale membrane bioreactors (MBRs) treating municipal wastewater: impact of biofilm formation.
  Yuki Miura; Yoshimasa Watanabe; Satoshi Okabe
  Environmental science & technology, 41, 2, 632, 8, 15 Jan. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Development of a super high-rate Anammox reactor and in situ analysis of biofilm structure and function.
  Ikuo Tsushima; Yuji Ogasawara; Masaki Shimokawa; Tomonori Kindaichi; Satoshi Okabe
  Water science and technology : a journal of the International Association on Water Pollution Research, 55, 8-9, 9, 17, 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Views on youth job satisfaction of non-regular employment: Focusing on single male non-regular employees
  Satoshi Okabe
  SOCIOLOGICAL THEORY AND METHODS, 22, 2, 169, 187, 2007, [Peer-reviewed]
  Japanese, Scientific journal
• Structural transition in block and gradient copolymer aqueous solutions
  Satoshi Okabe; Chieko Fuse; Shinji Sugihara; Sadahito Aoshima; Mitsuhiro Shibayama
  PHYSICA B-CONDENSED MATTER, 385, 756, 758, Nov. 2006, [Peer-reviewed]
  English, Scientific journal
• PB-07 Interspecies Communication Modulates Antibiotic Tolerance, Virulence and a Wide Range of Gene Expression in Pseudomonas aeruginosa(Symbiosis/Interaction,Session B,(1)Poster Presentation)
  YAWATA,Yutaka; Okabe,Satoshi; Ito,Akinobu; Maseda,Hideaki; UCHIYAMA,Hiroo; NOMURA,Nobuhiko; NAKAJIMA,Toshiaki
  日本微生物生態学会講演要旨集, 0, 22, 125, 125, Japanese Society of Microbial Ecology, Oct. 2006
  Japanese, Scientific journal
• Population dynamics and in situ kinetics of nitrifying bacteria in autotrophic nitrifying biofilms as determined by real-time quantitative PCR
  Tomonori Kindaichi; Yoshiko Kawano; Tsukasa Ito; Hisashi Satoh; Satoshi Okabe
  BIOTECHNOLOGY AND BIOENGINEERING, 94, 6, 1111, 1121, Aug. 2006, [Peer-reviewed]
  English, Scientific journal
• Community structures and activities of nitrifying and denitrifying bacteria in industrial wastewater-treating biofilms
  H Satoh; T Yamakawa; T Kindaichi; T Ito; S Okabe
  BIOTECHNOLOGY AND BIOENGINEERING, 94, 4, 762, 772, Jul. 2006, [Peer-reviewed]
  English, Scientific journal
• Alternative indicators of fecal pollution: relations with pathogens and conventional indicators, current methodologies for direct pathogen monitoring and future application perspectives.
  Olga Savichtcheva; Satoshi Okabe
  Water research, 40, 13, 2463, 76, Jul. 2006, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Community structure, abundance, and in situ activity of nitrifying bacteria in river sediments as determined by the combined use of molecular techniques and microelectrodes.
  Yoshiyuki Nakamura; Hisashi Satoh; Tomonori Kindaichi; Satoshi Okabe
  Environmental science & technology, 40, 5, 1532, 9, 01 Mar. 2006, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• A vista for microbial ecology and environmental biotechnology
  BE Rittmann; M Hausner; F Loffler; NG Love; G Muyzer; S Okabe; DB Oerther; J Peccia; L Raskin; M Wagner
  ENVIRONMENTAL SCIENCE & TECHNOLOGY, 40, 4, 1096, 1103, Feb. 2006, [Peer-reviewed]
  English
• Distribution analyses of multi-modal dynamic light scattering data
  Satoshi Okabe; Takeshi Karino; Mitsuhiro Shibayama
  Polymer Preprints, Japan, 55, 2, 3218, 3219, 2006
  Japanese, International conference proceedings
• Application of a direct fluorescence-based live/dead staining combined with fluorescence in situ hybridization for assessment of survival rate of Bacteroides spp. in drinking water.
  Olga Savichtcheva; Noriko Okayama; Tsukasa Ito; Satoshi Okabe
  Biotechnology and bioengineering, 92, 3, 356, 63, 05 Nov. 2005, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• PB-37 Interspecies communication modulates antibiotic tolerance, virulence and a wide range of gene expressions in Pseudomonas aeruginosa(SYMBIOSIS/INTERACTIONS,Session B,(1) Poster presentations)
  YAWATA,Yutaka; OKABE,Satoshi; ITO,Akinobu; MASEDA,Hideaki; UCHIYAMA,Hiro; NOMURA,Nobuhiko
  日本微生物生態学会講演要旨集, 0, 21, 157, 157, Japanese Society of Microbial Ecology, Oct. 2005
  Japanese, Scientific journal
• Involvement of cyclin D3 in liver metastasis of colorectal cancer, revealed by genome-wide copy-number analysis
  H Tanami; H Tsuda; S Okabe; T Iwai; K Sugihara; Imoto, I; J Inazawa
  LABORATORY INVESTIGATION, 85, 9, 1118, 1129, Sep. 2005, [Peer-reviewed]
  English, Scientific journal
• Use of microelectrodes to investigate the effects of 2-chlorophenol on microbial activities in biofilms
  H Satoh; Y Sasaki; Y Nakamura; S Okabe; T Suzuki
  BIOTECHNOLOGY AND BIOENGINEERING, 91, 2, 133, 138, Jul. 2005, [Peer-reviewed]
  English, Scientific journal
• Fate of C-14-labeled microbial products derived from nitrifying bacteria in autotrophic nitrifying biofilms
  S Okabe; T Kindaichi; T Ito
  APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 71, 7, 3987, 3994, Jul. 2005, [Peer-reviewed]
  English, Scientific journal
• Succession of internal sulfur cycles and sulfur-oxidizing bacterial communities in microaerophilic wastewater biofilms.
  Satoshi Okabe; Tsukasa Ito; Kenichi Sugita; Hisashi Satoh
  Applied and environmental microbiology, 71, 5, 2520, 9, May 2005, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Thiovirga sulfuroxydans gen. nov., sp. nov., a chemolithoautotrophic sulfur-oxidizing bacterium isolated from a microaerobic waste-water biofilm.
  Tsukasa Ito; Kenichi Sugita; Isao Yumoto; Yoshinobu Nodasaka; Satoshi Okabe
  International journal of systematic and evolutionary microbiology, 55, Pt 3, 1059, 1064, May 2005, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Isolation, characterization, and in situ detection of a novel chemolithoautotrophic sulfur-oxidizing bacterium in wastewater biofilms growing under microaerophilic conditions.
  Tsukasa Ito; Kenichi Sugita; Satoshi Okabe
  Applied and environmental microbiology, 70, 5, 3122, 9, May 2004, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Photosynthesis in sediments determined at high spatial resolution by the use of microelectrodes.
  Yoshiyuki Nakamura; Hisashi Satoh; Satoshi Okabe; Yoshimasa Watanabe
  Water research, 38, 9, 2439, 47, May 2004, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Ecophysiological Interaction between Nitrifying Bacteria and Heterotrophic Bacteria in Autotrophic Nitrifying Biofilms as Determined by Microautoradiography-Fluorescence In Situ Hybridization
  Tomonori Kindaichi; Tsukasa Ito; Satoshi Okabe
  Applied and Environmental Microbiology, 70, 3, 1641, 1650, 3, Mar. 2004, [Peer-reviewed]
  English, Scientific journal
• Macroscale and microscale analyses of nitrification and denitrification in biofilms attached on membrane aerated biofilm reactors
  H Satoh; H Ono; B Rulin; J Kamo; S Okabe; KI Fukushi
  WATER RESEARCH, 38, 6, 1633, 1641, Mar. 2004, [Peer-reviewed]
  English, Scientific journal
• Macroscale and microscale analyses of nitrification and denitrification in biofilms attached on membrane aerated biofilm reactors
  H Satoh; H Ono; B Rulin; J Kamo; S Okabe; KI Fukushi
  WATER RESEARCH, 38, 6, 1633, 1641, Mar. 2004
  English, Scientific journal
• Ecophysiological interaction between nitrifying bacteria and heterotrophic bacteria in autotrophic nitrifying biofilms as determined by microautoradiography-fluorescence in situ hybridization.
  Tomonori Kindaichi; Tsukasa Ito; Satoshi Okabe
  Applied and environmental microbiology, 70, 3, 1641, 50, Mar. 2004, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Analysis of size distribution and areal cell density of ammonia-oxidizing bacterial microcolonies in relation to substrate microprofiles in biofilms.
  Satoshi Okabe; Tomonori Kindaichi; Tsukasa Ito; Hisashi Satoh
  Biotechnology and bioengineering, 85, 1, 86, 95, 05 Jan. 2004, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• MAR-FISH-An Ecophysiological Approach to Link Phylogenetic Affiliation and in Situ Metabolic Activity of Microorganisms at a Single-Cell Resolution
  Satoshi Okabe; Tomonori Kindaichi; Tsukasa Ito
  Microbes and Environments, 19, 2, 83, 98, 2004
  English, Scientific journal
• Analysis of microbial community structure and in situ activity of nitrifying biofilms
  Okabe S; Satoh H; Ito T; Watanabe Y
  Journal of Water and Environment Technology, 2, 2, 65, 74, Japan Society on Water Environment, 2004
  English, Wastewater biofilms are very complex multispecies biofilms, displaying considerable heterogeneity with respect to both the microorganisms present and their physicochemical microenvironments. To understand the eco-physiology of individual microorganisms in the biofilm, techniques and tools with a high spatial and temporal resolution are required for direct detection of the spatial distributions of microbial species and their activities in minimally disturbed their natural habitats (e.g., biofilms). In this paper, we will, therefore, address the great potential of the combined use of the current FISH technique and microelectrodes to study the microbial ecology of complex microbial communities such as biofilms. The combination of these two techniques will provide reliable and direct information about relationships between in situ microbial activity and the occurrence of specific microorganisms in biofilms. As an example of the combined study, we will illustrate the in situ spatial organization of ammonia-oxidizing and nitrite-oxidizing bacteria on fine scale in autotrophic nitrifying biofilms by applying the full-cycle of 16S rRNA approach followed by fluorescence in situ hybridization (FISH), which is linked to their in situ activity distributions at a similar resolution determined by use of microelectrodes. The combination of these techniques allows relating in situ microbial activity directly to occurrence of nitrifying bacteria population.
• Cyclooxygenase-2 expression and its relationship with proliferation of colorectal adenomas
  T Sato; K Yoshinaga; S Okabe; T Okawa; T Higuchi; M Enomoto; T Takizawa; K Sugihara
  JAPANESE JOURNAL OF CLINICAL ONCOLOGY, 33, 12, 631, 635, Dec. 2003, [Peer-reviewed]
  English, Scientific journal
• Effect of oxygen concentration on nitrification and denitrification in single activated sludge flocs
  H Satoh; Y Nakamura; H Ono; S Okabe
  BIOTECHNOLOGY AND BIOENGINEERING, 83, 5, 604, 607, Sep. 2003, [Peer-reviewed]
  English, Scientific journal
• Dynamic response of nitrifying activated sludge batch culture to increased chloride concentration
  GH Chen; MT Wong; S Okabe; Y Watanabe
  WATER RESEARCH, 37, 13, 3125, 3135, Jul. 2003, [Peer-reviewed]
  English, Scientific journal
• Evaluation of the impact of bioaugmentation and biostimulation by in situ hybridization and microelectrode
  H Satoh; S Okabe; Y Yamaguchi; Y Watanabe
  WATER RESEARCH, 37, 9, 2206, 2216, May 2003, [Peer-reviewed]
  English, Scientific journal
• Effect of nitrite and nitrate on in situ sulfide production in an activated sludge immobilized agar gel film as determined by use of microelectrodes.
  Satoshi Okabe; Cecilia M Santegoeds; Dirk De Beer
  Biotechnology and bioengineering, 81, 5, 570, 7, 05 Mar. 2003, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Influence of different cultivars on populations of ammonia-oxidizing bacteria in the root environment of rice.
  Aurelio M Briones; Satoshi Okabe; Yoshiaki Umemiya; Niels-Birger Ramsing; Wolfgang Reichardt; Hidetoshi Okuyama
  Applied and environmental microbiology, 68, 6, 3067, 75, Jun. 2002, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Successional development of sulfate-reducing bacterial populations and their activities in an activated sludge immobilized agar gel film.
  Satoshi Okabe; Cecilia M Santegoeds; Yoshimasa Watanabe; Dirk de Beer
  Biotechnology and bioengineering, 78, 2, 119, 30, 20 Apr. 2002, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Successional development of sulfate-reducing bacterial populations and their activities in a wastewater biofilm growing under microaerophilic conditions.
  Tsukasa Ito; Satoshi Okabe; Hisashi Satoh; Yoshimasa Watanabe
  Applied and environmental microbiology, 68, 3, 1392, 402, Mar. 2002, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Phylogenetic identification and substrate uptake patterns of sulfate-reducing bacteria inhabiting an oxic-anoxic sewer biofilm determined by combining microautoradiography and fluorescent in situ hybridization.
  Tsukasa Ito; Jeppe L Nielsen; Satoshi Okabe; Yoshimasa Watanabe; Per H Nielsen
  Applied and environmental microbiology, 68, 1, 356, 64, Jan. 2002, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• ANAEROBIC SRB BIOFILMS IN INDUSTRIAL WATER-SYSTEMS - A PROCESS ANALYSIS
  S OKABE; WL JONES; W LEE; WG CHARACKLIS
  BIOFOULING AND BIOCORROSION IN INDUSTRIAL WATER SYSTEMS, 189, 204, 1994, [Peer-reviewed]
  English, International conference proceedings
• Anaerobic biofilms in industrial water-systems
  Abstracts of Papers of the American Chemical Society, 204, 9999, 1993
• Effects of temperature and phosphorous concentration on microbial sulfate reduction by Desulfovibrio desulfuricans
  S. Okabe; W. G. Characklis
  Biotechnology and Bioengineering, 39, 10, 1031, 1042, 01 Jan. 1992
• Corrosion of mild steel underneath aerobic biofilms containing sulfate-reducing bacteria
  Corrosion, 47, 1, 15, 1992
• Factors affecting microbial sulfate reduction by Desulfovibrio desulfuricans in continuous culture: Limiting nutrients and sulfide concentration
  S. Okabe; P. H. Nielsen; P. H. Nielsen; W. G. Characklis
  Biotechnology and Bioengineering, 40, 6, 725, 734, 01 Jan. 1992

• Valuable Products Synthesis by Bio-photoelectrochemical Cells
  松尾稜介; 糸入祐也; 渡辺精一; 岡部聡, 日本水環境学会年会講演集, 58th, 2024
• Light-driven microbial-photoelectrochemical cell for H₂ generation
  松尾稜介; 糸入祐也; 高橋優樹; 渡辺精一; 岡部聡, 日本水環境学会年会講演集, 57th, 2023
• NGS based sequencing of environmentally derived antibiotic resistance plasmids and elucidation of plasmid transfer frequency・host range in activated sludge
  樋口宏介; 新谷政己; 徳田真穂; 北島正章; 岡部聡; 押木守, 日本水環境学会年会講演集, 57th, 2023
• Dual nitrogen and oxygen isotope fractionation during complete ammonia oxidation by comammox ba teria “Nitrospira inopinata”.
  塚田麦; 小林香苗; 小林香苗; 福島慶太郎; 大西雄二; 押木守; 木庭啓介; 岡部聡, 日本水環境学会年会講演集, 56th, 2022
• Conjugal Transfer of an IncP Plasmid Carrying Multidrug Resistance Genes: Determination of Frequency and Host Range in Activated Sludge Using Flowcytometry and Amplicon Sequencing
  樋口宏介; 本田樹; 北島正章; 岡部聡; 押木守, 日本水環境学会年会講演集, 56th, 2022
• 活性汚泥における多剤耐性IncP-1群プラスミドpB10の伝播頻度・宿主域の解明
  樋口宏介; 北島正章; 岡部聡; 押木守, 日本農芸化学会東北支部大会プログラム・講演要旨集, 2022, 2022
• Mechanism for Suppression of Membrane Resistance using an SMP-degrading Bacteriophage
  渡部慶彦; 北島正章; 大坪千穂; 石崎創; 荒川千智; 石井聡; 押木守; 岡部聡, 日本水環境学会年会講演集, 55th, 2021
• Quantitative Analysis of Pathogenic and Indicator Viruses at a Wastewater Treatment Plant with Pilot-scale MBR
  石崎知依; 木村克輝; 岡部聡; 北島正章, 日本水環境学会年会講演集, 55th, 2021
• Extracellular electron transfer mechanism affected by bacteriophages infecting an iron-reducing bacterium, Shewanella oneidensis
  石原令梧; 岡本章玄; 岡部聡; 北島正章, 日本水環境学会年会講演集, 54th, 2020
• Intra Population Genetic Diversity of Rotavirus A Strain Impacts on Free Chlorine Sensitivity
  門屋俊祐; 西村修; 佐野大輔; 浦山俊一; 布浦拓郎; 北島正章; 岡部聡; 中込とよ子; 中込治, 日本水環境学会年会講演集, 54th, 2020
• Intra-Population Diversity of Rotavirus Changes the Chlorine Sensitivity
  門屋俊祐; 浦山俊一; 布浦拓郎; 中込治; 中込とよ子; 北島正章; 岡部聡; 西村修; 佐野大輔, 日本水環境学会シンポジウム講演集, 23rd, 2020
• Effects of Electron Acceptors on Metabolism and Membrane Fouling Potential of Fouling Causing Bacteria (FCB)
  藤平卓也; 石崎創; 木村善一郎; 岡部聡, 日本水環境学会年会講演集, 54th, 2020
• Analysis of nitrogen and oxygen isotope effects of a marine anammox species; “Ca. Scalindua sp.”
  小林香苗; 福島慶太郎; 大西雄二; 仁科一哉; 眞壁明子; 押木守; 金田一智規; 木庭啓介; 岡部聡, 日本水環境学会年会講演集, 54th, 2020
• Acetic Acid Synthesis by an Inorganic-Biological Hybrid Artificial Photosynthetic System
  松尾稜介; 高橋優樹; 百瀬皓太; 渡辺精一; 岡部聡, 日本水環境学会年会講演集, 54th, 2020
• 嫌気性アンモニア酸化細菌“Ca.Scalindua sp.”の酸素同位体分別の解析
  小林香苗; 福島慶太郎; 大西雄二; 眞壁明子; 矢野翠; 押木守; 金田一智規; 木庭啓介; 岡部聡, 日本微生物生態学会大会(Web), 33rd, 2019
• Specific interactions of rotavirus HAL1166 with Enterobacter cloacae SENG-6 and their contribution on rotavirus HAL1166 removal.
  Mohan Amarasiri; Hiroki Kawai; Masaaki Kitajima; Satoshi Okabe; Daisuke Sano, Water science and technology : a journal of the International Association on Water Pollution Research, 79, 2, 342, 348, Jan. 2019, [Peer-reviewed], [International Magazine]
  {IWA} Publishing, English
• nos欠損型脱窒菌による窒素含有廃水の処理及びN₂O回収による新エネルギー源の創出
  石丸美穂; 押木守; 荒木信夫; 岡部聡; 幡本将史; 山口隆司, 日本水環境学会年会講演集, 52nd, 656, 09 Mar. 2018
  Japanese
• アナモックス細菌の窒素・酸素同位体効果の解析
  小林香苗; 眞壁明子; 押木守; 金田一智規; 岡部聡, 日本水環境学会年会講演集, 52nd, 379, 09 Mar. 2018
  Japanese
• 共存細菌との結合が水系感染症ウイルスの感染効率に与える影響
  河合大樹; 北島正章; 岡部聡; 佐野大輔, 日本水環境学会年会講演集, 52nd, 2018
• 金属腐食抑制への応用に向けた鉄還元細菌Shewanellaの溶菌性バクテリオファージの単離と特性解析
  石原令梧; 岡本章玄; 高木達馬; 岡部聡; 北島正章, 日本水環境学会年会講演集, 52nd, 2018
• 下水処理水中のβ-グルクロニダーゼ活性を利用した簡易迅速大腸菌定量法の開発
  菊地凱; 片寄由貴; 石井聡; 北島正章; 岡部聡; 高橋正宏; 佐藤久, 日本水環境学会年会講演集, 52nd, 2018
• DNAアプタマーを用いた簡易ノロウイルス検出法の開発
  吉原光; 北島正章; 岡部聡; 高橋正宏; 佐藤久; 佐野大輔, 日本水環境学会年会講演集, 52nd, 2018
• 環境水から単離した溶菌性バクテリオファージによる水中病原細菌の低減効果
  高木達馬; 佐野大輔; 岡部聡; 北島正章, 日本水環境学会年会講演集, 52nd, 2018
• ウイルス干渉現象がIntegrated cell culture-PCRによる感染性ウイルス検出に与える影響
  渡邊亮介; 北島正章; 岡部聡; 佐野大輔, 土木学会北海道支部論文報告集(CD-ROM), 74, 2018
• β-グルクロニダーゼを用いた新規簡易大腸菌数測定法の開発
  菊地凱; 片寄由貴; 北島正章; 高橋正宏; 岡部聡; 佐藤久; 平野麗子, 下水道研究発表会講演集, 55th, 2018
• ウイルス干渉現象がIntegrated cell culture-PCRによる感染性アデノウイルス検出に与える影響
  佐野大輔; 渡邊亮介; 北島正章; 岡部聡, 日本水環境学会シンポジウム講演集, 21st, 2018
• 遊離塩素耐性ロタウイルスの変異遺伝子同定に関する研究
  門屋俊祐; 浦山俊一; 布浦拓郎; 北島正章; 岡部聡; 佐野大輔, 日本水環境学会年会講演集, 51st, 2017
• DNAアプタセンサー:水中ノロウイルスの即時・高感度検出に適した新技術
  平野誠也; 岡本章玄; 佐野大輔; 岡部聡; 北島正章, 日本水環境学会年会講演集, 51st, 2017
• 病原性レジオネラの水系感染制御に資する溶菌性バクテリオファージの探索
  高木達馬; 佐野大輔; 岡部聡; 北島正章, 日本水環境学会年会講演集, 51st, 2017
• 水環境におけるノロウイルスの遺伝子型別存在実態の把握
  宮村明帆; 植木洋; 三浦尚之; 風間しのぶ; 北島正章; 岡部聡; 佐野大輔, 日本水環境学会年会講演集, 51st, 2017
• ウイルス吸着性細菌との結合が水系感染症ウイルスの感染能力に与える影響
  河合大樹; 中込とよ子; 中込治; 北島正章; 岡部聡; 佐野大輔, 日本水環境学会年会講演集, 51st, 2017
• 環境水中からのノロウイルス吸着性大腸菌の単離と吸着因子同定に関する研究
  羽柴聡; AMARASIRI Mohan; 原本英司; 北島正章; 岡部聡; 佐野大輔, 日本水環境学会年会講演集, 51st, 2017
• 遊離塩素耐性ロタウイルスの変異遺伝子および耐性メカニズムの解明
  門屋俊祐; 浦山俊一; 布浦拓郎; 北島正章; 岡部聡; 佐野大輔, 環境工学研究フォーラム講演集, 54th, 2017
• 水系感染性病原細菌に対するバクテリオファージの単離および溶菌特性解析
  高木達馬; 佐野大輔; 岡部聡; 北島正章, 環境工学研究フォーラム講演集, 54th, 2017
• 大腸菌のβ-グルクロニダーゼ生産能の解析
  菊地凱; 北島正章; 岡部聡; 高橋正宏; 佐藤久, 環境工学研究フォーラム講演集, 54th, 2017
• DNAアプタマーを用いた簡易ノロウイルス検出法の開発
  吉原光; 北島正章; 佐野大輔; 岡部聡; 高橋正宏; 佐藤久, 環境工学研究フォーラム講演集, 54th, 2017
• 下水再生利用のためのノロウイルス目標除去効率算定に関する研究
  伊藤寿宏; 北島正章; 加藤毅; 石井聡; 瀬川高弘; 岡部聡; 佐野大輔, 日本微生物生態学会大会(Web), 2017, 2017
• 組織細胞におけるイオンチャネル遺伝子発現プロファイルに着目した水中感染性エンテロウイルス迅速検出手法の開発
  渡邊亮介; 稲葉愛美; 岡部聡; 佐野大輔; 北島正章, 日本水環境学会年会講演集, 51st, 2017
• DNAアプタマーを用いた簡易ノロウイルス検出法の開発
  吉原光; 北島正章; 佐野大輔; 岡部聡; 高橋正宏; 佐藤久, 全国会議(水道研究発表会)講演集, 2017, 2017
• Aptamer: The potential application to norovirus research, diagnosis, and therapeutics
  Seiya Hirano; Daisuke Sano; Satoshi Okabe; Masaaki Kitajima, Noroviruses: Outbreaks, Control and Prevention Strategies, 223, 242, 01 Jan. 2017
• ヒドラジンを合成するオルガネラ:嫌気性アンモニウム酸化細菌のアナモキソソーム
  押木守; 岡部聡, 日本微生物生態学会大会(Web), 2017, ROMBUNNO.S‐070 (WEB ONLY), 2017
  Japanese
• Genome Sequence ofEnterobacter cloacaeStrain SENG-6, a Bacterium Producing Histo-Blood Group Antigen-Like Substances That Can Bind with Human Noroviruses
  Satoshi Ishii; Mohan Amarasiri; Satoshi Hashiba; Peiyi Yang; Satoshi Okabe; Daisuke Sano, Genome Announcements, 4, 4, e00893, 16, Aug. 2016
  American Society for Microbiology
• Anammox細菌の窒素同位体分別に関する研究
  小林香苗; 押木守; 金田一智規; 眞壁明子; 岡部聡, 日本水環境学会年会講演集, 50th, 664, 10 Mar. 2016
  Japanese
• 遊離塩素処理がノロウイルスの遺伝的多様性に与える影響
  中村新; 渡辺幸三; 八重樫咲子; 岡部聡; 中込とよ子; 中込治; 佐野大輔, 日本水環境学会年会講演集, 50th, 398, 10 Mar. 2016
  Japanese
• ヒト細胞由来遺伝子マーカーを用いた感染性ウイルスの迅速検出
  稲葉愛美; 伊藤寿宏; 大村達夫; 岡部聡; 佐野大輔, 日本水環境学会年会講演集, 50th, 2016
• Bayesian modeling of virus removal efficiency in wastewater treatment processes
  T. Ito; T. Kato; K. Takagishi; S. Okabe; D. Sano, WATER SCIENCE AND TECHNOLOGY, 72, 10, 1789, 1795, Nov. 2015
  English
• 嫌気性アンモニウム酸化細菌由来ヒドラジン合成酵素の精製
  押木守; 荒木信夫; 岡部聡, 日本微生物生態学会大会(Web), 30th, PD‐051 (WEB ONLY), 2015
  Japanese
• Trends in Anammox Research and Development
  岡部 聡, 水環境学会誌, 37, 9, 316, 320, Sep. 2014
  日本水環境学会 ; 1992-, Japanese
• ノロウイルスの塩素消毒耐性獲得メカニズム解明に関する基礎的研究
  富岡哲史; 渡辺幸三; 岡部聡; 佐野大輔, 土木学会北海道支部論文報告集(CD-ROM), 70, ROMBUNNO.G-01, Feb. 2014
  Japanese
• O21-02 Identification of key N_2O production pathways in aerobic partial nitrifying granules :
  Ishii Satoshi; Song Yanjun; Rathnayake Lashitha; Tumendelger Azzaya; Satoh Hisashi; Sakae Toyoda; Yoshida Naohiro; Okabe Satoshi, 日本微生物生態学会講演要旨集, 2014, 94, 94, 2014
  日本微生物生態学会, English
• ゲノミクス,プロテオミクス解析から読み解くアンモニア酸化(anammox)細菌“Ca.Scalindua japonica”の生活環
  押木守; 水戸佳祐; 木村善一郎; 金田一智規; 佐藤久; 岡部聡, 日本ゲノム微生物学会年会要旨集, 8th, 69, 2014
  Japanese
• Source identification of nitrous oxide on autotrophic partial nitrification in a granular sludge reactor
  R. M. L. D. Rathnayake; Y. Song; A. Tumendelger; M. Oshiki; S. Ishii; H. Satoh; S. Toyoda; N. Yoshida; S. Okabe, WATER RESEARCH, 47, 19, 7078, 7086, Dec. 2013, [Last author, Corresponding author]
  English
• 2S-Cp04 Physiological and genomic insights into an anammox bacterium "Candidatus Brocadia sinica"
  Oshiki Mamoru; Satoh Hisashi; Okabe Satoshi, 日本生物工学会大会講演要旨集, 65, 89, 89, 25 Aug. 2013
  公益社団法人日本生物工学会, Japanese
• 変色型ボロンジピロメテン蛍光色素を用いた路面排水中Zn²⁺濃度の定量
  羽深昭; 吉川弘晃; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 分析化学討論会講演要旨集, 73rd, 149, 04 May 2013
  Japanese
• Introduction of a Degassing Membrane Technology into Anaerobic Wastewater Treatment
  W. M. K. R. T. W. Bandara; M. Ikeda; H. Satoh; M. Sasakawa; Y. Nakahara; M. Takahashi; S. Okabe, WATER ENVIRONMENT RESEARCH, 85, 5, 387, 390, May 2013
  English, Others
• MBR膜ファウリングを支配する細菌の探索
  井川裕介; 吉田圭太郎; 福島寿和; 岡部聡; 三好太郎; 渡辺義公, 日本水環境学会年会講演集, 47th, 255, 11 Mar. 2013
  Japanese
• 網羅的重金属イオン分析に向けた新規変色型蛍光色素の開発
  吉川弘晃; 羽深昭; 菅藤亮輔; 大屋光平; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 47th, 431, 11 Mar. 2013
  Japanese
• 環境サンプル測定のためのリン酸マイクロセンサーの開発
  宮崎悠爾; 谷内翔; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 47th, 321, 11 Mar. 2013
  Japanese
• 新規変色型蛍光色素を用いた路面排水中亜鉛濃度の定量
  菅藤亮輔; 羽深昭; 吉川弘晃; 大屋光平; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 47th, 432, 11 Mar. 2013
  Japanese
• 重金属測定用蛍光色素の理論的分子設計による高感度化
  大屋光平; 羽深昭; 菅藤亮輔; 吉川弘晃; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 47th, 692, 11 Mar. 2013
  Japanese
• リン酸マイクロセンサーのイオノフォアの検討
  谷内翔; 宮崎悠爾; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 47th, 322, 11 Mar. 2013
  Japanese
• 表面プラズモン共鳴を利用した病原微生物バイオセンサの開発
  坂槙有紀恵; 山田健太; 佐野大輔; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 47th, 436, 11 Mar. 2013
  Japanese
• 遺伝子発現解析に基づく再生水中残留医薬品の毒性評価
  中島弘司; 原(山村)宏江; 木村克輝; 岡部聡; 三好太郎; 渡辺義公, 日本水環境学会年会講演集, 47th, 412, 11 Mar. 2013
  Japanese
• ヒト由来培養細胞を用いた塩素消毒下水処理水の毒性評価
  福島寿和; 木村克輝; 岡部聡; 三好太郎; 渡辺義公, 日本水環境学会年会講演集, 47th, 516, 11 Mar. 2013
  Japanese
• 細胞応答に基づいた膜処理再生水中の毒性画分の探索―粒径に着目して
  原(山村)宏江; HOQUE Asiful; 木村克輝; 岡部聡; 三好太郎; 渡辺義公, 日本水環境学会年会講演集, 47th, 517, 11 Mar. 2013
  Japanese
• 広島湾により集積されたScalindua属アナモックス細菌の生理学的特性
  粟田貴宣; 金田一智規; 尾崎則篤; 大橋晶良; 押木守; 岡部聡, 日本水環境学会年会講演集, 47th, 160, 11 Mar. 2013
  Japanese
• 環境サンプル測定のためのリン酸マイクロセンサーの開発
  宮崎悠爾; 谷内翔; 押木守; 佐藤久; 高橋正宏; 岡部聡, 土木学会北海道支部論文報告集(CD-ROM), 69, ROMBUNNO.G-02, Feb. 2013
  Japanese
• Key Technologies for Water Reclamation : Membrane Separation and Biotechnology
  OKABE Satoshi, 水環境学会誌 = Journal of Japan Society on Water Environment, 36, 1, 15, 18, 10 Jan. 2013
  日本水環境学会 ; 1992-, Japanese
• 病原微生物の許容感染リスクに基づく水質基準設定方法の構築-遺伝子マーカーの利用-
  小林彩乃; 小澤就志; 加藤毅; 佐野大輔; 三浦尚之; 石井聡; 岡部聡, 日本水環境学会シンポジウム講演集, 16th, 2013
• 微生物学的安全性を担保するための科学的根拠に基づく衛生水質基準値設定方法の提案
  小林彩乃; 佐野大輔; 小澤就志; 加藤毅; 三浦尚之; 石井聡; 岡部聡, 環境工学研究フォーラム講演集, 50th, 2013
• Hydrogenophaga sp.AR20のGeobacter sulfurreducensとの水素を介した共生的電気生産
  寺田浩太朗; 木村善一郎; 石崎創; 岡部聡, 日本水環境学会年会講演集, 47th, 2013
• 環境サンプル測定のためのリン酸マイクロセンサーの開発
  宮崎悠爾; 谷内翔; 押木守; 高橋正宏; 岡部聡; 佐藤久, 衛生工学シンポジウム論文集, 20th, 24, 04 Dec. 2012
  Japanese
• 表面プラズモン共鳴を利用した病原微生物バイオセンサの開発
  坂槙有紀恵; 山田健太; ピタックティーラタム ニティ; 石井聡; 佐野大輔; 高橋正宏; 岡部聡; 佐藤久, 環境工学研究フォーラム講演集, 49th, 28, 30, 28 Nov. 2012
  Japanese
• 新規蛍光分子プローブを用いた環境水中重金属イオン分析
  菅藤亮輔; 羽深昭; 吉川弘晃; 大屋光平; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 環境工学研究フォーラム講演集, 49th, 31, 33, 28 Nov. 2012
  Japanese
• 環境サンプル測定のためのリン酸マイクロセンサーの開発
  宮崎悠爾; 谷内翔; 押木守; 佐藤久; 高橋正宏; 岡部聡, 環境工学研究フォーラム講演集, 49th, 25, 27, 28 Nov. 2012
  Japanese
• PK-24 Syntrophic acetate oxidation by the couple of anaerobic acetate oxidizing bacteria and hydrogenotrophic exoelectrogenic bacteria in the MFC fed with acetate(PK Interaction and symbiosis,Poster session)
  Kimura Zen-ichiro; Terada Kohtaro; Okabe Satoshi, 日本微生物生態学会講演要旨集, 28, 176, 176, 19 Sep. 2012
  日本微生物生態学会, English
• PGa-04 Elucidating a metabolic pathway for the anaerobic ammonium oxidation of Candidatus "Brocadia sinica" by metagenomics analysis
  Oshiki Mamoru; Shinyako Kaori; Satoh Hisashi; Okabe Satoshi, 日本微生物生態学会講演要旨集, 28, 160, 160, 19 Sep. 2012
  日本微生物生態学会, English
• Next-generation DNA Sequencing Dramatically Accelerates Environmental Researches
  OKABE Satoshi, 水環境学会誌 = Journal of Japan Society on Water Environment, 35, 9, 289, 289, 10 Sep. 2012
  Japanese
• 表面プラズモン共鳴を利用した水中病原微生物検出バイオセンサの開発
  佐藤久; 坂槙有紀恵; 山田健太; ピタックティーラタムニティ; 石井聡; 佐野大輔; 高橋正宏; 岡部聡, 日本水環境学会シンポジウム講演集, 15th, 233, 234, 10 Sep. 2012
  Japanese
• 嫌気性アンモニア酸化(アナモックス)細菌のゲノム解析が明らかにする生理学的特性
  押木守; 佐藤久; 岡部聡; 新家子香織, 日本水環境学会シンポジウム講演集, 15th, 157, 10 Sep. 2012
  Japanese
• トリベンジルチンクロライドを用いたリン酸マイクロセンサーの開発
  谷内翔; 宮崎悠爾; 高橋正宏; 岡部聡; 佐藤久, 日本分析化学会年会講演要旨集, 61st, 324, 05 Sep. 2012
  Japanese
• 新規変色型蛍光色素を用いた路面排水中亜鉛濃度の定量
  吉川弘晃; 菅藤亮輔; 羽深昭; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本分析化学会年会講演要旨集, 61st, 315, 05 Sep. 2012
  Japanese
• 表面プラズモン共鳴を用いた水中病原性微生物バイオセンサ
  坂槙有紀恵; 山田健太; 高橋正宏; 岡部聡; 佐藤久, 日本分析化学会年会講演要旨集, 61st, 397, 05 Sep. 2012
  Japanese
• バイオフィルム感染症の新治療戦略 大腸菌RelEが誘導する菌体密度依存的休眠化
  岡部 聡; 田代 陽介; 谷内 亜沙美; Thithiwat May; 柿沼 建至; 川田 耕司, 日本生物工学会大会講演要旨集, 平成24年度, 100, 100, Sep. 2012
  (公社)日本生物工学会, Japanese
• 重金属センサアレイに向けた変色型ボロンジピロメテン蛍光色素群の開発
  菅藤亮輔; 吉川弘晃; 谷山拓生; 羽深昭; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 分析化学討論会講演要旨集, 72nd, 130, 05 May 2012
  Japanese
• 微小電極を用いた堆積型堆肥表層中の一酸化二窒素および一酸化窒素の測定
  日向寺崇文; 前田高輝; 岡部聡; 高橋正宏; 佐藤久, 日本水環境学会年会講演集, 46th, 510, 14 Mar. 2012
  Japanese
• 新規変色型蛍光色素を用いた環境サンプル中の重金属イオン分析
  谷山拓生; 羽深昭; 菅藤亮輔; 吉川弘晃; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 46th, 506, 14 Mar. 2012
  Japanese
• 新規変色型蛍光色素を用いたクロムイオン分析
  吉川弘晃; 羽深昭; 谷山拓生; 菅藤亮輔; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 46th, 676, 14 Mar. 2012
  Japanese
• 新規変色型蛍光色素を用いた亜鉛イオン分析
  羽深昭; 谷山拓生; 菅藤亮輔; 吉川弘晃; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 46th, 622, 14 Mar. 2012
  Japanese
• トキシコゲノミクス的アプローチを用いた再生水の水質評価~残留医薬品の影響~
  中島弘司; 原宏江; HOQUE Asiful; 木村克輝; 岡部聡; 三好太郎; 渡辺義公, 日本水環境学会年会講演集, 46th, 93, 14 Mar. 2012
  Japanese
• トキシコゲノミクス的アプローチを用いた膜処理再生水の水質評価の試み
  原(山村)宏江; HOQUE Asiful; 木村克輝; 岡部聡; 中島弘司; 三好太郎; 渡辺義公, 日本水環境学会年会講演集, 46th, 74, 14 Mar. 2012
  Japanese
• Anammox菌による鉄酸化硝酸還元能の解析
  石黒真規; 押木守; 石井聡; 岡部聡, 日本水環境学会年会講演集, 46th, 151, 14 Mar. 2012
  Japanese
• Anammox活性の菌体密度依存的制御機構の解明
  平泉晴菜; 押木守; 岡部聡, 日本水環境学会年会講演集, 46th, 152, 14 Mar. 2012
  Japanese
• 環境サンプル測定のためのリン酸マイクロセンサーの開発
  宮崎悠爾; 谷内翔; 高橋正宏; 岡部聡; 佐藤久, 化学系学協会北海道支部冬季研究発表会講演要旨集, 2012, 148, 31 Jan. 2012
  Japanese
• 変色型ボロンジピロメテン蛍光色素を用いた重金属イオン分析
  菅藤亮輔; 吉川弘晃; 谷山拓生; 羽深昭; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 化学系学協会北海道支部冬季研究発表会講演要旨集, 2012, 101, 31 Jan. 2012
  Japanese
• PM-09 Characterization of Eschehchia coli small colony variants frequently emerged in biofilms(PM Biofilm and surface microbiology,Poster session)
  Eida Hiroaki; Tashiro Yosuke; Okabe Satoshi, 日本微生物生態学会講演要旨集, 28, 182, 182, 2012
  日本微生物生態学会, English
• Characterization of microbial community structures and their activities in single anaerobic granules by beta imaging, microsensors and fluorescence in situ hybridization
  H. Satoh; I. Tsushima; Y. Miura; T. Ito; S. Okabe, WATER SCIENCE AND TECHNOLOGY, 65, 12, 2125, 2131, 2012
  English
• N2O emission from a partial nitrification-anammox process and identification of a key biological process of N2O emission from anammox granules
  Satoshi Okabe; Mamoru Oshiki; Yoshitaka Takahashi; Hisashi Satoh, WATER RESEARCH, 45, 19, 6461, 6470, Dec. 2011
  English
• Adsorption characteristics of an enteric virus-binding protein to norovirus, rotavirus and poliovirus
  Takahiro Imai; Daisuke Sano; Takayuki Miura; Satoshi Okabe; Keishi Wada; Yoshifumi Masago; Tatsuo Omura, BMC BIOTECHNOLOGY, 11, 123, 1, 11, Dec. 2011
  English
• Enterobactin is required for biofilm development in reduced-genome Escherichia coli
  Thithiwat May; Satoshi Okabe, ENVIRONMENTAL MICROBIOLOGY, 13, 12, 3149, 3162, Dec. 2011
  English
• Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge
  Tsukasa Ito; Kazumi Yoshiguchi; Herto Dwi Ariesyady; Satoshi Okabe, ISME JOURNAL, 5, 12, 1844, 1856, Dec. 2011
  English
• 新規蛍光色素を用いた重金属イオン分析
  羽深昭; 谷山拓生; 菅藤亮輔; 吉川弘晃; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 環境工学研究フォーラム講演集, 48th, 214, 216, 25 Nov. 2011
  Japanese
• 重金属イオン分析に向けた新規蛍光色素の開発
  菅藤亮輔; 羽深昭; 谷山拓生; 吉川弘晃; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 環境工学研究フォーラム講演集, 48th, 220, 222, 25 Nov. 2011
  Japanese
• 環境サンプル測定のためのリン酸マイクロセンサーの開発
  谷内翔; 宮崎悠爾; 押木守; 佐藤久; 高橋正宏; 岡部聡, 環境工学研究フォーラム講演集, 48th, 217, 219, 25 Nov. 2011
  Japanese
• 微生物燃料電池内に存在する細胞外キノンの生態学的意義に関する研究
  木村善一郎; 伊藤皓亮; 岡部聡, 日本微生物生態学会講演要旨集, 27th, 27, 74, 74, 08 Oct. 2011
  日本微生物生態学会, Japanese
• PA-034 Anammox細菌Candidatus "Brocadia sinica"の嫌気性アンモニア酸化活性に及ぼす菌体密度の影響(PA 水処理生態系,ポスター発表)
  平泉 晴菜; 新家子 香織; 押木 守; 佐藤 久; 岡部 聡, 日本微生物生態学会講演要旨集, 27, 73, 73, 08 Oct. 2011
  日本微生物生態学会, Japanese
• PA-030 メタゲノム・プロテオームアプローチによる嫌気性アンモニア酸化(anammox)細菌Candidatus 'Brocadia sinica'の生理生態学的特性の解明(PA 水処理生態系,ポスター発表)
  押木 守; 新家子 香織; 佐藤 久; 岡部 聡, 日本微生物生態学会講演要旨集, 27, 72, 72, 08 Oct. 2011
  日本微生物生態学会, Japanese
• 部分硝化‐AnammoxプロセスからのN₂O生成
  岡部聡; 押木守; 高橋慶考; 佐藤久, 日本水環境学会シンポジウム講演集, 14th, 43, 44, 10 Sep. 2011
  Japanese
• オンサイト重金属イオン分析に向けた新規変色型蛍光色素の開発
  谷山拓生; 羽深昭; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 土木学会年次学術講演会講演概要集(CD-ROM), 66th, ROMBUNNO.VII-192, 05 Aug. 2011
  Japanese
• 新規変色型蛍光色素を用いた水サンプル中重金属イオンの簡易分析
  羽深昭; 谷山拓生; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 土木学会年次学術講演会講演概要集(CD-ROM), 66th, ROMBUNNO.VII-191, 05 Aug. 2011
  Japanese
• 環境サンプル測定のためのリン酸マイクロセンサーの開発
  宮崎悠爾; 押木守; 高橋正宏; 岡部聡; 佐藤久, 土木学会年次学術講演会講演概要集(CD-ROM), 66th, ROMBUNNO.VII-029, 05 Aug. 2011
  Japanese
• 重金属イオンの識別が可能な変色型ボロンジピロメテン蛍光色素の開発
  谷山拓生; 菅藤亮輔; 羽深昭; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本化学会北海道支部夏季研究発表会講演要旨集, 2011, 150, 01 Jul. 2011
  Japanese
• 変色型ボロンジピロメテン蛍光色素を用いた含水サンプル中での重金属イオンの簡易分析
  菅藤亮輔; 谷山拓生; 羽深昭; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本化学会北海道支部夏季研究発表会講演要旨集, 2011, 149, 01 Jul. 2011
  Japanese
• Development of long-term stable partial nitrification and subsequent anammox process
  Satoshi Okabe; Mamoru Oshiki; Yoshitaka Takahashi; Flisashi Satoh, BIORESOURCE TECHNOLOGY, 102, 13, 6801, 6807, Jul. 2011
  English
• 二員培養系微生物燃料電池の電力増大因子の解明
  木村善一郎; 伊藤皓亮; 岡部聡, 環境バイオテクノロジー学会大会プログラム講演要旨集, 44th, 25, 20 Jun. 2011
  Japanese
• Physiological characteristics of the anaerobic ammonium-oxidizing bacterium 'Candidatus Brocadia sinica'
  Mamoru Oshiki; Masaki Shimokawa; Naoki Fujii; Hisashi Satohl; Satoshi Okabe, MICROBIOLOGY-SGM, 157, 6, 1706, 1713, Jun. 2011
  English
• Removal of residual dissolved methane gas in an upflow anaerobic sludge blanket reactor treating low-strength wastewater at low temperature with degassing membrane
  Wasala M. K. R. T. W. Bandara; Hisashi Satoh; Manabu Sasakawa; Yoshihito Nakahara; Masahiro Takahashi; Satoshi Okabe, WATER RESEARCH, 45, 11, 3533, 3540, May 2011
  English
• Exposure of conjugative plasmid carrying Escherichia coli biofilms to male-specific bacteriophages
  Thithiwat May; Kenji Tsuruta; Satoshi Okabe, ISME JOURNAL, 5, 4, 771, 775, Apr. 2011
  English
• 一槽型バイオ燃料電池における正極反応の促進による電力上昇
  藤木一到; 石崎創; 木村善一郎; 岡部聡, 日本水環境学会年会講演集, 45th, 168, 18 Mar. 2011
  Japanese
• 酢酸を基質とする微生物燃料電池内の電子フローに関する研究
  木村善一郎; 岡部聡, 日本水環境学会年会講演集, 45th, 166, 18 Mar. 2011
  Japanese
• オンサイト重金属イオン分析に向けた新規変色型蛍光色素の開発
  谷山拓生; 羽深昭; 菅藤亮輔; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 45th, 293, 18 Mar. 2011
  Japanese
• 新規変色型蛍光色素を用いた水サンプル中の重金属検出
  菅藤亮輔; 羽深昭; 谷山拓生; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 45th, 295, 18 Mar. 2011
  Japanese
• 新規変色型蛍光色素を用いたレシオメトリー測定による重金属イオン分析
  羽深昭; 谷山拓生; 菅藤亮輔; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 45th, 294, 18 Mar. 2011
  Japanese
• Development of an Aerobic Granule Reactor for Partial Nitrification Combined with Anammox
  SONG Yanjun; 押木守; 岡部聡, 日本水環境学会年会講演集, 45th, 161, 18 Mar. 2011
  Japanese
• Anammox細菌の代謝活性に及ぼす菌体密度の影響
  平泉晴菜; 新家子香織; 押木守; 岡部聡, 日本水環境学会年会講演集, 45th, 47, 18 Mar. 2011
  Japanese
• 新規anammox細菌Candidatus ‘Brocadia sinica’における網羅的プロテオーム解析
  新家子香織; 押木守; 佐藤久; 岡部聡, 日本水環境学会年会講演集, 45th, 46, 18 Mar. 2011
  Japanese
• Ecophysiology of Uncultured Filamentous Anaerobes Belonging to the Phylum KSB3 That Cause Bulking in Methanogenic Granular Sludge
  Takeshi Yamada; Kae Kikuchi; Toshihiro Yamauchi; Koji Shiraishi; Tsukasa Ito; Satoshi Okabe; Akira Hiraishi; Akiyoshi Ohashi; Hideki Harada; Yoichi Kamagata; Kazunori Nakamura; Yuji Sekiguchi, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 77, 6, 2081, 2087, Mar. 2011
  English
• 脱気膜を用いた有機性廃水の水素発酵プロセスの高効率化
  佐藤久; 池田真之; 高橋正宏; 岡部聡; 笹川学; 中原禎仁, 環境浄化技術, 10, 1, 85, 90, 01 Feb. 2011
  Japanese
• Quantification and Genotyping of Human Sapoviruses in the Llobregat River Catchment, Spain
  Daisuke Sano; Unai Perez-Sautu; Susana Guix; Rosa Maria Pinto; Takayuki Miura; Satoshi Okabe; Albert Bosch, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 77, 3, 1111, 1114, Feb. 2011
  English
• Effect of feeding regimens on polyhydroxybutyrate production from food wastes by Cupriavidus necator
  Akira Hafuka; Kenji Sakaida; Hisashi Satoh; Masahiro Takahashi; Yoshimasa Watanabe; Satoshi Okabe, BIORESOURCE TECHNOLOGY, 102, 3, 3551, 3553, Feb. 2011
  English
• PB-056 アミロイド様細胞外タンパクcurliが引き起こす水処理膜上のバイオフィルム形成(PB 界面/バイオフィルム,ポスター発表)
  石川 寛恭; 田代 陽介; 吉田 圭太朗; May Thithiwat; 岡部 聡, 日本微生物生態学会講演要旨集, 27, 98, 98, 2011
  日本微生物生態学会, Japanese
• PB-060 バイオフィルム内における形態変異株の発生とその性質の解析(PB 界面/バイオフィルム,ポスター発表)
  榮田 弘明; 田代 陽介; 岡部 聡, 日本微生物生態学会講演要旨集, 27, 99, 99, 2011
  日本微生物生態学会, Japanese
• A POLYPHASIC APPROACH TO STUDY ECOPHYSIOLOGY OF COMPLEX MULTISPECIES NITRIFYING BIOFILMS
  Satoshi Okabe; Hisashi Satoh; Tomonori Kindaichi, METHODS IN ENZYMOLOGY, VOL 46: RESEARCH ON NITRIFICATION AND RELATED PROCESSES, PT B, 496, 163, 184, 2011
  English
• Analyses of Three Dominant Membrane Proteins from Anammox Planctomycete Candidatus 'Brocadia sinica'
  TOJO FUYUMI; ITOH YOSHIKANE; OKABE SATOSHI, Journal of environmental biotechnology, 11, 1-2, 1, 81, 2011
  環境バイオテクノロジー学会, English
• Development of a simultaneous partial nitrification and anaerobic ammonia oxidation process in a single reactor
  Sunja Cho; Naoki Fujii; Taeho Lee; Satoshi Okabe, BIORESOURCE TECHNOLOGY, 102, 2, 652, 659, Jan. 2011
  English
• Effect of formation of biofilms and chemical scale on the cathode electrode on the performance of a continuous two-chamber microbial fuel cell
  Kyungmi Chung; Itto Fujiki; Satoshi Okabe, BIORESOURCE TECHNOLOGY, 102, 1, 355, 360, Jan. 2011
  English
• A polyphasic approach to study ecophysiology of complex multispecies nitrifying biofilms
  Satoshi Okabe; Hisashi Satoh; Tomonori Kindaichi, Methods in Enzymology, 496, 163, 184, 2011
  English
• Analyses of three dominant membrane proteins from anammox planctomycete Candidatus 'Brocadia sinica'
  TOJO FUYUMI; ITOH YOSHIKANE; OKABE SATOSHI, Journal of Environmental Biotechnology, 11, 1-2, 1, 81, 2011
  環境バイオテクノロジー学会, English
• A Great Leap forward in Microbial Ecology
  Satoshi Okabe; Mamoru Oshiki; Yoichi Kamagata; Nobuyasu Yamaguchi; Masanori Toyofuku; Yutaka Yawata; Yosuke Tashiro; Nobuhiko Nomura; Hiroyuki Ohta; Moriya Ohkuma; Akira Hiraishi; Kiwamu Minamisawa, MICROBES AND ENVIRONMENTS, 25, 4, 230, 240, Dec. 2010
  English, Book review
• P-46 Metagenomic analyses for a novel anammox bacterium, Candidatus "Brocadia gluttonica", responsible for high-rate nitrogen removal(Poster Session)
  SHINYAKO KAORI; OSHIKI MAMORU; SATOU HISASHI; OKABE SATOSHI, 日本微生物生態学会講演要旨集, 26, 117, 117, 23 Nov. 2010
  日本微生物生態学会, English
• 蛍光色素を用いたレシオメトリー測定による重金属イオン分析
  羽深昭; 谷山拓生; 山田幸司; 高橋正宏; 岡部聡; 佐藤久, 環境工学研究フォーラム講演集, 47th, 184, 186, 12 Nov. 2010
  Japanese
• 環境サンプル測定のためのリン酸マイクロセンサーの開発
  宮崎悠爾; 押木守; 佐藤久; 高橋正宏; 岡部聡, 環境工学研究フォーラム講演集, 47th, 4, 6, 12 Nov. 2010
  Japanese
• Microbial Fuel Cells : Wastewater Treatment Technology that Kills Three Birds with One Stone
  OKABE Satoshi, 水環境学会誌 = Journal of Japan Society on Water Environment, 33, 11, 347, 347, 10 Nov. 2010
  Japanese
• Characterization and global gene expression of F- phenocopies during Escherichia coli biofilm formation
  Thithiwat May; Akinobu Ito; Satoshi Okabe, MOLECULAR GENETICS AND GENOMICS, 284, 5, 333, 342, Nov. 2010
  English
• 微小電極を用いた放牧地からのN₂O生成速度の測定
  佐藤久; 日向寺崇文; 高橋正宏; 岡部聡, 土木学会年次学術講演会講演概要集(CD-ROM), 65th, ROMBUNNO.VII-176, 05 Aug. 2010
  Japanese
• DNA‐SIP法を用いた微生物燃料電池内の炭素フローの解析
  木村善一郎; 岡部聡, 日本水環境学会年会講演集, 44th, 507, 15 Mar. 2010
  Japanese
• 純粋培養系と複合系を用いた微生物燃料電池における電力生産の比較
  伊藤皓亮; 木村善一郎; CHUNG Kyungmi; 岡部聡, 日本水環境学会年会講演集, 44th, 512, 15 Mar. 2010
  Japanese
• 微小電極を用いたANAMMOXグラニュール内の微生物活性の解析
  佐藤久; 高橋慶考; 山田陽平; 高橋正宏; 岡部聡, 日本水環境学会年会講演集, 44th, 396, 15 Mar. 2010
  Japanese
• Nitrogen removal performance and microbial community analysis of an anaerobic up-flow granular bed anammox reactor
  Sunja Cho; Yoshitaka Takahashi; Naoki Fujii; Yohei Yamada; Hisashi Satoh; Satoshi Okabe, CHEMOSPHERE, 78, 9, 1129, 1135, Feb. 2010
  English
• P-184 High throughput assay to evaluate membrane biofouling(Poster Session)
  YOSHIDA KEITARO; TASHIRO YOSUKE; MAY THITHIWAT; OKABE SATOSHI, 日本微生物生態学会講演要旨集, 26, 186, 186, 2010
  日本微生物生態学会, English
• P-181 Aminoglycoside antibiotics promote Escherichia coli biofilm formation(Poster Session)
  EIDA HIROAKI; TASHIRO YOSUKE; MAY THITHIWAT; OKABE SATOSHI, 日本微生物生態学会講演要旨集, 26, 185, 185, 2010
  日本微生物生態学会, English
• 1B-2 Factor identification for RelE toxin sensitivity in Eschelichia coli(Oral Session)
  KAKINUMA KENJI; TASHIRO YOSUKE; MAY THITHIWAT; OKABE SATOSHI, 日本微生物生態学会講演要旨集, 26, 69, 69, 2010
  日本微生物生態学会, English
• A great leap forward in microbial ecology.
  Satoshi Okabe; Mamoru Oshiki; Yoichi Kamagata; Nobuyasu Yamaguchi; Masanori Toyofuku; Yutaka Yawata; Yosuke Tashiro; Nobuhiko Nomura; Hiroyuki Ohta; Moriya Ohkuma; Akira Hiraishi; Kiwamu Minamisawa, Microbes and environments, 25, 4, 230, 40, 2010, [Peer-reviewed], [Domestic magazines]
  English
• Characterization of electrochemical activity of a strain ISO2-3 phylogenetically related to Aeromonas sp. isolated from a glucose-fed microbial fuel cell.
  Kyungmi Chung; Satoshi Okabe, Biotechnology and bioengineering, 104, 5, 901, 10, 01 Dec. 2009, [Peer-reviewed], [International Magazine]
  English
• 脱気膜を用いた有機性廃水の水素発酵プロセスの高効率化
  池田真之; 佐藤久; 高橋正宏; 岡部聡; 中原禎仁; 笹川学, 環境工学研究フォーラム講演集, 46th, 103, 104, 27 Nov. 2009
  Japanese
• 嫌気性消化プロセスへの脱気膜の適用
  佐藤久; 池田真之; 高橋正宏; 岡部聡; 中原禎仁; 笹川学, 用水と廃水, 51, 11, 925, 932, 01 Nov. 2009
  産業用水調査会, Japanese
• Induction of multidrug resistance mechanism in Escherichia coli biofilms by interplay between tetracycline and ampicillin resistance genes.
  Thithiwat May; Akinobu Ito; Satoshi Okabe, Antimicrobial agents and chemotherapy, 53, 11, 4628, 39, Nov. 2009, [Peer-reviewed], [International Magazine]
  English
• Microbial community structures and in situ sulfate-reducing and sulfur-oxidizing activities in biofilms developed on mortar specimens in a corroded sewer system
  Hisashi Satoh; Mitsunori Odagiri; Tsukasa Ito; Satoshi Okabe, WATER RESEARCH, 43, 18, 4729, 4739, Oct. 2009
  English
• 有機性廃棄物からのポリヒドロキシアルカン酸の生産
  羽深昭; 佐藤久; 高橋正宏; 岡部聡, 日本水環境学会シンポジウム講演集, 12th, 168, 169, 14 Sep. 2009
  Japanese
• In Vitro Toxicity of Silver Nanoparticles at Noncytotoxic Doses to HepG2 Human Hepatoma Cells
  Koji Kawata; Masato Osawa; Satoshi Okabe, ENVIRONMENTAL SCIENCE & TECHNOLOGY, 43, 15, 6046, 6051, Aug. 2009
  English
• Localized Expression Profiles of rpoS in Escherichia coli Biofilms
  Akinobu Ito; Thithiwat May; Asami Taninchi; Koji Kawata; Satoshi Okabe, BIOTECHNOLOGY AND BIOENGINEERING, 103, 5, 975, 983, Aug. 2009
  English
• A biofilm model for prediction of pollutant transformation in sewers
  Feng Jiang; Derek Hoi-wai Leung; Shiyu Li; Guang-Hao Chen; Satoshi Okabe; Mark C. M. van Loosdrecht, WATER RESEARCH, 43, 13, 3187, 3198, Jul. 2009
  English
• Continuous power generation and microbial community structure of the anode biofilms in a three-stage microbial fuel cell system
  Kyungmi Chung; Satoshi Okabe, APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, 83, 5, 965, 977, Jul. 2009
  English
• Increased Antibiotic Resistance of Escherichia coli in Mature Biofilms
  Akinobu Ito; Asami Taniuchi; Thithiwat May; Koji Kawata; Satoshi Okabe, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 75, 12, 4093, 4100, Jun. 2009
  English
• 溶存バイオガスに着目した新規嫌気性廃水処理リアクターの開発
  佐藤久; 池田真之; 高橋正宏; 岡部聡; 中原禎仁; 笹川学, 日本水環境学会年会講演集, 43rd, 253, 16 Mar. 2009
  Japanese
• 有機性廃棄物からのポリヒドロキシアルカン酸の生産
  羽深昭; 佐藤久; 高橋正宏; 岡部聡, 日本水環境学会年会講演集, 43rd, 623, 16 Mar. 2009
  Japanese
• P-168 The fate of male-specific filamentous bacteriophage in Escherichia coli biofilm formation :
  Thithiwat May, 日本微生物生態学会講演要旨集, 25, 125, 125, 2009
  日本微生物生態学会, English
• 微生物燃料電池内の嫌気的酢酸分解に寄与する微生物群集
  木村善一郎; 藤木一到; 岡部聡, 日本微生物生態学会講演要旨集, 25th, 25, YOSHI74, 74, 2009
  日本微生物生態学会, Japanese
• 二双培養を用いた微生物燃料電池における電力生産の評価と細菌間相互作用の評価
  伊藤皓亮; 木村善一郎; 鄭景美; 岡部聡, 日本微生物生態学会講演要旨集, 25th, 25, YOSHI73, 73, 2009
  日本微生物生態学会, Japanese
• The Response of Pseudomonas aeruginosa PAO1 Efflux Pump-Defective Mutants to N-Octanoyl-L-Homoserine Lactone
  Yutaka Yawata; Hideaki Maseda; Satoshi Okabe; Akinobu Ito; Isao Sawada; Hiroaki Kurashima; Hiroo Uchiyama; Nobuhiko Nomura, MICROBES AND ENVIRONMENTS, 24, 4, 338, 342, 2009
  English
• Qualitative and quantitative estimation of host-specific fecal pollution using Bacteroides-Prevotella 16S rRNA genetic markers by T-RFLP and real-time PCR analyses
  O. Savichtcheva; S. Okabe, WATER SCIENCE AND TECHNOLOGY, 59, 9, 1831, 1840, 2009
  English
• Comparison of Gene Expression Profiles in HepG2 Cells Exposed to Arsenic, Cadmium, Nickel, and Three Model Carcinogens for Investigating the Mechanisms of Metal Carcinogenesis
  Koji Kawata; Ryuhei Shimazaki; Satoshi Okabe, ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, 50, 1, 46, 59, Jan. 2009
  English
• 有機性廃棄物からのポリヒドロキシアルカン酸の生産
  羽深昭; 坂井田健司; 佐藤久; 深澤達矢; 高橋正宏; 岡部聡, 環境工学研究フォーラム講演集, 45th, 61, 63, 28 Nov. 2008
  Japanese
• 溶存バイオガスに着目した嫌気性廃水処理リアクターの開発
  佐藤久; 池田真之; 高橋慶多; 深澤達矢; 高橋正宏; 岡部聡; 中原禎仁; 笹川学, 環境工学研究フォーラム講演集, 45th, 58, 60, 28 Nov. 2008
  Japanese
• Escherichia coli Harboring a Natural IncF Conjugative F Plasmid Develops Complex Mature Biofilms by Stimulating Synthesis of Colanic Acid and Curli
  Thithiwat May; Satoshi Okabe, JOURNAL OF BACTERIOLOGY, 190, 22, 7479, 7490, Nov. 2008
  English
• Quantification of cell specific uptake activity of microbial products by uncultured Chloroflexi by microautoradiography combined with fluorescence in situ hybridization
  Yuki Miura; Satoshi Okabe, ENVIRONMENTAL SCIENCE & TECHNOLOGY, 42, 19, 7380, 7386, Oct. 2008
  English
• 脱気膜を用いたメタン発酵プロセスにおける高効率ガス回収
  佐藤久; 高橋慶多; 深澤達矢; 高橋正宏; 岡部聡; 中原禎仁; 笹川学, 土木学会年次学術講演会講演概要集(CD-ROM), 63rd, Disk 2, ROMBUNNO.7-043, 13 Aug. 2008
  Japanese
• 水系生物膜内の微生物活性解析への微小電極の適用
  佐藤 久; 岡部 聡, 水, 50, 10, 20, 28, Aug. 2008
  月刊「水」発行所, Japanese
• Bacterial community dynamics and conversion of inorganic nitrogen under aerobic and micro-aerobic conditions
  S. -J. Cho; S. Okabe; S. -J. Lee, ENVIRONMENTAL TECHNOLOGY, 29, 4, 463, 471, Apr. 2008
  English
• Significance of rpoS during maturation of Escherichia coli biofilms
  Akinobu Ito; Thithiwat May; Koji Kawata; Satoshi Okabe, BIOTECHNOLOGY AND BIOENGINEERING, 99, 6, 1462, 1471, Apr. 2008
  English
• MAR‐FISH法を用いた膜分離活性汚泥槽内の糸状性細菌Chloroflexiの生物由来有機物資化特性評価
  三浦佑己; 渡辺義公; 岡部聡, 日本水環境学会年会講演集, 42nd, 170, 19 Mar. 2008
  Japanese
• 嫌気性アンモニア酸化(ANAMMOX)細菌の生理・生態学的特性評価
  下川正貴; 高橋慶考; CHO Sun-ja; 岡部聡; 對馬育夫; 金田一智規, 日本水環境学会年会講演集, 42nd, 2008
• 04-074 Microbial community structure of biofilms in microbial fuel cells(Water/Wastewater treatment ecosystem)
  Kumano Keiichi; Chung Kyungmi; Okabe Satoshi, 日本微生物生態学会講演要旨集, 24, 95, 95, 2008
  日本微生物生態学会, Japanese
• 01-010 Cell density-dependent regulation of sensitivity to E. coli RellE toxin(Physiology/Growth)
  Taniuchi Asami; Kawata Koji; Okabe Satoshi, 日本微生物生態学会講演要旨集, 24, 63, 63, 2008
  日本微生物生態学会, Japanese
• 01-006 Antibiotic susceptibility of Escherichia coli in biofilms(Interface/Biofilms)
  Ito Akinobu; Taniuchi Asami; May Thithiwat; Okabe Satoshi, 日本微生物生態学会講演要旨集, 24, 61, 61, 2008
  日本微生物生態学会, Japanese
• S-C3 Microbial community structure and in situ function in complex multispecies biofilms
  Okabe Satoshi, 日本微生物生態学会講演要旨集, 24, 191, 191, 2008
  日本微生物生態学会, Japanese
• 有機性廃棄物からのポリヒドロキシアルカン酸の生産
  佐藤久; 坂井田健司; 岡部聡; 渡辺義公, 環境バイオテクノロジー学会大会プログラム講演要旨集, 34th, 27, 2008
  Japanese
• Toxicogenomics and DNA microarray
  OKABE Satoshi, Environmental conservation engineering, 36, 11, 778, 782, 20 Nov. 2007
  環境技術学会, Japanese
• 有機性廃棄物からのポリヒドロキシアルカン酸の生産
  佐藤久; 坂井田健司; 岡部聡; 渡辺義公, 環境工学研究フォーラム講演集, 44th, 224, 226, 16 Nov. 2007
  Japanese
• Layered structure of bacterial and archaeal communities and their in situ activities in anaerobic granules
  Hisashi Satoh; Yuki Miura; Ikuo Tsushima; Satoshi Okabe, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 73, 22, 7300, 7307, Nov. 2007
  English
• Significance of Chloroflexi in performance of submerged membrane Bioreactors (MBR) treating municipal wastewater
  Yuki Miura; Yoshimasa Watanabe; Satoshi Okabe, ENVIRONMENTAL SCIENCE & TECHNOLOGY, 41, 22, 7787, 7794, Nov. 2007
  English
• Persistence of host-specific Bacteroides-Prevotella 16S rRNA genetic markers in environmental waters: effects of temperature and salinity
  Satoshi Okabe; Yoko Shimazu, APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, 76, 4, 935, 944, Sep. 2007
  English
• In situ activity and spatial organization of anaerobic ammonium-oxidizing (anammox) bacteria in biofilms
  Tomonori Kindaichi; Ikuo Tsushima; Yuji Ogasawara; Masaki Shimokawa; Noriatsu Ozaki; Hisashi Satoh; Satoshi Okabe, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 73, 15, 4931, 4939, Aug. 2007
  English
• Relationships between Bacteroides 16S rRNA genetic markers and presence of bacterial enteric pathogens and conventional fecal indicators
  Olga Savichtcheva; Noriko Okayama; Satoshi Okabe, WATER RESEARCH, 41, 16, 3615, 3628, Aug. 2007
  English
• Phylogenetic and functional diversity of propionate-oxidizing bacteria in an anaerobic digester sludge
  Herto Dwi Ariesyady; Tsukasa Ito; Kazurni Yoshiguchi; Satoshi Okabe, APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, 75, 3, 673, 683, Jun. 2007
  English
• Classification of heavy-metal toxicity by human DNA microarray analysis
  Koji Kawata; Hiroyuki Yokoo; Ryuhes Shimazaki; Satoshi Okabe, ENVIRONMENTAL SCIENCE & TECHNOLOGY, 41, 10, 3769, 3774, May 2007
  English
• Development of high-rate anaerobic ammonium-oxidizing (anammox) biofilm reactors
  Ikuo Tsushima; Yuji Ogasawara; Tomonori Kindaichi; Hisashi Satoh; Satoshi Okabe, WATER RESEARCH, 41, 8, 1623, 1634, Apr. 2007
  English
• Functional bacterial and archaeal community structures of major trophic groups in a full-scale anaerobic sludge digester.
  Herto Dwi Ariesyady; Tsukasa Ito; Satoshi Okabe, Water research, 41, 7, 1554, 68, Apr. 2007, [Peer-reviewed], [International Magazine]
  English
• 有機性廃棄物からのポリヒドロキシアルカン酸の生産
  坂井田健司; 佐藤久; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 41st, 335, 15 Mar. 2007
  Japanese
• 膜分離活性汚泥法における糸状性細菌Chloroflexiの生物代謝由来有機物資化特性評価
  三浦佑己; 渡辺義公; 岡部聡, 日本水環境学会年会講演集, 41st, 227, 15 Mar. 2007
  Japanese
• Quantification of host-specific Bacteroides-Prevotella 16S rRNA genetic markers for assessment of fecal pollution in freshwater
  Satoshi Okabe; Noriko Okayama; Olga Savichtcheva; Tsukasa Ito, APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, 74, 4, 890, 901, Mar. 2007
  English
• Bacterial community structures in MBRs treating municipal wastewater: Relationship between community stability and reactor performance
  Yuki Miura; Mirian Noriko Hiraiwa; Tsukasa Ito; Takanori Itonaga; Yoshimasa Watanabe; Satoshi Okabe, WATER RESEARCH, 41, 3, 627, 637, Feb. 2007
  English
• Quantification of anaerobic ammonium-oxidizing bacteria in enrichment cultures by real-time PCR
  Ikuo Tsushima; Tomonori Kindaichi; Satoshi Okabe, WATER RESEARCH, 41, 4, 785, 794, Feb. 2007
  English
• Influences of infaunal burrows on the community structure and activity of ammonia-oxidizing bacteria in intertidal sediments
  Hisashi Satoh; Yoshiyuki Nakamura; Satoshi Okabe, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 73, 4, 1341, 1348, Feb. 2007
  English
• Succession of sulfur-oxidizing bacteria in the microbial community on corroding concrete in sewer systems
  Satoshi Okabe; Mitsunori Odagiri; Tsukasa Ito; Hisashi Satoh, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 73, 3, 971, 980, Feb. 2007
  English
• 嫌気性アンモニア酸化(ANAMMOX)細菌の最適培養条件の検討
  下川正貴; 對馬育夫; 高橋慶考; 岡部聡; 金田一智規, 日本水環境学会年会講演集, 41st, 2007
• 上向流ANAMMOXバイオフィルムリアクターの構築と処理特性
  下川正貴; 高橋慶考; 岡部聡; 對馬育夫; 金田一智規, 日本水環境学会シンポジウム講演集, 10th, 2007
• PB-14 Microbial community structure of biofims in microbial fuel cells(Waste water treatment ecosystem,Poster presentation B) :
  Chung Kyungmi; Okabe Satoshi, 日本微生物生態学会講演要旨集, 23, 121, 121, 2007
  日本微生物生態学会, English
• PB-13 Key physiology of ANAMMOX bacteria(Waste water treatment ecosystem,Poster presentation B) :
  Shimokawa Masaki; Tsushima Ikuo; Takahashi Yoshitaka; Cho Sun-Ja; Kindaichi Tomonori; Okabe Satoshi, 日本微生物生態学会講演要旨集, 23, 121, 121, 2007
  日本微生物生態学会, English
• PB-17 In situ physiology of candidate division TM7 in a wastewater treatment plant(Waste water treatment ecosystem,Poster presentation B) :
  Kindaichi Tomonori; Ozaki Noriatsu; Ohashi Akiyoshi; Okabe Satoshi, 日本微生物生態学会講演要旨集, 23, 123, 123, 2007
  日本微生物生態学会, English
• Ecophysiology of sulphate-reducing bacteria in environmental biofilms
  Satoshi Okabe, Sulphate-Reducing Bacteria: Environmental and Engineered Systems, 359, 382, 01 Jan. 2007
  Cambridge University Press, English
• Nitrogen removal performance of Two Step-Feeding Up-Flow anammox Biofilm Reactor
  TAKAHASHI Yoshitaka; TSUSHIMA Ikuo; SHIMOKAWA Masaki; OKABE Satoshi, Doboku Gakkai Ronbunshuu G, 44, 201, 206, 2007
  The anaerobic ammonium-oxidizing (anammox) process is a new and promising alternative to the conventional nitrogen removal processes. We have previously developed a high rate anammox biofilm reactor. However, no anammox activity was detected at the second half of the reactor even though sufficient amounts of NH₄⁺ and NO₂^- and high abundance of anammox bacteria were still present.We, therefore, modified our reactor configuration to two step-feeding system and investigated the performance of the modified two step-feeding up-flow anammox (anaerobic ammonium oxidation) biofilm reactor. A nonwoven fabric sheet was used a carrier material of the biomass in the reactor. Synthetic medium was fed into the reactor at the bottom and the middle part of the reactor at the same flow rate. The reactor was operated over 120 days, during which the HRT was gradually reduced to increase the nitrogen loading rate. During the operation with the two step-feeding, pH at the second half of the reactor was maintained below 8.0, which increased the nitrogen removal in the second half of the reactor. Consequently, a maximum nitrogen removal rate of 31.2 Kg-N/m³/day was attained. To our knowledge, such a high rate has never been reported before., Japan Society of Civil Engineers, Japanese
• Development of a super high-rate Anammox reactor and in situ analysis of biofilm structure and function
  Ikuo Tsushima; Yuji Ogasawara; Masaki Shimokawa; Tomonori Kindaichi; Satoshi Okabe, WATER SCIENCE AND TECHNOLOGY, 55, 8-9, 9, 17, 2007
  English
• Membrane biofouling in pilot-scale membrane bioreactors (MBRs) treating municipal wastewater: Impact of biofilm formation
  Yuki Miura; Yoshimasa Watanbe; Satoshi Okabe, ENVIRONMENTAL SCIENCE & TECHNOLOGY, 41, 2, 632, 638, Jan. 2007
  English
• Population dynamics and in situ kinetics of nitrifying bacteria in autotrophic nitrifying biofilms as determined by real-time quantitative PCR
  Tomonori Kindaichi; Yoshiko Kawano; Tsukasa Ito; Hisashi Satoh; Satoshi Okabe, BIOTECHNOLOGY AND BIOENGINEERING, 94, 6, 1111, 1121, Aug. 2006
  English
• Community structures and activities of nitrifying and denitrifying bacteria in industrial wastewater-treating biofilms
  H Satoh; T Yamakawa; T Kindaichi; T Ito; S Okabe, BIOTECHNOLOGY AND BIOENGINEERING, 94, 4, 762, 772, Jul. 2006
  English
• Alternative indicators of fecal pollution: Relations with pathogens and conventional indicators, current methodologies for direct pathogen monitoring and future application perspectives
  Olga Savichtcheva; Satoshi Okabe, WATER RESEARCH, 40, 13, 2463, 2476, Jul. 2006
  English, Book review
• Community structure, abundance, and in situ activity of nitrifying bacteria in river sediments as determined by the combined use of molecular techniques and microelectrodes
  Y Nakamura; H Satoh; T Kindaichi; S Okabe, ENVIRONMENTAL SCIENCE & TECHNOLOGY, 40, 5, 1532, 1539, Mar. 2006
  English
• A vista for microbial ecology and environmental biotechnology
  BE Rittmann; M Hausner; F Loffler; NG Love; G Muyzer; S Okabe; DB Oerther; J Peccia; L Raskin; M Wagner, ENVIRONMENTAL SCIENCE & TECHNOLOGY, 40, 4, 1096, 1103, Feb. 2006
  English, Others
• 微小電極を用いたUASBグラニュール汚泥内の微生物活性の解析
  佐藤久; 對馬育夫; 岡部聡, 環境工学研究フォーラム講演集, 43rd, 2006
• C-13 Persistence of Bacteroides-Prevotella genetic markers as alternative fecal indicator(Environmental sanitation,(2) Oral presentation)
  Shimazu Yoko; Olga Savichtcheva; Kawata Koji; Okabe Satoshi, 日本微生物生態学会講演要旨集, 22, 277, 277, 2006
  日本微生物生態学会, Japanese
• B-29 Function analysis of a novel Betaproteobacteria universally inhabiting wastewater treatment system(Water/Wastewater treatment ecosystem,(2)Oral presentation)
  Ono Kaori; Ito Tsukasa; Okabe Satoshi, 日本微生物生態学会講演要旨集, 22, 261, 261, 2006
  日本微生物生態学会, Japanese
• B-03 The contribution of rpoS to formation of Escherichia coli biofilms(Interface/Biofilm,(2)Oral presentation)
  Ito Akinobu; May Thithiwat; Okabe Satoshi, 日本微生物生態学会講演要旨集, 22, 235, 235, 2006
  日本微生物生態学会, Japanese
• B-30 Function analysis and cultivation attempts of uncultivated filamentous microbes which cause fatal anaerobic filamentous bulking(Water/Wastewater treatment ecosystem,(2)Oral presentation)
  Sekiguchi Yuji; Yamada Takeshi; Shiraishi Koji; Ito Tsukasa; Okabe Satoshi; Ohashi Akiyoshi; Harada Hideki; Kamagata Yoichi; Nakamura Kazunori, 日本微生物生態学会講演要旨集, 22, 262, 262, 2006
  日本微生物生態学会, Japanese
• UASBグラニュール内の水素濃度分布の解析
  佐藤 久; 岡部 聡, 衛生工学シンポジウム論文集, 13, 199, 202, 16 Nov. 2005
  北海道大学衛生工学会, Japanese
• ANAMMOX反応を利用した窒素除去リアクターの開発と群集構造解析
  金田一 智規; 尾崎 則篤; 對馬 育夫; 小笠原 雄二; 岡部 聡, 衛生工学シンポジウム論文集, 13, 13, 195, 198, 16 Nov. 2005
  第13回衛生工学シンポジウム（平成17年11月17日（木）-18日（金） 北海道大学クラーク会館） . 一般セッション . 6 水処理 . 6-4, 北海道大学衛生工学会, Japanese
• Application of a direct fluorescence-based live/dead staining combined with fluorescence in situ hybridization for assessment of survival rate of Bacteroides spp. in drinking water
  O Savichtcheva; N Okayama; T Ito; S Okabe, BIOTECHNOLOGY AND BIOENGINEERING, 92, 3, 356, 363, Nov. 2005
  English
• Measurement of growth rate of ammonia oxidizing bacteria in partially submerged rotating biological contactor by fluorescent in situ hybridization (FISH)
  A Jang; S Okabe; Y Watanabe; IS Kim; PL Bishop, JOURNAL OF ENVIRONMENTAL ENGINEERING AND SCIENCE, 4, 5, 413, 420, Sep. 2005
  English
• Fate of 14C-labeled microbial products derived from nitrifying bacteria in autotrophic nitrifying biofilms.
  Satoshi Okabe; Tomonori Kindaichi; Tsukasa Ito, Applied and environmental microbiology, 71, 7, 3987, 94, Jul. 2005, [Peer-reviewed], [International Magazine]
  English
• Thiovirga sulfuroxydans gen. nov., sp nov., a chemolithoautotrophic sulfur-oxidizing bacterium isolated from a microaerobic waste-water biofilm
  T Ito; K Sugita; Yumoto, I; Y Nodasaka; S Okabe, INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY, 55, 3, 1059, 1064, May 2005
  English
• Succession of internal sulfur cycles and sulfur-oxidizing bacterial communities in microaerophilic wastewater biofilms
  Satoshi Okabe; Tsukasa Ito; Kenichi Sugita; Hisashi Satoh, Applied and Environmental Microbiology, 71, 5, 2520, 2529, May 2005
  English
• Membrane Bioreactorの運転性に伴う微生物群集構造の解析
  三浦佑己; 伊藤司; 渡辺義公; 岡部聡, 日本水環境学会年会講演集, 39th, 41, 17 Mar. 2005
  Japanese
• ヨシ根圏生物膜内の物質濃度分布および微生物群集構造の解析
  中村吉志; 渡辺義公; 岡部聡; 佐藤久, 日本水環境学会年会講演集, 39th, 231, 17 Mar. 2005
  Japanese
• B-20 Microbial community involved in glucose degradation pathway in anaerobic digester sludge analyzed by RNA-SIP and MAR-FISH.(WATER-TREATMENT ECOSYSTEM,(2) Oral presentation)
  Yoshiguchi Kazumi; Ito Tsukasa; Ariesyady Herto Dwi; Okabe Satoshi, 日本微生物生態学会講演要旨集, 21, 240, 240, 2005
  日本微生物生態学会, Japanese
• B-19 Mcrobial community in biofilm on membrane surface of MBR(WATER-TREATMENT ECOSYSTEM,(2) Oral presentation)
  Miura Yuki; Ito Tsukasa; Watanabe Yoshimasa; Okabe Satoshi, 日本微生物生態学会講演要旨集, 21, 239, 239, 2005
  日本微生物生態学会, Japanese
• PA-38 Diversity and abundance of propionate-oxidizing bacteria in anaerobic digester sludge analyzed by RNA-SIP and MAR-FISH.(WATER-TREATMENT ECOSYSTEM,Session A,(1) Poster presentations)
  Ito Tsukasa; Ariesyady Herto Dwi; Yoshiguchi Kazumi; Okabe Satoshi, 日本微生物生態学会講演要旨集, 21, 84, 84, 2005
  日本微生物生態学会, Japanese
• 3S4-AM5 Eco-physiological interactions among microbial community members in nitrifying biofilms
  OKABE Satoshi, 日本生物工学会大会講演要旨集, 17, 47, 47, 2005
  日本生物工学会, Japanese
• A-10 Analysis of microbial structure and function in ANAMMOX reactor(MICROBIAL COMMUNITY ANALYSIS,(2) Oral presentation)
  Tsushima Ikuo; Ogasawara Yuji; Kindaichi Tomonori; Okabe Satoshi, 日本微生物生態学会講演要旨集, 21, 206, 206, 2005
  日本微生物生態学会, Japanese
• Eco-physiology of autotrophic nitrifying biofilms
  S Okabe; T Kindaichi; Y Nakamura; T Ito, WATER SCIENCE AND TECHNOLOGY, 52, 7, 225, 232, 2005
  English
• 微生物群集構造解析技術の現状と今後の展開・課題
  水環境学会誌, 28, 8, 460, 465, 2005
• バイオフィルムの概論・理論 : バイオフィルム : 細菌の生き延びるためのストラテジー (小特集 バイオフィルム)
  岡部 聡; 伊藤 暁信, 配管技術, 46, 8, 1, 7, Jul. 2004
  日本工業出版, Japanese
• Isolation, characterization, and in situ detection of a novel chemolithoautotrophic sulfur-oxidizing bacterium in wastewater biofilms growing under microaerophilic conditions
  T Ito; K Sugita; S Okabe, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 70, 5, 3122, 3129, May 2004
  English
• ジルコニウムメゾ構造体による下水汚泥からのリン回収
  巽善彦; 渡辺義公; 岡部聡, 日本水環境学会年会講演集, 38th, 196, 17 Mar. 2004
  Japanese
• MBR(Membrane Bioreactor)を用いた都市下水処理システムにおける女性ホルモン様物質の挙動に関する研究
  久保広明; 渡辺義公; 岡部聡; 木村克輝, 日本水環境学会年会講演集, 38th, 363, 17 Mar. 2004
  Japanese
• Real‐Time PCR法によるBacteroidalesを指標とした糞便汚染度評価
  岡山紀子; SAVICHTCHEVA O; 金田一智規; 伊藤司; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 38th, 313, 17 Mar. 2004
  Japanese
• MAR‐FISH法を用いた硝化細菌生物膜内における硝化細菌由来有機物の追跡
  金田一智規; 伊藤司; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 38th, 380, 17 Mar. 2004
  Japanese
• ANAMMOX集積汚泥の微生物構造および機能解析
  対馬育夫; 金田一智規; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 38th, 370, 17 Mar. 2004
  Japanese
• 根に形成される生物膜内の物質濃度および微生物群集構造解析
  中村吉志; 岡部聡; 渡辺義公; 佐藤久, 日本水環境学会年会講演集, 38th, 508, 17 Mar. 2004
  Japanese
• Macroscale and microscale analyses of nitrification and denitrification in biofilms attached on membrane aerated biofilm reactors
  H Satoh; H Ono; B Rulin; J Kamo; S Okabe; KI Fukushi, WATER RESEARCH, 38, 6, 1633, 1641, Mar. 2004
  English
• Analysis of Size Distribution and Areal Cell Density of Ammonia-Oxidizing Bacterial Microcolonies in Relation to Substrate Microprofiles in Biofilms
  Satoshi Okabe; Tomonori Kindaichi; Tsukasa Ito; Hisashi Satoh, Biotechnology and Bioengineering, 85, 1, 86, 95, 05 Jan. 2004
  English
• A-30 コンクリート腐食の進行に関与する微生物群集構造解析(水処理生態系,口頭発表)
  小田切 光典; 伊藤 司; 佐藤 久; 岡部 聡, 日本微生物生態学会講演要旨集, 20, 152, 152, 2004
  日本微生物生態学会, Japanese
• C-06 ヨシ根圏内の窒素循環と関連細菌群集構造の解析(水圏生態系,口頭発表)
  中村 吉志; 岡部 聡; 佐藤 久; 渡辺 義公, 日本微生物生態学会講演要旨集, 20, 208, 208, 2004
  日本微生物生態学会, Japanese
• P-020 16S rRNAアプローチとSIP法を用いた嫌気性消化汚泥内における酸生成および酸分解に関与する微生物群の構造解析(水処理生態系,ポスター発表)
  吉口 和美; 伊藤 司; Ariesyady Herto Dwi; 岡部 聡, 日本微生物生態学会講演要旨集, 20, 42, 42, 2004
  日本微生物生態学会, Japanese
• Effects of hydroxylamine on microbial community structure and function of autotrophic nitrifying biofilms determined by in situ hybridization and the use of microelectrodes
  T Kindaichi; S Okabe; H Satoh; Y Watanabe, WATER SCIENCE AND TECHNOLOGY, 49, 11-12, 61, 68, 2004
  English
• Developing the new leachate treatment system using membrane bioreactor of anaerobic ammonia oxidation type and establishing the safety evaluation method of treated water using DNA chip.
  渡辺義公; 岡部聡; 木村克輝, 第4回廃棄物対策研究発表会成果発表抄録集 平成16年度廃棄物対策研究推進事業, I.35-I.37, 2004
  Japanese
• Effects of hydroxylamine on microbial community structure and function of autotrophic nitrifying biofilms determined by in situ hybridization and the use of microelectrodes
  T. Kindaichi; S. Okabe; H. Satoh; Y. Watanabe, Water Science and Technology, 49, 11-12, 61, 68, 2004
  English
• Microbial communities and their interactions in biofilm systems: an overview
  S Wuertz; S Okabe; M Hausner, WATER SCIENCE AND TECHNOLOGY, 49, 11-12, 327, 336, 2004
  English
• Photosynthesis in sediment at a tidal area of Niida River, Hachinohe, Japan
  Water Research, 38, 9, 2439, 2447, 2004
• MAR-FISH: An ecophysiological approach to link phylogenetic identity and in situ metabolic activity of microorganisms at single-cell resolution
  Microb. Environ, 19, 2, 83, 98, 2004
• Eco-physiological interaction between nitrifying bacteria and heterotrophic bacteria in autotrophic nitrifying biofilms
  KINDAICHI T; ITO T; OKABE S, Applied and Environmental Microbiology, 70, 3, 1641, 1650, 2004
• Population Dynamics of Nitrifying Bacteria in Biofilms Determined by Real-Time PCR
  KINDAICHI Tomonori; KAWANO Yoshiko; ITO Tsukasa; OKABE Satoshi, ENVIRONMENTAL ENGINEERING RESEARCH, 41, 41, 321, 330, 2004
  We investigated the population dynamics of nitrifying bacteria in autotrophic nitrifying biofilms by using Real-Time PCR and fluorescent in situ hybridization (FISH). Primers and TaqMan probe specific to genus Nitrospira including uncultured Nitrospira sp. in the biofilms were newly designed and applied to the biofilms. The populations of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) determined by Real-Time PCR during steady-state condition were 1.2×10⁸cells/cm² and 3.5×10⁸cells/cm², respectively. The population dynamics of nitrifying bacteria corresponded with the reactor performance and the development of nitrifying bacteria in the biofilms determined by FISH. Real-Time PCR revealed that specific growth rates of uncultured Nitrospira sp. were 0.021h^-1 in the suspended enrichment culture and 0.014h^-1 in the biofilms. Average specific growth rates of both nitrifying bacteria during the steady-state condition in the biofilms were significantly lower than that during the log phase, might suggest that metabolic pathway of nitrifying bacteria in the biofilms was different in the log and stationary phase. We speculated that Real-Time PCR was powerful and suitable technique for understanding of microbial population dynamics in the complex microbial communities., Japan Society of Civil Engineers, Japanese
• バイオフィルム内の細菌の特異的検出とその分布の測定
  Bacterial Adherence & Biofilm, 17, 102, 107, 2004
• Sulfate-reducing bacterial community structure and their contribution to carbon mineralization in a wastewater biofilm growing under microaerophilic conditions
  S Okabe; T Ito; H Satoh, APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, 63, 3, 322, 334, Dec. 2003
  English
• Eco-physiological interaction between nitrifying bacteria and heterotrophic bacteria in autotrophic nitrifying biofilms as determined by MAR-FISH
  Kindaichi Tomonori; Ito Tsukasa; Okabe Satoshi; Watanabe Yoshimasa, 衛生工学シンポジウム論文集, 11, 131, 134, 31 Oct. 2003
  北海道大学衛生工学会, English
• 微小電極を用いた下水道構造物の腐食機構の検討
  佐藤 久; 佐々木 裕一; 小山田 浩之; 岡部 聡, 衛生工学シンポジウム論文集, 11, 69, 72, 31 Oct. 2003
  北海道大学衛生工学会, Japanese
• MBR(Membrane Bioreactor)を用いた下水処理水の安全性評価およびMicropollutantsの挙動に関する研究
  久保広明; 岡部聡; 木村克輝; 渡辺義公, 土木学会年次学術講演会講演概要集(CD-ROM), 58th, Disk 2, VII-085, 01 Sep. 2003
  Japanese
• コンクリート腐食に関与する微生物群集の構造解析
  岡部聡; 小田切光典; 伊藤司; 佐藤久; 小山田浩之; 渡辺義公, 土木学会年次学術講演会講演概要集(CD-ROM), 58th, Disk 2, VII-189, 01 Sep. 2003
  Japanese
• Effect of oxygen concentration on nitrification and denitrification in single activated sludge flocs
  H Satoh; Y Nakamura; H Ono; S Okabe, BIOTECHNOLOGY AND BIOENGINEERING, 83, 5, 604, 607, Sep. 2003
  English
• Dynamic response of nitrifying activated sludge batch culture to increased chloride concentration
  GH Chen; MT Wong; S Okabe; Y Watanabe, WATER RESEARCH, 37, 13, 3125, 3135, Jul. 2003
  English
• Evaluation of the impact of bioaugmentation and biostimulation by in situ hybridization and microelectrode
  H Satoh; S Okabe; Y Yamaguchi; Y Watanabe, WATER RESEARCH, 37, 9, 2206, 2216, May 2003
  English
• MAR‐FISH法を用いた硝化生物膜の生態学的構造と機能の解析
  金田一智規; 伊藤司; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 37th, 62, 04 Mar. 2003
  Japanese
• 省エネルギー型の新規窒素除去プロセスの検討
  対島育夫; 金田一智規; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 37th, 507, 04 Mar. 2003
  Japanese
• 下水生物膜内における新規硫黄酸化細菌の機能と構造の解析
  杉田謙一; 伊藤司; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 37th, 67, 04 Mar. 2003
  Japanese
• Ammonia-oxidizing bacteria on root biofilms and their possible contribution to N use efficiency of different rice cultivars
  AM Briones; S Okabe; Y Umemiya; NB Ramsing; W Reichardt; H Okuyama, PLANT AND SOIL, 250, 2, 335, 348, Mar. 2003
  English
• Effect of nitrite and nitrate on in situ sulfide production in an activated sludge immobilized agar gel film as determined by use of microelectrodes
  S Okabe; CM Santegoeds; D De Beer, BIOTECHNOLOGY AND BIOENGINEERING, 81, 5, 570, 577, Mar. 2003
  English
• 28-B-10 MAR-FISH法を用いた下水管渠内の付着生物膜を構成するbeta-, gamma-Proteobacteriaの群集構造と機能解析(水処理生態系,一般講演)
  伊藤 司; 岡部 聡, 日本微生物生態学会講演要旨集, 19, 105, 105, 2003
  日本微生物生態学会, Japanese
• 28-B-11 下水生物膜から単離した新規硫黄酸化細菌の生理機能と生態(水処理生態系,一般講演)
  杉田 謙一; 伊藤 司; 岡部 聡; 渡辺 義公, 日本微生物生態学会講演要旨集, 19, 106, 106, 2003
  日本微生物生態学会, Japanese
• Effect of dissolved oxygen concentration on the biofilm and in situ analysis by fluorescence in situ hybridization (FISH) and microelectrodes
  A Jang; PL Bishop; S Okabe; SG Lee; IS Kim, WATER SCIENCE AND TECHNOLOGY, 47, 1, 49, 57, 2003
  English
• Effect of nitrite and nitrate on biogenic sulfide production in sewer biofilms determined by the use of microelectrodes
  S Okabe; T Ito; H Satoh; Y Watanabe, WATER SCIENCE AND TECHNOLOGY, 47, 11, 281, 288, 2003
  English
• Effect of nitrite and nitrate on biogenic sulfide production in sewer biofilms determined by the use of microelectrodes
  S. Okabe; T. Ito; H. Satoh; Y. Watanabe, Water Science and Technology, 47, 11, 281, 288, 2003
  English
• Effect of dissolved oxygen concentration on the biofilm and in situ analysis by fluorescence in situ hybridization (FISH) and microelectrodes
  A Jang; PL Bishop; S Okabe; SG Lee; IS Kim, WATER SCIENCE AND TECHNOLOGY, 47, 1, 49, 57, 2003
  English
• Diversity of Ammonia-oxidizing Bacteria Based on 16S rDNA Sequence Analysis
  KINDAICHI Tomonori; ITO Tsukasa; OKABE Satoshi; WATANABE Yoshimasa, ENVIRONMENTAL ENGINEERING RESEARCH, 40, 40, 71, 79, 2003
  We investigated the phylogenetic diversity of ammonia-oxidizing bacteria (AOB) in different environments based on 16S ribosomal DNA (rDNA) sequence analysis with the specific primer set. The sequence analysis revealed that the Nitrosomonas oligotropha-like AOB were the dominant in low-ammonium environments such as river and drinking water treatment systems. In contrast, the Nitrosomonas europaea-like AOB were the dominant in high-ammonium environments in which the concentration of ammonium is more than 1000 mg-N/L. In medium-ammonium environments, the coexistence of the distinct AOB related to the Nitrosomonas europaea-, Nitrosomonas oligotropha-, and Nitrosospira sp.-like clusters were found, indicating a high phylogenetic diversity. These observations support the hypothesis that Nitmsomonas europaea is r-strategist, whereas Nitrosospira sp. is K-strategist, indicating that Nitrosomonas europaea can outcompete the Nitrosospira sp. at high ammonium concentration. These results provide insight into the type of AOB responsible for nitrification in different engineered systems, which should help direct future studies aimed at characterizing relevant AOB growth., Japan Society of Civil Engineers, Japanese
• バイオフィルム内における硫黄循環と関連微生物群集構造の解析
  月刊海洋号外「海洋微生物Ⅱ－基礎，応用研究とその利用」, 35, 54, 63, 2003
• 微好気性生物膜内における硫酸塩還元細菌の空間分布と硫黄の挙動解析
  岡部聡; 伊藤司; 佐藤久; 渡辺義公, 用水と廃水, 44, 11, 961, 970, 01 Nov. 2002
  産業用水調査会, Japanese
• t-RFLP法によるBacteroidesを指標とした河川の糞便性汚染の評価
  伊藤 司; 岸田 秀; 岡山 紀子; 岡部 聡; 渡辺 義公, 衛生工学シンポジウム論文集, 10, 117, 120, 31 Oct. 2002
  北海道大学衛生工学会, Japanese
• 微小電極を用いたコンクリート表面に形成された生物膜内の硫酸塩還元反応の解析
  小山田 浩之; 佐藤 久; 岡部 聡; 伊藤 司, 衛生工学シンポジウム論文集, 10, 109, 112, 31 Oct. 2002
  北海道大学衛生工学会, Japanese
• 河川底泥の窒素循環に及ぼす底生動物の影響
  中村 吉志; 佐藤 久; 岡部 聡, 衛生工学シンポジウム論文集, 10, 105, 108, 31 Oct. 2002
  北海道大学衛生工学会, Japanese
• 下水生物膜内における硫黄酸化細菌群集の解析
  杉田謙一; 岡部聡; 伊藤司; 渡辺義公, 土木学会年次学術講演会講演概要集(CD-ROM), 57th, VII-284, 01 Sep. 2002
  Japanese
• Influence of different cultivars on populations of ammonia-oxidizing bacteria in the root environment of rice
  AM Briones; S Okabe; Y Umemiya; NB Ramsing; W Reichardt; H Okuyama, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 68, 6, 3067, 3075, Jun. 2002
  English
• Successional development of sulfate-reducing bacterial populations and their activities in an activated sludge immobilized agar gel film
  S Okabe; CM Santegoeds; Y Watanabe; D de Beer, BIOTECHNOLOGY AND BIOENGINEERING, 78, 2, 119, 130, Apr. 2002
  English
• 生物膜内における硫黄酸化反応機構および関連微生物群集の解析
  伊藤司; 岡部聡; 渡辺義公; 杉田謙一; 佐藤久, 日本水環境学会年会講演集, 36th, 40, 14 Mar. 2002
  Japanese
• ヒドロキシルアミンの添加が硝化反応に及ぼす影響
  金田一智規; 岡部聡; 渡辺義公; 対馬郁夫, 日本水環境学会年会講演集, 36th, 375, 14 Mar. 2002
  Japanese
• t‐RFLP法よるBacteroidesを指標とした河川の糞便性汚染の評価
  岸田秀; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 36th, 345, 14 Mar. 2002
  Japanese
• 16S rDNA解析によるアンモニア酸化細菌の多様性評価
  河野快子; 岡部聡; 渡辺義公; 高倉恭子, 日本水環境学会年会講演集, 36th, 374, 14 Mar. 2002
  Japanese
• Successional development of sulfate-reducing bacterial populations and their activities in a wastewater biofilm growing under microaerophilic conditions
  T Ito; S Okabe; H Satoh; Y Watanabe, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 68, 3, 1392, 1402, Mar. 2002
  English
• B-16 下廃水処理系生物膜内の新規硫黄酸化細菌の特異的検出と機能評価(水処理生態系1,口頭発表)
  伊藤 司; 杉田 謙一; 岡部 聡; 渡辺 義公, 日本微生物生態学会講演要旨集, 18, 84, 84, 2002
  日本微生物生態学会, Japanese
• Structure and function of nitrifying biofilms as determined by molecular techniques and the use of microelectrodes
  S Okabe; H Naitoh; H Satoh; Y Watanabe, WATER SCIENCE AND TECHNOLOGY, 46, 1-2, 233, 241, 2002
  English
• Phylogenetic identification and substrate uptake patterns of sulfate-reducing bacteria inhabiting an oxic-anoxic sewer biofilm determined by combining microautoradiography and fluorescent in situ hybridization
  T Ito; JL Nielsen; S Okabe; Y Watanabe; PH Nielsen, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 68, 1, 356, 364, Jan. 2002
  English
• Biofilm formation potentials in drinking waters treated by different advanced treatment processes
  S Okabe; T Kokazi; Y Watanabe, 2ND WORLD WATER CONGRESS: WATER DISTRIBUTION AND WATER SERVICES MANAGEMENT, 2, 4, 97, 104, 2002
  English
• Structure and function of nitrifying biofilms as determined by molecular techniques and the use of microelectrodes
  S Okabe; H Naitoh; H Satoh; Y Watanabe, WATER SCIENCE AND TECHNOLOGY, 46, 1-2, 233, 241, 2002
  English
• 生物膜内における硫黄酸化反応および関連微生物の解析
  伊藤司; 岡部聡; 渡辺義公, 日本微生物生態学会講演要旨集, 17th, 17, 27, 27, 09 Nov. 2001
  日本微生物生態学会, Japanese
• 貧栄養条件下にある浄水処理プロセス内の微生物群集解析
  志水豊晴; 山川岳志; 岡部聡; 渡辺義公, 土木学会年次学術講演会講演概要集 第7部, 56th, 468, 469, 01 Sep. 2001
  Japanese
• 配水過程における生物膜生成能に及ぼす異なる浄水処理プロセスの影響
  岡部聡; 渡辺義公; 小鍛冶利彦; 小沢源三, 土木学会年次学術講演会講演概要集 第7部, 56th, 470, 471, 01 Sep. 2001
  Japanese
• Analysis of microbial structure and function of nitrifying biofilm
  OKABE Satoshi, Bioscience & industry, 59, 6, 385, 388, 01 Jun. 2001
  バイオインダストリ-協会, Japanese
• 配水過程における生物膜生成能に及ぼす異なる浄水処理プロセスの影響
  小鍛冶利彦; 岡部聡; 渡辺義公; 木村克輝, 全国水道研究発表会講演集, 52nd, 278, 279, 27 Apr. 2001
  Japanese
• 亜硝酸酸化細菌の優占種を決定する環境因子の検討
  山川岳志; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 35th, 533, 14 Mar. 2001
  Japanese
• 貧栄養条件下にある浄水処理プロセス内の微生物群集解析
  志水豊晴; 山川岳志; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 35th, 318, 14 Mar. 2001
  Japanese
• Analysis of microbial structure and function of nitrifying biofilms
  S Okabe; H Satoh; Y Watanabe, MICROBIAL GROWTH IN BIOFILMS, PT B, 337, 213, 224, 2001
  English, Book review
• Kinetic analysis of nitrifying biofilm growing on the rotating membrane disk
  K Kimura; Y Watanabe; S Okabe; H Satoh, WATER SCIENCE & TECHNOLOGY: WATER SUPPLY, VOL 1, NO 4, 1, 4, 111, 118, 2001
  English
• 廃水処理プラント内担体付着生物膜のin situ活性及び微生物相の解析
  山川岳志; 岡部聡; 渡辺義公, 日本微生物生態学会講演要旨集, 16th, 16, 71, 71, 12 Nov. 2000
  日本微生物生態学会, Japanese
• MAR‐FISH法を用いた生物膜内in situでの硫酸塩還元細菌の特異的検出と機能解析
  伊藤司; 岡部聡; NIELSEN P H; NIELSEN J L; 渡辺義公, 日本微生物生態学会講演要旨集, 16th, 16, 39, 39, 12 Nov. 2000
  日本微生物生態学会, Japanese
• 16S rRNAアプローチによる硝化菌生物膜の生態学的構造解析
  岡部聡; 渡辺義公; 内藤初夏, 土木学会年次学術講演会講演概要集 第7部, 55th, 122, 123, 31 Aug. 2000
  Japanese
• 微小電極を用いた生物膜内の溶存酸素輸送機構の解析
  佐藤久; 岡部聡; 渡辺義公, 土木学会年次学術講演会講演概要集 第7部, 55th, 114, 115, 31 Aug. 2000
  Japanese
• 微小電極と分子生物学的手法を併用した廃水処理プラントの評価
  山川岳志; 岡部聡; 渡辺義公, 土木学会年次学術講演会講演概要集 第7部, 55th, 112, 113, 31 Aug. 2000
  Japanese
• 微好気性生物膜内における硫酸塩還元細菌の多様性評価
  山川岳志; 伊藤司; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 34th, 372, 15 Mar. 2000
  Japanese
• 混合培養系生物膜内の硝化機構
  佐藤久; 山口有希; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 34th, 158, 15 Mar. 2000
  Japanese
• モデル生物膜内における硫酸塩還元細菌の動態解析
  岡部聡; 渡辺義公, 日本水環境学会年会講演集, 34th, 373, 15 Mar. 2000
  Japanese
• Significance of substrate C/N ratio on structure and activity of nitrifying biofilms determined by in situ hybridization and the use of microelectrodes
  H Satoh; S Okabe; N Norimatsu; Y Watanabe, WATER SCIENCE AND TECHNOLOGY, 41, 4-5, 317, 321, 2000
  English
• Structure and function of nitrifying biofilms as determined by in situ hybridization and the use of microelectrodes
  S Okabe; Y Watanabe, WATER SCIENCE AND TECHNOLOGY, 42, 12, 21, 32, 2000
  English
• 微小電極とFISH法を用いた硝化細菌生物膜の生態学的構造と機能の解析
  岡部聡; 佐藤久; 渡辺義公, 日本微生物生態学会講演要旨集, 15th, 36, 05 Nov. 1999
  Japanese
• Analyses of spatial distributions of sulfate-reducing bacteria and their activity in aerobic wastewater biofilms
  S Okabe; T Itoh; H Satoh; Y Watanabe, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 65, 11, 5107, 5116, Nov. 1999
  English
• Analyses of spatial distributions of sulfate-reducing bacteria and their activity in aerobic wastewater biofilms
  Satoshi Okabe; Tsukasa Itoh; Hisashi Satoh; Yoshimasa Watanabe, Applied and Environmental Microbiology, 65, 11, 5107, 5116, Nov. 1999
  English
• Population Dynamics of Nitrifying Bacteria in Wastewater Biofilms Analyzed by Fluorescent in situ Hybridization.
  岡部聡; 乗松直生子; 内藤初夏; 渡辺義公, 水環境学会誌, 22, 8, 683, 691, 10 Aug. 1999
  Time dependent developments of in situ spatial distributions of NH4+- and NO2-- oxidizing bacterial populations in domestic wastewater biofilms and in synthetic nitrifying biofilms were investigated by fluorescent in situ hybridization (FISH) with a set of 16S rRNA-targeted oligonucleotide probes. NH4+-oxidizing bacterial populations were classified into three groups according to the probe specificity, and population dynamics of these groups was correlated with the biofilm performance. In situ hybridization indicated that Nitrosomonas spp. (excluding probe NEU stained NH4+-oxidizing bacteria : i.e., N. marina-lineage, N. europaea-lineage, N. eutropha, and N. halophila) and Nitrospira-like bacteria were the numerically dominant species in the domestic wastewater biofilms. However, probe NEU stained NH4+-oxidizing bacteria became dominant populations in the synthetic nitrifying biofilms (which were initially cultured with the primary settling tank effluent) after switching to the synthetic media. This population shift might be attributed to the accumulation of NO2--N and relatively higher loads of NH4+-N which accelerate the growth of N. europaea-lineage and N. eutropha. This evidence indirectly supported that N. europaea has been most commonly isolated and studied in most of the previous researches. These observations have considerable significance to our understanding of microbial nitrification process in wastewater treatment processes and in natural environment., Japan Society on Water Environment, Japanese
• テトラゾリウム塩還元法を応用した硝化細菌の検出方法の検討
  岡部 聡, 水環境学会誌 = Journal of Japan Society on Water Environment, 22, 8, 645, 645, Aug. 1999
  Japanese
• Effect of biofilm structure on transportation of suspended fine particle into biofilm.
  岡部聡; 渡辺義公; 前嶋恵; 黒田浩史, 土木学会年次学術講演会講演概要集 第7部, 54th, 432, 433, 01 Aug. 1999
  Japanese
• Nitrification mechanism in biofilm of mixed culture.
  佐藤久; 岡部聡; 渡辺義公, 土木学会年次学術講演会講演概要集 第7部, 54th, 428, 429, 01 Aug. 1999
  Japanese
• Kinetic analysis of biofilm attached to surface of separation membrane.
  木村克輝; 渡辺義公; 岡部聡; 佐藤久, 土木学会年次学術講演会講演概要集 第7部, 54th, 430, 431, 01 Aug. 1999
  Japanese
• In situ analysis of nitrifying biofilms as determined by in situ hybridization and the use of microelectrodes
  S Okabe; H Satoh; Y Watanabe, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 65, 7, 3182, 3191, Jul. 1999
  English
• Ammonium Oxidation in Mixed-population Biofilms Determined with the Use of Microelectrodes and In Situ Hybridization.
  佐藤久; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 33rd, 189, 15 Mar. 1999
  Japanese
• Microelectrode Measurements of Simultaneous Nitrification and Denitrification in Wastewater Biofilms.
  山川岳志; 佐藤久; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 33rd, 191, 15 Mar. 1999
  Japanese
• In Situ Analysis of Sulfide Oxidation Mechanism in Microaerophilic Biofilms.
  伊藤司; 佐藤久; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 33rd, 190, 15 Mar. 1999
  Japanese
• FISH法を用いた硝化細菌生物膜内の生態学的構造解析
  水環境学会誌, 22, 8, 683, 691, 1999
• Biofilm modeling: Present status and future directions
  DR Noguera; S Okabe; C Picioreanu, WATER SCIENCE AND TECHNOLOGY, 39, 7, 273, 278, 1999
  English
• Microbial ecology of sulfate-reducing bacteria in wastewater biofilms analyzed by microelectrodes and fish (fluorescent in situ hybridization) technique
  S Okabe; H Satoh; T Itoh; Y Watanabe, WATER SCIENCE AND TECHNOLOGY, 39, 7, 41, 47, 1999
  English
• Ammonium Oxidation in Mixed-population Biofilms Determined with the Use of Microelectrodes and in situ Hybridization
  SATOH Hisashi; OKABE Satoshi; WATANABE Yoshimasa, Journal of Japan Society on Water Environment, 22, 3, 206, 214, 1999
  Ammonium oxidation in wastewater biofilms grown on rotating biological contactors (RBCs) was investigated by using microelectrodes and fluorescent in situ hybridization (FISH) technique. The density of ammonia-oxidizers which formed dense cell cluster was about 5 times higher in the innermost biofilm than in the middle and surface of the biofilm. Due to the presence of ammonia-oxidizers throughout the biofilm, ammonium oxidation zone was expanded with increasing in oxygen penetration depth, which consequently resulted in an increase of the overall ammonium flux into the biofilm. Specific ammonium oxidation rate was dependent upon the density of ammonia-oxidizers. Although more ammonia-oxidizers were detected in the innermost layer, they might be in the dormant state and not contribute ammonium oxidation during the RBC operation because of substrate transport limitation. Furthermore, the fraction of O2 consumption for nitrification to total O2 consumption was in the range of 35% -53% in a medium with ammonium as the sole electron donor, indicating the biofilm consumed a significant amount of oxygen for other than nitrification. It implied that heterotrophs would grow and outcompete nitrifiers in biofilms even though there was no organic carbon source in the medium. In conclusion, the combination of microelectrode measurements and FISH technique made it possible to relate the spatial organization of ammonia-oxidizers with their in situ ammonium oxidation rates in biofilms, which obviously providing more insight into the nitrification process in wastewater biofilm systems., Japan Society on Water Environment, Japanese
• Spatial Distributions of Ammonia-Oxidizing Bacteria in Wastewater Biofilms Analyzed by Fluorescent in situ Hybridization
  OKABE Satoshi; NAITOH Hatsuka; WATANABE Yoshimasa, Journal of Japan Society on Water Environment, 22, 3, 191, 198, 1999
  In situ spatial organization of ammonia-oxidizing bacteria in wastewater biofilms was investigated using fluorescent in situ hybridization (FISH) with 16S rRNA-targeted oligonucleotide probes in combination with confocal scanning laser microscopy (CSLM) and digital image analysis. In situ hybridization of steady-state biofilm samples indicated more than 65% of ammonia-oxidizing bacteria present in the biofilm formed dense spherical clusters with the diameter of less than 10 μm and 10∼20% formed clusters with the diameter of more than 10 μm. Most of ammonia-oxidizing bacteria were present in states of small clusters (d<5 μm) in the surface biofilm, because the bigger clusters were imposed on the higher shear stress and consequently sloughed off.
  On the other hand, about 4∼10 times higher bacterial population were found as the bigger clusters (d=5∼20 μm) in the bottom biofilm than in the surface, creating a spatial gradient of ammonia-oxidizing bacteria throughout the biofilm. Furthermore, evaluation of series of optical sections through the clusters taken by the CSLM showed that a cluster with the diameter of approximately 25 μm consisted of up to 9,000 rod-shaped cells. Areal cell density within the clusters was found to be in the range of 0.9∼1.1 cells·μm^-2 with areal fraction of cells of 51 ± 6%, indicating that these clusters have relatively large openings. These experimental results suggested that the interior biofilm structure was porous and heterogeneous, the spatial distribution of ammonia-oxidizing bacteria was strongly influenced by the hydraulic shear stress and substrate concentration profiles within the biofilm., Japan Society on Water Environment, Japanese
• Significance of Substrate C/N Ratio on Structure and Activity of Nitrifying Biofilms Determined by In Situ Hybridization and the Use of Microelectrodes
  SATOH Hisashi; OKABE Satoshi; WATANABE Yoshimasa, Journal of Japan Society on Water Environment, 22, 9, 763, 769, 1999
  Effects of substrate C/N ratio on the spatial distributions of ammonia-oxidizing bacterial population and their activities in biofilms were investigated by fluorescent in situ hybridization (FISH) with 16S rRNA-targeted oligonucleotide probes and the use of microelectrodes. The increase in substrate C/N ratio (i.e., addition of acetate) immediately intensified the interspecies competition for oxygen between ammonia-oxidizing bacteria and heterotrophic bacteria, and consequently resulted in deterioration of ammonium oxidation rate especially in the surface of the biofilm. This decrease in the ammonium oxidation rate in the surface could explain a steep spatial gradient of ammonia-oxidizing bacterial population within the biofilms cultured at high substrate C/N ratios.Furthermore, development of the spatial distributions of ammonia-oxidizing bacteria and their activities within the biofilm was followed during biofilm development. The active ammonium oxidation zone gradually shifted from the upper layer to the inner layer of the biofilm, which corresponded with the development of the spatial distributions of ammonia-oxidizing bacteria within the biofilm. Based on in situ analyses of microbial structure and activity, we discussed on mechanisms of population dynamics of ammonia-oxidizing bacteria in biofilms., Japan Society on Water Environment, Japanese
• Spatial distribution of sulfate-reducing bacteria and behavior of sulfur in microaerophile biofilm.
  伊藤司; 佐藤久; 岡部聡; 渡辺義公, 環境工学研究フォーラム講演集, 35th, 147, 149, Nov. 1998
  Japanese
• Ecological structure analysis of nitrifying bacterial biofilm using FISH.
  岡部聡; 乗松直生子; 渡辺義公, 環境工学研究フォーラム講演集, 35th, 162, 164, Nov. 1998
  Japanese
• Existence form of ammonia oxidation bacteria in municipal sewage biofilm using FISH method.
  内藤初夏; 佐藤久; 岡部聡; 渡辺義公; 乗松直生子, 土木学会年次学術講演会講演概要集 第7部, 53rd, 152, 153, Oct. 1998
  Japanese
• Transition of ammonia oxidation mechanism in mixed bacterial culture biofilm.
  佐藤久; 岡部聡; 渡辺義公; 乗松直生子, 土木学会年次学術講演会講演概要集 第7部, 53rd, 154, 155, Oct. 1998
  Japanese
• Structure analysis of biofilm using confocus laser microscope and measurement of flow distribution in film.
  岡部聡; 渡辺義公; 川村美穂, 土木学会年次学術講演会講演概要集 第7部, 53rd, 158, 159, Oct. 1998
  Japanese
• Existence form of sulfate-reducing bacteria in aerobe film by FISH method.
  大西徳子; 伊藤司; 岡部聡; 渡辺義公, 土木学会年次学術講演会講演概要集 第7部, 53rd, 156, 157, Oct. 1998
  Japanese
• Study on circulating sludge contact type MF membrane treatment apparatus. (Ministry of Education S).
  渡辺義公; 岡部聡; 鈴木辰彦, マンガン自触媒反応と嫌気性膜洗浄を利用した膜処理の効率化 平成9年度 No.08555135, 6,7-23, 1998
  Japanese
• Study on active carbon circulation type MF membrane treatment apparatus. (Ministry of Education S).
  渡辺義公; 岡部聡; 鈴木辰彦, マンガン自触媒反応と嫌気性膜洗浄を利用した膜処理の効率化 平成9年度 No.08555135, 24,25-49, 1998
  Japanese
• AOCを指標とした高度浄水処理システムの性能評価
  笠原 伸介; 相澤 拓; 渡辺 義公; 小澤 源三; 岡部 聡, 水道協会雑誌, 67, 11, 12, 21, 1998
  日本水道協会, Japanese
• テトラゾリウム塩還元法を応用した硝化細菌の検出方法の検討
  岡部聡, 水環境学会誌, 21, 2, 88, 97, 1998
• Microelectrode Measurements of Sulfate Reduction in Microaerobic Biofilms
  SATOH Hisashi; OKABE Satoshi; ITOH Tsukasa; WATANABE Yoshimasa, Journal of Japan Society on Water Environment, 21, 6, 367, 375, 1998
  The vertical zonation of 0₂ respiration, NO₃^- respiration, H₂S oxidation and SO₄^2- reduction in microaerobic biofilms grown on rotating biological contactors (RBCs) of treating domestic wastewater was studied by measuring concentration profiles in the biofilms with microelectodes for 0₂, NO₃^-, H₂S and pH. From those profiles, in situ specific reaction rates and substrate fluxes were calculated by using a simple one-dimensional deffusion reaction model and were related to population densities of sulfate-reducing bacteria (SRB) and potential sulfate reduction rates determined by standard batch experiments. The maximum population densities and the highest potential sulfate reduction rates were found in the outermost biofilm. On the contrary, the in situ sulfate reduction rates were restricted in a narrow zone located in the middle biofilm incubated DO=100 μmol·l^-1. An increase in the O₂ and/or NO₃^- penetration depth in the biofilm induced a shift of sulfate reduction zone to the deeper biofilm and a decrease in the specific sulfate reduction rate. This is probably because that the potential sulfate reduction rate decreased toward the depth and addition of nitrate enhanced oxidation of the produced sulfide or increased competition for electron donor with denitrifiers, or both. The microelectrode measurements with the high spatial resolution enable us to quantitatively measure in situ SO₄^2- reduction rate in microaerobic biofilms, which could not be detected measureing sulfide or sulfate flux across the water-biofilm interface., Japan Society on Water Environment, Japanese
• Sulfate reduction and sulfide oxidation in aerobic mixed population biofilms
  S Okabe; T Matsuda; H Satoh; T Itoh; Y Watanabe, WATER SCIENCE AND TECHNOLOGY, 37, 4-5, 131, 138, 1998
  English
• Significance of biofilm structure on transport of inert particulates into biofilms
  S Okabe; H Kuroda; Y Watanabe, WATER SCIENCE AND TECHNOLOGY, 38, 8-9, 163, 170, 1998
  English
• 微小電極を用いた微好気性生物膜内の硫酸塩還元の測定
  佐藤 久; 伊藤 司; 岡部 聡; 渡辺 義公, 衛生工学シンポジウム論文集, 5, 222, 227, 01 Nov. 1997
  北海道大学衛生工学会, Japanese
• Ecological structure analysis of nitrifying biofilm.
  伊藤司; 乗松直生子; 佐藤久; 岡部聡; 渡辺義公; 境一澄, 環境工学研究フォーラム講演集, 34th, 91, 93, Nov. 1997
  Japanese
• Sulfate reduction and sulphide oxidation in mixed bacterial culture aerobic biofilm.
  佐藤久; 岡部聡; 伊藤司; 渡辺義公; 松田尚之, 環境工学研究フォーラム講演集, 34th, 94, 96, Nov. 1997
  Japanese
• Ecological structure and function of nitrifying bacteria biofilms.
  佐藤久; 岡部聡; 渡辺義公; 境一澄, 土木学会年次学術講演会講演概要集 第7部, 52nd, 294, 295, Sep. 1997
  Japanese
• Examination of detection method for nitrifying bacteria using tetrazolium salt reduction method.
  岡部聡; 渡辺義公; 境一澄, 土木学会年次学術講演会講演概要集 第7部, 52nd, 296, 297, Sep. 1997
  Japanese
• Effects of flow velocity on biofilm structure in early stage of biofilm formation.
  岡部聡; 佐藤久; 渡辺義公; 尾原裕昌, 土木学会年次学術講演会講演概要集 第7部, 52nd, 330, 331, Sep. 1997
  Japanese
• In Situ Analysis of Nitrifying Bacteria in Biofilms using Fluorescently Labeled 16S rRNA-Targeted Oligonucleotide Probes.
  岡部聡; 乗松直生子; 境一澄; 渡辺義公; 船田良, 日本水環境学会年会講演集, 31st, 135, Mar. 1997
  Japanese
• Significance of Heterogeneous Structures on Transport of Inert Fluorescent Microparticles in Biofilms.
  黒田浩史; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 31st, 134, Mar. 1997
  Japanese
• Microelectrode Measurements of Sulfide in Biofilms at Low Dissolved Oxygen Concentration.
  佐藤久; 伊藤司; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 31st, 136, Mar. 1997
  Japanese
• In situ Identification of Nitrifiers in Biofilms using an INT Reduction Assay.
  境一澄; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 31st, 133, Mar. 1997
  Japanese
• Uptake and release of inert fluorescence particles by mixed population biofilms
  S Okabe; T Yasuda; Y Watanabe, BIOTECHNOLOGY AND BIOENGINEERING, 53, 5, 459, 469, Mar. 1997
  English
• A novel biofilm-membrane reactor for ammonia oxidation at low concentrations
  Y Watanabe; K Kimura; S Okabe; G Ozawa; N Ohkuma, WATER SCIENCE AND TECHNOLOGY, 36, 1, 51, 60, 1997
  English, Book review
• 木質系および石炭系粒状活性炭を用いたオゾン・生物活性炭処理
  水道協会雑誌, 66, 12, 20, 29, 1997
• Significance of the spatial distribution of microbial species in mixed-population biofilms
  S Okabe; K Hirata; Y Watanabe, BIOFOULING, 11, 2, 119, 136, 1997
  English
• Behavior of ammonia nitrogen and assimilable organic carbon (AOC) in biological activated carbon.
  笠原伸介; 相沢拓; 渡辺義公; 小沢源三; 岡部聡; 丹保憲仁, 土木学会年次学術講演会講演概要集 第7部, 51st, 212, 213, Aug. 1996
  Japanese
• Competition of desulfuricants and methane bacteria in sediment of Ibato Lake.
  乗松直生子; 岡部聡; 渡辺義公, 土木学会年次学術講演会講演概要集 第7部, 51st, 340, 341, Aug. 1996
  Japanese
• Effect of biofilm structure on microorganism activity distribution in aerobic treatment.
  佐藤久; 黒田浩史; 岡部聡; 渡辺義公, 土木学会年次学術講演会講演概要集 第7部, 51st, 102, 103, Aug. 1996
  Japanese
• Sulfur compounds in anaerobic sediment. Exemplifying lake basin in lower part of Ibato Lake.
  井野場誠治; 岡部聡; 渡辺義公, 土木学会年次学術講演会講演概要集 第7部, 51st, 342, 343, Aug. 1996
  Japanese
• Basic research on behavior of fine particles in biofilm.
  岡部聡; 渡辺義公; 安田岳雄, 土木学会年次学術講演会講演概要集 第7部, 51st, 112, 113, Aug. 1996
  Japanese
• Spatial microbial distributions of nitrifiers and heterotrophs in mixed-population biofilms
  S Okabe; K Hiratia; Y Ozawa; Y Watanabe, BIOTECHNOLOGY AND BIOENGINEERING, 50, 1, 24, 35, Apr. 1996
  English
• Sulfur Cycles in Aerobic Biofilms treating Wastewater.
  松田尚之; 岡部聡; 渡辺義公, 日本水環境学会年会講演集, 30th, 131, Mar. 1996
  Japanese
• Relationship between population dynamics of nitrifiers in biofilms and reactor performance at various C:N ratios
  S. Okabe; Y. Oozawa; K. Hirata; Y. Watanabe, Water Research, 30, 7, 1563, 1572, 1996
  Pergamon Press Inc, English
• Transport of Inert Fluorescent Microparticles in Multispecies Biofilms
  OKABE Satoshi; YASUDA Takeo; SATOH Hisashi; WATANABE Yoshimasa, Doboku Gakkai Ronbunshuu G, 33, 103, 114, 1996
  The dynamics of spatial distribution of particulate components in mixed population biofilms was investigated using lμm fluorescent microparticles as tracer. Shifts of the tracer bead spatial distribution in the biofilm were measured by sectioning the biofilm with a microslicer and were compared with model simulations to evaluate the growthadvection concept in the existing biofilm models. The tracer beads could traverse throughout a 360 μm thick biofilm within 23 minutes, could be attributed to advective transport via water channels and pores. The release of the entrapped beads were much slower than predicted by a one dimensional model due to spatial and temporal changes in cell density in the biofilm. This evidence implied that cell growth and advection was not balanced due to the presence of biofilm heterogeneity (e. g., pores and voids). Three dimensional observation by a confocal scanning laser microscope clearly indicated that the biofilm consisted of semicountiguous base film and relatively high thickness variation of loose surface film. The substratum was not uniformly covered by the biofilm and cell-free spaces and voids were observed near the substratum. This suggested that the pores, voids and cell-free spaces in the biofilm were firstly filled with growing biomass, thereafter displacement of the tracer beads took place once the cell density reached certain levels. Model assumptions of constant cell density and a continuum concept (flat biomass) are clearly over simplified and should be revised. It was concluded that microbial population dynamics in the biofilm can be determined by not only microbial growth kinetics and physiology, but also by the biofilm structure and growth pattern. One dimensional approach (modeling) is, therefore, adequate to predict biofilm accumulation and its performance, but inadequate to accurately describe the microbial population dynamics in the biofilm., Japan Society of Civil Engineers
• Biological and Chemical Characterization of Anaerobic Sediments of A Eutrophic Lake Barato
  OKABE Satoshi; INOBA Seizi; NORIMATSU Naoko; WATANABE Yoshimasa, Doboku Gakkai Ronbunshuu G, 33, 331, 340, 1996
  Chemical and biological characterization of anaerobic sediments of a eutrophic brackish lake Barato, Sapporo were performed with emphases on sulfur cycle in the sediment. Vertical distributions of sulfide compounds (FeS, FeS₂ and S⁰) were measured and related to sediment oxygen demand (SOD). The SOD was divided into biological and chemical components by using specific inhibitors. The chemical SOD was further separated by ferrous, sulfide and manganous demands. The experimental results indicated that SOD ranged 0.3-1.4 mgO₂/cm³ and the major component was ferrous demand accounting for 29-75%(avg.=55.4%). The content of sulfide compounds accounted for 1-2% of total dry weight of the sediment, which was responsible for about 40-50% of total SOD. Sulfate reduction and methane production in the sediment were limited by fatty acid (i. e., acetate) production. The addition of molybdate and chloroform to inhibit sulfate reduction and methanogenesis, respectively, gave a quantitative measure of fatty acid utilization rates by sulfate reduction and methane production. The experimental results revealed that acetate, propionate and n-butyrate accounted for approximately 60%, 25%, and 10%, respectively, of the electron donors of the sulfate reducing bacteria in this sediment. Acetate accounted for 40-60% of the electron donor of methane producing bacteria. These experimental results imply that the oxidation of sulfide, generated by microbial sulfate reduction is a key process in the biogeochemistry of brackish sediments. The detail information on the sediment of lake Barato will be useful for development of a new means to improve the overlaying water quality., Japan Society of Civil Engineers
• テトラゾリウム塩還元法を用いた硝化細菌の計測方法
  岡部聡; 渡辺義公; 境一澄, 土木学会年次学術講演会講演概要集 第2部, 50th, B, 1142, 1143, Sep. 1995
  Japanese
• Sulfide product inhibition of Desulfovibrio desulfuricans in batch and continuous cultures
  S. Okabe; P. H. Nielsen; W. L. Jones; W. G. Characklis, Water Research, 29, 2, 571, 578, 01 Jan. 1995
• SIMULTANEOUS REMOVAL OF ORGANIC MATERIALS AND NITROGEN BY MICRO-AEROBIC BIOFILMS
  Y WATANABE; S OKABE; K HIRATA; S MASUDA, WATER SCIENCE AND TECHNOLOGY, 31, 1, 195, 203, 1995
  English
• RATE AND STOICHIOMETRY OF MICROBIAL SULFATE REDUCTION BY DESULFOVIBRIO-DESULFURICANS IN BIOFILMS
  S OKABE; PH NIELSEN; WL JONES; WG CHARACKLIS, BIOFOULING, 9, 1, 63, 83, 1995
  English
• Dynamic changes in spatial microbial distribution in mixed-population biofilms: Experimental results and model simulation
  S Okabe; K Hirata; Y Watanabe, WATER SCIENCE AND TECHNOLOGY, 32, 8, 67, 74, 1995
  English
• 上向流バイオフィルターを用いた都市下水処理
  岡部聡; 渡辺義公, 環境工学研究フォーラム講演集, 31st, 124, 126, Nov. 1994
  Japanese
• 流入基質C:N比の生物膜内の硝化菌の挙動に与える影響
  岡部聡; 渡辺義公; 平田貴紅子, 土木学会年次学術講演会講演概要集 第2部, 49th, B, 1074, 1075, Sep. 1994
  Japanese
• ハイブリッド高度下水処理システム
  渡辺義公; 岩崎義彦; 岡部聡, 水文・水資源学会研究発表会要旨集, 1994, 368, 369, Aug. 1994
  Japanese
• 生物膜形成時における細菌分布特性に関する研究
  岡部聡; 渡辺義公; 大沢祐子, 土木学会西部支部研究発表会講演概要集, 1993, 312, 313, Mar. 1994
  Japanese
• 上向流バイオフィルターによる都市下水処理
  三木幸浩; 岡部聡; 渡辺義公, 土木学会西部支部研究発表会講演概要集, 1993, 310, 311, Mar. 1994
  Japanese
• Effects of limiting nutrients and sulfide concentration on kinetics and stoichiometry of desulfovibrio desulfuricants
  Okabe Satoshi, Memoirs of the Faculty of Engineering, Miyazaki University, 23, 49, 68, Feb. 1994
  Miyazaki University, English
• STUDY ON THE PERFORMANCE OF AN UP-FLOW AERATED BIOFILTER (UAB) IN MUNICIPAL WASTE-WATER TREATMENTS
  Y WATANABE; S OKABE; T ARATA; Y HARUTA, WATER SCIENCE AND TECHNOLOGY, 30, 11, 25, 33, 1994
  English
• Estimation of cellular and extracellular carbon contents in sulfate-reducing bacteria biofilms by lipopolysaccharide assay and epifluorescence microscopic technique
  S. Okabe; P. H. Nielsen; W. L. Jones; W. G. Characklis, Water Research, 28, 11, 2263, 2266, 01 Jan. 1994
• STUDY ON THE PERFORMANCE OF AN UP-FLOW AERATED BIOFILTER (UAB) IN MUNICIPAL WASTE-WATER TREATMENTS
  Y WATANABE; S OKABE; T ARATA; Y HARUTA, WATER SCIENCE AND TECHNOLOGY, 30, 11, 25, 33, 1994
  English
• Corrosion of mild steel underneath aerobic biofilms containing sulfate-reducing bacteria part I: At low dissolved oxygen concentration
  Whonchee Lee; Zbigniew Lewandowski; Sathoshi Okabe; William G. Characklis; Recep Avci, Biofouling, 7, 1, 15, 01 Nov. 1993
• 上向流バイオフィルターに関する研究
  岡部聡; 渡辺義公; 春田勇二; 荒田朋睦, 土木学会年次学術講演会講演概要集 第2部, 48th, 1312, 1313, Sep. 1993
  Japanese
• Mass transfer in rotating biological contactor (RBC).
  渡辺義公; 石黒政儀; 岡部聡; 田代雄児, 土木学会年次学術講演会講演概要集 第2部, 41st, 807, 808, Nov. 1986
  Japanese

• Nitrification
  ASM Press, 2011
• バイオ燃料電池の最新動向
  シーエムシー出版, 2011
• Research on Nitrification and Related Processes, Part B
  Elsevier, 2011
• Nitrification
  ASM Press, 2011
• Recent treands in microbial fuel cells
  CMC, 2011
• Research on Nitrification and Related Processes, Part B
  Elsevier, 2011
• 水再利用学
  技報堂出版, 2010
• 難培養微生物研究の最新技術II
  シーエムシー出版, 2010
• Wastewater Treatment
  Caister Academic Press, 2010
• Water Reuse
  2010
• Wastewater Treatment
  Caister Academic Press, 2010

• 教科教育法（工業Ⅰ）, 2024年, 学士課程, 教育学部
• 大学院共通授業科目（教育プログラム）：JICA開発大学院連携プログラム, 2024年, 修士課程, 大学院共通科目
• 水・公衆衛生特論, 2024年, 修士課程, 工学院
• 一般教育演習(ﾌﾚｯｼｭﾏﾝｾﾐﾅｰ), 2024年, 学士課程, 全学教育
• 水・公衆衛生特論, 2024年, 博士後期課程, 工学院
• 上水工学, 2024年, 学士課程, 工学部
• 微生物工学, 2024年, 学士課程, 工学部

• 国際微生物生態学会
• International Water Association
• 「Environmental Technology」編集委員
• 「Biodegradation」編集委員
• American Society for Microbiology
• 土木学会
• 「Microbes and Environments」副編集委員長
• 「Water Research」Associate Editor
• 「Water Science and Technology」Associate Editor
• 日本微生物生態学会
• International society for microbial ecology

• Creation of novel bioelectrochemical nitrogen conversion technologies to revolutionize the non-sustainable nitrogen cycle
  Grants-in-Aid for Scientific Research
  01 Apr. 2023 - 31 Mar. 2027
  岡部 聡; 押木 守
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 23H00192
• 日本-フィリピン「水の安全保障」
  国際的な科学技術共同研究などの推進 国際共同研究
  2024 - 2027
  古米 弘明; 岡部 聡; 鼎 信次郎; 滝沢 智; 都留 稔了; 福士 謙介; 藤井 滋穂; 藤原 拓; 松井 佳彦
  中央大学
• Development of an energy self-sufficient hybrid electrochemical membrane bioreactor
  Grants-in-Aid for Scientific Research
  30 Jun. 2022 - 31 Mar. 2025
  岡部 聡; 山村 寛
  本研究では、酸素供給(曝気)を必要とせず固体電極を最終電子受容体として用いるバイオ燃料電池(MFC)を膜分離バイオリアクター(MBR)に導入することにより、下水処理と電気エネルギーの直接回収を行い、得られた電力を利用し電導性膜分離の電位を人為的に制御し、膜ファウリングを抑制しながら膜分離による高度下水処理を同時に達成する、新規MFC搭載型エネルギー自給式ハイブリッド電気化学的膜分離バイオリアクター (He-MBR)を開発する。
  本年度は、既存のMBR槽内にカセット式空気カソードMFCを複数ユニット挿入したHe-MBRを構築した。アノード電極は、高密度で充填可能なグラファイトカーボンブラシを使用した。カソード電極はステンレス膜(膜口径2 ㎜)を基盤とし、微粉末活性炭(PAC)を添加したポリフッ化ビニリデン(PVDF)を塗布することで作製した。鍵となる導電性分離膜は、ステンレススチールメッシュ (孔径: 0.11 mm, 厚さ:0.06 mm) を基盤とし、ポリエチレングリコール(PEG-600)とDimethyl Sulfoxide (DMSO)を添加したPVDF混合高分子溶液を塗布することにより作製することに成功した。作成した電導性分離膜の物理電気化学的特性（孔径、表面凹凸、など）を評価した。さらに、デッドエンド式膜ろ過実験を行い膜の透過性、ファウりング特性、COD除去率、微生物（大腸菌）の除去率を評価した。
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Pioneering), Hokkaido University, 22K18296
• Developent of a MFC driven anammox MEC system for self-sustaining wastewater treatment
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
  01 Apr. 2019 - 31 Mar. 2023
  岡部 聡; 北島 正章; 佐藤 久; 押木 守
  嫌気性アンモニア酸化(Anammox)プロセスは、省エネ型窒素除去プロセスとして工場排水や嫌気性消化脱水ろ液処理などに適用が始まっているが、メインストリームの都市下水処理への適用は一向に進んでいない。メインストリームの都市下水処理への適用の鍵は、前段の部分硝化(NH4+をNO2-まで酸化する)プロセスの安定化・高効率化である。
  本研究では、前段に有機物除去を担うバイオ燃料電池(MFC)を設け、MFCで発生する電圧を用いてMECアノード電極電位を制御することで、アンモニア酸化細菌(AOB)がアノード電極を電子受容体としてNH4+をNO2-まで酸化し、Anammox細菌が生成されたNO2-とNH4+を窒素ガス(N2)へ変換するMFC駆動型部分硝化(PN)-Anammox 生物電解セル(MEC)システムを開発するものである。本年度は以下の2点について検討した。① MFCを補助電源とし、アンモニア酸化細菌（AOB）は、アノード電極を電子受容体としてNH4+をNO2-へ酸化できるか？さらに、Anammox細菌は、アノード電極を電子受容体としてNH4+を直接N2へ酸化できるか？
  ② 亜硝酸酸化細菌(NOB; NO2-をNO3-に酸化する細菌)に特異的に感染し溶菌させるバクテリオファージは存在するのか？そして、それをNOB増殖抑制剤として利用し部分硝化反応(NH4+ → NO2-)の安定化を効率的に達成できるか？その結果、①関してはMFCを補助電源とするMECを構築し、NH4+の除去性能を確認できた。②に関しては、活性汚泥などからファージを濃縮しNitrospiraのバイオマスと混合し、ファージ感染の有無を確認する実験を行ったが、NOBに特異的に感染するバクテリオファージを獲得するには至らなかった。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 19H00776
• Development of an abiotic - biotic hybrid artificial photosynthetic system toward sustainable acetic acid production
  Grants-in-Aid for Scientific Research Challenging Research (Pioneering)
  28 Jun. 2019 - 31 Mar. 2022
  岡部 聡; 渡辺 精一; 佐藤 久
  Japan Society for the Promotion of Science, Challenging Research (Pioneering), Hokkaido University, 19H05582
• Development of an abiotic - biotic hybrid artificial photosynthetic system toward sustainable acetic acid production
  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Pioneering)
  28 Jun. 2019 - 31 Mar. 2022
  Okabe Satoshi
  Bio-photoelectrochemical (Bio-PEC) cells have much attention due to their ability to convert solar energy and wastewater energy into electrical or chemical energy. To develop Bio-PECs, three-dimensional heterostructures ZnO/CuO NFRs, ZnO nanorods (NRs) on CuO nanowire (NWs) (ZnO@CuO) with high photoelectrochemical performance were successfully synthesized via thermal oxidation and followed by UV irradiation in pure water at ambient temperature and pressure. The longer UV irradiation time significantly improved the photocurrent generation due to the higher light absorption, larger BET specific surface area, and lower charge recombination opportunity. However, ZnO sputtering was not necessarily. The obtained photocurrent density was about three times higher than the previously reported values for ZnO/CuO composites with a similar three-dimensional nanostructure.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Pioneering), Hokkaido University, 20K20486
• Elucidation of the fate of human noroviruses in water environments
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
  01 Apr. 2012 - 31 Mar. 2015
  TATSUO Omura; HARADA Hideki; SANO Daisuke; WATANABE Toru
  In this study, we confirmed that the oxidative stress marker detection of viral capsid protein can be applied to the infectivity evaluation of human noroviruses in water environments when 4-log reduction of infectious titer is expected. Furthermore, a novel methodology to recover intact viral genomic RNA from environmental samples was newly established, in which only the target viral genomic RNA can be specifically recovered. In the investigation of cultivated oysters about norovirus contamination, we applied next generation sequencing technology to identify norovirus genotypes contaminatinng cultivated oysters, and found that not only predominant genotypes but laos minor strains can be detected.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Tohoku University, 24246089
• 糞便汚染マーカー定量検出を基盤とした微生物学的水質管理手法の確立
  科学研究費助成事業 基盤研究(A)
  01 Apr. 2011 - 31 Mar. 2014
  岡部 聡; 石井 聡; 佐藤 久; 佐野 大輔
  現行の糞便汚染指標である大腸菌群数による微生物学的水質管理は、水環境中での大腸菌群の増殖、糞便に由来しない大腸菌群の存在など、数多くの問題点が指摘されている。このため、合理的な糞便性汚染指標の確立および水域の微生物学的水質管理手法の確立が急務となっている。このような背景のもと、本研究では、宿主特異的遺伝子マーカー（腸内蛋白質分解細菌の最優占種であるBacteroides-Prevotella 属由来遺伝子）をもとに水域の糞便汚染レベルを定量的に評価し、さらに糞便汚染源（ヒト、家畜及び野生動物等）を迅速かつ正確に特定する新規方法論を確立し、具体的な汚染防止対策の構築を含む合理的な微生物学的水質管理を実現することを目的としている。
  本年度は、昨年度開発した各宿主特異的糞便汚染マーカーを実際の水環境に適用し、糞便汚染の実態を明らかにした。さらに、遺伝子マーカーを糞便汚染指標として活用するためには、生存細胞と死細胞を区別して定量することが求められる。そこで、Propidium monoazide (PMA)を併用した定量PCR法を確立し、糞便汚染源の特定を行うために重要となる生菌由来の糞便性汚染マーカーの定量が可能となった。
  次に、環境水中における糞便汚染マーカー（ヒト、ブタ、ウシ、ニワトリ、カモの各宿主特異的遺伝子マーカー）の挙動を解析した。さらに、既存の糞便汚染指標である大腸菌群数、糞便生大腸菌群及び大腸菌の定量も行い、減衰速度の違いを評価した。
  最後に、水系感染する腸管系感染症起因細菌及びノロウイルス等の腸管系ウイルスの特異的検出を行い、各宿主特異的遺伝子マーカーと病原微生物の環境水中における存在比の相関関係を調査した。
  日本学術振興会, 基盤研究(A), 北海道大学, 23246094
• 水循環の基盤となる革新的水処理システムの創出
  ＪＳＴ戦略的創造研究推進制度（研究チーム型） （戦略的基礎研究推進事業：ＣＲＥＳＴ）
  2009 - 2014
  Competitive research funding
• Development of innovative water and wastewater treatment systems for sustainable urban water metabolism
  JST Basic Research Programs (Core Research for Evolutional Science and Technology :CREST)
  2009 - 2014
  Competitive research funding
• Development of microbial Fuel Cells(MFCs) for Wastewatertreatment and energy recovery
  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
  2011 - 2012
  OKABE Satoshi
  The goal of this study was to improve the MFCperformance (wastewater treatment and power generation) by enhanching the the cathode reaction of air-cathode MFC. To enhance the cathode reaction, we examined trhe effect of external proton supply by introducing the gas containing various concentrations of CO 2 and humidity to the cathode chamber. In addition, we could estimate quantitatively contribution of proton sources consumed by cathode reaction of air-cathode MFCs. Carbonate dissolution was a main proton source and water shortage was the most critical problem of cathode- reaction limitation. Finally, these results could suggest importance of adjustment of CO 2 content and humidity.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 23656324
• トキシコゲノミクスによる新規機能性ナノ高分子(デンドリマー)の毒性評価
  科学研究費助成事業 挑戦的萌芽研究
  2009 - 2010
  岡部 聡
  PAMAM(polyamidoamine)デンドリマーの生物学的活性は世代が大きくなる程高くなるため、毒性は世代に強く依存すると考えられる。世代依存毒性を含むPAMAMデンドリマーの毒性のより詳細な解明が必須であり、本研究ではPAMAMデンドリマーの毒性及びその発現メカニズムの解明を目的とした。ヒト肝癌由来細胞株HepG2細胞を用いて、PAMAMデンドリマーG4-G7の毒性評価を行った。全ての試験通して、PAMAMデンドリマーとBSAの相互作用による影響を除く為、PAMAMデンドリマーの溶媒にHBSS(Hank's balanced salt solution)にHEPESを10mMとなるように加えたものを用いた。また、暴露濃度にはNeutral red(NR)assayで細胞生存率が80%となる濃度をそれぞれ用いた。その結果、PAMAMデンドリマーの世代依存的な細胞毒性を確認した。同じNR assayで細胞生存率が80%となる濃度でも、世代の大きいPAMAMデンドリマーほどROSの産生能が高いことが明らかとなった。ROS産生は120minで最高値をとった。さらに、DNA損傷性を評価するために、H_2O_2をPositive Controlとしてコメットアッセイを行った。実験結果の解析は、尾の長さ、面積、濃さにより、尾の無いもの(I)から,核内のDNA全てが断片化した頭部の無いものあるいは頭部の極微少なもの(V)までI～Vの5段階に分けて評価した。その結果、AMAMデンドリマーで処理していないHBSS(negative control)の細胞群では、クラスIが大部分であった(75.2%)のに対し、PAMAMデンドリマー暴露系ではクラスIが40%～55%と低く、G7で最低値の40.4%%となった。また、G6,G7では損傷の重篤であるIV,Vの割合が高く、コメット値はG5を除いて世代が増加するに従い、増加する傾向が認められた。以上の結果より、PAMAMデンドリマーがDNA損傷性を有しており、DNA損傷の程度は世代が大きい程より重篤であることが明らかとなった。また、1mM H_2O_2とPAMAMデンドリマーG6はROS産生量がほぼ同程度であったにも関わらず、DNA損傷レベルはH_2O_2の方がPAMAMデンドリマーに比べかなり高い値となった。このことから、酸化ストレスがPAMAMデンドリマーの毒性の直接的な原因ではない可能性が示唆された。
  日本学術振興会, 挑戦的萌芽研究, 北海道大学, 21656129
• Analysis of mixture toxicity for dual combinations of heavy metals and herbicides using toxicogenomic approach
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2008 - 2010
  OKABE Satoshi
  The single chemical cytotoxicity showed that heavy metals and silver nanoparticles had high toxicity, respectively, but herbicides had relatively low toxicity. In contrast, the dual combinations cytotoxicity showed that the combination of silver nanoparticles and heavy metals tended to be much more toxic than silver nanoparticles or heavy metals alone, excluding the combination of silver nanoparticles and chromium (AgNPs-Cr). However, the toxicity of the combination of herbicides and heavy metals was similar to that of herbicides exposure alone. From cytotoxicity results, 5 μM of silver nanoparticles, 2.6 μM of cadmium, 7μM of arsenic and 1.1 μM of chromium were used for the DNA microarray analyses to further elucidate the mechanisms of mixture toxicity. The treatments with AgNPs-Cd (70% cytoviability), AgNPs-As (100% cytoviability) and AgNPs-Cr (140% cytoviability) altered the expression levels of 107 genes, 500 genes and 196 genes, respectively. There was a significant difference between 2 combinations (AgNPs-Cr and AgNPs-Cd) and silver nanoparticles alone on DNA replication genes such as MCM2, MCM5, MCM6, and GINS2 that are important for DNA replication fork. Furthermore, FABP1 gene was down regulated 41-fold by AgNPs-As combination. FABPs play an important role in the transport of lipids to specific compartments in the cell. In conclusion, toxicogenomic approach could elucidate synergistic toxicity by AgNPs and heavy metals, which clearly demonstrate the possible use of DNA microarray analysis for evaluation of mixture toxicity.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 20360235
• ヒトDNAマイクロアレイを用いたナノ粒子の細胞毒性評価
  科学研究費助成事業 萌芽研究
  2007 - 2008
  岡部 聡
  現在生産されているナノ粒子の毒性に関する情報は限られており、人体への影響は解明されてはいない。本研究では、この技術を銀ナノ粒子存在下ヒト由来細胞に応用し、銀ナノ粒子の毒性の有無およびその毒性作用について考察を行った。ニュートラルレッド法と形態観察の結果より、遺伝子発現解析を実施する暴露濃度を低濃度でありながら形態変化が明らかであった40μg/Lと、より高濃度の1000μg/Lに決定した。対照系で紡錘形であった細胞が、銀ナノ粒子暴露群では仮足が伸びたような形態へと変化し、細胞内に多数の空隙が認められた。データベースを基に有意変動遺伝子の機能分類を行った結果、銀、ポリスチレン両ナノ粒子暴露においてM-phaseに分類され、細胞分裂を促進する作用を持つ遺伝子群の上昇変動が顕著であった。また、DNA-repairに分類される遺伝子群の上昇変動も顕著であった。これは、DNAの修復と対応していると考えられ、遺伝子傷害の可能性が示唆された。また、銀ナノ粒子暴露に特異的な遺伝子発現パターンとして、活性酸素種の解毒に重要な役割を担う遺伝子をはじめとする酸化ストレス応答遺伝子の下降変動が挙げられた。小核試験の結果、銀ナノ粒子暴露系にのみ多くの小核が確認され(50.2%)、銀ナノ粒子暴露による遺伝子障害の可能性を強く支持していると考えられる。また、アスコルビン酸を蓄積させた細胞で同様の実験を行った結果、小核形成率が低下したことから(50.2%→26.3%)、銀ナノ粒子暴露による遺伝子障害性に、活性酸素種の関与が示唆された。以上の結果をまとめると、銀、ポリスチレンナノ粒子において発癌作用に関連すると推測される細胞増殖刺激、遺伝子障害を示唆する遺伝子発現パターンが確認された。さらに、これらの結果は、小核試験によって支持され、また、遺伝子傷害性がアスコルビン酸によって抑制されることから、銀ナノ粒子暴露による遺伝子障害性に対する活性酸素種の関与が示唆された。
  日本学術振興会, 萌芽研究, 北海道大学, 19656129
• Evaluation of environmental chemical toxicity by using human DNA microarray analysis
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2005 - 2007
  OKABE Satoshi
  Carcinogenesis is an important chronic toxicity of heavy metals, although their mechanisms are still unclear. Comparison of gene expression patterns induced by heavy metals and model carcinogens would give an insight into understanding of their carcinogenic mechanisms. In this study, we examined the gene expression alteration in human hepatoma cell line, HepG2 following exposures of three heavy metals; arsenic, cadmium and nickel and three carcinogens; N-dimethylnitrosoamine (DMN), 12-O-tetradecanoylphorbol-13-acetate (TPA) and tetrachloroethylene (TCE) using DNA microarray with 8795 human genes. Of the genes altered by As, Cd and Ni exposure, 31-55% were overlapped with those by three model carcinogen exposures in our experiments. In particular, three heavy metals shared certain characteristics with TPA and TCE in remarkable up-regulations of the genes associated with progression of cell cycle, which might play a central role in heavy metal carcinogenesis.
  In addition, this characteristic of gene expression alteration was counteracted by intracellular accumulation of vitamine C in As-exposed cells but not in Cd- and Ni-exposed cells. These results suggest that the cell proliferative responses are caused by reactive oxygen species (ROS) mainly in As exposure, while other mechanisms would be involved in these responses in Cd and Ni exposures. Furthermore, based on the results of Q-PCR, the oncogene PTTG1, which was up-regulated by all carcinogenic chemicals in the array experiments, was up-regulated by heavy metals in a dose dependent manner, suggesting that this gene might be a useful biomarker for evaluation of carcinogenesis of heavy metals.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 17360250
• Identification and quantification of fecal pollutions by using genetic and chemical markers
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2003 - 2004
  OKABE Satoshi; KIMURA Katsuki
  Identification and quantification of microbial contaminants of fecal origin are major priority in the control of drinking and recreational water qualities. In this study, we proposed a new PCR-based approach using 16S rRNA gene markers of enteric anaerobes, Bacteroides-Prevotella spp for discriminating human, cow, and pig fecal contamination in environmental waters without culturing indicator organisms. One human-, three cow-, and two pig-specific Bacteroides-Prevotella 16S rRNA genetic markers were identified based on 16S rRNA gene clone libraries constructed from each fecal samples, respectively. Host-specific markers suggested that there are species composition differences in Bacteroides-Prevotella community in feces of each host species. Additionally, all host-specific genetic markers were detected in river water collected from area frequently contaminated with fecal pollution. We further developed a real-time polymerase chain reaction (qPCR) assay to quantify each host-specific genetic marker in fecal and environmental water samples. First we designed host-specific primers for the real-time PCR assay and validated their specificity on human, cow, and pig fecal samples. The real-time PCR detection of serially diluted DNA extracted DNA from pure cultured B.fragilis and plasmid DNAs was linear ranging from 4.0 to 4.0×10^5 copies/PCR and 6.0×10^1 to 6.0×10^8 copies/PCR, respectively. Using a simple filtration method, the quantification limit of newly developed qPCR assay was 10-70 genetic marker copies/100mL. Second, we applied this qPCR assay with each host-specific primer set to ratural river for over one year and confirmed that our qPCR assay could discriminate human, cow, and pig sources of fecal contamination with high specificity. These results implied that the qPCR assay described here should be widely applicable for monitoring spatial and temporal fluctuations in specific fecal contaminations in natural environments.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, 15360283
• Hybrid municipal wastewater treatment system for recovering the reclaimed water and phosphorous resource
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
  2002 - 2004
  WATANABE Yoshimasa; OKABE Satoshi; KIMURA Katsuki
  A novel membrane Bioreactor(MBR) in which nitrification and denitrification simultaneously proceed in a single reaction chamber has been proposed for advanced municipal wastewater treatment. Anoxia/aerobic conditions are separately created in the proposed MBR by inserting baffles inside of the membrane chamber and consequently simultaneous nitrification/denitriication can be carried out. The technology established in this study can easily be applied to almost all of existing MBR's. Pilot-scale experiment to examine performance of the proposed MBR was carried out at an existing municipal wastewater treatment plant. Inserting baffles inside the membrane chamber actually increased removal of nitrogen by 30%.
  In order to evaluate the reclaimed water quality, new method for detecting the indicator microorganisms. Molecular microbiological procedures such as T-RFLP and Real-Time PCR areused to detect the both bacteria. We can distinguish their original among human, cow and pig. We have successfully applied the new method in Toyohira River basin. Ortho-phosphate ion in aqueous solution could be effectively trapped in the zirconium sulfate-surfactant micelle mesostructure (ZS). The reaction proceeded through anion exchange between HSO_4-and OH-in ZS and HPO_3-. Maximum sorption capacity of ZS for HPO3-was330 μmol/gZS. This value is 1.6 times higher than the existing best sorbent. The microbial community structure of a pilot-scale conventional membrane bioreactor (CMBR), hybrid MBR (HMBR) and a full-scale activated sludge (AS) process, treating the same municipal wastewater, were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and fluorescence in situ hybridization (FISH) techniques. Both techniques demonstrated that the HMBR supported a significantly different microbial community structure comparing with the CMBR and with that of a full-scale AS process. FISH analysis revealed also that the population of Chloroflexi bacteria (formerly known as green nonsulfur bacteria), in the CMBR was four times greater than the HMBR and two times greater than the AS process.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), HOKKAIDO UNIVERSITY, 14205077
• バイオ燃料電池の開発
  2004
  Competitive research funding
• Development of microbial fuel cells
  2004
  Competitive research funding
• 世界の環境改善という視点から見た環境工学の未来とその発展のための政策提案
  科学研究費助成事業 基盤研究(C)
  2003 - 2003
  福士 謙介; 飯田 俊彰; 岡部 聡; 大瀧 雅寛; 滝沢 智; 徳永 光晴
  我が国の環境工学はこれまで一定の成果をあげてきた。そのおかげで、国民は衛生的かつ快適な生活を送り、世界の最長寿国として知られるようになった。また、生物が住めないような極度に汚染された河川・湖沼・海洋は日本中に存在しない。その一方で、目を東南アジア、南アジア、アフリカ、南アメリカなどに向けると、環境の崩壊は確実に進みつつある。
  本研究は世界に目を向けた場合、開発が必要である環境工学の諸分野とそのタスクを明らかにすることを第一の目的とした。次に、それらの研究開発(技術移転を含む)を効率的に行い、内外の研究者が開発に専一に取り組むための政府や助成団体ならびの大学の研究助成体制のあり方や総合的援助システムを提言することを第二の目的とした。最終的には本研究理念を具現化するための研究グループを立ち上げる為の活動を具体的に行う提案をする事を活動の最終的な目的とした。
  本研究活動として平成15年8月に北海道イトムカにおいて第1回ワークショップを合宿形式で開催した。約20名の若手研究者が集まり、次世代の環境工学について協議を行った。次に、タイ・バンコク市において外国の研究者を交えて第2回ワークショップを開催した。その結果平成16年度、文部科学省・科学技術振興調整費・我が国の国際的リーダーシップの確保のプログラムへ「アジアの持続的発展のための国際協議会企画」というプロジェクトの提案を行った。この提案課題は中堅〜若手の柔軟性のある研究者や実務者が参集し長時間にわたり、持続的な環境について協議する場を提案するもので、最終的にはアジアにおける、環境を中心テーマとした、いわゆるダボス会議(世界経済フォーラム年次総会)を目指す物である。
  日本学術振興会, 基盤研究(C), 東京大学, 15636011
• Phylogenetic identification and substrate uptake patterns of sulfate-reducing bacteria by MAR-FISH
  Grants-in-Aid for Scientific Research
  2001 - 2002
  OKABE Satoshi
  We simultaneously determined the phylogenetic identification and substrate uptake patterns of sulfate-reducing bacteria (SRB) inhabiting a sewer biofilm with oxygen, nitrate, or sulfate as electron acceptors by combining microautoradiography and fluorescenct in situ hybridization (MAR-FISH) with family- and genus-specific 16S rRNA probes. The MAR-FISH analysis revealed that Desulfobulbus hybridized with probe 660 was a dominant SRB subgroup in this sewer biofilm, which accounted for 23% of total SRB. Approximately 9% and 27% of Desulfobulbus detected with probe 660 could take up [^<14>C]propionate with oxygen and nitrate as electron acceptor, respectively, which might explain the high abundance of this species in various oxic environments. Furthermore, more than 40% of Desulfobulbus incorporated acetate into cells under anoxic conditions. SRB were also numerically important members of H_2-utilizing and [^<14>C]CO_2-fixing microbial populations in this sewer biofiim, which roughly acccunted for 42% of total H_2-utilizing bacteria hybridized with probe EUB338. A comparative 16S rDNA analysis revealed that two SRB populations, related to the Desulfomicrobium hypogeium and the Desultfovibrio desulfuricans MB lineages, were found to be important H_2-utilizers in this biofilms. Substrate uptake characteristics of different phylogenetic SRB subgroups was compared with the characteristics described to date. These results provide further insight into the correlation between 16S rRNA phylogenetic diversity and physiological diversity of SRB populations inhabiting sewer biofilms.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), HOKKAIDO UNIVERSITY, 13650593
• PCR-DGGE法による都市下水生物膜内の硝化細菌群の多様性評価
  科学研究費助成事業
  1999 - 2000
  岡部 聡
  本研究は、生物学的窒素除去プロセスを安定的に運転管理し、処理効率をより向上させることを目的として、16S rRNA遺伝子のクローニング解析とFISH法により都市下水生物膜内に存在する硝化細菌群の多様性を評価するとともに、in stiuでの優占種の動態解析を行うことを目的としたものである。16S rRNA遺伝子解析により都市下水中で培養された生物膜内ではNitrosomonas ureaeに近縁なクローン(相同性約96%)が、人工基質により培養された生物膜内では増殖速度の大きいNitrosomonas eutrophaに近縁な硝化細菌のクローン(約相同性96%)が高頻度で検出され、これら生物膜内のアンモニア酸化細菌の優占種と推定された。その他にも両生物膜より多種多様のアンモニア酸化細菌に近縁なクローンを検出することができた。さらにこの結果は人工基質によって培養されたことにより、優占種が変化したことを示唆しており、FISH法により生物膜形成過程におけるアンモニア酸化細菌の優占種の遷移について検討した。その結果、生物膜の形成とともにNso190とNsm156の両プローブではハイブリするがNEUではハイブリしないアンモニア酸化細菌(すなわちN.ureae)から、N.eutropha及びN.europaeaへのアンモニア酸化細菌の優占種が変化することを視覚的に示すことができた。この結果は16S rRNA遺伝子のクローニング解析の結果と一致するものであった。一方、亜硝酸酸化細菌に関しては生物膜内における存在比率が非常に小さく、本研究で用いた真正細菌に特異的なプライマーセットではその存在が確認できなかった。
  日本学術振興会, 奨励研究(A), 北海道大学, 11750483
• バイオフィルムの形成機構に関する研究
  2000
  Competitive research funding
• トキシコゲノミクスを用いた化学物質の毒性評価手法の開発
  2000
  Competitive research funding
• Study on biofilm development
  2000
  Competitive research funding
• Evaluation of chemical toxicity by using toxicogenomics
  2000
  Competitive research funding
• 16SrRNA蛍光遺伝子プローグと微小電極を用いた生物膜の構造と機能の解析
  科学研究費助成事業
  1997 - 1998
  岡部 聡
  本研究の目的は、安定した生物学的窒素除去を行うために、(1)混合系生物膜内in situでの硝化細菌の空間的分布及びその動態を微生物種レベルで明らかにすること、(2)硝化細菌分布と硝化活性との関係を明らかにすることである。更にこれら生物膜内のマイクロスケールの情報と生物膜全体の処理能力(メソスケール)との関係を明らかにすることである。本研究の結果は以下のようである。
  (1) アンモニア酸化細菌と亜硝酸酸化細菌に特異的な16S rRNA標的蛍光DNAプローブを用いたFluorescent in situ hybridization(FISH)法により、都市下水生物膜内における両硝化細菌の時間的・空間的分布の解析を行った。その結果、アンモニア酸化細菌は主に直径5-10μmの球状の密な集塊(クラスター)を形成して、生物膜中層及び底層部に多く存在することが明らかとなった。また亜硝酸酸化細菌に関しては、Nitrobacter属ではなくNitrospira属が優占種であり、これらの細菌はアンモニア酸化細菌クラスターの周辺に、比較的小さな集塊を形成して存在していた。このことは、アンモニア酸化細菌と亜硝酸酸化細菌の間で、効率の良いNO_2^-の授受が行われていることを示唆するものである。
  (2) 生物膜内in situにおける硝化活性を測定するために、先端径が5-10μmのDO,NH_4^+,NO_3^-,NO_2^-及びpH測定用の微小電極を開発した。これら微小電極を用いて生物膜内のアンモニア及び亜硝酸酸化活性分布を測定することが可能となった。生物膜内の硝化細菌分布と硝化活性分布を対応させることにより、生物学的硝化反応のより詳細なメカニズムが明らかとなった。
  日本学術振興会, 奨励研究(A), 北海道大学, 09750627
• Hybrid Wastewater Treatment System for Water Reuse and P Recovery
  Grants-in-Aid for Scientific Research
  1996 - 1998
  WATANABE Yoshimasa; KIMURA Katsuki; OKABE Satoshi; TADANO Toshiaki
  1) This research dealt with the coagulation characteristics of polysilicato-iron (PSI), a new inorganic polymer coagulant, when it was applied to coagulate algae and municipal wastewater. The experimental results obtained with jar tests indicate that PSI was more effective than PAC and AS in coagulating and separating Microcystis sp. and Stephanodiscus sp. When the jet mixed separator (JMS) was used as a unit of simultaneous flocculation and sedimentation, PSI had almost the same effect as PAC at the same dosage of 5 mg/l Al or Fe in coagulating municipal wastewater.
  2) This research has developed a novel membrane process in which ammonia oxidizers are fixed en the membrane disk. In this study, the characteristics of the membrane filtration resistance was investigated The results derived from this study were summarized as follows : (1) The magnitude of the filtration resistance was strongly affected by the initial inoculation. (2) The filtration resistance due to the accumulate cake was found to be dominant. (3) Increasing the disk rotational speed was found to be efficient for removing cake. About 3000 hours of the operation could be continued by only implementing this simple cleaning method every 500 hours. (4) Filtration resistance excluding the cake resistance seemed to be caused by humic substances and extracellular polymeric substance produced by biomass.
  3) The density of ammonia-oxidizers which formed dense cell cluster was about 5 times higher in the innermost biofilm than in the middle and surface of the biofilm. Due to the presence of ammonia-oxidizers throughout the biofilm, ammonium oxidation zone was expanded with increasing in oxygen penetration depth, which consequently resulted in an increase of the overall ammonium flux into the biofilm. Specific ammonium oxidation rate was dependent upon the density of ammonia-oxidizers.
  4) Phosphorus deficiency induces the synthesis of acid phosphatases in roots of lupin and other plant species. In this study we examined the induction of secretory acid phosphatase (S-Apase) at both the molecular and cellular levels. Lupin plants had increased levels of total acid phosphatase activity within two to five days after P was withered and levels approximately doubled by 15 days. Lateral roots and not main taproots were responsible for this increase in acid phosphatase activity. Immunoblot analysis using antibodies raised against a purified S-Apase showed that the synthesis of this protein was induced as early as 2 days in the P deficient treatment and that levels dramatically increased by 15 days. In contrast, no immunoreactive polypeptide was evident from crude extracts prepared from root tissues of-P treated plants.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, 08458160
• マンガン自触媒反応と嫌気性膜洗浄を利用した膜処理の効率化
  科学研究費助成事業
  1996 - 1997
  渡辺 義公; 鈴木 辰彦; 岡部 聡; 中埜渡 丈嘉
  除濁と溶解性マンガン除去を主目的とした、マンガン自触媒汚泥循環式MF膜処理装置に関する研究を、パイロットプラント実験により行った。得られた結果は下記のとおりである。
  (1) 生成した二酸化マンガンを含む自触媒汚泥は、粒径約3.3μmの粒子であった。本返送汚泥を塩素で活性化させた時の、溶解性マンガンの吸着等温式はフロントリッヒ型で近似された。
  (2) 原水にアンモニアが含まれると、クロラミン生成の方が早く進行し、その後溶解性マンガンの酸化が起こると考えられる。よって、溶解性マンガンの酸化除去には、クロラミン生成に要する塩素量以上を添加する必要がある。モノクロラミン生成に必要な塩素要求量を、添加塩素濃度から差引いた塩素濃度が0.5mg/l以上では、90%以上の溶解性マンガンの除去が可能であった。
  (3) 膜透過係数K_<20>はマンガン除去効率に影響された。マンガン除去効率が高い程、K_<20>は緩やかに減少した。
  (4) 膜モジュールに付着した金属類を調べると、適切な塩素添加率で運転され、マンガン除去性が良好な時は、膜に直接付着しているマンガン量は少なかった。塩素添加率が不十分でマンガン除去性が低下した時は、膜付着のマンガン量は1オーダー高い値となった。よって、原水に対し適切な運転条件が保持できれば、自触媒汚泥の循環により、膜面でのマンガンの析出は防止できる。
  日本学術振興会, 基盤研究(B), 北海道大学, 08555135
• 好気性生物膜内における硫黄(S)のサイクルに関する研究
  科学研究費助成事業
  1996 - 1996
  岡部 聡
  本研究では、反応槽におけるSの物質収支によってのみでは解明できない生物膜内の硫黄(S)の循環を明らかにするために、生物膜内の硫酸塩還元活性、硫黄酸化活性及び代謝産物である硫化化合物の濃度分布を測定した。研究の結果、以下のような知見を得た。
  (1)硫酸塩還元細菌及び硫黄酸化細菌の細菌密度分布と存在的な活性度分布
  硫酸塩還元細菌(SRB)は好気性生物膜表面部に最も多く存在し(5×10^5 MPN/cm^3程度)、膜深さ方向に減少した。硫黄酸化細菌も生物膜全体に一様に分布していた。硫酸塩還元活性は表層部ではほとんど検出されなかったが、表層部から徐々に増加し中層部(膜表面から300μm程度)で最大値(30μm/cm^3/h)を示した。膜表面でSRB菌体密度が高いにもかかわらず活性が低い原因は、表層部では溶存酸素(DO)濃度が高くSRB活性が抑制されているためと考えられる。膜深部でSRB活性は有機物律速のため再び低い値を示した。一方、硫黄脱窒細菌(SDB)活性は膜全体で一様に認められたが深部で最も高い値を示した。膜深部ではDO濃度が低くNO_3,H_2S濃度が比較的高く、SDBの増殖に有利であったと考えられる。
  (2)生物膜内の硫化化合物(S^0,FeS及びFeS_2)の濃度分布の測定
  生物膜厚が一定となった実験開始から30日目の生物膜内の硫化化合物(S^0,FeS及びFeS_2)の濃度分布を測定した。S^0はFeS及びFeS_2に比較して、膜全体に30μmol-S/cm^3程度蓄積していた。これは硫酸塩還元活性により生成されたH_2Sの生物化学的酸化に起因するものと思われる。FeSはSRB活性の高かった膜表面から250μm付近で著しいピークを示し、表層部及び深層部では検出されなかった。
  以上の結果をまとめると、好気性生物膜内にも絶対嫌気性細菌であるSRBが存在すること、また測定された硫化化合物の濃度分布とSRB及びSDBの活性度分布との間には良い相関関係が見られたことから500μm程度の好気性生物膜内にの硫黄循環が存在することが明らかとなった。
  日本学術振興会, 奨励研究(A), 北海道大学, 08750661
• Simulation of the operational conditions of the full-scale municipal wastewater treatment plant to improve the performance of nutrient removal
  Grants-in-Aid for Scientific Research
  1995 - 1996
  TAKAKUWA Tetsuo; OKABE Satoshi; FUNAMIZU Naoyuki
  Simulation analysis based on a mathematical model is one of the powerful tools for determining the operational conditions for a full scale biological nutrient removal plant. The model that included the Activated Sludge Model No.2 was developed for simulating the performance of the plant in Sapporo City. The investigated plant has the biological reaction basin which consists of the four zones, anaerobic-aerobic-anoxic-aerobic phases with the step feed of the primary effluent to the anaerobic and anoxic zones. We performed three experiments to calibrate and verify our model : (i) Characterization of organic matters in the influent of the reaction basin with the OUR measurement method ; (ii) Measurement of COD and nutrient concentration at the plant ; (iii) Lab-scale batch experiments with the anaerobic-aerobic-anoxic-aerobic phases. The calibrating process of the model showed that no modification of parameter values was required to evaluate the performance of the plant and population of the activated sludge. Simulated results showed that the choice of the sewage step feed ratio did not affect the nitrogen removal and that the denitrification rate in the anoxic zone was controlled by the hydrolysis rate of the slowly biodegradable organic matters. The results of the lab-scale experiment and simulation results showed that the addition of the readily biodegradable organic matters like fermentation products of the primary settler sludge was effective to improve the performance of nitrogen removal.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 07650632
• 混合系生物膜内の硝化菌と他栄養性細菌の競合に関する研究
  科学研究費助成事業
  1995 - 1995
  岡部 聡
  本年度は前処理なしで生物膜を膜深さ方向に10-50μm間隔でスライスできるマイクロスライサ-^を用いて次の3点、(1)細菌密度分布と生物膜の処理特性の関係、(2)流入基質C:N比の硝化菌密度分布に与える影響、(3)In Situでの細菌活性密度分布の測定、について検討した。その結果以下のような知見が得られた。
  (1)細菌密度分布と生物膜の処理特性の関係 生物膜内の全硝化細菌数は同じであっても、膜深さ方向の密度分布が異なれば生物膜へのアンモニアfluxが異なる結果を得た。つまり硝化細菌が膜深部に優占的に存在する場合(例えば有機物負荷が高い場合、C:N=1.5)のアンモニアfluxは生物膜全体に一様に分布する場合(例えばC:N=0,0.25)に比べて約25%低い値を示した。この結果より生物膜の基質消費速度などの動力学的係数を正確に求めるためには、生物膜内の菌体量のみでなくその膜深さ方向の密度分布も測定しなければならないと考えられる。
  (2)流入基質C:N比の硝化菌密度分布に与える影響 流入基質C:N=1.5の場合、硝化細菌は膜深部に優占的に存在し膜表面では深部の1/100-1/1000程度しか存在しておらず膜深さ方向に険しい密度勾配を形成した。一方、C:N=0,0.25の場合においては、C:N=1.5で見られたような膜深さ方向の密度勾配は存在せず、生物膜全体に一様に分布していた。この結果からC:N=1.5の場合には、硝化細菌と他栄養性細菌が溶存酸素と空間をめぐって競合し、増殖速度の遅い硝化細菌は生物膜表面では存在することができず膜深部のみに存在可能であることが明らかとなった。
  (3)In Situでの細菌活性密度分布の測定 テトラゾリウム塩還元法を用いて生物膜内の細菌活性密度分布を測定した。生物膜表面では活性菌は全細菌数の35±13%であり、膜深さ方向に徐々に減少し膜深部では15±4%となった。故に生物膜内には多くの不活性細菌が存在することが明らかとなった。
  日本学術振興会, 奨励研究(A), 北海道大学, 07750632
• 上向流のバイオフィルターによる都市下水処理に関する研究
  科学研究費助成事業
  1994 - 1994
  岡部 聡
  生物膜による濾過作用と吸着作用により下水中の懸濁性汚濁物を除去し,生物学的酸化作用により溶解性有機物とアンモニア性窒素の酸化を目的とする上向流バイオフィルターを用いて都市下水処理に関する研究を行い以下のような結果を得た。上向流バイオフィルターは装置下部より導入された空気が形成された生物膜によって抑留され空気層を形成するという効率的な曝気機構を持ったため、比較的少ない曝気量(曝気量:下水流量比,A/W=2)で高い槽内DO濃度を得ることができた.そのためBOD,SS,濁度の除去及び硝化率はHRT=5hr(水量負荷=86L/m^2・d)でそれぞれ80%以上と良好な処理水が得られた.フィルター枚数を増加させれば,抑留させる空気層が増加するとともに水量負荷が軽減され,有機物酸化が促進される.そのため,装置後段で高いDO濃度が維持され硝化は促進された.生物膜に抑留された懸濁性有機物は可溶化され生物学的に酸化されるため.余剰汚泥の発生量は少なく,フィルターの目詰まりもほとんど生じなかった.本装置はまだフィルター枚数を増加させることが可能であり,更に処理効率の向上が期待できる.槽内全体に各種細菌(硝化菌及び他栄養性細菌)が棲息しており,運転条件を適切に操作することにより脱窒も可能となることが示唆された.また本法は流入負荷変動に対して十分に対応可能であった.本研究で行った実験条件では,単一槽での最大窒素除去率は曝気位置を最下部に置き,処理水の返送比=1:3,曝気量=360mL/minで50%程度が得られた.上向流バイオフィルターを多段に連結するまたは他の下水処理プロセスと併用する事により,更に安定した処理効率が期待できると思われる.上向流バイオフィルターは構造上の利点より建設・運転費が安価であり維持管理も容易であるため,小規模下水処理システムや合併浄化槽への適用が今後期待できる.
  日本学術振興会, 奨励研究(A), 北海道大学, 06750592
• Sewage treatment system combining upgraded RBC and jet mixed separator
  Grants-in-Aid for Scientific Research
  1992 - 1993
  MASUDA Sumio; OKABE Satoshi; WATANABE Yoshimasa
  This research deals with the experimental results obtained by the pilot plant of an upgraded Rotating Biological Contactor(RBC). This is a two-story RBC which is designed to simultaneously achieve the biological oxidation and removal of detached biomass in the trough. The authors constructed a three-stage pilot plant with an octagonal stainless mesh contactor 2 m across to collect the design information of an upgraded RBC.The municipal wastewater treatment was conducted to examine the RBC's performance. According to experimental results, with a contactor rotating speed of 2 rpm, the effluent TOC and NH_4-N concentrations were about 10 g/m^3 and 5 g/m^3, respectively, at the hydraulic loading of 70 L/m^2/d, corresponding to a BOD loading of about 8 g/m^2/d. The electrical power consumption of the RBC was 0.005 kwh/m^2/d at a contactor rotating speed of 1 rpm. A jet mixed separator (JMS) was used as the physico-chemical pre-treatment unit of the RBC.With the addition of a coagulant, simultaneous flocculation and sedimentation of the suspended particles occurred in the JMS.This combined system of the JMS and RBC produced a clean effluent.
  Japan Society for the Promotion of Science, Grant-in-Aid for Developmental Scientific Research (B), Miyazaki University, 04555136
• 生物膜の機能と生態学的構造に関する研究
  Competitive research funding
• Biofilm structure and function
  Competitive research funding