2023年03月, 日本水環境学会, 学生ポスター発表賞（ライオン賞）　　　　　　　　　　　　　　　
DHSろ床を用いたPET原料製造廃水処理UASB反応器の後段処理技術の開発
髙井麻帆;中屋佑紀;佐藤久;相沢智康;大西裕季;熊木康裕;成廣隆;黒田恭平

2023年03月, 日本水環境学会, 学生ポスター発表賞（ライオン賞）　　　　　　　　　　　　　　　
緑色蛍光タンパク質遺伝子導入大腸菌を用いた活性汚泥フロックの大腸菌吸着部位の解明
石崎翔大;石塚祐介;樋口宏介;押木守;中屋佑紀;佐藤久

2022年11月, 日本微生物生態学会, 優秀ポスター賞　　　　　　　　　　　　　　　
金ナノ粒子プローブを用いた環境中微生物の簡易核酸分析法の開発
中島 芽梨;中屋佑紀;黒田恭平;成廣隆;佐藤久

2022年11月, 日本微生物生態学会, 優秀ポスター賞　　　　　　　　　　　　　　　
PCRフリーの金ナノ粒子プローブ法を用いた廃水処理汚泥中のPatescibacteriaとメタン生成アーキアの迅速定量の試み
半田 久純;中島 芽梨;黒田 恭平;成廣 隆;佐藤 久

2022年08月, 日本下水道協会, 下水道研究発表会口頭発表優秀賞　　　　　　　　　　　　　　　
活性汚泥診断の自動化に向けたフロック定量化技術の開発
間嶋義喜;野田周平;松代武士;平岡由紀夫;佐藤久

2021年03月, 日本水環境学会, 年会優秀発表賞（クリタ賞）　　　　　　　　　　　　　　　
光導波路分光装置を用いた下水処理プロセスの微生物モニタリング
中島芽梨;佐藤久平野麗子;高橋浩三

2020年05月, 日本下水道協会, 令和2年度 優秀論文 学術部門　　　　　　　　　　　　　　　
特定酵素蛍光基質を用いた下水中の大腸菌群の簡易迅速測定法の開発
佐藤久;津田収;菊地凱;平野麗子

2020年03月, 日本水環境学会, 年会学生ポスター発表特別賞(ライオン特別賞)　　　　　　　　　　　　　　　
ディープラーニングを用いた活性汚泥フロックの認識
柏本ゆかり;佐藤久

2020年01月, 化学系学協会北海道支部, 優秀講演賞（ポスター部門）　　　　　　　　　　　　　　　
金ナノ粒子を用いた細菌の16S rRNAの比色分析
中島芽梨・北大;平野麗子・セルスペクト株式会社;佐藤久・北大

2019年12月, 土木学会, 環境工学研究フォーラム優秀ポスター発表賞　　　　　　　　　　　　　　　
金ナノ粒子を用いた 16S rRNA をターゲットとした細菌の比色分析
中島芽梨

2019年12月, 土木学会, 土木学会環境工学研究フォーラム環境技術・プロジェクト賞　　　　　　　　　　　　　　　
ディープラーニングを用いた画像認識による活性汚泥中微生物の検出
柏本ゆかり

2019年07月, 日本水環境学会, The WET Excellent Presentation Award at WET2019　　　　　　　　　　　　　　　
松永 光司

2018年12月, 土木学会, 土木学会環境工学研究フォーラム環境技術・プロジェクト賞　　　　　　　　　　　　　　　
三価と五価のヒ素を分別定量可能な新規光学的簡易バイオセンサーの開発
松永光司

2018年07月, 下水道研究発表会, ポスター発表優秀賞　　　　　　　　　　　　　　　
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

2018年03月, 日本水環境学会, 年会優秀発表賞（クリタ賞）　　　　　　　　　　　　　　　
DNAアプタマーを用いた簡易ヒ素分析法の開発
松永光司

2017年11月, 土木学会, 土木学会環境工学研究フォーラム環境技術・プロジェクト賞　　　　　　　　　　　　　　　
DNAアプタマーを用いた簡易ヒ素分析法の開発
松永光司

2017年11月, 土木学会, 土木学会環境工学研究フォーラム優秀ポスター発表賞　　　　　　　　　　　　　　　
菊地凱

2017年10月, 土木学会, 環境工学研究フォーラム環境技術・プロジェクト賞　　　　　　　　　　　　　　　
特定酵素蛍光基質を用いた簡易大腸菌数測定法の開発
片寄由貴

2017年03月, 水環境学会, 年会学生ポスター発表賞（ライオン賞）　　　　　　　　　　　　　　　
山口拓郎

2017年03月, 水環境学会, 年会優秀発表賞（クリタ賞）　　　　　　　　　　　　　　　
奥山優

2015年03月, 水環境学会, 年会優秀発表賞（クリタ賞）　　　　　　　　　　　　　　　
山田健太

2014年09月, 水環境学会, 博士研究奨励賞（オルガノ賞）　　　　　　　　　　　　　　　
羽深 昭

2014年03月, 水環境学会, 年会優秀発表賞（クリタ賞）　　　　　　　　　　　　　　　
坂槙有紀恵

2014年01月, 土木学会, 環境工学フォーラム論文奨励賞　　　　　　　　　　　　　　　
羽深 昭

2013年01月, 日本化学会, 優秀論文　　　　　　　　　　　　　　　
BODIPY-based ratiometric fluoroionophores with bidirectional spectral shifts for the selective recognition of heavy metal ions
佐藤 久

2012年06月, Best Presentation Award at WET2012　　　　　　　　　　　　　　　
佐藤 久

2011年11月, 土木学会環境工学研究フォーラム優秀ポスター発表賞　　　　　　　　　　　　　　　
日本国

2011年10月, Best Student Award　　　　　　　　　　　　　　　

2010年06月, WET2010 Best Presentation Award　　　　　　　　　　　　　　　

2008年01月, IWA, Paper Award at IWA Biofilm Technologies Conference　　　　　　　　　　　　　　　

2006年05月, 第5回インテリジェント・コスモス奨励賞　　　　　　　　　　　　　　　
佐藤 久

2005年06月, 日本水環境学会論文奨励賞（廣瀬賞）　　　　　　　　　　　　　　　
佐藤 久

2004年11月, 土木学会環境工学研究フォーラム優秀ポスター発表賞　　　　　　　　　　　　　　　
佐藤 久

2003年09月, 土木学会年次学術講演会優秀講演者賞　　　　　　　　　　　　　　　
佐藤 久

1997年09月, 土木学会年次学術講演会優秀講演者賞　　　　　　　　　　　　　　　
佐藤 久

Physicochemical parameters affecting the adhesion of ciprofloxacin-resistant Escherichia coli to activated sludge.
Yuki Nakaya, Natsumi Nagahashi, Reiko Hirano, Yusuke Ishizuka, Hisashi Satoh
Water science and technology : a journal of the International Association on Water Pollution Research, 89, 9, 2457, 2467, 2024年05月, ［国際誌］
英語, 研究論文（学術雑誌）, To investigate the physicochemical conditions necessary to stably remove antibiotic-resistant bacteria (ARB) via contact with activated sludge (AS), the adhesion of ciprofloxacin (CIP)-resistant and -susceptible Escherichia coli to AS was simulated by contact tests in the laboratory. The CIP-resistant E. coli and susceptible E. coli were removed by a 3 log smaller concentration by a 5 h contact test at maximum. Considering the hydraulic retention time of a reaction tank (∼5 h) and step-feeding operation, we considered the removal rate of E. coli in the current simulated contact test to be in agreement with the actual situation where 1-2 log concentrations of E. coli were reported to be removed from an AS reaction tank. With the increase in the AS concentration and/or dissolved oxygen, the removal rate of E. coli increased. The removal rate of CIP-resistant E. coli was greater than that of susceptible E. coli under all experimental conditions. Although the mechanism by which CIP-resistant E. coli preferably adhered to AS was not clearly understood in detail, finding optimum conditions under which bacteria, including ARB, were efficiently removed by the AS process may be possible.

Development of an internal two-stage upflow anaerobic reactor integrating biostimulation strategies to enhance the degradation of aromatic compounds in wastewater from purified terephthalic acid and dimethyl terephthalate manufacturing processes
Kyohei Kuroda, Maho Takai, Takeo Sekiguchi, Tomoya Ikarashi, Hazuki Kurashita, Meri Nakajima, Masaru K. Nobu, Masashi Hatamoto, Takashi Yamaguchi, Yuki Nakaya, Hisashi Satoh, Masahito Yamauchi, Masayoshi Yamada, Takashi Narihiro
Water Research, 258, 121762, 121762, Elsevier BV, 2024年05月, ［国際誌］
英語, 研究論文（学術雑誌）, In this study, we aimed to establish high-rate biological treatment of purified terephthalic acid (PTA) and dimethyl terephthalate (DMT) wastewater that minimizes the inhibitory effects of high concentration benzoate and acetate. To achieve this, we developed a novel bioreactor system and biostimulation strategy. An internal two-stage upflow anaerobic (ITUA) reactor was operated with (i) a packed bed containing green tuff medium underlying (ii) a compartment seeded with anaerobic granular sludge. Ethylene glycol was amended to stimulate syntrophic interactions. Continuous operation of the system for 1,026 days achieve an organic removal rate of 11.0 ± 0.6 kg COD/m3/d. The abundance of aromatic degraders significantly increased during operation. Thus, we successfully developed a high-rate treatment system to treat wastewater from the PTA/DMT manufacturing processes by activating syntrophs in an ITUA reactor.

Microbiological insights into anaerobic phenol degradation mechanisms and bulking phenomenon in a mesophilic upflow anaerobic sludge blanket reactor in long-term operation
Kyohei Kuroda, Ryota Maeda, Futaba Shinshima, Kampachiro Urasaki, Kengo Kubota, Masaru K. Nobu, Taro Q.P. Noguchi, Hisashi Satoh, Masahito Yamauchi, Takashi Narihiro, Masayoshi Yamada
Water Research, 253, 121271, 121271, Elsevier BV, 2024年02月, ［国際誌］
英語, 研究論文（学術雑誌）, In this study, a long-term operation of 2,747 days was conducted to evaluate the performance of the upflow anaerobic sludge blanket (UASB) reactor and investigated the degradation mechanisms of high-organic loading phenol wastewater. During the reactor operation, the maximum chemical oxygen demand (COD) removal rate of 6.1 ± 0.6 kg/m3/day under 1,680 mg/L phenol concentration was achieved in the mesophilic UASB reactor. After a significant change in the operating temperature from 24.0 ± 4.1 °C to 35.9 ± 0.6 °C, frequent observations of floating and washout of the bloated granular sludge (novel types of the bulking phenomenon) were made in the UASB reactor, suggesting that the change in operating temperature could be a trigger for the bulking phenomenon. Through the metagenomic analysis, phenol degradation mechanisms were predicted that phenol was converted to 4-hydroxybenzoate via two possible routes by Syntrophorhabdaceae and Pelotomaculaceae bacteria. Furthermore, the degradation of 4-hydroxybenzoate to benzoyl-CoA was carried out by members of Syntrophorhabdaceae and Smithellaceae. In the bulking sludge, a predominant presence of Nanobdellota, belonging to DPANN archaea, was detected. The metagenome-assembled genome of the Nanobdellota lacks many biosynthetic pathways and has several genes for the symbiotic lifestyle such as trimeric autotransporter adhesin-related protein. Furthermore, the Nanobdellota have significant correlations with several methanogenic archaea that are predominantly present in the UASB reactor. Considering the results of this study, the predominant Nanobdellota may negatively affect the growth of the methanogens through the parasitic lifestyle and change the balance of microbial interactions in the granular sludge ecosystem.

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, ycad007, Oxford University Press (OUP), 2024年01月01日, ［国際誌］
英語, 研究論文（学術雑誌）, 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).

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, 136, 6, 430, 437, Elsevier BV, 2023年11月, ［国内誌］
英語, 研究論文（学術雑誌）, Nitrosomonas europaea, an aerobic ammonia oxidizing bacterium, is responsible for the first and rate-limiting step of the nitrification process, and their ammonia oxidation activities are critical for the biogeochemical cycling and the biological nitrogen removal of wastewater treatment. In the present study, N. europaea cells were cultivated in the inorganic or organic media (the NBRC829 and the nutrient-rich, NR, media, respectively), and the cells proliferated in the form of planktonic and biofilm in those media, respectively. The N. europaea cells in the biofilm growth mode produced larger amounts of the extracellular polymeric substances (EPS), and the composition of the EPS was characterized by the chemical analyses including Fourier transform infrared spectroscopy (FT-IR) and 1H-nuclear magnetic resonance (NMR) measurements. The RNA-Seq analysis of N. europaea in the biofilm or planktonic growth mode revealed that the following gene transcripts involved in central nitrogen metabolisms were abundant in the biofilm growth mode; amo encoding ammonia monooxygenase, hao encoding hydroxylamine dehydrogenase, the gene encoding nitrosocyanine, nirK encoding copper-containing nitrite reductase. Additionally, the transcripts of the pepA and wza involved in the bacterial floc formation and the translocation of EPS, respectively, were also abundant in the biofilm-growth mode. Our study was first to characterize the EPS production and transcriptome of N. europaea in the biofilm and planktonic growth mode.

A simple and rapid method for detecting fecal pollution in urban rivers by measuring the intrinsic β-D-glucuronidase activity of Escherichia coli
Mohomed N.M. Shayan, Yuna Tanaka, Reiko Hirano, Yuki Nakaya, Hisashi Satoh
Water Research, 246, 120689, 120689, Elsevier BV, 2023年11月, ［国際誌］
英語, 研究論文（学術雑誌）, As urban rivers are domestic, industrial, and agricultural water resources, fecal pollution poses human health and environmental risks. In this study, we developed a simple and rapid method to detect fecal pollution in urban rivers. Water samples were mixed with liquid medium, including a fluorescent substrate and fluorescence intensity (F.I.) was measured using a microplate reader to determine Escherichia coli (E. coli) β-D-glucuronidase (GUS) activity instead of E. coli concentration. GUS activities measurements in pure E. coli cultures revealed that E. coli incubated with a GUS substrate accumulated GUS enzymes in their cells, whereas those incubated without a GUS substrate did not. The increase in GUS activity corresponded to the proliferation of E. coli and the GUS activity increased linearly even during the lag growth phase of E. coli, indicating the presence of intrinsic GUS (iGUS) in E. coli cells before incubation. iGUS activity persisted at 81 % in the chlorinated samples, even though the E. coli concentration was reduced by a factor of 106. The iGUS activity persisted for approximately three days. Therefore, we assumed that E. coli present in fecal contaminants, in which GUS substrates are present, could be distinguished from those surviving in the natural environment for three days or longer by measuring iGUS activity. River water samples were collected upstream and downstream of the discharge outlets of municipal wastewater treatment plants and a combined sewer outlet. The iGUS activities were <0.24 mMFU/mL for the upstream samples and >0.21 mMFU/mL for the downstream samples. Interestingly, E. coli concentrations were not necessarily associated with fecal pollution. This indicates that by setting a threshold for iGUS activity, our method can be used as a simple and rapid method for detecting fecal pollution in urban rivers. Because the limit of detection for our method is 20 CFU/mL, our method is applicable to detecting high fecal pollution in a small river.

Analysis of Unamplified 16S rRNA of Ammonia-Oxidizing Bacteria in Activated Sludge by Spectrophotometry Using Gold Nanoprobes
Meri Nakajima, Reiko Hirano, Yuki Nakaya, Hisashi Satoh
ACS ES&T Water, American Chemical Society (ACS), 2023年08月23日
研究論文（学術雑誌）

Tracing morphological characteristics of activated sludge flocs by using a digital microscope and their effects on sludge dewatering and settling
Yuki Nakaya, Jinming Jia, Hisashi Satoh
Environmental Technology, 45, 20, 1, 11, Informa UK Limited, 2023年08月04日, ［国際誌］
英語, 研究論文（学術雑誌）, ABSTRACTIn wastewater treatment by the activated sludge (AS) process, settleability and dewaterability of AS are key issues that are directly related to the treated water quality and sludge treatment costs. Several studies investigated the relationship between the shape of AS flocs and their settling/dewatering property. To quantify the floc morphology, it is imperative to attach a camera to a microscope or move the stage manually. Hence, labour and equipment costs may increase. In this study, by combining a digital microscope and an automatic stage, more than 100 magnified floc images were rapidly obtained from one AS sample dropped on a slide glass, and shape parameters were collectively calculated using an analysis software. During 1-year monitoring of four wastewater treatment plants in Sapporo City (Hokkaido, Japan), the morphological parameters and extracellular polymeric substances (EPS) quantity/quality of AS were analyzed on the basis of their correlation to the time to filtration (TTF) and sludge volume index (SVI), which are indicators for describing the dewatering and settling properties of AS, respectively. In one plant, larger, denser, and smoother flocs tended to contain less EPS and exhibited better sludge dewaterability. In another plant, larger, denser, and smoother flocs were considered to contribute to better settlement. Especially, an equivalent high-density floc diameter and the ratio of mixed liquor suspended solids (MLSS) concentration to the total floc area were commonly suggested to explain AS dewaterability and settleability.

Candidate phyla radiation (CPR)/Candidatus Patescibacteriaの実態を廃水処理システムの視点から理解する
黒田 恭平, 成廣 隆, 藤井 直樹, 中島 芽梨, 景政 柊蘭, 中井 亮佑, 佐藤 久, 久保田 健吾, 金田一 智規
日本微生物生態学会誌, 38, 1, 2, 13, 日本微生物生態学会, 2023年03月01日
日本語

Highly sensitive and homogeneous detection of unamplified RNA based on the light scattering properties of gold nanoparticle probes
Hisashi Satoh, Meri Nakajima, Reiko Hirano, Yuki Nakaya
Biosensors and Bioelectronics: X, 12, 100249, 100249, Elsevier BV, 2022年12月
研究論文（学術雑誌）, 40558276

Elucidation of the biodegradation pathways of bis(2-hydroxyethyl) terephthalate and dimethyl terephthalate under anaerobic conditions revealed by enrichment culture and microbiome analysis
Kyohei Kuroda, Takashi Narihiro, Yuki Nakaya, Taro Q.P. Noguchi, Ryota Maeda, Masaru K. Nobu, Yuki Ohnishi, Yasuhiro Kumaki, Tomoyasu Aizawa, Hisashi Satoh
Chemical Engineering Journal, 450, 1, 137916, 137916, Elsevier BV, 2022年11月, ［査読有り］
英語, 研究論文（学術雑誌）, With the globally rising usage of plastics, including polyethylene terephthalate (PET), the environmental risk that disposal of waste plastics to landfills and discharge of microplastics to the marine environment pose have also increased. For example, observation of animal ingestion of fragmented waste plastics (micro-and nano-plastics) has driven awareness for the need of proper environmental risk assessment. In evaluating the biodegradability of PET-derived byproducts and their precursors, most work has focused on hydrolytic enzymes and aerobic or-ganisms that possess such genes, but only few reports on biodegradation in the absence of oxygen (i.e., anaerobic) are available. Here, to elucidate the fate of PET-derived materials under anaerobic environments, a sludge -derived microbial community was cultured with bis(2-hydroxyethyl) terephthalate (BHET) as a model sub-strate for byproducts of PET degradation and dimethyl terephthalate (DMT) as a potential environmental pollutant discharged from the PET manufacturing process. Metagenome-and metabolome-informed microbiome analyses identified anaerobic BHET and DMT degradation pathways, uncultured organisms affiliated with Spi-rochaetota and Negativicutes predominant in the BHET-fed cultures, and Methanomethylovorans and Trepone-ma_G predominant in the DMT-fed cultures. Metagenomic analyses newly identified three BHET-degrading and two DMT-degrading enzymes from the genomes of Spirochaeota. In addition, the Negativicutes in the BHET enrichment cultures possessed genes for acetogenically metabolizing EG and/or ethanol. Overall, this study successfully established anaerobic BHET-and DMT-degrading microbial consortia and newly proposed these degradation mechanisms under anaerobic conditions. This study indicated that the cultivation, microbiome, and metabolome analyses can be powerful tools for elucidating consortia capable of degrading plastics-associated waste compounds and the relevant metabolic mechanisms., 40558276

Separate determination of arsenite and arsenate in groundwater samples by simple analytical methods
Koji Matsunaga, Yuki Nakaya, Hisashi Satoh
Water Supply, 22, 10, 7635, 7642, IWA Publishing, 2022年09月17日, ［査読有り］
英語, 研究論文（学術雑誌）, Abstract

We investigated the interaction of As(III) with As(III)-binding DNA aptamers (Ars-3). The binding of Ars-3 to As(III) was investigated using an Ars-3 sequence and a few control DNA sequences. As a result, we conclude that Ars-3 cannot bind As(III) and As(III) can adsorb onto gold nanoparticles with selectivity. However, the As(III) concentration could be determined by a simple As(III) analysis method using Ars-3, and we measured the As(III) and As(V) concentrations separately in As(III)/As(V) mixed samples in ultrapure water and groundwater using a simple analytical method for As(III) and As(V), respectively. As(III) in the sample was measured by a simple As(III) analytical method using DNA aptamers and gold nanoparticles, and As(V) in the sample was measured by a simple As(V) analysis method using cerium oxide nanoparticles and fluorescence-labeled DNA. We can measure As(III) and As(V) concentrations in ultrapure water and groundwater in the simple analytical method for As(III) and As(V), separately., 40558276

Screening Antibiotic-Resistant Escherichia coli in Wastewater and River Water Using a Novel Simple Phenotypic Antibiotic-Susceptibility Testing Method
Hisashi Satoh, Natsumi Nagahashi, Kai Kikuchi, Reiko Hirano
ACS EST Water, 2, 8, 1301, 1308, American Chemical Society (ACS), 2022年06月27日, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）, 40558276

Development of the simple analytical method for determination of arsenate(V) ion using fluorescence-labeled DNA and cerium oxide nanoparticles
Koji Matsunaga, Hisashi Satoh, Reiko Hirano
Water Supply, 22, 5, 5524, 5534, IWA Publishing, 2022年03月24日, ［査読有り］
英語, 研究論文（学術雑誌）, Abstract

Arsenic (As) contamination in groundwater presents a major health and environmental concern. As is found in two oxidation states and most chemical tests for inorganic arsenic are focused on As(III), and few have been developed for As(V). We developed the simple analytical method for determining As(V) concentrations in groundwater using CeO2NPs and fluorescein (FAM)-labeled DNA. Prior to sample measurements, we investigated the key operational parameters that affect the sensing performance. The optimal CeO2NPs final concentration, FAM-labeled DNA final concentration, the sequence and length of FAM-labeled DNA, and incubation time were 15 μg/mL, 400 nM, 6-mer poly-cytosine sequence, and 6 min, respectively. After optimizing the parameters, the total analysis time was about 20 min and the limit of detection was 0.61 μM. This method has a high selectivity against the same concentrations of Cu(II), Cd(II), Hg(II) and Pb(II). Pretreatment by cation extraction to remove interfering ions was beneficial for determination of As(V) concentrations in groundwater containing a variety of metal cations at high concentration. We could determine As(V) concentration in groundwater. Modification of the reactions of the method is necessary. This study provides the first step in the development of a simple method for on-site As(V) analysis., 40558276

Simple enumeration of Escherichia coli concentrations in river water samples by measuring β-d-glucuronidase activities in a microplate reader
Hisashi Satoh, Yutaka Katayose, Reiko Hirano
Water Science and Technology, 83, 6, 1399, 1406, IWA Publishing, 2021年03月15日, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）,
Monitoring of Escherichia coli concentrations in river water (RW) is essential to identify fecal pollution of the river. The objective of this study was to assess the suitability of a novel, simple and high throughput method developed in our laboratory to enumerate E. coli concentrations in RW samples. The method is based on the use of the synthetic substrate specific for the β-d-glucuronidase (GUS) produced by E. coli. GUS activities and E. coli concentrations were monitored at eight selected sites in rivers running through Sapporo, Japan. Because the fluorescence intensities of the synthetic substrate in the RW samples increased linearly over a 4-h incubation period, we could estimate the GUS activities of the RW samples. The GUS activities were highly correlated with E. coli concentrations at &gt;100 most probable numbers 100 mL−1 with a correlation coefficient of 0.87. The GUS activities of the RW samples collected from all sampling sites fitted well to a single correlation equation, which indicates that it was applicable to the estimation of E. coli concentrations regardless of the sampling sites. This method is simple, rapid, reliable, inexpensive, and high throughput, and is therefore useful for monitoring E. coli in RW., 13465201

Bubble drag in electrolytically generated microbubble swarms with bubble-vortex interactions
Yasunori Watanabe, Haruhi Oyaizu, Hisashi Satoh, Yasuo Niida
International Journal of Multiphase Flow, 136, 103541, 103541, Elsevier BV, 2021年03月, ［査読有り］
英語, 研究論文（学術雑誌）, Air bubbles entrained in ocean breaking waves play various roles in air-sea gas transfer, wave energy dissipation, and surface layer mixing. While sub-mm bubbles dominate the distribution of sizes observed in bubble plumes created by breaking waves, the dynamics of such microbubbles in a swarm are poorly understood, and most previous experimental and computational studies have focused on the behavior of homogeneous swarms of larger mm-scale bubbles for industrial applications. Here, we propose novel probabilistic empirical models of rise velocity and bubble drag for a microbubble swarm incorporating bubble- vortex interactions. These are based on image measurements of the motion of electrolytically generated microbubbles. We found that convective interactions between bubbles and vortex-induced flows, that is, Rayleigh-Taylor instability caused by density difference near the electrodes, induce counter-rotating vortices that accelerate bubbles and align them along paths in the flow induced between them, resulting in an increase in rise velocity and its variance in the statistical equilibrium state. We describe the statistical features of bubble rise in such swarms in our proposed empirical model and deduce its optimal parameters. We anticipate our findings being a starting point for understanding behaviors of oceanic bubbles possessing an analogous size distribution to the present electrolytically generated microbubbles.(c) 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Deep learning-based morphology classification of activated sludge flocs in wastewater treatment plants
Hisashi Satoh, Yukari Kashimoto, Naoki Takahashi, Takashi Tsujimura
Environmental Science: Water Research & Technology, Royal Society of Chemistry (RSC), 2021年, ［筆頭著者, 責任著者］
研究論文（学術雑誌）,

A deep learning-based two-label classifier 1 recognized a 20% morphological change in the activated flocs. Classifier-2 quantitatively recognized an abundance of filamentous bacteria in activated flocs.

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, Elsevier BV, 2021年01月, ［査読有り］, ［責任著者］, ［国際誌］
英語, 研究論文（学術雑誌）, 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.

下水中の細菌の16S rRNA検出用ペーパー分析チップの開発
中島芽梨, 石田晃彦, 渡慶次学, 佐藤久
分析化学, 69, 12, 715, 722, JAPAN SOC ANALYTICAL CHEMISTRY, 2020年12月, ［査読有り］, ［責任著者］
日本語, 研究論文（学術雑誌）, Analysis of bacteria in the sewage wastewater treatment process is essential for process stabilization and upgrading. Although bacteria are currently being analyzed by molecular biology techniques targeting the 16S rRNA gene, there is a problem that they are time-consuming and labor-intensive. In this study, we developed a paper-based analytical chip by using two types of DNA molecules that specifically bind to bacterial 16S rRNA. We optimized the fabrication method of the detection probe and the paper-based analytical chip, and then detected synthetic DNA having a nucleotide sequence that hybridizes with the designed DNA molecules and bacterial 16S rRNA extracted from an activated sludge sample. We evaluated the amount of nucleic acids quantitatively by taking images of the detection line on the paper-based analytical chip with a smartphone and analyzing its brightness with an open-source image processing program, ImageJ. Our method was able to detect 85 nM of bacterial 16S rRNA concentration in the extract. Nucleic acids that did not hybridize with either of the designed DNA molecules were not detected, demonstrating high selectivity of our method.

Synthesis of a Fluorescent Solvatochromic Resin Using Suzuki–Miyaura Cross-Coupling and Its Optical Waveguide Spectra to Measure the Solvent Polarity on the Surface
Yu Otsuka, Guanglei Li, Hiromi Takahashi, Hisashi Satoh, Koji Yamada
Materials, 13, 20, 4483, 4483, MDPI AG, 2020年10月10日, ［査読有り］
英語, 研究論文（学術雑誌）, We have established a novel analytical method for solvent polarity on resin surface by combining the synthesis of fluorescent solvatochromic resin with optical waveguide spectrometry. The fluorescent solvatochromic resin was obtained via Suzuki–Miyaura cross-coupling between 4-iodobenzoic acid immobilized on Wang resin and 5-[4-(N,N-dihexylamino)phenyl]-2-thienylboronic acid N-methyl-iminodiacetic acid (MIDA) ester. The optical waveguide spectrometry studies on the resin showed a strong fluorescent solvatochromism in various organic solvents., 11819065

Redox stratification within cryoconite granules influences the nitrogen cycle on glaciers
Takahiro Segawa, Nozomu Takeuchi, Hiroshi Mori, Rathnayake M L D Rathnayake, Zhongqin Li, Ayumi Akiyoshi, Hisashi Satoh, Satoshi Ishii
FEMS Microbiology Ecology, Oxford University Press (OUP), 2020年09月29日, ［査読有り］
研究論文（学術雑誌）,
Cryoconite granules are naturally occurring microbial structures on glacier surfaces worldwide. They play a key role in carbon and nitrogen cycling in glacier ecosystems and can accelerate the melting of snow and ice. However, detailed mechanism of nitrogen cycling in cryoconite granules remain unclear. Here, we demonstrate that redox stratification affects the spatial distribution of N cycling processes in cryoconite granules. Based on microsensor measurements for O2, NH4+, NO2–, and NO3–, we identified the presence of fine scale redox stratification within cryoconite granules. Cyanobacteria at the surface layer of the granules created oxic conditions, whereas the inner core of the granules was anoxic. Metatranscriptomic analyses indicated the active occurrences of nitrification in the inner core, whereas denitrification actively occurred both in the inner core and the surface layer of the granules. Cyanobacteria in the inner core of the granules were inactive, and likely dead and being degraded, providing carbon and nitrogen to support nitrifiers and denitrifiers. Quantities of nitrification genes/transcripts were greater in large cryoconite granules than small ones, most likely because nitrogen substrates were more abundantly present in inner core of large granules due to distinct redox stratification. Our results suggest that development of a granular structure of cryoconite granules can largely affect carbon and nitrogen cycling on glaciers.

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 Environ., 35, 4, 2020年08月, ［査読有り］, ［国内誌］
英語, 研究論文（学術雑誌）, 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.

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
Science of the Total Environment, 715, 2020年05月01日, ［査読有り］, ［筆頭著者, 最終著者, 責任著者］
英語, 研究論文（学術雑誌）, © 2020 Elsevier B.V. Monitoring of Escherichia coli concentrations at wastewater treatment plants (WWTPs) is important to ensure process performance and protect public health. However, conventional E. coli enumeration methods are complicated and time- and labor-consuming. Here, we report a novel simple and reliable method based on β-D-glucuronidase (GUS) activity assay to enumerate E. coli concentrations in wastewater (WW) samples. An aliquot (20 μL) of the medium with fluorogenic enzyme substrate for E. coli and 180 μL of a WW sample were added to one well of a 96-well microplate. The microplate was placed in a microplate reader at 37 °C. To this end, the fluorescence intensity of a fluorogenic enzyme substrate for E. coli was measured every 10 min over 3 h to determine GUS activity. The linear increase in the fluorescence intensity representing the GUS activities showed a positive correlation with E. coli concentrations in wastewater samples. However, the correlation equations were specific to WWTPs, which could be due to the difference in the E. coli population structures among WWTPs. We observed that the wastewater matrix is not a limitation to measure the GUS activity, and a WWTP-specific correlation equation can be used as a calibration curve to estimate the E. coli concentrations in the samples collected from that site. A comparison of the results with those of culture-dependent Colilert method proved that the current method is simple and useful for the enumeration of E. coli concentrations in wastewater samples reliably., 13465201

特定酵素蛍光基質を用いた下水中の大腸菌群の簡易迅速測定法の開発
佐藤 久
下水道協会誌, 56, 684, 110, 117, 2019年10月, ［査読有り］
日本語, 研究論文（学術雑誌）, 11819084

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, PERGAMON-ELSEVIER SCIENCE LTD, 2019年06月, ［査読有り］
英語, 研究論文（学術雑誌）, A simple analytical method was developed to determine the arsenite (As(III)) concentration using a DNA aptamer and gold nanoparticles (AuNPs). Prior to sample measurements, the method sensing mechanism was confirmed by analyzing the particle size of the AuNPs at each step of the analysis procedure, and the key operational parameters that affect the method performance were optimized. The optimal final NaCl concentration, incubation time with NaCl and pH of a 3-(N-morpholino) propanesulfonic acid buffer were 60 mM, 10 min and 7.3, respectively. A calibration curve was created under optimized operational conditions. The calibration curve was linear from a 1.0- to 10-mu M As(III) concentration. The detection limit was 2.1 mu M (161 mu g/L). Using the calibration curve, we evaluated groundwater samples spiked with As(III). As(III) concentrations in groundwater pretreated with a 0.2-mu m-pore-size membrane filter and cation-exchange resin were determined by using the method, which suggests that the proposed method can be used to determine the As(III) concentration in groundwater. (C) 2019 Elsevier Ltd. All rights reserved., 11819065

Digestion performance and contributions of organic and inorganic fouling in an anaerobic membrane bioreactor treating waste activated sludge.
Hafuka A, Mashiko R, Odashima R, Yamamura H, Satoh H, Watanabe Y
Bioresource technology, 272, 63, 69, ELSEVIER SCI LTD, 2019年01月, ［査読有り］
英語, 研究論文（学術雑誌）, This study evaluates the performance of an anaerobic membrane bioreactor (AnMBR) digesting waste activated sludge. A digestion reactor equipped with an external hollow fiber microfiltration membrane module was operated in continuous-mode for 248 days. The system demonstrated 56% volatile solids degradation at an organic loading rate of 0.40 g-VS/(L.d) in 15 days of hydraulic retention time. The average methane content in the biogas produced was 76% which is considerably high compared to that from a typical continuously stirred tank reactor. The transmembrane pressure remained under 12 kPa without membrane cleaning during the experimental period due to low filtration flux (0.01-0.07 m/d) and cross-flow-mode filtration. Ex situ membrane cleaning revealed that physically irreversible fouling was the dominant form of membrane fouling. Inorganic and organic fouling accounted for 16% and 45% of total membrane fouling, respectively.

Experimental Evidence for in Situ Nitric Oxide Production in Anaerobic Ammonia-Oxidizing Bacterial Granules.
Rathnayake RMLD, Oshiki M, Ishii S, Segawa T, Satoh H, Okabe S
Environmental science & technology, 52, 10, 5744, 5752, AMER CHEMICAL SOC, 2018年05月, ［査読有り］
英語, 研究論文（学術雑誌）, Although nitric oxide (NO) emissions from anaerobic ammonium oxidation (anammox)-based processes were reported previously, the NO production pathways are poorly understood. Here, we investigated the NO production pathways in anammox granules in detail by combining N-15-stable isotope tracer experiments with various inhibitors, microsensor measurements, and transcriptome analysis for key genes of NO2 reduction. NO was emitted from the anammox granules, which account for 0.07% of the N-2 emission. N-15-stable isotope-tracer experiments indicated that most of the N-2 was produced by anammox bacteria, whereas NO was produced from NO2- reduction by anammox and denitrifying bacteria. The NO emission rate was highest at pH 8.0 and accelerated by increasing NH4+ and NO2- concentrations in the culture media. The microsensor analyses showed the in situ NO production rate was highest in the outer layer of the anammox granule where anammox activity was also highest. The detected in situ NO concentrations of up to 2.7 mu M were significantly above physiological thresholds known to affect a wide range of microorganisms present in wastewater. Hence, NO likely plays pivotal roles in the microbial interactions in anammox granules, which needs to be further investigated.

3-[Bis(pyridin-2-ylmethyl)amino]-5-(4-carboxyphenyl)-BODIPY as Ratiometric Fluorescent Sensor for Cu².
Hafuka A, Satoh H, Yamada K, Takahashi M, Okabe S
Materials (Basel, Switzerland), 11, 5, MDPI, 2018年05月, ［査読有り］
英語, 研究論文（学術雑誌）, We developed an asymmetric fluorescent sensor 1 for Cu2+, based on 4,4-difluoro-4-bora- 3a, 4a-diaza-s-indacene (BODIPY), by introducing 4-carboxyphenyl and bis(pyridin-2-ylmethyl) amine groups at the 5- and 3-positions, respectively, of the BODIPY core. We then investigated the photophysical and cation-sensing properties of the sensor. BODIPY 1 showed large absorption and fluorescence spectral shifts on binding to Cu2+. The fluorescence peak at 580 nm red-shifted to 620 nm. The binding stoichiometry of BODIPY 1 and Cu2+ was 1:3. The ratio of the fluorescence intensity at 620 nm to that at 580 nm (F-620/F-580) increased with increasing concentration of Cu2+ (3-10 equiv); this enabled ratiometric determination of Cu2+. Although BODIPY 1 showed good selectivity for Cu2+, there was an interfering effect of Fe3+. BODIPY 1 could be used for the naked-eye detection of Cu2+ in a water-containing sample.

Development of novel polysulfone membranes with embedded zirconium sulfate-surfactant micelle mesostructure for phosphate recovery from water through membrane filtration
Kenji Furuya, Akira Hafuka, Miho Kuroiwa, Hisashi Satoh, Yoshimasa Watanabe, Hiroshi Yamamura
WATER RESEARCH, 124, 521, 526, PERGAMON-ELSEVIER SCIENCE LTD, 2017年11月, ［査読有り］
英語, 研究論文（学術雑誌）, We prepared novel membranes that could adsorb phosphate from water through membrane filtration for use in a phosphate recovery system. Zirconium sulfate surfactant micelle mesostructure (ZS), which was the phosphate adsorbent, was embedded hi a polysulfone matrix and flat sheet ultrafiltration membranes were made by nonsolvent induced phase separation. Scanning electron microscopy showed that the ZS particles existed on both the top surface and in the internal surface of the membrane. Increases in ZS content led to greater pure water flux because of increases in the surface porosity ratio. The amount of phosphate adsorbed on the membrane made from the polymer solution containing 10.5 wt% ZS was 0.071 mg P/cm(2) (64.8 mg P/g-ZS) during filtration of 50 mg P/L synthetic phosphate solution. The membrane could be repeatedly used for phosphate recovery after regeneration by filtration of 0.1 M NaOH solution to desorb the phosphate. We applied the membrane to treat the effluent from an anaerobic membrane bioreactor as a real sample and successfully recovered phosphate. (C) 2017 Elsevier Ltd. All rights reserved.

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, 768, 775, ELSEVIER SCI LTD, 2017年11月, ［査読有り］
英語, 研究論文（学術雑誌）, A hollow fiber degassing membrane (DM) was applied to enhance organic matter degradation and methane gas production of anaerobic granular sludge process by reducing the dissolved hydrogen gas (D-H-2) concentration in the liquid phase. DM was installed in the bench-scale anaerobic granular sludge reactors and D-H-2 was removed through DM using a vacuum pump. Degasification improved the organic matter degradation efficiency to 79% while the efficiency was 62% without degasification at 12,000 mg L-1 of the influent T-COD concentration. Measurement of D-H-2 concentrations in the liquid phase confirmed that D-H-2 was removed by degasification. Furthermore, the effect of acetate concentrations on the organic matter degradation efficiency was investigated. At acetate concentrations above 3 g L-1, organic matter degradation deteriorated. Degasification enhanced the propionate and acetate degradation. These results suggest that degasification reduced D-H-2 concentration and volatile fatty acids concentrations, prevented pH drop, and subsequent enhanced organic matter degradation.

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, WILEY, 2017年10月, ［査読有り］
英語, 研究論文（学術雑誌）, Anaerobic ammonium-oxidizing (anammox) bacteria affiliated with the genus Candidatus Scalindua' are responsible for significant nitrogen loss in oceans, and thus their ecophysiology is of great interest. Here, we enriched a marine anammox bacterium, Ca. S. japonica' from a Hiroshima bay sediment in Japan, and comparative genomic and proteomic analyses of Ca. S. japonica' were conducted. Sequence of the 4.81-Mb genome containing 4019 coding regions of genes (CDSs) composed of 47 contigs was determined. In the proteome, 1762 out of 4019 CDSs in the Ca. S. japonica' genome were detected. Based on the genomic and proteomic data, the core anammox process and carbon fixation of Ca. S. japonica' were further investigated. Additionally, the present study provides the first detailed insights into the genetic background responsible for iron acquisition and menaquinone biosynthesis in anammox bacterial cells. Comparative analysis of the Ca. Scalindua' genomes revealed that the 1502 genes found in the Ca. S. japonica' genome were not present in the Ca. S. profunda' and Ca. S. rubra' genomes, showing a high genomic diversity. This result may reflect a high phylogenetic diversity of the genus Ca. Scalindua'.

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, 17, 10, MDPI AG, 2017年10月, ［査読有り］
英語, 研究論文（学術雑誌）, Simple analytical methods are needed for determining the cadmium (Cd) content of brown rice samples. In the present study, we developed a new analytical procedure consisting of the digestion of rice using HCl, Cd purification using anion exchange resin, and then determining the Cd content using fluorescence spectroscopy. Digestion with 0.1 M HCl for 10 min at room temperature was sufficient to extract Cd from the ground rice samples. The Cd in the extract was successfully purified in preference to other metals using Dowex 1X8 chloride form resin. Low concentrations of Cd in the eluate could be determined using fluorescence spectroscopy with a fluoroionophore. Overall, the actual limit of quantification value for the Cd content in rice was about 0.1 mg-Cd/kg-rice, which was sufficiently low compared with the regulatory value (0.4 mg-Cd/kg-rice) given by the Codex Alimentarius Commission. We analyzed authentic brown rice samples using our new analytical procedure and the results agreed well with those determined using inductively coupled plasma optical emission spectrometry (ICP-OES). Since the fluoroionophore recognized Zn2+ and Hg2+ as well as Cd2+, a sample containing high concentration of Zn2+ or Hg2+ might cause a false positive result.

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, 33, 7, 825, 830, JAPAN SOC ANALYTICAL CHEMISTRY, 2017年07月, ［査読有り］
英語, 研究論文（学術雑誌）, An ionophore-doped sensing membrane phosphate (PO4) microsensor based on bis(dibromophenylstannyl)methane (Bis microsensor) is described. The Bis microsensor showed a Nernstian response. The response of the Bis microsensor was log-linear down to a monohydrogen phosphate ion (HPO42-) concentration of 0.5 mu M (corresponding to 1.0 mu M of orthophosphate at pH 7.2), whereas the detection limit of PO4-microsensors based on trialkyl/aryltin chloride was 50 mu M of HPO42-. The Bis microsensor showed excellent selectivity for HPO42- against nitrite, nitrate, chloride, bicarbonate and sulfate, as compared with PO4 microsensors based on trialkyl/aryltin chloride. Dissolved oxygen, which is known to interfere with the response of a previously developed cobalt-based potentiometric solid-state PO4 microsensor, had no effect on the response of the ionophore-doped sensing membrane-type microsensors described herein. Only OH- (i.e., pH) interfered with the ionophore-doped sensing membrane-type microsensors.

High spatial resolution analysis of the distribution of sulfate reduction and sulfide oxidation in hypoxic sediment in a eutrophic estuary
Rathnayake M. L. D. Rathnayake, Shogo Sugahara, Hideaki Maki, Gen Kanaya, Yasushi Seike, Hisashi Satoh
WATER SCIENCE AND TECHNOLOGY, 75, 2, 418, 426, IWA PUBLISHING, 2017年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Bottom hypoxia and consequential hydrogen sulfide (H2S) release from sediment in eutrophic estuaries is a major global environmental issue. We investigated dissolved oxygen, pH and H2S concentration profiles with microsensors and by sectioning sediment cores followed by colorimetric analysis. The results of these analyses were then compared with the physicochemical properties of the bottom water and sediment samples to determine their relationships with H2S production in sediment. High organic matter and fine particle composition of the sediment reduced the oxidation-reduction potential, stimulating H2S production. Use of a microsensor enabled measurement of H2S concentration profiles with submillimetre resolution, whereas the conventional sediment-sectioning method gave H2S measurements with a spatial resolution of 10 mm. Furthermore, microsensor measurements revealed H2S consumption occurring at the sediment surface in both the microbial mat and the sediment anoxic layer, which were not observed with sectioning. This H2S consumption prevented H2S release into the overlying water. However, the microsensor measurements had the potential to underestimate H2S concentrations. We propose that a combination of several techniques to measure microbial activity and determine its relationships with physicochemical properties of the sediment is essential to understanding the sulfur cycle under hypoxic conditions in eutrophic sediments.

Performance of anaerobic membrane bioreactor during digestion and thickening of aerobic membrane bioreactor excess sludge
Akira Hafuka, Kazuhisa Mimura, Qing Ding, Hiroshi Yamamura, Hisashi Satoh, Yoshimasa Watanabe
BIORESOURCE TECHNOLOGY, 218, 476, 479, ELSEVIER SCI LTD, 2016年10月, ［査読有り］
英語, 研究論文（学術雑誌）, In this study, we evaluated the performance of an anaerobic membrane bioreactor in terms of digestion and thickening of excess sludge from an aerobic membrane bioreactor. A digestion reactor equipped with an external polytetrafluoroethylene tubular microfiltration membrane module was operated in semi-batch mode. Solids were concentrated by repeated membrane filtration and sludge feeding, and their concentration reached 25,400 mg/L after 92 d. A high chemical oxygen demand (COD) removal efficiency, i.e., 98%, was achieved during operation. A hydraulic retention time of 34 d and a pulse organic loading rate of 2200 mg-COD/(L-reactor) gave a biogas production rate and biogas yield of 1.33 L/(reactor d) and 0.08 L/g-CODinput, respectively. The external membrane unit worked well without membrane cleaning for 90 d. The transmembrane pressure reached 25 kPa and the filtration flux decreased by 80% because of membrane fouling after operation for 90 d. (C) 2016 Elsevier Ltd. All rights reserved.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2016年10月, ［査読有り］
英語, 研究論文（学術雑誌）, Nitrous oxide (N2O) production pathway in a signal-stage nitritation-anammox sequencing batch reactor (SBR) was investigated based on a multilateral approach including real-time N2O monitoring, N2O isotopic composition analysis, and in-situ analyses of spatial distribution of N2O production rate and microbial populations in granular biomass. N2O emission rate was high in the initial phase of the operation cycle and gradually decreased with decreasing NH4+ concentration. The average emission of N2O was 0.98 +/- 0.42% and 135 +/- 0.72% of the incoming nitrogen load and removed nitrogen, respectively. The N2O isotopic composition analysis revealed that N2O was produced via NH2OH oxidation and NO2- reduction pathways equally, although there is an unknown influence from N2O reduction and/or anammox NO2 production. However, the N2O isotopomer analysis could not discriminate the relative contribution of nitrifiler denitrification and heterotrophic denitrification in the NO2- reduction pathway. Various in-situ techniques (e.g. microsensor measurements and FISH (fluorescent in-situ hybridization) analysis) were therefore applied to further identify N2O producers. Microsensor measurements revealed that aproximately 70% of N2O was produced in the oxic surface zone, where nitrifiers were predominantly localized. Thus, NH2OH oxidation and NO2 reduction by nitrifiers (nitrifler-denitrification) could be responsible for the N2O production in the oxic zone. The rest of N2O (ca. 30%) was produced in the anammox bacteria-dominated anoxic zone, probably suggesting that NO2- reduction by coexisting putative heterotrophic denitrifiers and some other unknown pathway(s) including the possibility of anammox process account for the anaerobic N2O production. Further study is required to identify the anaerobic N2O production pathways. Our multilateral approach can be useful to quantitatively examine the relative contributions of N2O production pathways. Good understanding of the key N2O production pathways is essential to establish a strategy to mitigate N2O emission from biological nitrogen removal processes. (C) 2016 Elsevier Ltd. All rights reserved.

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, 3143, WILEY-BLACKWELL, 2016年09月, ［査読有り］
英語, 研究論文（学術雑誌）, Although metabolic pathways and associated enzymes of anaerobic ammonium oxidation (anammox) of 'Ca. Kuenenia stuttgartiensis' have been studied, those of other anammox bacteria are still poorly understood. NO2- reduction to NO is considered to be the first step in the anammox metabolism of 'Ca. K. stuttgartiensis', however, 'Ca. Brocadia' lacks the genes that encode canonical NO-forming nitrite reductases (NirS or NirK) in its genome, which is different from 'Ca. K. stuttgartiensis'. Here, we studied the anammox metabolism of 'Ca. Brocadia sinica'. N-15-tracer experiments demonstrated that 'Ca. B. sinica' cells could reduce NO2- to NH2OH, instead of NO, with as yet unidentified nitrite reductase(s). Furthermore, N2H4 synthesis, downstream reaction of NO2- reduction, was investigated using a purified 'Ca. B. sinica' hydrazine synthase (Hzs) and intact cells. Both the 'Ca. B. sinica' Hzs and cells utilized NH2OH and NH1+, but not NO and NH1+, for N2H4 synthesis and further oxidized N2H4 to N-2 gas. Taken together, the metabolic pathway of 'Ca. B. sinica' is NH2OH-dependent and different from the one of 'Ca. K. stuttgartiensis', indicating metabolic diversity of anammox bacteria.

Effects of organic matter in livestock manure digester liquid on microbial community structure and in situ activity of anammox granules
Tomonori Kindaichi, Takanori Awata, Yuichiro Mugimoto, Rathnayake M. L. D. Rathnayake, Shinsuke Kasahara, Hisashi Satoh
CHEMOSPHERE, 159, 300, 307, PERGAMON-ELSEVIER SCIENCE LTD, 2016年09月, ［査読有り］
英語, 研究論文（学術雑誌）, Anaerobic ammonium oxidation (anammox) is a promising process for NH4+-rich wastewaters such as anaerobic digester liquids. In the present study, we investigated various properties of an up-flow column reactor containing anammox granules and fed with a real digester liquid at four different concentrations (Phases 1 to 4). The efficiencies of NH4+ and NO2- removal decreased by up to 32% and 42%, respectively, in the digester-liquid-fed reactor (reactor-DL). When the performance of reactor-DL deteriorated, the community structure, spatial distribution, and in situ anammox activity in the two reactors were further investigated using 16S rRNA gene-based phylogenetic analysis, fluorescence in situ hybridization (FISH), and microelectrode measurements. The phylogenetic analysis and FISH results showed that non-anammox bacteria were predominant in the granule outer layers in reactor-DL, whereas anammox bacteria still dominated the granule interiors. Microelectrode measurements showed clear evidence of NH4+ oxidation activity in the interiors of granules from reactor-DL. Batch experiments using anammox granules at different acetate concentrations indicated that concentrations up to 50 mM had no effects on the anammox activity, whereas inorganic carbon uptake decreased in the presence of acetate. The present study clearly shows that the anammox activity and anammox bacterial density in the granules were maintained after feeding the digester liquid to the reactor for 140 days. (C) 2016 Elsevier Ltd. All rights reserved.

Ecology and physiology of anaerobic ammonium oxidizing bacteria
Mamoru Oshiki, Hisashi Satoh, Satoshi Okabe
ENVIRONMENTAL MICROBIOLOGY, 18, 9, 2784, 2796, WILEY-BLACKWELL, 2016年09月, ［査読有り］
英語, Anaerobic ammonium oxidation (anammox) is a microbial process in which NH4+ is oxidized to N-2 gas with NO2- as an electron acceptor. The anammox process is mediated by bacterial members affiliated with the phylum Planctomycetes, which are ubiquitously detected from anoxic natural and man-made ecosystems and a key player in the global nitrogen cycle. In the past two decades, phylogenetically different anammox bacteria have been recognized in natural and synthetic ecosystems (i.e. 'Candidatus Kuenenia', 'Candidatus Brocadia', 'Candidatus Jettenia', 'Candidatus Anammoxoglobus' and 'Candidatus Scalindua' genera), and the geographic distributions of these anammox bacteria indicate that they have genus-specific or species-specific habitats. Recently, we revealed the physiological characteristics of 'Ca. Jettenia' in addition to 'Ca. Kuenenia', 'Ca. Brocadia' and 'Ca. Scalindua', and, as a result, it is possible to compare the physiological characteristics of the anammox bacteria and discuss their niche partitioning. Therefore, we summarize the current knowledge of anammox bacterial ecology and physiology in this review to assess the potential ecological niche partitioning of anammox bacteria in natural and synthetic ecosystems.

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, American Society for Microbiology, 2016年, ［査読有り］
英語, 研究論文（学術雑誌）, A draft genome sequence of an anaerobic ammonium-oxidizing (anammox) bacterium, "Candidatus Brocadia sinica," was determined by pyrosequencing and by screening a fosmid library. A 4.07-Mb genome sequence comprising 3 contigs was assembled, in which 3,912 gene-coding regions, 47 tRNAs, and a single rrn operon were annotated.

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, ELSEVIER SCI LTD, 2015年12月, ［査読有り］
英語, 研究論文（学術雑誌）, The effects of dissolved oxygen (DO) and pH on nitrous oxide (N2O) production rates and pathways in autotrophic partial nitrification (PN) granules were investigated at the granular level. N2O was primarily produced by betaproteobacterial ammonia-oxidizing bacteria, mainly Nitrosomonas europaea, in the oxic surface layer (<200 mu m) of the autotrophic PN granules. N2O production increased with increasing bulk DO concentration owing to activation of the ammonia (i.e., hydroxylamine) oxidation in this layer. The highest N2O emissions were observed at pH 7.5, although the ammonia oxidation rate was unchanged between pH 6.5 and 8.5. Overall, the results of this study suggest that in situ analyses of PN granules are essential to gaining insight into N2O emission mechanisms in a granule. (C) 2015 Elsevier Ltd. All rights reserved.

Interactions of dissolved humic substances with oppositely charged fluorescent dyes for tracer techniques
Akira Hafuka, Qing Ding, Hiroshi Yamamura, Koji Yamada, Hisashi Satoh
WATER RESEARCH, 85, 193, 198, PERGAMON-ELSEVIER SCIENCE LTD, 2015年11月, ［査読有り］
英語, 研究論文（学術雑誌）, To investigate interactions between oppositely charged fluorescent dyes and dissolved humic substances, fluorescence quenching of fluorescein and rhodamine 6G with dissolved humic substances was performed. Binding coefficients were obtained by the Stern-Volmer equation. The fluorescence of rhodamine 6G was largely quenched by the addition of humic acid and a non-linear Stern-Volmer plot was obtained. This strong quenching may be caused by the electrostatic interaction between cationic rhodamine 6G and humic acid and strengthened by the hydrophobic repulsion. In contrast, the quenching and interactive effects of dissolved humic substances for fluorescein were relatively weak. (C) 2015 Elsevier Ltd. All rights reserved.

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, 157, PERGAMON-ELSEVIER SCIENCE LTD, 2015年08月, ［査読有り］
英語, 研究論文（学術雑誌）, Rapid start-up of anaerobic ammonium oxidation (anammox) process in up-flow column reactors was successfully achieved by immobilizing minimal quantity of biomass in polyvinyl alcohol (PVA)-sodium alginate (SA) gel beads. The changes in the reactor performance (i.e., nitrogen removal rate; NRR) were monitored with time. The results demonstrate that the reactor containing the immobilized biomass concentration of 0.33 g-VSS L-1 achieved NRR of 10.8 kg-N m(-3) d(-1) after 35-day operation, whereas the reactor containing the granular biomass of 2.5 g-VSS L-1 could achieve only NRR of 3.5 kg-N m(-3) d(-1). This indicates that the gel immobilization method requires much lower seeding biomass for start-up of anammox reactor. To explain the better performance of the immobilized biomass, the biological and physicochemical properties of the immobilized biomass were characterized and compared with the naturally aggregated granular biomass. Effective diffusion coefficient (De) in the immobilized biomass was directly determined by microelectrodes and found to be three times higher than one in the granular biomass. High anammox activity (i.e., NH4+ and NO2- consumption rates) was evenly detected throughout the gel beads by microelectrodes due to faster and deeper substrate transport. In contrast, anammox activity was localized in the outer layers of the granular biomass, indicating that the inner biomass could not contribute to the nitrogen removal. This difference was in good agreement with the spatial distribution of microbes analysed by fluorescence in situ hybridization (FISH). Based on these results, PVA-SA gel immobilization is an efficient strategy to initiate anammox reactors with minimal quantity of anammox biomass. (C) 2015 Elsevier Ltd. All rights reserved.

Physiological characterization of anaerobic ammonium oxidizing bacterium "CandidatusJettenia 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, 2189, WILEY-BLACKWELL, 2015年06月, ［査読有り］
英語, 研究論文（学術雑誌）, To date, six candidate genera of anaerobic ammonium-oxidizing (anammox) bacteria have been identified, and numerous studies have been conducted to understand their ecophysiology. In this study, we examined the physiological characteristics of an anammox bacterium in the genus CandidatusJettenia'. Planctomycete KSU-1 was found to be a mesophilic (20-42.5 degrees C) and neutrophilic (pH 6.5-8.5) bacterium with a maximum growth rate of 0.0020h(-1). Planctomycete KSU-1 cells showed typical physiological and structural features of anammox bacteria; i.e. N-29(2) gas production by coupling of (NH4+)-N-15 and (NO2-)-N-14, accumulation of hydrazine with the consumption of hydroxylamine and the presence of anammoxosome. In addition, the cells were capable of respiratory ammonification with oxidation of acetate. Notably, the cells contained menaquinone-7 as a dominant respiratory quinone. Proteomic analysis was performed to examine underlying core metabolisms, and high expressions of hydrazine synthase, hydrazine dehydrogenase, hydroxylamine dehydrogenase, nitrite/nitrate oxidoreductase and carbon monoxide dehydrogenase/acetyl-CoA synthase were detected. These proteins require iron or copper as a metal cofactor, and both were dominant in planctomycete KSU-1 cells. On the basis of these experimental results, we proposed the name Ca. Jettenia caeni' sp. nov. for the bacterial clade of the planctomycete KSU-1.

Draft Genome Sequence of an Anaerobic Ammonium-Oxidizing Bacterium, "Candidatus Brocadia sinica"
Oshiki M, Shinyako-Hata K, Satoh H, Okabe S
Genome Announc, 3, 2, AMER SOC MICROBIOLOGY, 2015年03月, ［査読有り］
英語, 研究論文（学術雑誌）, A draft genome sequence of an anaerobic ammonium-oxidizing (anammox) bacterium, "Candidatus Brocadia sinica," was determined by pyrosequencing and by screening a fosmid library. A 4.07-Mb genome sequence comprising 3 contigs was assembled, in which 3,912 gene-coding regions, 47 tRNAs, and a single rrn operon were annotated.

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, CHEMICAL SOC JAPAN, 2015年03月, ［査読有り］
英語, 研究論文（学術雑誌）, In this paper, we investigated the effects of substitution at the 5-position of an asymmetric BODIPY cation sensor to tune its spectroscopic, photophysical, and cation-sensing properties. We introduced substituent groups with differing electron density at the 5-position of 3-[bis(pyridine-2-ylmethyl)amino]-BODIPY, which contains a cation recognition moiety at the 3-position of the BODIPY core, to develop four sensors which all exhibited distinctive ratiometric spectral changes in the presence of Cu2+. Aromatic substitution increased the Stokes shift. Substitution with the electron-withdrawing sulfonylphenyl group resulted in the highest fluorescence quantum yield, largest absorption coefficient, and largest spectral shift in the presence of Cu2+. The sulfonylphenyl-substituted sensor also exhibited excellent selectivity for Cu2+.

嫌気性アンモニア酸化(anammox)細菌の廃水処理への適用 (特集総説 極限生物たちが切り拓く未来の環境バイオテクノロジー)
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, 2014年10月, ［査読有り］
日本語

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, 3180, WILEY-BLACKWELL, 2014年10月, ［査読有り］
英語, 研究論文（学術雑誌）, The identification of the key nitrous oxide (N2O) production pathways is important to establish a strategy to mitigate N2O emission. In this study, we combined real-time gas-monitoring analysis, N-15 stable isotope analysis, denitrification functional gene transcriptome analysis and microscale N2O concentration measurements to identify the main N2O producers in a partial nitrification (PN) aerobic granule reactor, which was fed with ammonium and acetate. Our results suggest that heterotrophic denitrification was the main contributor to N2O production in our PN aerobic granule reactor. The heterotrophic denitrifiers were probably related to Rhodocyclales bacteria, although different types of bacteria were active in the initial and latter stages of the PN reaction cycles, most likely in response to the presence of acetate. Hydroxylamine oxidation and nitrifier denitrification occurred, but their contribution to N2O emission was relatively small (20-30%) compared with heterotrophic denitrification. Our approach can be useful to quantitatively examine the relative contributions of the three pathways (hydroxylamine oxidation, nitrifier denitrification and heterotrophic denitrification) to N2O emission in mixed microbial populations.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2014年05月, ［査読有り］
英語, 研究論文（学術雑誌）, Fluorescence spectroscopy has great potential for on-site and real-time monitoring of pollutants in aquatic environments; however, its application to environmental aquatic samples has been extremely limited. In this study, a novel fluoroionophore based on a BODIPY-terpyridine conjugate was developed and applied to determine Zn concentrations in urban runoff. The fluoroionophore selectively bound to Zn2+ in water, which led to an instant red-shift of the fluorescence peak of the fluoroionophore from 539 nm to 567 nm that could be seen by the naked eye. Zn concentrations could be quantified using the ratio of fluorescence intensities, and the detection limit was 9 mu g/L, which is sufficiently low for environmental aquatic samples. To demonstrate applicability of the method to environmental samples, we measured Zn concentrations in urban runoff samples with a complex matrix (similar to 60 mg/L dissolved organic carbon and similar to 20 mS/cm electrical conductivity). The total and dissolved fractions of Zn in the samples could be determined by fluorescence spectroscopy and its relative error was estimated to be less than 30% by inductively coupled plasma-atomic emission spectroscopy analysis. The proposed method is rapid and easy-to-use with simple pretreatment for Zn determination in environmental aquatic samples with complex matrices. (C) 2014 Elsevier Ltd. All rights reserved.

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, Elsevier {BV}, 2014年05月01日, ［査読有り］
英語, 研究論文（学術雑誌）, Fluorescence spectroscopy has great potential for on-site and real-time monitoring of pollutants in aquatic environments
however, its application to environmental aquatic samples has been extremely limited. In this study, a novel fluoroionophore based on a BODIPY-terpyridine conjugate was developed and applied to determine Zn concentrations in urban runoff. The fluoroionophore selectively bound to Zn2+ in water, which led to an instant red-shift of the fluorescence peak of the fluoroionophore from 539nm to 567nm that could be seen by the naked eye. Zn concentrations could be quantified using the ratio of fluorescence intensities, and the detection limit was 9μg/L, which is sufficiently low for environmental aquatic samples. To demonstrate applicability of the method to environmental samples, we measured Zn concentrations in urban runoff samples with a complex matrix (~60mg/L dissolved organic carbon and ~20mS/cm electrical conductivity). The total and dissolved fractions of Zn in the samples could be determined by fluorescence spectroscopy and its relative error was estimated to be less than 30% by inductively coupled plasma-atomic emission spectroscopy analysis. The proposed method is rapid and easy-to-use with simple pretreatment for Zn determination in environmental aquatic samples with complex matrices. © 2014 Elsevier Ltd.

Control of algal production in a high rate algal pond: investigation through batch and continuous experiments
H. Derabe Maobe, M. Onodera, M. Takahashi, H. Satoh, T. Fukazawa
WATER SCIENCE AND TECHNOLOGY, 69, 12, 2519, 2525, IWA PUBLISHING, 2014年, ［査読有り］
英語, 研究論文（学術雑誌）, For decades, arid and semi-arid regions in Africa have faced issues related to water availability for drinking, irrigation and livestock purposes. To tackle these issues, a laboratory scale greywater treatment system based on high rate algal pond (HRAP) technology was investigated in order to guide the operation of the pilot plant implemented in the 2iE campus in Ouagadougou (Burkina Faso). Because of the high suspended solids concentration generally found in effluents of this system, the aim of this study is to improve the performance of HRAPs in term of algal productivity and removal. To determine the selection mechanism of self-flocculated algae, three sets of sequencing batch reactors (SBRs) and three sets of continuous flow reactors (CFRs) were operated. Despite operation with the same solids retention time and the similarity of the algal growth rate found in these reactors, the algal productivity was higher in the SBRs owing to the short hydraulic retention time of 10 days in these reactors. By using a volume of CFR with twice the volume of our experimental CFRs, the algal concentration can be controlled during operation under similar physical conditions in both reactors.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2013年12月, ［査読有り］
英語, 研究論文（学術雑誌）, Emission of nitrous oxide (N2O) during biological wastewater treatment is of growing concern since N2O is a major stratospheric ozone-depleting substance and an important greenhouse gas. The emission of N2O from a lab-scale granular sequencing batch reactor (SBR) for partial nitrification (PN) treating synthetic wastewater without organic carbon was therefore determined in this study, because PN process is known to produce more N2O than conventional nitrification processes. The average N2O emission rate from the SBR was 0.32 +/- 0.17 mgN L-1 h(-1), corresponding to the average emission of N2O of 0.8 +/- 0.4% of the incoming nitrogen load (1.5 +/- 0.8% of the converted NI-14"). Analysis of dynamic concentration profiles during one cycle of the SBR operation demonstrated that N2O concentration in off-gas was the highest just after starting aeration whereas N2O concentration in effluent was gradually increased in the initial 40 min of the aeration period and was decreased thereafter. Isotopomer analysis was conducted to identify the main N2O production pathway in the reactor during one cycle. The hydroxylamine (NH2OH) oxidation pathway accounted for 65% of the total N2O production in the initial phase during one cycle, whereas contribution of the NO reduction pathway to N2O production was comparable with that of the NH2OH oxidation pathway in the latter phase. In addition, spatial distributions of bacteria and their activities in single microbial granules taken from the reactor were determined with microsensors and by in situ hybridization. Partial nitrification occurred mainly in the oxic surface layer of the granules and ammonia-oxidizing bacteria were abundant in this layer. N2O production was also found mainly in the oxic surface layer. Based on these results, although N2O was produced mainly via NH2OH oxidation pathway in the autotrophic partial nitrification reactor, N2O production mechanisms were complex and could involve multiple N2O production pathways. (C) 2013 Elsevier Ltd. All rights reserved.

Cultivation of Planktonic Anaerobic Ammonium Oxidation (Anammox) Bacteria Using Membrane Bioreactor
Oshiki M, Awata T, Kindaichi T, Satoh H, Okabe S
Microbes and Environments, 28, 4, 436, 443, JAPANESE SOC MICROBIAL ECOLOGY, DEPT BIORESOURCE SCIENCE, 2013年12月, ［査読有り］
英語, 研究論文（学術雑誌）, Enrichment cultures of anaerobic ammonium oxidation (anammox) bacteria as planktonic cell suspensions are essential for studying their ecophysiology and biochemistry, while their cultivation is still laborious. The present study aimed to cultivate two phylogenetically distinct anammox bacteria, "Candidatus Brocadia sinica" and "Ca. Scalindua sp." in the form of planktonic cells using membrane bioreactors (MBRs). The MBRs were continuously operated for more than 250 d with nitrogen loading rates of 0.48-1.02 and 0.004-0.09 kgN m(-3) d(-1) for "Ca. Brocadia sinica" and "Ca. Scalindua sp.", respectively. Planktonic anammox bacterial cells were successfully enriched (>90%) in the MBRs, which was confirmed by fluorescence in-situ hybridization and 16S rRNA gene sequencing analysis. The decay rate and half-saturation constant for NO2- of "Ca. Brocadia sinica" were determined to be 0.0029-0.0081 d(-1) and 0.47 mgN L-1, respectively, using enriched planktonic cells. The present study demonstrated that MBR enables the culture of planktonic anammox bacterial cells, which are suitable for studying their ecophysiology and biochemistry.

フルオロイオノフォアを用いた蛍光分光法による工場廃水中Zn²⁺の定量
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
土木学会論文集G（環境）, 69, 7, III_275, III_280, 公益社団法人 土木学会, 2013年11月, ［査読有り］
日本語, 本研究では, 新規に開発した特異的イオン認識蛍光色素(フルオロイオノフォア)を用い, 蛍光分光法により工場廃水中のZn²⁺を定量することを試みた. フルオロイオノフォアはZn²⁺と結合すると蛍光スペクトルが長波長シフトし, Zn²⁺濃度に依存したレシオメトリック型の蛍光スペクトル変化を示した. フルオロイオノフォアを実廃水試料に適用したところ, CrやNiが高濃度に含まれている廃水においても誤差20%以内でZn²⁺を定量できた.

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, 2013年07月, ［査読有り］
英語, 研究論文（学術雑誌）, We examined nitrate-dependent Fe2+ oxidation mediated by anaerobic ammonium oxidation (anammox) bacteria. Enrichment cultures of "Candidatus Brocadia sinica" anaerobically oxidized Fe2+ and reduced NO3- to nitrogen gasat rates of 3.7±0.2 and 1.3±0.1 (mean±standard deviation [SD]) nmol mg protein-1 min-1, respectively (37°C and pH 7.3). This nitrate reduction rate is an order of magnitude lower than the anammox activity of "Ca. Brocadia sinica" (10 to 75 nmol NH4+ mg protein-1 min-1). A 15N tracer experiment demonstrated that coupling of nitrate-dependent Fe2+ oxidation and the anammox reaction was responsible for producing nitrogen gas from NO3- by "Ca. Brocadia sinica." The activities of nitrate-dependent Fe2+ oxidation were dependent on temperature and pH, and thehighest activities were seen at temperatures of 30 to 45°C and pHs ranging from 5.9 to 9.8. The mean half-saturation constant for NO3 -±SD of "Ca. Brocadia sinica" was determined to be 51±21 μM. Nitrate-dependent Fe2+ oxidation was further demonstrated by another anammox bacterium, "Candidatus Scalindua sp.," whose rates of Fe2+ oxidation and NO3- reduction were 4.7±0.59 and 1.45±0.05 nmol mg protein-1 min-1, respectively (20°C and pH 7.3). Co-occurrence of nitrate-dependent Fe2+ oxidation and the anammox reaction decreased the molar ratios of consumed NO2 - to consumed NH4 + (δNO2-/δNH4 +) and produced NO3- to consumed NH4 + (δNO3 -/δNH4 +). These reactions are preferable to the application of anammox processes for wastewater treatment. © 2013, American Society for Microbiology.

High efficiency removal of phosphate from water by zirconium sulfate-surfactant micelle mesostructure immobilized on polymer matrix
Pitakteeratham N, Hafuka A, Satoh H, Watanabe Y
Water Research, 47, 11, 3583, 3590, PERGAMON-ELSEVIER SCIENCE LTD, 2013年07月, ［査読有り］
英語, 研究論文（学術雑誌）, A zirconium sulfate-surfactant micelle mesostructure (ZS) was synthesized to investigate its capacity for phosphate removal from water. Its phosphate adsorption kinetics, the effect of pH and interfering anions, adsorption isotherm, desorption capacity, and reusability were investigated. The adsorption isotherms could be described by the Langmuir model., The ZS was an effective adsorbent for phosphate with a very high adsorption capacity (114 mg P/g ZS). The phosphate adsorption capacity increased with decrease in pH. Although the adsorption of nitrate, chloride and acetate ions was negligible, bicarbonate ions were found to be possible interfering anions. The adsorbed phosphate was desorbed effectively using NaOH solution. Since breakage of ZS particles resulted when using NaOH, ZS was immobilized on a polymer matrix and a 50-cycle adsorption-desorption test was carried out to determine the ZS-immobilized polymer (P-ZS) reusability. The P-ZS retained its functionality and adsorption and desorption capacity over 50 cycles without loss of original capacity. A phosphate solution containing about 10 mg P/L was treated in a column packed with P-ZS. The phosphate could be adsorbed completely onto P-ZS up to 1020 bed volumes. These results indicate clearly that ZS is a highly effective adsorbent for phosphate and enables the removal of phosphate from water. (C) 2013 Elsevier Ltd. All rights reserved.

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, 291, ELSEVIER SCI LTD, 2013年07月, ［査読有り］
英語, 研究論文（学術雑誌）, In this study, partial nitrifying (PN) aerobic granules were developed in a sequencing batch airlift reactor by controlling the airflow rate and NH4+ loading rate. The PN reactor produced an effluent with a NO2-/NH4+ ratio of approximately one and with an NH4+ conversion rate of 1.22 kg N m(-3) day(-1). More than 95% of the total organic carbon was removed during the process. On the basis of clone library analysis and fluorescence in situ hybridization, ammonia-oxidizing bacteria (AOB) closely related to Nitrosomonas eutropha and putative heterotrophic denitrifiers were mainly present near the surface of the PN aerobic granules. Microelectrode measurements revealed that both NH4+ and NO2- were consumed near the. surface (<200 mu m), whereas no nitrate (NO3-) accumulation was observed throughout the granules. These results indicate that PN by AOB and nitrite denitrification by heterotrophs, but not nitrite oxidation, simultaneously occurred near the surface of the PN aerobic granules. (C) 2013 Elsevier Ltd. All rights reserved.

Spatial and temporal oxygen dynamics in macrofaunal burrows in sediments: a review of analytical tools and observational evidence
Satoh Hisashi, Okabe Satoshi
Microbes and Environments, 28, 2, 166, 179, JAPANESE SOC MICROBIAL ECOLOGY, DEPT BIORESOURCE SCIENCE, 2013年06月, ［査読有り］
英語, The availability of benthic O-2 plays a crucial role in benthic microbial communities and regulates many important biogeochemical processes. Burrowing activities of macrobenthos in the sediment significantly affect O-2 distribution and its spatial and temporal dynamics in burrows, followed by alterations of sediment microbiology. Consequently, numerous research groups have investigated O-2 dynamics in macrofaunal burrows. The introduction of powerful tools, such as microsensors and planar optodes, to sediment analysis has greatly enhanced our ability to measure O-2 dynamics in burrows at high spatial and temporal resolution with minimal disturbance of the physical structure of the sediment. In this review, we summarize recent studies of O-2-concentration measurements in burrows with O-2 microsensors and O-2 planar optodes. This manuscript mainly focuses on the fundamentals of O-2 microsensors and O-2 planar optodes, and their application in the direct measurement of the spatial and temporal dynamics of O-2 concentrations in burrows, which have not previously been reviewed, and will be a useful supplement to recent literature reviews on O-2 dynamics in macrofaunal burrows.

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, WATER ENVIRONMENT FEDERATION, 2013年05月, ［査読有り］
英語, The effectiveness of degasification using a degassing membrane to improve chemical oxygen demand (COD) removal efficiency was investigated using a bench-scale upflow anaerobic sludge blanket (UASB) reactor. Vacuum degasification was able to transfer dissolved gas in the bulk liquid of the UASB reactor inside the membrane. Such a process might provide thermodynamically favorable conditions for the degradation of organic compounds. The COD-removal efficiency improved from 83% during normal operation to 90% during the degassing operation.

Explicit temperature-based model for anaerobic digestion: Application in domestic wastewater treatment in a UASB reactor
A. Donoso-Bravo, W. M K R T W Bandara, H. Satoh, G. Ruiz-Filippi
Bioresource Technology, 133, 437, 442, Elsevier Ltd, 2013年, ［査読有り］
英語, 研究論文（学術雑誌）, Temperature is an important environmental variable that can strongly affect the performance of anaerobic reactors working at ambient temperatures. This study presents a mechanistic mathematical model which depends in an explicit way on the operating temperature. The cardinal temperature model function is proposed to describe the temperature dependence of the kinetic parameters and the experimental data from an UASB-degasification system was used to calibrate and validate the model. The performance of the model is compared with the classic Arrhenius approach. The results showed that the temperature-based model of the anaerobic digestion is able to reproduce a long-term reactor operation in terms of biogas production and the concentration of organic matter at fluctuating ambient temperature. © 2013 Elsevier Ltd.

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, CHEMICAL SOC JAPAN, 2013年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Two novel asymmetric BODIPY fluoroionophores with dipicolylamine (BDP-DPA, dipicolylamine: bis(pyridyl-methyl)) and terpyridine (BDP-TPY) are described. These fluoroionophores display opposite wavelength responses on complexation with heavy metal ions. Furthermore, the fluorescence spectra vary depending on the ionic species. In particular, BDP-DPA shows a high affinity toward Cr3+ and upon complexation, the fluorescence spectrum blue-shifts from 591 to 566 nm. In contrast, BDP-TPY preferentially binds to Zn2+ and the fluorescence spectra red-shifts from 539 to 567 nm. BDP-TPY is the first example of asymmetric BODIPY with a pyridyl receptor at the 3 position showing red-shifted fluorescence by complexation with metal ions. The concentration of each metal ion was successfully determined by ratiometric measurement. The wavelength-responses characteristics of these fluoroionophores could be very useful in the development of novel ratiometric fluoroionophores for metal ions.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2012年11月, ［査読有り］
英語, 研究論文（学術雑誌）, Anaerobic treatment is an attractive option for the biological treatment of municipal wastewater. In this study, municipal wastewater was anaerobically treated with a bench-scale upflow anaerobic sludge blanket (UASB) reactor at temperatures from 6 to 31 degrees C for 18 months to investigate total chemical oxygen demand (COD) removal efficiency, archaeal community structure, and dissolved methane (D-CH4) recovery efficiency. The COD removal efficiency was more than 50% in summer and below 40% in winter with no evolution of biogas. Analysis of the archaeal community structures of the granular sludge from the UASB using 16S rRNA gene-cloning indicated that after microorganisms had adapted to low temperatures, the archaeal community had a lower diversity and the relative abundance of acetoclastic methanogens decreased together with an increase in hydrogenotrophic methanogens. D-CH4, which was detected in the UASB effluent throughout the operation, could be collected with a degassing membrane. The ratio of the collection to recovery rates was 60% in summer and 100% in winter. For anaerobic treatment of municipal wastewater at lower temperatures, hydrogenotrophic methanogens play an important role in COD removal and D-CH4 can be collected to reduce greenhouse gas emissions and avoid wastage of energy resources. (C) 2012 Elsevier Ltd. All rights reserved.

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, 249, JAPANESE SOC MICROBIAL ECOLOGY, DEPT BIORESOURCE SCIENCE, 2012年09月, ［査読有り］
英語, 研究論文（学術雑誌）, The amount of oxygen released by Phragmites roots and the community structure and in situ activity of nitrifying bacteria in the root biofilms were analyzed by the combined use of 16S rRNA gene-cloning analysis, quantitative PCR (qPCR) assay and microelectrodes. Axial and radial O-2 microprofiles were obtained for individual roots of Phragmites in a horizontal flow reactor fed with artificial medium continuously. Axial O-2 profiles revealed that O-2 was released at a rate of 0.21 mu mol O-2 cm(-2) (root surface area) h(-1) only in the apical region (up to ca. 40 mm from the root apex), where there was a high abundance (10(7) to 10(8) copies g(-1) biomass) of Nitrosomonas-like AOB and Nitrospira-like NOB. This abundance, however, sharply declined to the detection limit at positions more basal than 80 mm. Phylogenetic analysis based on 16S rRNA gene identified strains related to Nitrosomonas oligotropha and Nitrosomonas cryotolerans as the predominant AOB and strains related to Nitrospira marina and Nitrospira moscoviensis as the predominant NOB in the root biofilms. Based on radial O-2 microprofiles, the oxic region only extended about 0.5 mm into the surrounding sediment due to a high rate of O-2 consumption in the rhizosphere. The net NH4+ and O-2 consumption rates in the apical region were higher than those determined at the oxic sediment surface in which the abundance of AOB and NOB was one order of magnitude lower than in the rhizosphere. These results clearly indicated that Phragmites root biofilms played an important role in nitrification in the waterlogged anoxic sediment.

Revealing microbial community structures in large- and small-scale activated sludge systems by barcoded pyrosequencing of 16S rRNA gene
Purnika Damindi Ranasinghe, Hiroyasu Satoh, Mamoru Oshiki, Kenshiro Oshima, Wataru Suda, Masahira Hattori, Takashi Mino
WATER SCIENCE AND TECHNOLOGY, 66, 10, 2155, 2161, IWA PUBLISHING, 2012年, ［査読有り］
英語, 研究論文（学術雑誌）, The diversity of bacterial groups in activated sludge from large- and small-scale wastewater treatment plants was explored by barcoded pyrosequencing of 16S rRNA gene. Activated sludge samples (three small and 17 large scale) were collected from 12 wastewater treatment plants to clarify precise taxonomy and relative abundances. DNA was extracted, and amplified by 4 base barcoded 27f/519r primer set. The 454 Titanium (Roche) pyrosequences were obtained and analyses performed by Quantitative Insight Into Microbial Ecology (QIIME) with around 100,000 reads. Sequence statistics were computed, while constructing a phylogenetic tree and heatmap. Computed results explained total microbial diversity at phylum and class level and resolution was further extended to Operational Taxonomic Unit (OTU) based taxonomic assignment for investigating community distribution based on individual sample. Composition of sequence reads were compared and microbial community structures for large- and small-scale treatment plants were identified as major phyla (Proteobacteria and Bacteroidetes) and classes (Betaproteobacteria and Bacteroidetes). Also, family level breakdowns were explained and differences in family Nitrospiraceae and phylum Actinobacteria found at their species level were also illustrated. Thus, the pyrosequencing method provides high resolution insight into microbial community structures in activated sludge that might have been unnoticed with conventional approaches.

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, IWA PUBLISHING, 2012年, ［査読有り］
英語, 研究論文（学術雑誌）, The spatial distribution of microorganisms and their in situ activities in anaerobic granules were investigated by fluorescence in situ hybridization (FISH), beta imaging and microsensors. FISH results revealed a layered structure of microorganisms in the granule, where Chloroflexi was present in the outermost layer, Smithella spp. and Syntrophobacter spp. were found in a depth of ca. 100 mu m, and Archaea was restricted to the inner layer (below ca. 300 mu m from the surface). Substrate uptake patterns elucidated by beta imaging demonstrated that glucose uptake was highest at 50 mu m depth, whereas propionate uptake had a peak at 200 mu m depth. In addition, microsensor measurements revealed that acid was produced mainly at 100 mu m depth and H-2 production was detected at a depth from 100 to 200 mu m. H-2 consumption and corresponding CH4 production were found below 200 mu m from the surface. Direct comparison of these results implied sequential degradation of complex organic compounds in anaerobic granules; Chloroflexi contributed to fermentation of organic compounds and acid production in the outermost layer, volatile fatty acids were oxidized and H-2 was produced mainly by Smithella spp. and Syntrophobacter spp. at a depth from 100 to 200 mu m, and Archaea produced CH4 below ca. 300 mu m from the surface.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2011年12月, ［査読有り］
英語, 研究論文（学術雑誌）, Emission of nitrous oxide (N2O) during biological wastewater treatment is of growing concern. The emission of N2O from a lab-scale two-reactor partial nitrification (PN)-anammox reactor was therefore determined in this study. The average emission of N2O from the PN and anammox process was 4.0 +/- 1.5% (9.6 +/- 3.2% of the removed nitrogen) and 0.1 +/- 0.07% (0.14 +/- 0.09% of the removed nitrogen) of the incoming nitrogen load, respectively. Thus, a larger part (97.5%) of N2O was emitted from the PN reactor. The total amount of N2O emission from the PN reactor was correlated to nitrite (NO2-) concentration in the PN effluent rather than DO concentration. In addition, further studies were performed to indentify a key biological process that is responsible for N2O emission from the anammox process (i.e., granules). In order to characterize N2O emission from the anammox granules, the in situ N2O production rate was determined by using microelectrodes for the first time, which was related to the spatial organization of microbial community of the granule as determined by fluorescence in situ hybridization (FISH). Microelectrode measurement revealed that the active N2O production zone was located in the inner part of the anammox granule, whereas the active ammonium consumption zone was located above the N2O production zone. Anammox bacteria were present throughout the granule, whereas ammonium-oxidizing bacteria (AOB) were restricted to only the granule surface. In addition, addition of penicillin G that inhibits most of the heterotrophic denitrifiers and AOB completely inhibited N2O production in batch experiments. Based on these results obtained, denitrification by putative heterotrophic denitrifiers present in the inner part of the granule was considered the most probable cause of N2O emission from the anammox reactor (i.e., granules). (C) 2011 Elsevier Ltd. All rights reserved.

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, ELSEVIER SCI LTD, 2011年07月, ［査読有り］
英語, 研究論文（学術雑誌）, The partial nitrification reactor was successfully started up and operated stably for more than 250 days with a maximum nitrite production rate of 1.12 kg-N m(-3) day(-1). The important factors for successful partial nitrification were high ammonium loading rate (>1.0 kg-N m(-3) day(-1)) and relatively high pH (ca. 8.0), giving high free ammonia concentrations (>10 mg NH(3)-N L(-1)). In addition, the air flow rate must be controlled at the ratio of air flow rate to ammonium loading rate below 0.1 (m(air)(3) day(-1))/(kg-N m(-3) day(-1)). After the establishment of stable partial nitrification, the effluent NO(2)(-)-N/NH(4)(+)-N ratio and effluent NO(3)(-)-N concentration were 1.20 +/- 0.33 and 1.2 +/- 1.0 mg-N L(-1), respectively, which was then fed into an granular-sludge anammox reactor. Consistent nitrogen removal was achieved for more than 250 days with a maximum nitrogen removal rate of 15.0 kg-TN m(-3) day(-1). (C) 2011 Elsevier Ltd. All rights reserved.

Physiological characteristics of the anaerobic ammonium-oxidizing bacterium 'Candidatus Brocadia sinica'
Mamoru Oshiki, Masaki Shimokawa, Naoki Fujii, Hisashi Satoh, Satoshi Okabe
MICROBIOLOGY-SGM, 157, 1706, 1713, SOC GENERAL MICROBIOLOGY, 2011年06月, ［査読有り］
英語, 研究論文（学術雑誌）, The present study investigated the phylogenetic affiliation and physiological characteristics of bacteria responsible for anaerobic ammonium oxidization (anammox); these bacteria were enriched in an anammox reactor with a nitrogen removal rate of 26.0 kg N m(-3) day(-1). The anammox bacteria were identified as representing 'Candidatus Brocadia sinica' on the basis of phylogenetic analysis of rRNA operon sequences. Physiological characteristics examined were growth rate, kinetics of ammonium oxidation and nitrite reduction, temperature, pH and inhibition of anammox. The maximum specific growth rate (mu(max).) was 0.0041 h(-1), corresponding to a doubling time of 7 days. The half-saturation constants (K(s)) for ammonium and nitrite of 'Ca. B. sinica' were 28 +/- 4 and 86 +/- 4 mu M, respectively, higher than those of 'Candidatus Brocadia anammoxidans' and 'Candidatus Kuenenia stuttgartiensis'. The temperature and pH ranges of anammox activity were 25-45 degrees C and pH 6.5-8.8, respectively. Anammox activity was inhibited in the presence of nitrite (50% inhibition at 16 mM), ethanol (91% at 1 mM) and methanol (86% at 1 mM). Anammox activities were 80 and 70% of baseline in the presence of 20 mM phosphorus and 3% salinity, respectively. The yield of biomass and dissolved organic carbon production in the culture supernatant were 0.062 and 0.005 mol C (mol NH(4)(+))(-1), respectively. This study compared physiological differences between three anammox bacterial enrichment cultures to provide a better understanding of anammox niche specificity in natural and man-made ecosystems.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2011年05月, ［査読有り］
英語, 研究論文（学術雑誌）, In this study, we investigated the efficiency of dissolved methane (D-CH(4)) collection by degasification from the effluent of a bench-scale upflow anaerobic sludge blanket (UASB) reactor treating synthetic wastewater. A hollow-fiber degassing membrane module was used for degasification. This module was connected to the liquid outlet of the UASB reactor. After chemical oxygen demand (COD) removal efficiency of the UASB reactor became stable, D-CH(4) discharged from the UASB reactor was collected. Under 35 degrees C and a hydraulic retention time (HRT) of 10 h, average D-CH(4) concentration could be reduced from 63 mg COD L(-1) to 15 mg COD L(-1); this, in turn, resulted in an increase in total methane (CH(4)) recovery efficiency from 89% to 97%. Furthermore, we investigated the effects of temperature and HRT of the UASB reactor on degasification efficiency. Average D-CH(4) concentration was as high as 104 mg COD L(-1) at 15 degrees C because of the higher solubility of CH(4) gas in liquid; the average D-CH(4) concentration was reduced to 14 mg COD L(-1) by degasification. Accordingly, total CH(4) recovery efficiency increased from 71% to 97% at 15 degrees C as a result of degasification. Moreover, degasification tended to cause an increase in particulate COD removal efficiency. The UASB reactor was operated at the same COD loading rate, but different wastewater feed rates and HRTs. Although average D-CH(4) concentration in the UASB reactor was almost unchanged (ca. 70 mg COD L(-1)) regardless of the HRT value, the CH(4) discharge rate from the UASB reactor increased because of an increase in the wastewater feed rate. Because the D-CH(4) concentration could be reduced down to 12 +/- 1 mg COD L(-1) by degasification at an HRT of 6.7 h, the CH(4) recovery rate was 1.5 times higher under degasification than under normal operation. (C) 2011 Elsevier Ltd. All rights reserved.

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, ELSEVIER SCI LTD, 2011年02月, ［査読有り］
英語, 研究論文（学術雑誌）, We investigated the effects of different feeding regimens (1-pulse, stepwise, and continuous) of fermented food-waste liquid on polyhydroxybutyrate (PHB) production. The fermentation liquid was filtered with a membrane filter (pore size, 0.45 mu m) to remove anaerobic microorganisms and solids and used as a carbon source for Cupriavidus necator. One-pulse feeding yielded the highest cell concentration of C. necator. However, the PHB concentration was higher in the stepwise- and continuous-feeding regimens. Therefore, the continuous-feeding regimen was used for continuous PHB production. PHB could be produced over 259 h (8 draw-fill cycles) with a maximal PHB content of 87%, but the PHB concentration and content decreased with an increase in the operation time. (C) 2010 Elsevier Ltd. All rights reserved.

Rapid quantification of polyhydroxyalkanoates (PHA) concentration in activated sludge with the fluorescent dye Nile blue A
M. Oshiki, H. Satoh, T. Mino
WATER SCIENCE AND TECHNOLOGY, 64, 3, 747, 753, IWA PUBLISHING, 2011年, ［査読有り］
英語, 研究論文（学術雑誌）, The present study was conducted (1) to develop a rapid quantification method of polyhydroxyalkanoates (PHA) concentration in activated sludge by Nile blue A staining and fluorescence measurement and (2) to perform on-line monitoring of PHA concentrations in activated sludge. Activated sludge samples collected from laboratory scale sequencing batch reactors and full-scale wastewater treatment plants were stained with Nile blue A and their fluorescence intensities were determined. There was a high correlation (R(2)>0.97) between the fluorescence intensities of Nile blue A and PHA concentrations in activated sludge determined by gas chromatography. The Nile blue A staining and fluorescence measurement method allows us to determine PHA concentrations in activated sludge within only five minutes and up to 96 samples can be measured at once by using microplate reader. On-line monitoring of PHA concentrations in activated sludge was achieved by using a fluorometer equipped with a flow cell and the time point at which PHA concentration in activated sludge reached the maximum level could be identified. In addition, we examined the influence of pH, floc size and co-existing chemicals in activated sludge suspension on the fluorescence intensities of Nile blue A.

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, ELSEVIER ACADEMIC PRESS INC, 2011年, ［査読有り］
英語, 論文集(書籍)内論文, This chapter aims to highlight the great potential of the combined use of microautoradiography (MAR) combined with fluorescent in situ hybridization (FISH) and microsensor technology in studies of complex multispecies nitrifying biofilms. The combination of FISH and microsensor technology is a powerful and reliable tool to link the spatial organization of microbial communities and their in situ function at community levels. MAR-FISH can be used to simultaneously examine the 16S rRNA-based phylogenetic identity and specific metabolic activity of cultivable or uncultivable microorganisms within complex microbial communities at a single-cell level. Information obtained at both resolution levels must be combined to draw a clear picture of a complex multispecies biofilm ecosystem. In addition, ecophysiological interactions among community members in complex multispecies biofilms can be investigated by tracing the fate of radiolabeled [ (14)C] atom incorporated in nitrifying bacteria with MAR-FISH. The structure, function, and ecophysiological interactions among community members in complex multispecies nitrifying biofilms will be illustrated as an example of the combined use of MAR-FISH and microsensor technology.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2010年02月, ［査読有り］
英語, 研究論文（学術雑誌）, We investigated nitrogen removal performance and responsible microbial community in an anaerobic up-flow granular bed anammox reactor. The anammox reactor was operated more than 1 year. Biomass in the reactor formed granules after about 2 months of operation, and a sufficient amount of the granules was retained in the reactor with a metallic net to avoid biomass washout during the entire operation. The average diameter of the granules was 3.6 mm at day 310. After 8 months of operation, stable nitrogen removal (60%) was achieved at an average total inorganic nitrogen removal rate of 14 kg-N m(-3) d(-1). The phylogenetic analysis and fluorescence in situ hybridization results revealed that the anammox granules consisted of mono species of anammox bacteria, "Candidatus Brocadia-like species", affiliated with "Candidatus Brocadia anammoxidans" with 16S rRNA gene sequence similarity of 95.7%. The relative abundance of the anammox bacteria in the granules was more than 80% of the total bacteria stained with 4',6-diamidino-2-phenylindole. The anammox bacteria were present throughout the granules whereas the other bacterial groups. Chloroflexi-like filamentous bacteria and betaproteobacterial ammonia-oxidizing bacteria, were mainly present on the surface of the anammox granules and around the anammox bacterial clusters. The in situ anammox activity was detected mainly from near the surface of granules to the upper 800 pm of the granules with microsensors. The granular anammox biomass tolerated higher concentrations of nitrite (400 mg-N L(-1)) than did the homogenized biomass (200 mg-N L(-1)) probably due to substrate diffusion limitation. (C) 2009 Elsevier Ltd. All rights reserved.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2009年10月, ［査読有り］
英語, 研究論文（学術雑誌）, Microbially induced concrete corrosion (MICC) caused by sulfuric acid attack in sewer systems has been a serious problem for a long time. A better understanding of microbial community structures of sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) and their in situ activities is essential for the efficient control of MICC. in this study, the microbial community structures and the in situ hydrogen sulfide production and consumption rates within biofilms and corroded materials developed on mortar specimens placed in a corroded manhole was investigated by culture-independent 16S rRNA gene-based molecular techniques and microsensors for hydrogen sulfide, oxygen, pH and the oxidation-reduction potential. The dark-gray gel-like biofilm was developed in the bottom (from the bottom to 4 cm) and the middle (4-20 cm from the bottom of the manhole) parts of the mortar specimens. White filamentous biofilms covered the gel-like biofilm in the middle part. The mortar specimens placed in the upper part (30 cm above the bottom of the manhole) were corroded. The 16S rRNA gene-cloning analysis revealed that one clone retrieved from the bottom biofilm sample was related to an SRB, 12 clones and 6 clones retrieved from the middle biofilm and the corroded material samples, respectively, were related to SOB. In situ hybridization results showed that the SRB were detected throughout the bottom biofilm and filamentous SOB cells were mainly detected in the upper oxic layer of the middle biofilm. Microsensor measurements demonstrated that hydrogen sulfide was produced in and diffused out of the bottom biofilms. In contrast, in the middle biofilm the hydrogen sulfide produced in the deeper parts of the biofilm was oxidized in the upper filamentous biofilm. pH was around 3 in the corroded materials developed in the upper part of the mortar specimens. Therefore, it can be concluded that hydrogen sulfide provided from the bottom biofilms and the sludge settling tank was emitted to the sewer atmosphere, then oxidized to corrosive compounds in the upper and middle parts of the manhole, and only the upper part of the mortar specimens were corroded, because in the middle part of the manhole the generated corrosive compounds (e.g., sulfuric acid) was reduced in the deeper parts of the biofilm. (C) 2009 Elsevier Ltd. All rights reserved.

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, AMER SOC MICROBIOLOGY, 2007年11月, ［査読有り］
英語, 研究論文（学術雑誌）, The microbial community structure and spatial distribution of microorganisms and their in situ activities in anaerobic granules were investigated by 16S rRNA gene-based molecular techniques and microsensors for CH4, H-2, pH, and the oxidation-reduction potential (ORP). The 16S rRNA gene-cloning analysis revealed that the clones related to the phyla Alphaproteobacteria (detection frequency, 51%), Firmicutes (20%), Chloroflexi (9%), and Betaproteobacteria (8%) dominated the bacterial clone library, and the predominant clones in the archaeall clone library were affiliated with Methanosaeta (73%). In situ hybridization with oligonucleotide probes at the phylum level revealed that these microorganisms were numerically abundant in the granule. A layered structure of microorganisms was found in the granule, where Chloroflexi and Betaproteobacteria were present in the outer shell of the granule, Firmicutes were found in the middle layer, and aceticlastic Archaea were restricted to the inner layer. Microsensor measurements for CH4, H-2, pH, and ORP revealed that acid and H-2, production occurred in the upper part of the granule, below which H-2, consumption and CH4 production were detected. Direct comparison of the in situ activity distribution with the spatial distribution of the microorganisms implied that Chloroflexi contributed to the degradation of complex organic compounds in the outermost layer, H-2 was produced mainly by Firmicutes in the middle layer, and Methanosaeta produced CH4 in the inner layer. We determined the effective diffusion coefficient for H-2 in the anaerobic granules to be 2.66 X 10(-5) cm(2) s(-1), which was 57% in water.

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, AMER SOC MICROBIOLOGY, 2007年08月, ［査読有り］
英語, 研究論文（学術雑誌）, We investigated autotrophic anaerobic ammonium-oxidizing (anammox) biofilms for their spatial organization, community composition, and in situ activities by using molecular biological techniques combined with microelectrodes. Results of phyllogenetic analysis and fluorescence in situ hybridization (FISH) revealed that "Brocadia"-like anammox bacteria that hybridized with the Amx820 probe dominated, with 60 to 92% of total bacteria in the upper part (< 1,000 mu m) of the biofilm, where high anammox activity was mainly detected with microelectrodes. The relative abundance of anammox bacteria decreased along the How direction of the reactor. FISH results also indicated that Nitrosomonas-, Nitrosospira-, and Nitrosococcus-like aerobic ammonia-oxidizing bacteria (AOB) and Nitrospira-like nitrite-oxidizing bacteria (NOB) coexisted with anammox bacteria and accounted for 13 to 21% of total bacteria in the biofilms. Microelectrode measurements at three points along the anammox reactor revealed that the NH4+, and NO2- consumption rates decreased from 0.68 and 0.64 mu mol cm(-2) h(-1) at P2 (the second port, 170 mm from the inlet port) to 0.30 and 0.35 mu mol cm(-2) h(-1) at P3 (the third port, 205 rum from the inlet port), respectively. No anammox activity was detected at P4 (the fourth port, 240 mm from the inlet port), even though sufficient amounts of NH4+ and NO2- and a high abundance of anammox bacteria were still present. This result could be explained by the inhibitory effect of organic compounds derived from biomass decay and/or produced by anammox and coexisting bacteria in the upper parts of the biofilm and in the upstream part of the reactor. The anammox activities in the biofilm determined by microelectrodes reflected the overall reactor performance. The several groups of aerobic AOB lineages, Nitrospira-like NOB, and Betaproteobacteria coexisting in the anammox biofilm might consume a trace amount of O-2, or organic compounds, which consequently established suitable microenvironments for anammox bacteria.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2007年04月, ［査読有り］
英語, 研究論文（学術雑誌）, To promptly establish anaerobic ammonium oxidation (anammox) reactors, appropriate seeding sludge with high abundance and activity of anammox bacteria was selected by quantifying 16S rRNA gene copy numbers of anammox bacteria by real-time quantitative PCR (RTQ-PCR) and batch culture experiments. The selected sludge was then inoculated into up-flow fixed-bed biofilm column reactors with nonwoven fabric sheets as biomass carrier and the reactor performances were monitored over 1 year. The anammox reaction was observed within 50 days and a total nitrogen removal rate of 26.0 kg-N m(-3) day(-1) was obtained after 247 days. To our knowledge, such a high rate has never been reported before. Hydraulic retention time (HRT) and influent NH4+ to NO2- molar ratio could be important determinant factors for efficient nitrogen removal in this study. The higher nitrogen removal rate was obtained at the shorter HRT and higher influent NH4+/NO2- molar ratio. After anammox reactors were fully developed, the community structure, spatial organization and in situ activity of the anammox biofilms were analyzed by the combined use of a full-cycle of 16S rRNA approach and microelectrodes. In situ hybridization results revealed that the probe Amx820-hybridized anaerobic anammox bacteria were distributed throughout the biofilm (accounting for more than 70% of total bacteria), They were associated with Nitrosomonas-like aerobic ammonia-oxidizing bacteria (AAOB) in the surface biofilm. The anammox bacteria present in this study were distantly related to the Candidatus Brocadia anammoxidans with the sequence similarity of 95%. Microelectrode measurements showed that a high in situ anammox activity (i.e., simultaneous consumption of NH4+ and NO2-) of 4.45 g-N of (NH4++NO2-) m(-2) day(-1) was detected in the upper 800 mu m of the biofilm, which was consistent with the spatial distribution of anammox bacteria. (c) 2007 Elsevier Ltd. All rights reserved.

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, AMER SOC MICROBIOLOGY, 2007年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Microbially induced concrete corrosion (MICC) in sewer systems has been a serious problem for a long time. A better understanding of the succession of microbial community members responsible for the production of sulfuric acid is essential for the efficient control of MICC. In this study, the succession of sulfur-oxidizing bacteria (SOB) in the bacterial community on corroding concrete in a sewer system in situ was investigated over I year by culture-independent 16S rRNA gene-based molecular techniques. Results revealed that at least six phylotypes of SOB species were involved in the MICC process, and the predominant SOB species shifted in the following order: Thiothrix sp., Thiobacillus plumbophilus, Thiomonas intermedia, Halothiobacillus neapolitanus, Acidiphilium acidophilum, and Acidithiobacillus thiooxidans. A. thiooxidans, a hyperacidophilic SOB, was the most dominant (accounting for 70% of EUB338-mixed probe-hybridized cells) in the heavily corroded concrete after I year. This succession of SOB species could be dependent on the pH of the concrete surface as well as on trophic properties (e.g., autotrophic or mixotrophic) and on the ability of the SOB to utilize different sulfur compounds (e.g., H2S, S-0, and S2O32-). In addition, diverse heterotrophic bacterial species (e.g., halo-tolerant, neutrophilic, and acidophilic bacteria) were associated with these SOB. The microbial succession of these microorganisms was involved in the colonization of the concrete and the production of sulfuric acid. Furthermore, the vertical distribution of microbial community members revealed that A. thiooxidans was the most dominant throughout the heavily corroded concrete (gypsum) layer and thatA. thiooxidans was most abundant at the highest surface (1.5-mm) layer and decreased logarithmically with depth because of oxygen and H2S transport limitations. This suggested that the production of sulfuric acid by A. thiooxidans occurred mainly on the concrete surface and the sulfuric acid produced penetrated through the corroded concrete layer and reacted with the sound concrete below.

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, AMER SOC MICROBIOLOGY, 2007年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Influences of infaunal burrows constructed by the polychaete (Tylorrhynchus heterochaetus) on O-2 concentrations and community structures and abundances of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in intertidal sediments were analyzed by the combined use of a 16S rRNA gene-based molecular approach and microelectrodes. The microelectrode measurements performed in an experimental system developed in an aquarium showed direct evidence of O-2 transport down to a depth of 350 mm of the sediment through a burrow. The 16S rRNA gene-cloning analysis revealed that the betaproteobacterial AOB communities in the sediment surface and the burrow walls were dominated by Nitrosomonas sp. strain Nm143-like sequences, and most of the clones in Nitrospira-like NOB clone libraries of the sediment surface and the burrow walls were related to the Nitrospira marina lineage. Furthermore, we investigated vertical distributions of AOB and NOB in the infaunal burrow walls and the bulk sediments by real-time quantitative PCR (Q-PCR) assay. The AOB and Nitrospira-like NOB-specific 16S rRNA gene copy numbers in the burrow walls were comparable with those in the sediment surfaces. These numbers in the burrow wall at a depth of 50 to 55 rum from the surface were, however, higher than those in the bulk sediment at the same depth. The microelectrode measurements showed higher NH4+ consumption activity at the burrow wall than those at the surrounding sediment. This result was consistent with the results of microcosm experiments showing that the consumption rates of NH4+ and total inorganic nitrogen increased with increasing infaunal density in the sediment. These results clearly demonstrated that the infaunal burrows stimulated O-2 transport into the sediment in which otherwise reducing conditions prevailed, resulting in development of high NH4+ consumption capacity. Consequently, the infaunal burrow became an important site for NH4+ consumption in the intertidal sediment.

Response of NIPAAm-Ch gel to temperature changes and its effectiveness on nitrification as medium for immobilization
Linjiang Yuan, Tetsuya Kusuda, Hisashi Satoh
JOURNAL OF APPLIED POLYMER SCIENCE, 103, 2, 681, 686, JOHN WILEY & SONS INC, 2007年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Increase in mass transport resistance is one of the major difficulties in immobilization by the use of gels. Functional gels can change their volume and inner structure depending on ambient conditions as stimuli and may reduce the difficulty as a novel immobilization matrix. The response of poly N-isopropylacrylamide-co-chlorophyllin (NIPAAm-Ch) gel to temperature changes and its performance on nitrification with nitrifiers immobilized by the gel were investigated in a continuous-flow stirred-tank reactor (CFSTR) with cyclic temperature changes. The gel with an immobilized nitrifier swelled and shrank alternately with 1.2-1.6-fold volume change under a cyclic temperature change of 32-36 degrees C with a period of 2 or 4 h in the reactor. Volume changes of the gel brought periodic changes of its structure that accelerated dissolved oxygen transfer and concentrated ammonium into, and as a result, promoted nitrification compared with that at constant temperature. (c) 2006 Wiley Periodicals, Inc.

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, JOHN WILEY & SONS INC, 2006年08月, ［査読有り］
英語, 研究論文（学術雑誌）, Population dynamics of ammonia-oxidizing bacteria (AOB) and uncultured Nitrospira-like nitrite-oxidizing bacteria (NOB) dominated in autotrophic nitrifying biofilms were determined by using real-time quantitative polymerase chain reaction (RTQ-PCR) and fluorescence in situ hybridization (FISH). Although two quantitative techniques gave the comparable results the RTQ-PCR assay was easier and faster than the FISH technique for quantification of both nitrifying bacteria in dense microcolony-forming nitrifying biofilms. Using this RTQ-PCR assay, we could successfully determine the maximum specific growth rate (mu = 0.021/h) of uncultured Nitrospira-like NOB in the suspended enrichment culture. The population dynamics of nitrifying bacteria in the biofilm revealed that once they formed the biofilm, the both nitrifying bacteria grew slower than in planktonic cultures. We also calculated the spatial distributions of average specific growth rates of both nitrifying bacteria in the biofilm based on the concentration profiles of NH4+, NO2-, and O-2, which were determined by microelectrodes, and the double-Monod model. This simple model estimation could explain the stratified spatial distribution of AOB and Nitrospira-like NOB in the biofilm. The combination of culture-independent molecular techniques and microelectrode measurements is a very powerful approach to analyze the in situ kinetics and ecophysiology of nitrifying bacteria including uncultured Nitrospira-like NOB in complex biofilm communities. (c) 2006 Wiley Periodicals, Inc.

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, JOHN WILEY & SONS INC, 2006年07月, ［査読有り］
英語, 研究論文（学術雑誌）, The bacterial community structure, in situ spatial distributions and activities of nitrifying and denitrifying bacteria in biofilms treating industrial waste-water were investigated by combination of the 16S rRNA gene clone analysis, fluorescence in situ hybridization (FISH) and microelectrodes. These results were compared with the nitrogen removal capacity of the industrial wastewater treatment plant (IWTP). Both nitrification and denitrification occurred in the primary denitrification (PD) tank and denitrification occurred in the secondary denitrification (SD) tank. In contrast, nitrification and denitrification rates were very low in the nitrification (N) tank. 16S rRNA gene clone sequence analysis revealed that the bacteria affiliated with Alphaproteobacteria, followed by Betaproteobacteria, were numerically important microbial groups in three tanks. The many clones affiliated with Alphaproteobacteria were closely related to the denitrifying bacteria (e.g., Hyphomicrobium spp., Rhodopseudomonas palustris, and Rhodobacter spp.). In addition, Methylophilus leisingeri affiliated with Betaproteobacteria, which favorably utilized methanol, was detected only in the SD-tank to which methanol was added. Nitrosomonas europaea and Nitrosomonas marina were detected as the ammonia-oxidizing bacteria affiliated with Betaproteobacteria throughout this plant, although the dominant species of them was different among three tanks. Nitrifying bacteria were mainly detected in the upper parts of the PD-biofilm whereas their populations were low in the upper parts of the N-biofilm. The presence of denitrifying bacteria affiliated with Hyphomicrobium spp. in SD- and N-biofilms was verified by FISH analysis. Microelectrode measurements showed that the nitrifying bacteria present in the N- and PD-biofilms were active and the bacteria present in the SD-biofilm could denitrify. (c) 2006 Wiley Periodicals, Inc.

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, AMER CHEMICAL SOC, 2006年03月, ［査読有り］
英語, 研究論文（学術雑誌）, The community structure, spatial distributions, and in situ activity of ammonia-oxidizing bacteria (AOB) representing the Betaproteobacteria and nitrite-oxidizing bacteria (NOB) representing the genus Nitrospira in three different river sediments with different pollution sources and levels along the Niida River, Hachinohe, Japan, were investigated by the combined use of 16S rRNA gene-cloning analysis, real-time quantitative polymerase chain reaction (RTQ-PCR) assays, and microelectrodes. The goal of this research was to evaluate the contribution of nitrifying activity in the sediment to the overall nitrogen elimination rate in this river. The 16S rRNA gene-cloning analysis revealed that the community structures of AOB and Nitrospira-like NOB are present in three sediments. On the basis of the results of 16S rRNA gene-cloning analysis, the RTQ-PCR assay using a TaqMan probe was developed and optimized for the quantification of the Nitrospira-like NOB. In the sediments, AOB specific 16S rRNA genes were detected in the range of 10(6) to 10(7) copies/cm(3) and evenly distributed over the sampled sediment depth (0-5 mm), whereas the Nitrospira-like NOB 16S rRNA gene copy numbers per cm(3) were 1-2 orders of magnitude higher than the AOB copy numbers. Under light conditions, intensive oxygenic photosynthesis occurred in the surface and increased the maximal O-2 concentration and O-2 penetration depth in all sediments. This concomitantly stimulated nitrifying bacteria present in diurnally anoxic deeper zones and expanded nitrification zones, which consequently increased the total NH4+ consumption rate in the sediment (i.e., total NH4+ flux into the sediment). The results suggested that the in situ nitrifying activity was restricted mainly to the surface 2 mm of the sediment and linked with photosynthetic activity, which obviously plays an important role in nitrogen elimination in this river.

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, JOHN WILEY & SONS INC, 2005年07月, ［査読有り］
英語, 研究論文（学術雑誌）, In order to assess the applicability of using microelectrodes as a tool for inhibition tests, temporal and spatial inhibitory effects of 2-chlorophenol (2-CP) on O-2 respiration and nitrification activities in municipal wastewater biofilms were investigated using microelectrodes for O-2 and NH4+. The time-course microelectrode measurements demonstrated that 2-CP inhibited O-2 respiration and nitrification activities within 6-18 min. The microbial activities were inhibited only in the upper 400 pm of the biofilms by 2-CP, and the bacteria present in the deeper parts of the biofilms were still active, probably due to limited penetration of 2-CP. These results could reasonably explain the difference in inhibitory ratios of the O-2 respiration and nitrification activities in the biofilms. O-2 respiration activity was incompletely inhibited, which was attributed to the presence Of O-2 respiration activities in the deeper parts of the biofilm. In contrast, nitrification activity was significantly inhibited because ammonia-oxidizing bacteria were present in the upper parts of the biofilm. These results indicate that the microelectrodes with a very quick response time and a high spatial resolution are useful tools to study temporal and spatial inhibitory effects of inhibitors on in situ microbial activities in biofilms. (c) 2005 Wiley Periodicals, Inc.

Succession of internal sulfur cycles and sulfur-oxidizing bacterial communities in microaerophilic wastewater biofilms
S Okabe, T Ito, K Sugita, H Satoh
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 71, 5, 2520, 2529, AMER SOC MICROBIOLOGY, 2005年05月, ［査読有り］
英語, 研究論文（学術雑誌）, The succession of sulfur-oxidizing bacterial (SOB) community structure and the complex internal sulfur cycle occurring in wastewater biofilms growing under microaerophillic conditions was analyzed by using a polyphasic approach that employed 16S rRNA gene-cloning analysis combined with fluorescence in situ hybridization, microelectrode measurements, and standard batch and reactor experiments. A complete sulfur cycle was established via So accumulation within 80 days in the biofilms in replicate. This development was generally split into two phases, (i) a sulfur-accumulating phase and (ii) a sulfate-producing phase. In the first phase (until about 40 days), since the sulfide production rate (sulfate-reducing activity) exceeded the maximum sulfide-oxidizing capacity of SOB in the biofilms, H2S was only partially oxidized to S-0 by mainly Thiomicrospira denitirificans with NO3- as an electron acceptor, leading to significant accumulation of So in the biofilms. In the second phase, the SOB populations developed further and diversified with time. In particular, S-0 accumulation promoted the growth of a novel strain, strain SO07, which predominantly carried out the oxidation of S-0 to SO42- under oxic conditions, and Thiothrix sp. strain CT3. In situ hybridization analysis revealed that the dense populations of Thiothrix (ca. 10(9) cells cm(-3)) and strain SO07 (ca. 10(8) cells cm(-3)) were found at the sulfur-rich surface (100 μ m), while the population of Thiomicrospira denitirificans was distributed throughout the biofilms with a density of ca. 10(7) to 10(8) cells cm(-3). Microelectrode measurements revealed that active sulfide-oxidizing zones overlapped the spatial distributions of different phylogenetic SOB groups in the biofilms. As a consequence, the sulfide-oxidizing capacities of the biofilms became high enough to completely oxidize all H,S produced by SRB to SO42- in the second phase, indicating establishment of the complete sulfur cycle in the biofilms.

Photosynthesis in sediments determined at high spatial resolution by the use of microelectrodes
Y Nakamura, H Satoh, S Okabe, Y Watanabe
WATER RESEARCH, 38, 9, 2440, 2448, PERGAMON-ELSEVIER SCIENCE LTD, 2004年05月, ［査読有り］
英語, 研究論文（学術雑誌）, The present study investigated photosynthetic rates and their regulation by light within the upper 5 mm of sediment in a tidal area of Niida River in Hachinohe, Japan. Steady-state concentration profiles osf O-2, NH4+, NO2-, H2S, and pH in the sediment were measured with microelectrodes. Microzonation of O-2 respiration, denitrification and SO42- reduction was found in the sediment. When light intensities exceeded 1050 mumol photons/m(2)/S, net photosynthetic activity was detected in the upper 0.5 mm of the microbial mat colonizing on the sediment surface in the tidal area. In contrast, gross photosynthetic activity was detected in the upper 1.0 mm of the microbial mat at 19,00 mumol photons/m(2)/s. As light intensity increased, the net photosynthetic rate and O-2 penetration depth increased. The maximal net photosynthetic rate and O-2 penetration depth were 6.1 mumolO(2)/cm(3)/h and 2.2 mm, respectively, at 1900 mumol photons/m(2)/s. Net photosynthetic rates in the microbial mat in the tidal area were lower than in the upstream sediment. The analysis of continuous O-2 concentration measurements in different layers of the microbial mat during artificial light-dark cycles demonstrated that the photosynthetic activity response to changes in light intensity was extremely fast (a few seconds) and the O-2 concentration in the microbial mat became stable within 200 s. The measurement of physical and chemical parameters in river water revealed that the study site was relatively polluted and sunlight intensity significantly fluctuated temporally. These results suggested that the in situ microbial processes occurring in the sediment fluctuated in accordance with periodic fluctuations in sunlight intensity. (C) 2004 Elsevier Ltd. All rights reserved.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2004年03月, ［査読有り］
英語, 研究論文（学術雑誌）, A membrane aerated biofilm reactor (MABR), in which O-2 was supplied from the bottom of the biofilm and NH4+ and organic carbon were supplied from the biofilm surface, was operated at different organic carbon loading rates and intra-membrane air pressures to investigate the occurrence of simultaneous chemical oxygen demand (COD) removal, nitrification and denitrification. The spatial distribution of nitrification and denitrification zones in the biofilms was measured with microelectrodes for O-2, NH4+, NO2-, NO3- and pH. When the MABR was operated at approximately 1.0 g-COD/m(2)/day of COD loading rate, simultaneous COD removal, nitrification and denitrification could be achieved. The COD loading rates and the intra-membrane air pressures applied in this study had no effect on the startup and the maximum rates of NH4+ oxidation in the MABRs. Microelectrode measurements showed that O-2 was supplied from the bottom of the MABR biofilm and penetrated the whole biofilm. Because the biofilm thickness increased during the operations, an anoxic layer developed in the upper parts of the mature biofilms while an oxic layer was restricted to the deeper parts of the biofilms. The development of the anoxic zones in the biofilms coincided with increase in the denitrification rates. Nitrification occurred in the zones from membrane surface to a point of ca. 60 mum. Denitrification mainly occurred just above the nitrification zones. The COD loading rates and the intra-membrane air pressures applied in this study had no effect on location of the nitrification and denitrification zones. (C) 2004 Elsevier Ltd. All rights reserved.

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年
英語, 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.

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, I W A PUBLISHING, 2004年, ［査読有り］
英語, 研究論文（学術雑誌）, Effects of hydroxylamine (NH2OH), an intermediate of NH4+ oxidation, on microbial community structure and function of two autotrophic nitrifying biofilms fed with and without NH2OH were analyzed by a 16S rRNA approach and the use of microelectrodes. In the NH2OH-added biofilm, partial oxidation of NH4+ to NO2- was observed, whereas complete oxidation of NH4+ to NO3- was achieved in the control biofilm. In situ hybridization results revealed that no nitrite-oxidizing bacteria (NOB) hybridized with any specific probes were detected in the NH2OH-added biofilm. Thus, the addition of low concentrations of NH2OH (250 muM) completely inhibited the growth of NOR Phylogenetic analysis of 16S rDNA indicated that the ammonia-oxidizing bacteria (AOB) detected in both biofilms were closely related to Nitrosomonas europaea, and that the clone sequences from both biofilm libraries have more than 99% similarity to each other. However, in situ hybridization results revealed that the addition of NH2OH changed the form of growth pattern of the dominant Nitrosomonas spp. from dense clusters mode to single scattered cells mode. Microelectrode measurements revealed that the average NH4+ consumption rate calculated in the NH2OH-added biofilm was two times higher than that in the control biofilm. This clearly demonstrated that the oxidation of NH4+ was stimulated by NH2OH addition.

Analysis of size distribution and areal cell density of ammonia-oxidizing bacterial microcolonies in relation to substrate microprofiles in biofilms
S Okabe, T Kindaichi, T Ito, H Satoh
BIOTECHNOLOGY AND BIOENGINEERING, 85, 1, 86, 95, JOHN WILEY & SONS INC, 2004年01月, ［査読有り］
英語, 研究論文（学術雑誌）, A fine-scale in situ spatial organization of ammonia-oxidizing bacteria (AOB) in biofilms was investigated by combining molecular techniques (i.e., fluorescence in situ hybridization (FISH) and 16S rDNA-cloning analysis) and microelectrode measurements. Important parameters of AOB microcolonies such as size distribution and areal cell density of the microcolonies were determined and correlated with substrate microprofiles in the biofilms. In situ hybridization with a nested 16S rRNA-targeted oligonucleotide probe set revealed two different populations of AOB, Nitrosomonas europaea-lineage and Nitrosospira multiformis-lineage, coexisting in an autotrophic nitrifying biofilm. Nitrosospira formed looser microcolonies with an areal cell density of 0.51 cells mum(-2), which was half of the cell density of Nitrosomonas (1.12 cells mum(-2)). It is speculated that the formation of looser microcolonies facilitates substrate diffusion into the microcolonies, which might be a survival strategy to low O-2 and NH4+ conditions in the biofilm. A long-term experiment (4-week cultivation at different substrate C/N ratios) revealed that the size distribution of ACB microcolonies was strongly affected by better substrate supply due to shorter distance from the surface and the presence of organic carbon. The microcolony size was relatively constant throughout the autotrophic nitrifying biofilm, while the size increased by similar to80% toward the depth of the biofilm cultured at the substrate C/N = 1. A short-term (similar to 3 h) organic carbon addition experiment showed that the addition of organic carbon created interspecies competition for O-2 between AOB and heterotrophic bacteria, which dramatically decreased the in situ NH4+-uptake activity of AOB in the surface of the biofilms. This result might explain the spatial distribution of AOB microcolony size in the biofilms cultured at the substrate C/N = 1. These experimental results suggest O-2 and organic carbon were the main factors controlling the spatial organization and activity of AOB in biofilms. These findings are significantly important to further improve mathematical models used to describe how the slow-growing AOB develop their niches in biofilms and how that configuration affects nitrification performance in the biofilm. (C) 2004 Wiley Periodicals, Inc.

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, SPRINGER-VERLAG, 2003年12月, ［査読有り］
英語, 研究論文（学術雑誌）, The community structure of sulfate-reducing bacteria (SRB) and the contribution of SRB to carbon mineralization in a wastewater biofilm growing under microaerophilic conditions were investigated by combining molecular techniques, molybdate inhibition batch experiments, and microelectrode measurements. A 16S rDNA clone library of bacteria populations was constructed from the biofilm sample. The 102 clones analyzed were grouped into 53 operational taxonomic units (OTUs), where the clone distribution was as follows: Cytophaga-Flexibacter-Bacteroides (41%), Proteobacteria (41%), low-G+C Gram-positive bacteria (18%), and other phyla (3%). Three additional bacterial clone libraries were also constructed from SRB enrichment cultures with propionate, acetate, and H-2 as electron donors to further investigate the differences in SRB community structure due to amendments of different carbon sources. These libraries revealed that SRB clones were phylogenetically diverse and affiliated with six major SRB genera in the delta-subclass of the Proteobacteria. Fluorescent in situ hybridization (FISH) analysis revealed that Desulfobulbus and Desulfonema were the most abundant SRB species in this biofilm, and this higher abundance (ca. 2-4x10(9) cells cm(-3) and 5x10(7) filaments cm(-3), respectively) was detected in the surface of the biofilm. Microelectrode measurements showed that a high sulfate-reducing activity was localized in a narrow zone located just below the oxic/anoxic interface when the biofilm was cultured in a synthetic medium with acetate as the sole carbon source. In contrast, a broad sulfate-reducing zone was found in the entire anoxic strata when the biofilm was cultured in the supernatant of the primary settling tank effluent. This is probably because organic carbon sources diffused into the biofilm from the bulk water and an unknown amount of volatile fatty acids was produced in the biofilm. A combined approach of molecular techniques and batch experiments with a specific inhibitor (molybdate) clearly demonstrated that Desulfobulbus is a numerically important member of SRB populations and the main contributor to the oxidation of propionate to acetate in this biofilm. However, acetate was preferentially utilized by nitrate-reducing bacteria but not by acetate-utilizing SRB.

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, JOHN WILEY & SONS INC, 2003年09月, ［査読有り］
英語, 研究論文（学術雑誌）, Simultaneous nitrification and denitrification (SND) was investigated in the single aeration tank of a municipal wastewater treatment plant. Microelectrode measurements and batch experiments were performed to test for the presence of SND. Microelectrodes recorded the presence of O-2 concentration gradients in individual activated sludge flocs. When the O-2 concentration in the bulk liquid was <45 μM, anoxic zones were detected within flocs with a larger diameter (approximately 3000 pm). The O-2 penetration depth in the floc was found to be dependent on the O-2 concentration in the bulk liquid. Nitrification was restricted to the oxic zones, whereas denitrification occurred mainly in the anoxic zones. The nitrification rate of the activated sludge increased with increasing O-2 concentration in the bulk liquid, up to 40 μM, and remained constant thereafter. SND was observed in the aerated activated sludge when O-2 concentration was in the range of 10 to 35 μM. (C) 2003 Wiley Periodicals, Inc.

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, PERGAMON-ELSEVIER SCIENCE LTD, 2003年05月, ［査読有り］
英語, 研究論文（学術雑誌）, Three rotating disk biofilm reactors were operated to evaluate whether bioaugmentation and biostimulation can be used to improve the start-up of microbial nitrification. The first reactor was bioaugmented during start-up period with an enrichment culture of nitrifying bacteria, the second reactor received a synthetic medium containing NH4+ and NO2- to facilitate concomitant proliferation of ammonia- and nitrite-oxidizing bacteria, and the third reactor was used as a control. To evaluate the effectiveness of bioaugmentation and biostimulation approaches, time-dependent developments of nitrifying bacterial community and in situ nitrifying activity in biofilms were monitored by fluorescence in situ hybridization (FISH) technique and microelectrode measurements of NH4+, NO2-, NO3-, and O-2. In situ hybridization results revealed that addition of the enrichment culture of nitrifying bacteria significantly facilitated development of dense nitrifying bacterial populations in the biofilm shortly after, which led to a rapid start-up and enhancement of in situ nitrification activity. The inoculated bacteria could proliferate and/or survive in the biofilm. In addition, the addition of nitrifying bacteria increased the abundance of nitrifying bacteria in the surface of the biofilm, resulting in the higher nitrification rate. On the other hand, the addition of 2.1 mM NO2- did not stimulate the growth of nitrite-oxidizing bacteria and did inhibit the proliferation of ammonia-oxidizing bacteria instead. Thus, the start-up of NO2- oxidation was unchanged, and the start-up of NH4+ oxidation was delayed. In all the three biofilm reactors, data sets of time series analyses on population dynamics of nitrifying bacteria determined by FISH, in situ nitrifying activities determined by microelectrode measurements, and the reactor performances revealed an approximate agreement between the appearance of nitrifying bacteria and the initiation of nitrification activity, suggesting that the combination of these techniques was a very powerful monitoring tool to evaluate the effectiveness of bioaugmentation and biostimulation strategies. (C) 2002 Elsevier Science Ltd. All rights reserved.

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　　　　　　　　　　　　　　　
岡部聡, 伊藤司, 佐藤久
月刊 海洋, 35, 54, 63, 2003年

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, I W A PUBLISHING, 2003年, ［査読有り］
英語, 研究論文（学術雑誌）, The effects of O-2 and NO3- concentrations on in situ sulfate reduction and sulfide reoxidation in microaerophilic wastewater biofilms grown on rotating disk reactors were investigated by the use of microelectrodes for O-2, S2-, NO3-, NO2-, and pH. Microelectrocle measurements showed the vertical microzonation of O-2 respiration, NO3- respiration, H2S oxidation and SO42- reduction in the biofilms. The microelectrode measurements indicate that sulfate reducing activity was largely restricted to a narrow anaerobic zone located about 500 mum below the biofilm surface. An addition of nitrate forced the sulfate reduction zone deeper in the biofilm and reduced the specific sulfate reduction rate as well. The sulfate reduction zone was consequently separated from the O-2 and NO3- respiration zones. Anaerobic H2S oxidation with NO3- was also induced by addition of nitrate to the medium. Measurements of the reduced inorganic sulfur compounds (FeS, FeS2 and SO), total-Mn and total-Fe in the biofilm indicated that the produced H2S became immediately oxidized with O-2, NO3- and other oxidants, mainly ferric/ferrous hydrates. On the basis of the present results, it was estimated that of all sulfide produced, 13% of the sulfide was precipitated by metal ions as FeS and SO just above the sulfate reduction zone, 65% was anaerobically oxidized to SO42- with NO3- as an electron acceptor and 22% was aerobically oxidized within the biofilm incubated in 70 mumol l(-1) of DO and 280 mumol l(-1) of NO3-.

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, AMER SOC MICROBIOLOGY, 2002年03月, ［査読有り］
英語, 研究論文（学術雑誌）, A combination of fluorescence in situ hybridization, microprofiles, denaturing gradient gel electrophoresis of PCR-amplified 16S ribosomal DNA fragments, and 16S rRNA gene cloning analysis was applied to investigate successional development of sulfate-reducing bacteria (SRB) community structure and in situ sulfide production activity within a biofilm growing under microaerophilic conditions (dissolved oxygen concentration in the bulk liquid was in the range of 0 to 100 muM) and in the presence of nitrate. Microelectrode measurements showed that oxygen penetrated 200 mum from the surface during all stages of biofilm development. The first sulfide production of 0.32 mumol of H2S m(-2) s(-1) was detected below ca. 500 mum in the 3rd week and then gradually increased to 0.70 mumol H2S m(-2) s(-1) in the 8th week. The most active sulfide production zone moved upward to the oxic-anoxic interface and intensified with time. This result coincided with an increase in SRB populations in the surface layer of the biofilm. The numbers of the probe SRB385- and 660-hybridized SRB populations significantly increased to 7.9 x 10(9) cells cm(-3) and 3.6 x 10(9) cells cm(-3), respectively, in the surface 400 mum during an 8-week cultivation, while those populations were relatively unchanged in the deeper part of the biofilm, probably due to substrate transport limitation. Based on 16S rRNA gene cloning analysis data, clone sequences that related to Desulfomicrobium hypogeium (99% sequence similarity) and Desulfobulbus elongatus (95% sequence similarity) were most frequently found. Different molecular analyses confirmed that Desulfobulbus, Desulfovibrio, and Desulfomicrobium were found to be the numerically important members of SRB in this wastewater biofilm.

微小電極を用いた活性汚泥内の酸素消費機構の解析
佐藤 久, 中村 吉志, 小野 英樹
水環境学会誌 = Journal of Japan Society on Water Environment, 25, 1, 27, 32, Japan Society on Water Environment, 2002年01月10日
日本語, Microelectrode was used to investigate oxygen consumption mechanism in activated sludge. Oxygen fluxes and distributions of oxygen consumption activity were determined from the microprofiles. The spatial distributions of oxygen and nitrate consumption activity were heterogeneous. Under conditions in which oxygen concentration in the bulk liquid was less than 120μM, oxygen consumption activity was high in the outer zone and anoxic zone developed in the center part of the activated sludge. Oxygen consumption activity of the activated sludge was comparable to that of the domestic wastewater biofilm. Distribution of nitrate consumption activity showed that denitrification occurred in the anoxic zone of the activated sludge. Oxygen consumption activity increased as oxygen concentration in the bulk liquid increased, which resulted in increase in oxygen fluxes of the activated sludge. In contrast, when oxygen concentration in the bulk liquid was more than 120μM, oxygen fluxes were unchanged due to limitation of microbial density. Oxygen fluxes at more than 120μM of oxygen in the bulk liquid were lower than those at about 120μM of oxygen.

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, I W A PUBLISHING, 2002年, ［査読有り］
英語, 研究論文（学術雑誌）, The phylogenetic diversity of a nitrifying bacterial community of two types of nitrifying biofilms, a domestic wastewater biofilm and an autotrophic nitrifying biofilm grown on rotating disk reactors (RDR), was characterized by 16S ribosomal DNA (rDNA)-cloning analysis. Thereafter, successional development of nitrifying the bacterial community within both biofilms was visualized in situ by fluorescent in situ hybridization (FISH) with a set of fluorescently labeled 16S rRNA-targeted DNA probes. In situ hybridization revealed that Nitrosomonas ureae was the numerically dominant species of the ammonia-oxidizing population in the domestic wastewater biofilm and that a population shift from N. urea to N. europaea and N. eutropha occurred when the culture medium was switched to the synthetic media from the domestic wastewater. After reaching the steady-state condition, microprofiles of NH4+, NO2-, NO3-, and O-2 in the biofilms were measured by use of microsensors, and the spatial distributions of in situ nitrifying activities were determined. The relationship between the spatial organization of nitrifying bacterial populations and the in situ activity of these populations within the biofilms was discussed. Microelectrode measurements revealed that the active ammonia-oxidizing zone was vertically separated from the active nitrite-oxidizing zone. This vertical separation became more evident with increase of the substrate C/N ratio, leading to deterioration of nitrification efficiency. The combined use of these techniques made it possible to relate in situ nitrifying activity directly to the occurrence of nitrifying bacterial populations.

Analysis of microbial structure and function of nitrifying biofilms
S Okabe, H Satoh, Y Watanabe
MICROBIAL GROWTH IN BIOFILMS, PT B, 337, 213, 224, ACADEMIC PRESS INC, 2001年, ［査読有り］
英語

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, I W A PUBLISHING, 2000年, ［査読有り］
英語, 研究論文（学術雑誌）, The effect of substrate C/N ratio on the spatial distributions of ammonia-oxidizing bacteria and their activity was investigated by using microelectrodes with high spatial resolution and fluorescent in situ hybridization (FISH) technique. In this study, an interspecies competition for O-2 between ammonia-oxidizing bacteria and heterotrophic bacteria was experimentally evaluated. An autotrophic nitrifying biofilm originally cultured at C/N=0 was used as a model biofilm to study changes in specific NH; oxidation rate profiles in the biofilm when the substrate C/N ratio was varied. As C/N ratio increased, specific NH; oxidation rates decreased in the outer part of the biofilm due to interspecies competition, while they were unchanged in the inner part. The increase in substrate C/N ratio (i.e., addition of acetate) immediately induced the interspecies competition for O-2 between ammonia-oxidizing bacteria and heterotrophic bacteria at the outer part of the biofilm. As a result of the interspecies competition, NH4+ oxidation was restrained, resulting in a decrease in the ammonia-oxidizing bacterial populations. This experimental result clearly explains the stratified spatial distributions of ammonia-oxidizing bacteria within the biofilms at higher substrate C/N ratios. The combined application of microelectrodes and FISH techniques provides new insights into microbial ecology and population dynamics of nitrifying bacteria within multi-species biofilms.

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, AMER SOC MICROBIOLOGY, 1999年11月, ［査読有り］
英語, 研究論文（学術雑誌）, The vertical distribution of sulfate-reducing bacteria (SRB) in aerobic wastewater biofilms grown on rotating dish reactors was investigated by fluorescent in situ hybridization (FISH) with 16S rRNA-targeted oligonucleotide probes. To correlate the vertical distribution of SRB populations with their activity, the microprofiles of O-2, H2S, NO2-, NO3-, NH4+, and pH were measured with microelectrodes. In addition, a cross-evaluation of the FISH and microelectrode analyses was performed by comparing them with culture-based approaches and biogeochemical measurements. In situ hybridization revealed that a relatively high abundance of the probe SRB385-stained cells (approximately 10(9) to 10(10) cells per cm(3) of biofilm) were evenly distributed throughout the biofilm, even in the oxic surface. The probe SRB660-stained Desulfobulbus spp. were found to be numerically important members of SRB populations (approximately 10(8) to 10(9) cells per cm(3)). The result of microelectrode measurements showed that a high sulfate-reducing activity was found in a narrow anaerobic zone located about 150 to 300 mu m below the biofilm surface and above which an intensive sulfide oxidation zone was found. The biogeochemical measurements showed that elemental sulfur (S-0) was an important intermediate of the sulfide reoxidation in such thin wastewater biofilms (approximately 1,500 mu m), which accounted for about 75% of the total S pool in the biofilm. The contribution of an internal Fe-sulfur cycle to the overall sulfur cycle in aerobic wastewater biofilms was insignificant (less than 1%) due to the relatively high sulfate reduction rate.

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, AMER SOC MICROBIOLOGY, 1999年07月, ［査読有り］
英語, 研究論文（学術雑誌）, We investigated the in situ spatial organization of ammonia-oxidizing and nitrite-oxidizing bacteria in domestic wastewater biofilms and autotrophic nitrifying biofilms by using microsensors and fluorescent in situ hybridization (FISH) performed with 16S rRNA-targeted oligonucleotide probes. The combination of these techniques made it possible to relate in situ microbial activity directly to the occurrence of nitrifying bacterial populations. In situ hybridization revealed that bacteria belonging to the genus Nitrosomonas were the numerically dominant ammonia-oxidizing bacteria in both types of biofilms. Bacteria belonging to the genus Nitrobacter were not detected; instead, Nitrospira-like bacteria were the main nitrite-oxidizing bacteria in both types of biofilms. Nitrospira-like cells formed irregularly shaped aggregates consisting of small microcolonies, which clustered around the clusters of ammonia oxidizers. Whereas most of the ammonia-oxidizing bacteria were present throughout the biofilms, the nitrite-oxidizing bacteria were restricted to the active nitrite-oxidizing zones, which were in the inner parts of the biofilms. Microelectrode measurements showed that the active ammonia-oxidizing zone was located in the outer part of a biofilm, whereas the active nitrite-oxidizing zone was located just below the ammonia-oxidizing zone and overlapped the location of nitrite-oxidizing bacteria, as determined by FISH.

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, PERGAMON-ELSEVIER SCIENCE LTD, 1999年, ［査読有り］
英語, 研究論文（学術雑誌）, The vertical distribution of sulfate-reducing bacteria (SRB) in microaerophilic wastewater biofilms grown on fully submerged rotating disk reactors (RDR) was determined by the conventional culture-dependent MPN method and in situ hybridization of fluorescently-labelled 16S rRNA-targeted oligonucleotide probes for SRB in parallel. Chemical concentration profiles within the biofilm were also measured using microelectrodes for O-2, S2-, NO3- and pH. In situ hybridization revealed that the SRB probe-stained cells were distributed throughout the biofilm even in the oxic surface zone in ail states from single scattered cells to clustered cells. The higher fluorescence intensity and abundance of SRB probe-stained cells were found in the middle part of the biofilm. This result corresponded well with O-2 and H2S concentration profiles measured by microelectrodes, showing sulfate reduction was restricted to a narrow anaerobic zone located about 500 mu m below the biofilm surface. Results of the MPN and potential sulfate reducing activity (culture-dependent approaches) indicated a similar distribution of cultivable SRB in the biofilm, The majority of the general SRB probe-stained cells were hybridized with SRB 660 probe, suggesting that one important member of the SRB in the wastewater biofilm could be the genus Desulfobulbus. An addition of nitrate forced the sulfate reduction zone deeper in the biofilm and reduced the specific sulfate reduction rate as well. The sulfate reduction zone was consequently separated from O-2 and NO3- respiration zones. Anaerobic H2S oxidation with NO3- was also induced by addition of nitrate to the medium.

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, PERGAMON-ELSEVIER SCIENCE LTD, 1998年, ［査読有り］
英語, 研究論文（学術雑誌）, The microzonation of O-2 respiration, H2S oxidation and SO42- reduction in aerobic biofilms grown on rotating disk reactors of a sewage treatment plant was studied by measuring concentration profiles with microelectrodes for O-2, S2- and pH. The vertical distribution of sulfate-reducing bacteria (SRB) in the biofilms was also determined by the conventional culture-dependent MPN method and fluorescently labeled 16S rRNA-targeted oligonucleotide probes for SRB. The SRB probe stained cells were distributed throughout the biofilm with a distinct higher fluorescence intensity in the middle part of the biofilm. This result corresponded well with O-2 and S2- concentration gradients measured by microelectrodes, showing sulfate reducing activity was largely restricted to a narrow anaerobic zone located in the middle of the biofilm. Measurements of accumulation of reduced sulfur compounds (FeS, FeS2 and S-O) in the biofilm indicated that the H2S produced by SRB became oxidized by O-2 and other oxidants, probably ferric/ferrous hydrates, and precipitated as FeS and S-O just above the sulfate reduction zone. (C) 1998 IAWQ. Published by Elsevier Science Ltd.

混合培養系生物膜内の懸濁微粒子の挙動に関する基礎的研究
岡部 聡, 安田 岳雄, 佐藤 久, 渡辺 義公
環境工学研究論文集, 33, 103, 114, Japan Society of Civil Engineers, 1996年
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.

Microscopic and metatranscriptomic analyses revealed unique cross-domain symbiosis betweenCandidatusPatescibacteria/candidate phyla radiation (CPR) and methanogenic archaea in anaerobic ecosystems
Kyohei Kuroda, Meri Nakajima, Ryosuke Nakai, Yuga Hirakata, Shuka Kagemasa, Kengo Kubota, Taro Q.P. Noguchi, Kyosuke Yamamoto, Hisashi Satoh, Masaru K. Nobu, Takashi Narihiro, bioRxiv, 15, 3, e0310223, 2023年08月25日, ［国際誌］
To verify the parasitic lifestyle ofCandidatusPatescibacteria in the enrichment cultures derived from a methanogenic bioreactor, we applied multifaceted approaches combining cultivation, microscopy, metatranscriptomic, and protein structure prediction analyses. Cultivation experiments with the addition of exogenous methanogenic archaea with acetate, amino acids, and nucleoside monophosphates and 16S rRNA gene sequencing confirmed the increase in the relative abundance ofCa. Patescibacteria and methanogens. The predominantCa. Patescibacteria wereCa. Yanofskybacteria and 32-520 lineages (to which belongs to classCa. Paceibacteria) and positive linear relationships (r²≥ 0.70) between the relative abundance ofCa. Yanofskybacteria andMethanothrix, suggesting that the tendency of the growth rate is similar to that of the host. By fluorescencein situhybridization (FISH) observations, the FISH signals ofMethanothrixandMethanospirillumcells withCa. Yanofskybacteria and with 32-520 lineages, respectively, were significantly lower than those of the methanogens withoutCa. Patescibacteria, suggesting their parasitic interaction. The TEM and SEM observations also support parasitism in that the cell walls and plugs of these methanogens associated with submicron cells were often deformed. In particular, someMethanothrix-like filamentous cells were dented where the submicron cells were attached. Metatranscriptomic and protein structure prediction analyses identified highly expressed secreted genes from the genomes ofCa. Yanofskybacteria and 32-520, and these genes contain adhesion-related domains to the host cells. Considering the results through the combination of microscopic observations, gene expression, and computational protein modeling, we propose that the interactions betweenCa. Yanofskybacteria and 32-520 belonging to classCa. Paceibacteria and methanogenic archaea are parasitism., Cold Spring Harbor Laboratory, 英語

PCRフリーの金ナノ粒子プローブを用いたメタン生成アーキアと寄生性超微小細菌の迅速定量技術の開発
半田久純, 中島芽梨, 中屋佑紀, 佐藤久, 黒田恭平, 成廣隆, 日本水環境学会年会講演集, 57th, 2023年

北海道の河川における農業・下水処理由来物質に着目した溶存有機物や生物化学的指標の縦断分析
中屋佑紀, 赤澤優弥, 小野寺岳史郎, 宮島龍太, 佐藤久, 北林里佳子, 田中佑奈, 相沢智康, 大西裕季, 熊木康裕, 黒田恭平, 成廣隆, 日本水環境学会年会講演集, 57th, 2023年

Candidatus Patescibacteria/CPRとメタン生成アーキアの共培養系確立への挑戦
中島芽梨, 中島芽梨, 中井亮佑, 久保田健吾, 中屋佑紀, 佐藤久, 延優, 成廣隆, 黒田恭平, 日本水環境学会年会講演集, 57th, 2023年

金ナノ粒子プローブを用いたメタン生成アーキアと寄生性超微小細菌の迅速定量
半田久純, 中島芽梨, 中屋佑紀, 佐藤久, 成廣隆, 黒田恭平, 下水道研究発表会講演集, 60th, 2023年

都市河川における薬剤耐性遺伝子の消長
小野寺岳史郎, 岩崎隼, 赤澤優弥, 宮島龍太, 中屋佑紀, 佐藤久, 平野麗子, 黒田恭平, 成廣隆, 日本水環境学会年会講演集, 56th, 2022年

金ナノ粒子を用いた硝化細菌の16S rRNAの比色分析—第57回下水道研究発表会講演集
中島 芽梨, 佐藤 久, 平野 麗子, 下水道研究発表会講演集, 57, 16, 18, 2020年
日本下水道協会, 日本語

中空糸膜槽外型の嫌気性MBRによる下水汚泥の消化
益子理保, 羽深昭, 山村寛, 小田嶋龍飛, 佐藤久, 渡辺義公, 日本水環境学会年会講演集, 52nd, 271, 2018年03月09日
日本語

下廃水中からのリン回収に向けたジルコニウム‐メソ構造体包含ポリスルフォン膜の開発
古屋謙治, 羽深昭, 黒岩美帆, 山村寛, 佐藤久, 渡辺義公, 日本水環境学会年会講演集, 52nd, 60, 2018年03月09日
日本語

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年

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年

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年

嫌気性MBRを用いた下水汚泥のメタン発酵
羽深昭, 小田嶋龍飛, 益子理保, 山村寛, 佐藤久, 渡辺義公, 下水道研究発表会講演集, 54th, 221‐223, 2017年07月03日
日本語

嫌気性MBRの連続運転による下水汚泥の濃縮と消化
羽深昭, 小田嶋龍飛, 山村寛, 三村和久, 伊東賢洋, 佐藤久, 渡辺義公, 日本水環境学会年会講演集, 51st, 67, 2017年03月09日
日本語

ジルコニウム‐メソ多孔体を包含したリン回収多機能膜の開発
古屋謙治, 羽深昭, 黒岩美帆, 山村寛, 佐藤久, 渡辺義公, 日本水環境学会年会講演集, 51st, 232, 2017年03月09日
日本語

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年

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年

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年

鉄還元型嫌気性アンモニア酸化プロセスによる超省エネルギーかつ省コストな窒素除去技術の創出
押木守, 荒木信夫, 川上周司, 佐藤久, 環境助成研究成果 概要集 第35回・2014年度分:5件 第36回・2015年度分:28件 平成29年, 25‐26, 2017年
日本語

リン吸着能を有するジルコニウム担持分離膜の開発
古屋謙治, 羽深昭, 黒岩美帆, 佐藤久, 渡辺義公, 山村寛, 環境工学研究フォーラム講演集, 53rd, 15, 2016年12月06日
日本語

嫌気性膜分離法(AnMBR)を用いた余剰汚泥の消化と濃縮に関する研究
小田嶋龍飛, 羽深昭, 佐藤久, 渡辺義公, 山村寛, 環境工学研究フォーラム講演集, 53rd, 18, 2016年12月06日
日本語

嫌気性膜分離(AnMBR)を用いたMBR余剰汚泥の消化に関する研究
羽深昭, 山村寛, 佐藤久, 渡辺義公, 下水道研究発表会講演集, 53rd, 1130‐1132, 1132, 2016年07月01日
日本下水道協会, 日本語

嫌気性MBRを用いたMBR余剰汚泥の消化
羽深昭, 山村寛, 三村和久, 佐藤久, 渡辺義公, 日本水環境学会年会講演集, 50th, 181, 2016年03月10日
日本語

下水処理水中カリウムの回収に向けた好塩古細菌の動力学的解析 (第53回下水道研究発表会講演集)
楊 子然, 森 康弘, 中川 晴菜, 野村 惇喜, 高橋 正宏, 佐藤 久, 深澤 達矢, 下水道研究発表会講演集, 53, 959, 961, 2016年
日本下水道協会, 日本語

カリウム回収の仕上げ工程としての塩化物混合物からの塩化カリウムの分離
中山翔太, 高橋正宏, 佐藤久, 深澤達矢, 中川晴菜, 第５２回下水道研究発表会講演集, 52, 449, 451, 2015年07月
日本下水道協会, 日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

嫌気性MBRを用いたbMBR余剰汚泥からのリン溶出に関する研究
LU Tao, 羽深昭, 山村寛, 渡辺義公, 佐藤久, 下水道研究発表会講演集, 52nd, 197, 199, 2015年07月01日
日本下水道協会, 日本語

雑排水の農業利用のための高速酸化池におけるLASの除去
中山翔太, 高橋 正宏, 佐藤久, 深澤達矢, 第５１回下水道研究発表会講演集, 51, 304, 306, 2014年07月
日本下水道協会, 日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

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年
日本微生物生態学会, 英語

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年
日本語

2S-Cp04 嫌気性アンモニア酸化(anammox) 細菌の代謝多様性と廃水処理への応用(極限生物たちが切り拓く未来の環境バイオテクノロジー,シンポジウム)
押木 守, 佐藤 久, 岡部 聡, 日本生物工学会大会講演要旨集, 65, 89, 89, 2013年08月25日
公益社団法人日本生物工学会, 日本語

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, 2013年05月04日
日本語

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, 2013年03月11日
日本語

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, 2013年03月11日
日本語

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, 2013年03月11日
日本語

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, 2013年03月11日
日本語

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, 2013年03月11日
日本語

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, 2013年03月11日
日本語

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, 2013年02月
日本語

アフリカ-サヘル地域における高速酸化池法の再生水中固形物・栄養塩濃度の制御 (第50回下水道研究発表会講演集)
小野寺 正純, 高橋 正宏, 佐藤 久, 下水道研究発表会講演集, 50, 103, 105, 2013年
日本下水道協会, 日本語

東京湾奥部における底質間隙水中の遊離の硫化水素について
牧秀明, 金谷弦, 中村泰男, 管原庄吾, 清家泰, 佐藤久, 日本海洋学会大会講演要旨集, 2013, 2013年

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, 2012年12月04日
日本語

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, 2012年11月28日
日本語

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, 2012年11月28日
日本語

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, 2012年11月28日
日本語

PGa-04 嫌気性アンモニア酸化細菌Candidatus 'Brocadia sinica'メタゲノム解析による新規アナモックス代謝経路の同定(PGa 増殖・生理・代謝,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, 28, 160, 160, 2012年09月19日
日本微生物生態学会, 英語

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, 2012年09月10日
日本語

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, 2012年09月10日
日本語

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, 2012年09月05日
日本語

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, 2012年09月05日
日本語

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, 2012年09月05日
日本語

ジルコニアカラムを用いた極低濃度リン測定法の検討~摩周湖水を対象として~
速水裕人, 深澤達矢, 佐藤久, 高橋正宏, 五十嵐聖貴, 田中敦, 環境化学討論会要旨集(CD-ROM), 21st, ROMBUNNO.3E-07, 2012年07月10日
日本語

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, 2012年05月05日
日本語

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, 2012年03月14日
日本語

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, 2012年03月14日
日本語

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, 2012年03月14日
日本語

都市河川における底生生物相の劣化要因の調査
杉本昌也, 蔭浦一裕, 深澤達矢, 佐藤久, 高橋正宏, 日本水環境学会年会講演集, 46th, 131, 2012年03月14日
日本語

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, 2012年03月14日
日本語

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, 2012年01月31日
日本語

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, 2012年01月31日
日本語

東京湾奥部における底泥中の硫化物と酸素消費との関係
牧秀明, 金谷弦, 中村泰男, 管原庄吾, 清家泰, 佐藤久, 日本水環境学会年会講演集, 46th, 2012年

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, 2011年11月25日
日本語

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, 2011年11月25日
日本語

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, 2011年11月25日
日本語

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, 2011年10月08日
日本微生物生態学会, 日本語

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, 2011年10月08日
日本微生物生態学会, 日本語

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, 2011年09月10日
日本語

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, 2011年08月05日
日本語

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, 2011年08月05日
日本語

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, 2011年08月05日
日本語

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, 2011年07月01日
日本語

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, 2011年07月01日
日本語

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, 2011年03月18日
日本語

都市化による水系生物相劣化の原因
蔭浦一裕, 高橋正宏, 棚池竜也, 杉本昌也, 佐藤久, 深澤達矢, 日本水環境学会年会講演集, 45th, 243, 2011年03月18日
日本語

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, 2011年03月18日
日本語

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, 2011年03月18日
日本語

多段型生物処理装置における余剰汚泥減少機能の評価
谷内亜沙美, 松永祐紀, 佐藤久, 渡辺義公, 日本水環境学会年会講演集, 45th, 352, 2011年03月18日
日本語

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, 2011年03月18日
日本語

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, 2011年02月01日
日本語

P-46 超高速窒素除去に関与する新種anammox細菌Candidatus "Brocadia gluttonica"のメタゲノム解析(C.水処理生態系,ポスター発表)
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, 26, 117, 117, 2010年11月23日
日本微生物生態学会, 英語

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, 2010年11月12日
日本語

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, 2010年11月12日
日本語

摩周湖における透明度の低下とその影響因子の検討
高橋岳, 深澤達矢, 宇田川弘勝, 田中敦, 五十嵐聖貴, 小林拓, 濱田浩美, 南尚嗣, 佐藤久, 高橋正宏, 地球環境シンポジウム講演集, 18th, 135, 139, 2010年08月27日
土木学会, 日本語

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, 2010年08月05日
日本語

人口が減少する都市における水循環の再構築
木戸浦茂実, 佐藤久, 高橋正宏, 下水道研究発表会講演集, 47th, 74, 76, 2010年06月30日
日本下水道協会, 日本語

森林地域における金属成分の動態
宮川浩樹, 深澤達矢, 野口泉, 高橋正宏, 佐藤久, 福澤加里部, 柴田英昭, 野村睦, 高木健太郎, 三枝信子, 環境化学討論会講演要旨集, 19th, 130, 131, 2010年06月20日
日本語

都市河川における底生生物相の変化とその原因に関する研究
棚池竜也, 高橋正宏, 佐藤久, 深澤達矢, 工藤憲三, 日本水環境学会年会講演集, 44th, 574, 2010年03月15日
日本語

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, 2010年03月15日
日本語

温泉排水中のヒ素の制御~下水汚泥からの溶出抑制~
清水雄介, 深澤達矢, 佐藤久, 高橋正宏, 環境工学研究フォーラム講演集, 46th, 129, 131, 2009年11月27日
日本語

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, 2009年11月27日
日本語

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, 2009年11月01日
産業用水調査会, 日本語

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, 2009年09月14日
日本語

新規リン酸吸着剤を用いた汚泥からのリン回収
佐藤久, 渡辺義公, 日本水環境学会シンポジウム講演集, 12th, 170, 2009年09月14日
日本語

天塩研究林における大気汚染物質の沈着に関する研究
長谷川祥樹, 深澤達矢, 野口泉, 高橋正宏, 佐藤久, 福澤加里部, 柴田英昭, 野村睦, 高木健太郎, 藤沼康実, 佐々木巴え, 環境化学討論会講演要旨集, 18th, 78, 79, 2009年06月09日
日本語

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, 2009年03月16日
日本語

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, 2009年03月16日
日本語

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, 2008年11月28日
日本語

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, 2008年11月28日
日本語

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, 2008年08月13日
日本語

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, 2008年08月
月刊「水」発行所, 日本語

都市雨水排水中重金属の発生源とその水環境中における化学種の解明
高橋正宏, 佐藤久, 馬場省伍, 下水道研究発表会講演集, 45th, 422, 424, 2008年06月30日
日本下水道協会, 日本語

天塩研究林における大気降下物中の金属成分の測定と検討
深澤達矢, 長谷川祥樹, 佐藤久, 高橋正宏, 柴田英昭, 野村睦, 高木健太郎, 藤沼康実, 環境化学討論会講演要旨集, 17th, 214, 215, 2008年06月10日
日本語

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年
日本語

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, 2007年11月16日
日本語

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, 2007年03月15日
日本語

ジルコニウムメゾ構造体を利用した下水中リンの濃縮・高純度化
半沢拓, 佐藤久, 渡辺義公, 日本水環境学会年会講演集, 41st, 615, 2007年03月15日
日本語

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, 2005年11月16日
北海道大学衛生工学会, 日本語

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, 2005年03月17日
日本語

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, 2004年03月17日
日本語

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年
日本微生物生態学会, 日本語

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年
日本微生物生態学会, 日本語

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, 2003年10月31日
北海道大学衛生工学会, 日本語

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, 2003年09月01日
日本語

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, 2002年11月01日
日本語

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, 2002年10月31日
北海道大学衛生工学会, 日本語

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, 2002年10月31日
北海道大学衛生工学会, 日本語

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, 2002年03月14日
日本語

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年
The authors have proposed a novel water treatment process in which nitrifying bacteria are fixed on the surface of rotating membrane disks. This biofilm-membrane process can perform strict solid-liquid separation and oxidation of ammonia nitrogen simultaneously. In this research, applicability of the conventional biofilm model (assuming the biofilm structure to be flat, homogeneous and continuous) to analysis of the biofilm developing in the proposed process was examined. A long-term operation for culturing the active nitrifying biofilm was carried out prior to kinetic investigation. By cryosectioning of the biofilm and image analysis, the thickness of the biofilm was determined to be 87 pm. From this biofilm thickness and the result of the batch ammonia consumption test, the intrinsic zero-order ammonia consumption rate of the biofilm was estimated precisely to be 930 g/m(3)/h. Using these parameters, the ammonia concentration profile in the biofilm was calculated by the conventional model, and the applicability of the model was examined by comparing the calculated profile with the ones measured with a microelectrode. The calculated profile was very close to the measured ones, which indicated feasibility of the conventional model to the analysis of the biofilm grown in the proposed process. The studied biofilm actually had a simple, i.e. flat, homogeneous and continuous, structure due to membrane filtration. This was the reason why the conventional model could still be employed. In the analysis of the data dealing with low concentrations of ammonia, however, first-order kinetics should be used. The first-order ammonia consumption rate constant of the studied biofilm was estimated to be 808 h(-1)., I W A PUBLISHING, 英語

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, 2000年08月31日
日本語

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, 2000年03月15日
日本語

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, 1999年11月05日
日本語

混合培養系生物膜内の硝化機構
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, 1999年08月01日
日本語

分離膜表面に付着した生物膜の動力学的解析
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, 1999年08月01日
日本語

都市下水生物膜内のアンモニア酸化反応
佐藤久, 岡部聡, 渡辺義公, 日本水環境学会年会講演集, 33rd, 3, 189, 214, 1999年03月15日
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., 公益社団法人 日本水環境学会, 日本語

都市下水生物膜内における硝化・脱窒同時反応の検討
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, 1999年03月15日
日本語

微好気性生物膜内におけるH₂S酸化機構
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, 1999年03月15日
日本語

微小電極およびFISH法を用いた都市下水生物膜内のアンモニア酸化機構の検討
佐藤久, 岡部聡, 渡辺義公, 水環境学会誌, 22, 3, 206, 214, 1999年03月10日
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., 公益社団法人 日本水環境学会, 日本語

微小電極及びFISH法を用いた生物膜内アンモニア酸化細菌菌体密度分布及び活性分布に及ぼす流入基質C/N比の影響評価
佐藤久, 岡部聡, 渡辺義公, 水環境学会誌, 22, 9, 763, 769, 1999年
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., 公益社団法人 日本水環境学会, 日本語

微好気性生物膜内における硫酸塩還元細菌の空間的分布と硫黄の挙動
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, 1998年11月
日本語

FISH法を用いた都市下水生物膜内のアンモニア酸化細菌の存在形態
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, 1998年10月
日本語

混合培養系生物膜内のアンモニア酸化機構の遷移
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, 1998年10月
日本語

微小電極を用いた微好気性生物膜内の硫酸塩還元反応の検討
佐藤久, 岡部聡, 伊藤司, 渡辺義公, 水環境学会誌, 21, 6, 367, 375, 1998年06月
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., 公益社団法人 日本水環境学会, 日本語

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, 1997年11月01日
北海道大学衛生工学会, 日本語

硝化菌生物膜の生態学的構造解析
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, 1997年11月
日本語

混合培養系好気性生物膜における硫酸塩還元及び硫化物酸化
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, 1997年11月
日本語

硝化菌生物膜の生態学的構造と機能
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, 1997年09月
日本語

初期生物膜形成時における流速の生物膜構造に及ぼす影響
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, 1997年09月
日本語

微小電極を用いた微好気条件下での硫化水素の挙動に関する研究
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, 1997年03月
日本語

好気性処理における生物膜構造の,微生物活性度分布に及ぼす影響
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, 1996年08月
日本語

Methods in Enzymology　　　　　　　　　　　　　　　
A polyphasic approach to study ecophysiology of complex multispecies nitrifying biofilms
Elsevier, 2011年, ［共著］

Nitrification　　　　　　　　　　　　　　　
Nitrification in wastewater treatment
ASM Press, 2010年, ［共著］

北海道の河川における農業・下水処理由来物質に着目した溶存有機物や生物化学的指標の縦断分析　　　　　　　　　　　　　　　
中屋佑紀、赤澤優弥、小野寺岳史郎、宮島龍太、佐藤久、北林里佳子、田中佑奈、相沢智康、大西裕季、熊木康裕、黒田恭平、成廣隆
第57回日本水環境学会年会, 2023年03月17日
2023年03月15日 - 2023年03月17日, 松山市

活性汚泥フロックへの大腸菌吸着に影響を与える因子の検討　　　　　　　　　　　　　　　
石塚祐介、石崎翔大、中屋佑紀、佐藤久
第57回日本水環境学会年会, 2023年03月16日
2023年03月15日 - 2023年03月17日, 松山市

塩素処理が都市河川中の大腸菌数に与える影響　　　　　　　　　　　　　　　
田中佑奈、Mohomed Shayan、中屋佑紀、佐藤久
第57回日本水環境学会年会, 2023年03月15日
2023年03月15日 - 2023年03月17日, 松山市

DHSろ床を用いたPET原料製造廃水処理UASB反応器の後段処理技術の開発　　　　　　　　　　　　　　　
髙井麻帆、中屋佑紀、佐藤久、相沢智康、大西裕季、熊木康裕、成廣隆、黒田恭平
第57回日本水環境学会年会, 2023年03月15日
2023年03月15日 - 2023年03月17日, 松山市

緑色蛍光タンパク質遺伝子導入大腸菌を用いた活性汚泥フロックの大腸菌吸着部位の解明　　　　　　　　　　　　　　　
石崎翔大、石塚祐介、樋口宏介、押木守、中屋佑紀、佐藤久
第57回日本水環境学会年会, 2023年03月15日
2023年03月15日 - 2023年03月17日, 松山市

PCRフリーの金ナノ粒子プローブを用いたメタン生成アーキアと寄生性超微小 細菌の迅速定量技術の開発　　　　　　　　　　　　　　　
半田久純、中島芽梨、中屋佑紀、佐藤久、黒田恭平、成廣隆
第57回日本水環境学会年会, 2023年03月15日
2023年03月15日 - 2023年03月17日, 松山市

Candidatus Patescibacteria／CPRとメタン生成アーキアの共培養系確立への挑戦　　　　　　　　　　　　　　　
中島芽梨、中井亮佑、久保田健吾、中屋佑紀、佐藤久、延優、成廣隆、黒田恭平
第57回日本水環境学会年会, 2023年03月15日
2023年03月15日 - 2023年03月17日, 松山市

培養法とゲノム情報に基づいた嫌気性PETモノマー分解機構の解明　　　　　　　　　　　　　　　
黒田恭平、成廣隆、中屋佑紀、佐藤久、野口太郎、前田稜太
第57回日本水環境学会年会, 2023年03月15日
2023年03月15日 - 2023年03月17日, 松山市

光導波路分光装置を用いた高感度簡易核酸モニタリング法の開発
中島芽梨, 佐藤久
第58回環境工学研究フォーラム, 2021年11月17日, 日本語, ポスター発表
2021年11月16日 - 2021年11月18日, 11819082

Simple assay for spectroscopic quantification of 16S rRNA of ammonia oxidizing bacteria using DNA-modified gold nanoparticles
M. Nakajima, H. Satoh
International Conference on the Challenges in Environmental Science and Engineering (CESE-2021), 2021年11月06日, 英語, ポスター発表
2021年11月06日 - 2021年11月07日, 11819082

光導波路分光装置を用いた下水処理プロセスの微生物モニタリング
中島芽梨, 佐藤久
日本水環境学会第55回年会, 2021年03月11日, 日本語, 口頭発表（一般）
2021年03月10日 - 2021年03月12日, 11819082

Investigation and Troubleshooting of Filamentous bulking in a Wastewater Treatment Plant　　　　　　　　　　　　　　　
Jinming Jia, Hisashi Satoh
Water and Environment Technology Conference Online 2020 (WET2020), 2020年11月07日, 英語, ポスター発表
2020年11月07日 - 2020年11月08日

Development of a Simple Analytical Method for Determination of Arsenite Using a DNA Aptamer and Gold Nanoparticles
K. Matsunaga, H. Satoh
IWA Water Development Congress & Exhibition 2019, 2019年12月04日, 英語, ポスター発表
2019年12月01日 - 2019年12月06日, 11819065

蛍光色素修飾DNAと酸化セリウムナノ粒子を用いた簡易ヒ素(V)検出法の開発
松永光司, 佐藤久
日本分析化学会第68年会, 2019年09月12日, 日本語, ポスター発表
2019年09月11日 - 2019年09月13日, 11819065

Development of a Simple Analytical Method for Determination of Arsenate Using FAM-labeled DNA and Cerium Oxide Nanoparticles
K. Matsunaga, H. Satoh
Water and Environment Technology Conference 2019 (WET2019), 2019年07月13日, 英語
2019年07月13日 - 2019年07月14日, 11819065

Development of a Simple Analytical Method for Determination of Arsenite Using a DNA Aptamer and Gold Nanoparticles
K. Matsunaga, H. Satoh
IWA 9th International Young Water Professionals Conference, 2019年06月25日, 英語, 口頭発表（一般）
2019年06月23日 - 2019年06月27日, 11819065

DNAとナノ粒子を用いた簡易ヒ素検出法の開発　　　　　　　　　　　　　　　
松永 光司, 奥山 優, 平野 麗子, 岡部 聡, 高橋正宏, 佐藤 久
第53回日本水環境学会年会, 2019年03月07日, 日本語, ポスター発表
甲府, ［国内会議］

新規簡易迅速大腸菌測定法を用いた下水処理水中薬剤耐性大腸菌数の測定　　　　　　　　　　　　　　　
長橋 夏実, 片寄 由貴, 菊地 凱, 平野 麗子, 岡部 聡, 高橋 正宏, 佐藤 久
第58回環境工学研究フォーラム, 2018年12月18日, 日本語, ポスター発表
京都, ［国内会議］

深層学習を用いた画像認識による 活性汚泥の糸状性バルキングの兆候検出の試み　　　　　　　　　　　　　　　
鈴木 敬介, 山本 雅人, 高橋 正宏, 佐藤久
第57回環境工学研究フォーラム, 2018年12月18日, 日本語, ポスター発表
京都, ［国内会議］

特定酵素蛍光基質を用いた下水中腸球菌の新規薬剤感受性試験法の開発　　　　　　　　　　　　　　　
岩崎 隼, 平野 麗子, 岡部 聡, 高橋 正宏, 佐藤 久
第56回環境工学研究フォーラム, 2018年12月18日, 日本語, ポスター発表
京都, ［国内会議］

三価と五価のヒ素を分別定量可能な新規光学的簡易バイオセンサーの開発　　　　　　　　　　　　　　　
松永 光司, 奥山 優, 岡部 聡, 高橋 正宏, 佐藤 久
第55回環境工学研究フォーラム, 2018年12月18日, 日本語, ポスター発表
京都, ［国内会議］

DNAアプタマーを用いた簡易ヒ素(III)分析手法の開発　　　　　　　　　　　　　　　
松永 光司, 奥山 優, 岡部 聡, 高橋 正宏, 佐藤 久
地下水、土壌汚染とその防止対策に関する研究集会, 2018年10月30日, 日本語, ポスター発表
福島, ［国内会議］

新規簡易大腸菌数測定法による下水処理水中大腸菌数の網羅的測定　　　　　　　　　　　　　　　
片寄 由貴, 平野 麗子, 高橋 正宏, 岡部 聡, 佐藤 久
下水道研究発表会, 2018年07月24日, 日本語, ポスター発表
北九州, ［国内会議］

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, 平野 麗子, 北島 正章, 高橋 正宏, 岡部 聡, 佐藤 久
下水道研究発表会, 2018年07月24日, 日本語, ポスター発表
北九州, ［国内会議］

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　　　　　　　　　　　　　　　
佐藤 久, 平野 麗子, 高橋 正宏, 岡部 聡
下水道研究発表会, 2018年07月24日, 日本語, ポスター発表
北九州, ［国内会議］

水銀イオンとDNAチミン塩基の塩基対形成能を利用した簡易水銀分析法の開発　　　　　　　　　　　　　　　
小林ひかり, 吉原 光, 岡部 聡, 高橋 正宏, 佐藤 久
第52回日本水環境学会年会, 2018年03月15日, 日本語, ポスター発表
札幌, ［国内会議］

特定酵素蛍光基質を用いた簡易大腸菌数測定の開発　　　　　　　　　　　　　　　
片寄 由貴, 石井 聡, 岡部 聡, 高橋 正宏, 佐藤 久
第52回日本水環境学会年会, 2018年03月15日, 日本語, ポスター発表
札幌, ［国内会議］

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
第52回日本水環境学会年会, 2018年03月15日, 日本語, ポスター発表
札幌, ［国内会議］

蛍光色素を用いたMRSA簡易測定法の開発　　　　　　　　　　　　　　　
山口 拓郎, 岡部 聡, 高橋 正宏, 佐藤久
第52回日本水環境学会年会, 2018年03月15日, 日本語, ポスター発表
札幌, ［国内会議］

DNAアプタマーを用いた簡易ヒ素分析法の開発　　　　　　　　　　　　　　　
松永 光司, 奥山 優, 岡部 聡, 高橋 正宏, 佐藤 久
第52回日本水環境学会年会, 2018年03月15日, 日本語, ポスター発表
札幌, ［国内会議］

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
第52回日本水環境学会年会, 2018年03月15日, 日本語, ポスター発表
札幌, ［国内会議］

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
第47回日本水環境学会年会, 2013年03月11日, 日本語, ポスター発表
大阪, ［国内会議］

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
第49回環境工学研究フォーラム, 2012年11月28日, 日本語, ポスター発表
京都, ［国内会議］

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
第49回環境工学研究フォーラム, 2012年11月28日, 日本語, ポスター発表
京都, ［国内会議］

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, ピタックティーラム ニティ, 石井 聡, 佐野 大輔, 高橋 正宏, 岡部 聡, 佐藤 久
第49回環境工学研究フォーラム, 2012年11月28日, 日本語, ポスター発表
京都, ［国内会議］

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
日本分析化学会第61年会, 2012年09月19日, 日本語, ポスター発表
金沢, ［国内会議］

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
日本分析化学会第61年会, 2012年09月19日, 日本語, ポスター発表
金沢, ［国内会議］

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
日本分析化学会第61年会, 2012年09月19日, 日本語, ポスター発表
金沢, ［国内会議］

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
第15回水環境学会シンポジウム, 2012年09月10日, 日本語, ポスター発表
佐賀, ［国内会議］

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
第72回分析化学討論会, 2012年05月19日, 日本語, ポスター発表
鹿児島, ［国内会議］

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, 高橋正宏, 岡部 聡, 佐藤 久
第46回日本水環境学会年会, 2012年03月14日, 日本語, ポスター発表
東京, ［国内会議］

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, 佐藤 久
第46回日本水環境学会年会, 2012年03月14日, 日本語, ポスター発表
東京, ［国内会議］

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
第46回日本水環境学会年会, 2012年03月14日, 日本語, ポスター発表
東京, ［国内会議］

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　　　　　　　　　　　　　　　
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
第46回日本水環境学会年会, 2012年03月14日, 日本語, ポスター発表
東京, ［国内会議］

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
第46回日本水環境学会年会, 2012年03月14日, 日本語, ポスター発表
東京, ［国内会議］

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
第46回日本水環境学会年会, 2012年03月14日, 日本語, ポスター発表
東京, ［国内会議］

水環境保全工学　　　　　　　　　　　　　　　
北海道大学 工学部

水文学　　　　　　　　　　　　　　　
北海道大学 工学部

環境工学実験I　　　　　　　　　　　　　　　
北海道大学 工学部

Water chemistry　　　　　　　　　　　　　　　
北海道大学大学院工学研究院

水質化学特論　　　　　　　　　　　　　　　
北海道大学大学院工学研究院

環境工学概論　　　　　　　　　　　　　　　
北海道大学 工学部

土木環境工学　　　　　　　　　　　　　　　
北海道大学 工学部

分析化学　　　　　　　　　　　　　　　
北海道大学 工学部

ポストPCR時代を見据えた宿主認識分子の検出に基づく病原体センサーの開発
科学研究費助成事業
2023年06月30日 - 2025年03月31日
佐藤 久, 齋藤 伸吾, 中屋 佑紀
日本学術振興会, 挑戦的研究(萌芽), 北海道大学, 23K17767

廃水処理システムの新奇指標微生物「DPANNアーキア」の診断技術開発と実態解明
科学研究費助成事業
2021年04月01日 - 2025年03月31日
黒田 恭平, 成廣 隆, 延 優, 佐藤 久, 山田 真義, 野口 太郎
本研究の目的は，高有機物負荷，高窒素負荷，高カチオン濃度の廃水処理汚泥中で優占化する「DPANNアーキア」を廃水処理の新奇ストレス指標微生物として診断する技術を開発し，その“真”の機能を培養法とトランスクリプトム解析等により明らかにすることである。「DPANNアーキアは廃水処理のストレスを評価する新奇指標微生物になり得るのではないか?」という問い(仮説)について，培養と情報科学・微生物代謝能の観点から学術的に解明することである。
2021年度は，(1) DPANNアーキア優占化反応槽の運転管理と診断技術の開発，(2) DPANNアーキアの二者培養系の構築の試みの2項目について研究を実施した。(1) において，過去にDPANNアーキアの優占化と処理の不調が発生したフェノール模擬廃水を処理する上昇流嫌気性スラッジブランケット (UASB) 反応槽の16S rRNA遺伝子解析及びショットガンメタゲノム解析を実施し，2種のDPANNアーキアのドラフトゲノムの再構築に成功し，ゲノム情報からヌクレオシドを利用可能な代謝を持つことが明らかとなった。得られた知見を基にしてフェノールを基質とするUASB反応槽のスタートアップを行い，順調に有機物負荷を上昇させることに成功している。金ナノ粒子プローブ法を用いたDPANNアーキアの定量についても検討を進めている。
(2) において，ドラフトゲノムから得られた知見を基にしてDPANNアーキアの集積培養系構築を試みた結果，DPANNアーキアと同様の生理生態を持つと予測されているCandidate Phyla Radiation (CPR)/Patescibacteriaに属する系統の集積培養に成功し，DPANNアーキアの二者培養系確立に向けた宿主と共生細菌の動態に関する重要な情報を得た。加えて本培養系にはDPANNアーキアも維持されていることを確認した。
日本学術振興会, 基盤研究(B), 国立研究開発法人産業技術総合研究所, 21H01471

持続可能な小規模水道システム実現のための新しい水質センシング技術の開発
科学研究費助成事業 基盤研究(A)
2021年04月 - 2025年03月
佐藤 久, 山田 俊郎, 山村 寛, 黒田 恭平, 齋藤 伸吾
Legionella pneumophilaと結合できるDNAアプタマーを選抜した。選抜は、ポリマー増強キャピラリー過渡的等速電気泳動法（PectI）を用いておこなった。PectIでは、微生物の細胞は移動の初期に過渡的等速電気泳動（tITP）の原理に基づき、狭い単一ピークとなる。tITP積層モードが完了した後プロセスはキャピラリーゾーン電気泳動（CZE）モードに移行し、PectIにおけるピークの分離を行う。分離された単一ピークは、泳動バッファー中に添加されたポリエチレンオキサイド（600,000）（PEO）の効果により、CZEモードの間ずっと維持される。このようにして特異的な結合親和性を有するDNAアプタマーを獲得できる。
今年度は新規のLegionella pneumophila結合DNAアプタマーについて、PectI選抜法によるシングルラウンド選抜と、類似配列群に分けるクラスタリング法とディープラーニングを用いた定量的処理に基づく大規模NGS解析によって選抜することができた。この選抜システムで獲得できたDNAアプタマーの配列は、先行研究における、従来のCell-SELEXで選抜されたDNAアプタマーと比較して低い解離定数および速度定数を持っており、平衡論的、反応速度論的にLegionella pneumophilaと高い結合能を持ったDNAアプタマーを獲得できた。すなわち、先行研究で選抜されたDNAアプタマーよりもLegionella pneumophilaと特異的に結合し、安定した複合体を形成するアプタマーであると考えられ、我々が目標としているバイオセンサーの開発に適したDNAアプタマーを選抜できたと言える。
日本学術振興会, 基盤研究(A), 北海道大学, 研究代表者, 21H04568

革新的微生物モニタリング技術の開発と適用：アジアの水系感染症根絶への挑戦
科学研究費助成事業 国際共同研究加速基金(国際共同研究強化(B))
2020年10月 - 2024年03月
佐藤 久, 齋藤 伸吾, 山村 寛, 丁 青
本年度は開発済みの蛍光プローブを用いて、時間的にも空間的にも網羅的に河川水中の大腸菌濃度を測定した。札幌市の創成川の北10条（S1）、北12条（S2）、北14条（S3）、北23条（S4）、北30条（S5）、北49条（S6）の橋から河川水をサンプリングした。創成川水再生プラザからの放流水が流入する地点のすぐ下流に位置するS6においてのみ、大腸菌数が高いことが明らかとなった。公定法で求めた大腸菌数が、本研究室で開発した方法で求めた酵素活性と、大腸菌数が1000 cfu/L以上であれば相関があることがわかった。創成川流下方向の大腸菌数の変化を河川の水位と札幌市の降雨強度と比較した。2月の3回のサンプリングにおいて、創成川水再生プラザの上流（S1からS5）では、大腸菌数は2月16日や22日に高く、2月2日に最も低かった。2月2日は、前日の22時にのみ雨が降っており水位は高くない。このため、ノンポイントソースまたはCSOがなく、処理場上流で大腸菌数が低かったと考えられた。一方、2月16日は、前日から雨が降っており、サンプリング時の水位が高かった。このため、ノンポイントソースまたはCSOにより、処理場上流で大腸菌数が高くなったと考えられた。
核酸を検出する技術を開発した。本技術では病原体の核酸と特異的に結合する2種類のDNAを金ナノ粒子で修飾したDNAプローブを使う。サンプルから抽出したターゲットとDNAプローブを混合する。2つのDNAプローブがターゲットにハイブリダイズする。ターゲットはナノサイズなので2つの金ナノ粒子が互いに近接することになる。金ナノ粒子は近接すると散乱光強度が増強するので、ターゲットの濃度が高いサンプルほど散乱光強度が大きくなり、ターゲット濃度を分析できる。本年度は大腸菌O157の濃度を検出限界10^6 copies/μLで測定できた。
日本学術振興会, 国際共同研究加速基金(国際共同研究強化(B)), 北海道大学, 研究代表者, 20KK0090

バイオ燃料電池駆動型エネルギー自立式Anammox MECシステムの開発
科学研究費助成事業
2019年04月01日 - 2023年03月31日
岡部 聡, 北島 正章, 佐藤 久, 押木 守
本研究の目的は、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ことである。
本年度は昨年度に引き続き、研究開発項目として提示した、①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、②MFCを部分硝化-Anammox MECの補助電源として用いることは可能か？について検討した。複合微生物群集である活性汚泥とNitrosomonas europaeaの純粋株（ATCC19718)を用いて生物電解セル（MEC）を構築し、ポテンシオスタットを用いてMECアノード電極の標準還元電位を+0.8V (vs SHE)に制御し、NH4+および中間生成物であるNH2OHの酸化速度および発生電流量を測定した。また、１５Nでラベルした窒素化合物を添加して気相中のN2, NO, N2OをGC/MSを用いて分析した。その結果、活性汚泥およびNitrosomonas europaeaの両者は、生物電気化学的にNH4+をNH2OHへ酸化することができなかった。一方、NH2OHは電気化学的にN2へ、また、生物学的および電気化学的にN2Oへ変換されることが確認された。以上のことより、既往の研究等で報告されている生物電気化学的アンモニア酸化反応は、リアクターに混入した微量の酸素により、NH4+がNH2OHまで酸化された後、生成したNH2OHが生物電気化学的にN2,またはN2Oへ変換されている可能性を明らかにすることができた。
日本学術振興会, 基盤研究(A), 北海道大学, 19H00776

反応場をナノサイズにした高感度病原性微生物センサーの開発
科学研究費助成事業 挑戦的研究(萌芽)
2021年07月 - 2023年03月
佐藤 久
今年度は光導波路分光装置を用いて、下水を処理する活性汚泥中の硝化細菌（AOB）のRNA量を測定することに成功した。本手法ではAOBの16S rRNA（AOB-RNAと称す）と特異的に結合する2種類のDNA（プローブDNAと称す）を金ナノ粒子で修飾したAu-プローブと、活性汚泥から抽出したRNAをMgCl2を含むバッファー溶液に添加したものを試料とした。プローブDNAはAOB用のPCRプライマー（CTO189f A/B/CとRT1r）の塩基配列を参考に設計した。都市下水を処理する活性汚泥（A処理場またはB処理場）からRNAを抽出し、AOB-RNA濃度を上述のプライマーを用いて定量的逆転写PCR（RT-qPCR）により定量した。A処理場の活性汚泥またはNitrosomonas europaeaを添加した活性汚泥中のAOB-RNA濃度を測定した。活性汚泥から抽出したAOB-RNA濃度も、N. europaeaを添加した活性汚泥から抽出したAOB-RNA濃度（▲）も、RT-qPCRで測定した濃度と同程度であった。これより本手法では1.8×10の2乗から1.3×10の7乗 copies/μLの範囲で、RT-qPCRで定量した濃度に対する誤差27%から240%でAOB-RNAを定量可能であることがわかった。このように先行研究に比べて定量下限値が極めて低くなった理由として、全細菌とAOBでは使用するプローブDNAの塩基配列が異なりハイブリダイズした際の16S rRNAの立体構造や金ナノ粒子の位置関係が異なること、光導波路分光装置では金ナノ粒子の近接によってシグナル（散乱光）が増強されたことが考えられる。
日本学術振興会, 挑戦的研究(萌芽), 北海道大学, 研究代表者, 21K18737

非生物・生物ハイブリッド人工光合成システムの構築：持続可能な酢酸生成拠点の創出
科学研究費助成事業
2020年04月01日 - 2022年03月31日
岡部 聡, 渡辺 精一, 佐藤 久
本研究の目的は、CO2と水を原料とし太陽光エネルギー（可視光）と廃水をエネルギー源として、常温常圧、中性条件下で酢酸（2炭素化合物）を生産可能なバイオ‐光電気化学太陽電池（Bio-PEC)ハイブリッドシステムを構築することである。そのために必要なCuOナノワイヤー表面にZnOナノロッドを付加した3次元ナノ構造を持つZnO/CuO複合体を作成することに成功した。また、その電気化学的特性（水素生成速度や電流密度）は、既往の類似する三次元ナノ構造を有するZnO/CuOの値の約3倍であった。これにより、効率の良いBio-PECシステムの構築の可能性が示された。
日本学術振興会, 挑戦的研究(開拓), 北海道大学, 20K20486

蛍光プローブを用いた簡易・迅速・低コストのオンサイト指標細菌一斉計測技術の開発
科学研究費補助金 挑戦的研究（萌芽）
2019年08月 - 2021年03月
佐藤 久
日本学術振興会, 研究代表者, 競争的資金

IoT技術の基盤となるDNAアプタマーを用いた網羅的水質センサの開発
科学研究費補助金 基盤研究B
2017年04月 - 2020年03月
佐藤 久
日本学術振興会, 研究代表者, 競争的資金

特定酵素蛍光基質を用いた病原細菌および薬剤耐性細菌の簡易迅速定量法の開発
科学研究費補助金 挑戦的研究（萌芽）
2017年04月 - 2019年03月
佐藤 久
日本学術振興会, 研究代表者, 競争的資金

執行体制の脆弱化に対応した下水処理水中の細菌・ウイルスの簡易分析技術の開発
下水道技術研究開発（GAIAプロジェクト）
2016年12月 - 2019年02月
佐藤 久
国土交通省, 研究代表者, 競争的資金

術後眼内炎起因菌の簡易迅速多検体検出キットの開発
研究開発助成事業 イノベーション創出研究支援事業 スタートアップ研究補助金
2016年 - 2017年03月
佐藤 久
ノーステック財団, 研究代表者, 競争的資金

光導波路分光法を用いたオンサイト・リアルタイム網羅的環境中重金属分析技術の開発
科学研究費補助金 基盤研究B
2014年04月 - 2017年03月
佐藤 久
日本学術振興会, 研究代表者, 競争的資金

省エネ・多機能型の膜分離導入下廃水処理システムの実用化
科学研究費助成事業
2013年10月21日 - 2016年03月31日
渡辺 義公, 木村 克輝, 山村 寛, 佐藤 久, 羽深 昭
膜分離活性汚泥法(MBR)の改良型として渡辺が考案したbuffled MBRは単一槽で有機物酸化、窒素除去、リン除去が行える画期的方式である。本研究ではbuffled MBRの「信頼性の向上＋低コスト化」及びそこでの「余剰汚泥からのリン回収システム」について研究した。処理能力15 m3/日のパイロットプラント実験によって以下の点を明らかにした。長さ3mのPTFE中空糸膜による実験から動力消費量として0.35kWh/m3を得た。嫌気性MBRにジルコニアメソ構造体を担持したMF膜を用いることで画期的な余剰汚泥からのリン回収システムか構築できる可能性を示した。
日本学術振興会, 基盤研究(A), 中央大学, 25249073

近接場光による病原微生物蛍光マルチセンサの超小型・高感度化
科学研究費補助金 挑戦的萌芽研究
2014年04月 - 2016年03月
佐藤 久
日本学術振興会, 研究代表者, 競争的資金

DNAアプタマープローブによる新しいヒ素モニタリング検査法の開発
マッチングプランナープログラム探索試験
2015年 - 2016年
佐藤 久
JST, 研究代表者, 競争的資金

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
2011年04月01日 - 2014年03月31日
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

表面プラズモン共鳴を利用したO157ハイスループットスクリーニング法の開発
科学研究費補助金(挑戦的萌芽研究)
2012年04月 - 2014年03月
佐藤 久
病原微生物の検出には、迅速性、簡便性、信頼性、精度などが求められる。現在、病原微生物は培養により、遺伝子を検出することにより、または抗体を用いて検出されているが、それぞれに一長一短がある。本研究では腸管出血性大腸菌O157を表面プラズモン共鳴（SPR）で検出することを試みた。O157検出用SPRセンサ基板の表面を解析しを行い、センサ基板が問題なく作製できていることを明らかにした。このセンサ基板を装着したセンサを用いて、検出限界10の8乗cells/mLでO157サンプルを検出できた。本センサは繰り返し利用できた。
文部科学省, 挑戦的萌芽研究, 北海道大学, 研究代表者, 競争的資金, 24656306

水中亜鉛の現場分析法の開発と水生生物生態影響機構の解明
環境助成研究
2013年 - 2014年
佐藤 久
公益財団法人鉄鋼環境基金, 研究代表者, 競争的資金

水環境保全と再生水安全性確保のためのマルチ重金属センサの開発
技術研究助成
2014年
佐藤 久
公益財団法人JFE21世紀財団, 研究代表者, 競争的資金

北方圏に適した省エネ・創エネ型汚水処理プロセスの開発　　　　　　　　　　　　　　　
北海道ガス大学研究支援制度
2011年04月 - 2012年03月
佐藤 久
北海道ガス, 研究代表者, 競争的資金

表面プラズモン共鳴による水中病原ウイルスセンサの開発　　　　　　　　　　　　　　　
環境研究助成
2011年 - 2012年
佐藤 久
住友財団, 研究代表者, 競争的資金

新規蛍光分子を用いた環境水のオンサイト分析に耐えうるイオン一斉分析システムの開発
科学研究費補助金(若手研究(A))
2011年 - 2012年
佐藤 久
本研究では、環境サンプル(環境水・排水）中のイオンをオンサイトで一斉分析できる、新規の技術（蛍光ナノマテリアル）を用いた分析システムを開発する。具体的には①既存のイオン分析技術の欠点を補える、新規の分析技術を提案する。②多種多様な懸濁物や有機物を含む、極めて複雑な分析対象である環境サンプル中のイオンの、オンサイト一斉分析に耐えうる新規のイオン分析システムを開発する。開発した蛍光ナノマテリアルを用いて、路面排水中および工場排水中のZn濃度を、ICP-AESで測定した値と高い相関を持って定量できた。
文部科学省, 若手研究(A), 北海道大学, 研究代表者, 競争的資金, 23686074

蛍光分子とウイルス吸着タンパク質を用いた革新的水中病原ウイルスセンサの開発
科学研究費補助金(挑戦的萌芽研究)
2010年 - 2011年
佐藤 久, 佐野 大輔
本年度は、基礎的研究として、Hemagglutinating Virus of Japan Envelope(HVJ-E)をウイルス検出センサーに利用することが可能かどうかを検討した。具体的には、エンベロープとウイルス代替物質が反応した際にエンベロープが変形し内部に封入したプラスミドDNAを放出することの確認を行うこと、及びウイルス親和性エンベロープに提示するウイルス親和性物質の検討を行うことを目的とした。HVJ-EとHVJ-Eに親和性のある金ナノ粒子を用い、エンベロープの変形を電子顕微鏡により確認した。粒径30nmの抗HVJ-E抗体修飾金ナノ粒子はHVJ-Eに特異的に吸着しエンベロープの変形に寄与していることが確認された。しかし、粒径10nmのシアル酸含有糖鎖固定金ナノ粒子はHVJ-Eと吸着しても大きな形状の変化を与えることはなく、このことから30nm程度の粒子と吸着した際にエンベロープが変形しDNAが放出されることが明らかとなった。さらに、HVJ-Eと抗HVJ-E抗体修飾金ナノ粒子を混合し反応させ、エンベロープの変形によって内部に封入されたDNAが放出されることを定量PCR法によって確認した。まず、HVJ-EからのDNA放出量を定量する上で必要な情報として、HVJ-Eに封入されなかったDNAはDNase処理による除去が有効であり、約4,000bpのプラスミドDNAをHVJ...
文部科学省, 挑戦的萌芽研究, 北海道大学, 研究代表者, 競争的資金, 22656115

ゼロエミッション・高資源回収型下水汚泥処理プロセスの開発
建設技術研究開発助成制度
2007年04月 - 2010年03月
佐藤 久
国土交通省, 研究代表者, 競争的資金

超高速型アナモックスリアクターの安定化技術の確立と生物膜群集構造と機能の解析
科学研究費補助金(若手研究(B))
2007年 - 2008年
金田一 智規, 佐藤 久, 笠原 伸介
アナモックスリアクターの長期安定化をはかるために、実排水を想定した低分子有機酸存在下でのアナモックス活性の評価を行った。その結果、酢酸およびプロピオン酸はアナモックス活性に影響を与えないことが明らかとなった。本リアクター内には二種類のアナモックス細菌が存在し、その一方は有機酸に耐性のある種に近縁であった。リアクター内に共存する他栄養細菌は放射性同位元素を用いて有機物の追跡を行ったところ、アナモックス細菌由来の有機物質を分解しており、系内に有機物の蓄積を防ぐ役割をもつことが示唆された。
文部科学省, 若手研究(B), 広島大学, 連携研究者, 競争的資金, 19760373

様々な自然環境における温室効果ガス生成機構の解明を目的としたマイクロセンサの開発
科学研究費補助金(若手研究(B))
2006年 - 2007年
佐藤 久
現在までの多数の研究により、温室効果ガス(GHG)の排出が地球温暖化を促進することは明らかであるが、自然界におけるGHG消長過程の詳細については明らかにされていない。そこで本研究ではGHGの一つであるメタンガス(CH_4)測定用マイクロセンサを開発すること、これを用いて嫌気性廃水処理リアクターで生成されているCH_4濃度を測定することを目的とした。H18年度にCH_4測定用マイクロセンサを開発した。H19年度はCH_4測定用マイクロセンサの検量線を作成した。作製した全てのCH_4測定用マイクロセンサは、検出電流値がCH_4濃度に比例して変化した。代表的なマイクロセンサのCH_4濃度と検出電流値の近似曲線はy=-205x+5194であり、R^2=0.9633と相関は高かった。応答時間は濃度変化が大きい場合は数分、嫌気性廃水処理リアクター内に形成された微生物集塊(グラニュール)内のCH_4濃度を測定する場合には約60秒であった。これらマイクロセンサを用いてグラニュール内の濃度プロファイルを測定した。その結果、H_2生成反応およびH_2消費反応はともにグラニュール表層(厚さ数100μm)で、CH_4生成反応は中層および深層で生じていることが明らかとなった。さらに、グラニュール汚泥の培養条件(酢酸、H_2および炭酸濃度)を変化させて内部のH_2およびCH_4濃度を測定した。酢酸濃度を...
文部科学省, 若手研究(B), 八戸工業大学->北海道大学, 研究代表者, 競争的資金, 18710013

生物処理装置及び生物処理方法
特許権, 佐藤 久, 中原 禎仁, 笹川 学, 国立大学法人 北海道大学, 三菱レイヨン・エンジニアリング株式会社
特願2008-025668, 2008年02月05日
特開2009-183848, 2009年08月20日
200903044735059460

ポーラログラフ式電極のゲル状電解液およびその作成方法
特許権, 佐藤 久, 安川 基行, 財団法人青森県工業技術教育振興会
特願2005-252576, 2005年08月05日
特開2007-047135, 2007年02月22日
200903049090274656

排水処理方法
特許権, 小林 真澄, 加茂 純, 佐藤 久, 三菱レイヨン株式会社
特願2003-274523, 2003年07月15日
特開2005-034739, 2005年02月10日
200903030123323620