研究者データベース

研究者情報

マスター

アカウント(マスター)

  • 氏名

    押木 守(オシキ マモル), オシキ マモル

所属(マスター)

  • 工学研究院 環境工学部門 環境工学

所属(マスター)

  • 工学研究院 環境工学部門 環境工学

独自項目

syllabus

  • 2020, 物理化学要論, Elements of Physical Chemistry, 学士課程, 工学部, 物理化学、化学熱力学、溶液化学、電解質溶液、化学平衡
  • 2020, 水文学, Hydrology, 学士課程, 工学部, 降雨 流出 循環 水資源の開発 環境の保全
  • 2020, 環境工学実験Ⅰ, Environmental Engineering Laboratory I, 学士課程, 工学部, 分析化学実験、環境汚染物質濃度の化学測定、酸・塩基滴定、吸光光度法、水質汚濁測定、微生物量測定

researchmap

プロフィール情報

学位

  • 博士(環境学)(東京大学)

プロフィール情報

  • 押木, オシキ
  • 守, マモル
  • ID各種

    201501048419737354

業績リスト

研究キーワード

  • 硝化   栄養塩(窒素、リン)除去   アナモックス   嫌気性アンモニウム酸化   脱窒   活性汚泥   

研究分野

  • ライフサイエンス / 応用微生物学
  • ライフサイエンス / 水圏生命科学
  • 社会基盤(土木・建築・防災) / 土木環境システム

経歴

  • 2020年04月 - 現在 北海道大学大学院 工学研究院環境創成工学部門 准教授
  • 2016年04月 - 2020年03月 長岡工業高等専門学校 環境都市工学科 准教授
  • 2014年04月 - 2016年03月 長岡工業高等専門学校 環境都市工学科 助教
  • 2011年04月 - 2014年03月 日本学術振興会特別研究員(PD) 北海道大学大学院工学研究院
  • 2013年01月 - 2014年01月 Radboud university (オランダ) 理学部 客員研究員
  • 2010年01月 - 2011年03月 北海道大学 大学院・工学研究院 博士研究員
  • 2009年04月 - 2009年12月 東京大学大学院新領域創成科学研究科 東京大学大学院新領域創成科学研究科 特別研究員
  • 2007年04月 - 2009年03月 日本学術振興会特別研究員(DC2) 東京大学大学院新領域創成科学研究科

学歴

  • 2006年04月 - 2009年03月   東京大学   新領域創成科学研究科   社会文化環境学専攻 博士課程
  • 2004年04月 - 2006年03月   東京大学   新領域創成科学研究科   社会文化環境学 修士課程

委員歴

  • 2018年04月 - 現在   日本水環境学会   微生物生態と水環境工学 運営委員
  • 2020年05月 - 2023年05月   ISME Journal Editorial board
  • 2021年01月 - 2022年12月   日本微生物生態学会   日本微生物生態学会事務局代表幹事
  • 2017年12月 - 2019年08月   日本水環境学会   Japan-YWP企画委員
  • 2016年04月 - 2018年03月   日本水環境学会   WET部会委員

受賞

  • 2021年 長瀬科学技術振興財団 長瀬研究振興賞
  • 2019年 日本微生物生態学会 Microbes & Environments 2018 最優秀論文賞
     
    受賞者: 押木 守
  • 2018年 インテリジェント・コスモス インテリジェント・コスモス奨励賞
     
    受賞者: 押木 守
  • 2018年 第28回日本MRS年次大会 奨励賞
     
    受賞者: 押木 守
  • 2017年 イムラ・ジャパン 第1回イムラ・ジャパン賞
     
    受賞者: 押木 守
  • 2017年 建設工学研究振興会 建設工学奨励賞
     
    受賞者: 押木 守
  • 2011年 日本微生物生態学会 第27回日本微生物生態学会 優秀ポスター賞
     
    受賞者: 押木 守
  • 2011年 アナモックスシンポジウム 第一回国際アナモックスシンポジウム 最優秀講演賞
     
    受賞者: 押木 守
  • 2011年 国際硝化学会 第2回国際硝化学会・第16回ヨーロッパ窒素循環会議 発表賞
     
    受賞者: 押木 守
  • 2008年 日本水環境学会 博士研究奨励賞 (オルガノ賞)
     
    受賞者: 押木 守
  • 2002年 全国高専土木学会 近藤賞
     
    受賞者: 押木 守

論文

  • Satoshi Okabe, Amrini Amalia Shafdar, Kanae Kobayashi, Lei Zhang, Mamoru Oshiki
    The ISME journal 15 5 1287 - 1301 2021年05月 
    Presence of glycogen granules in anaerobic ammonium-oxidizing (anammox) bacteria has been reported so far. However, very little is known about their glycogen metabolism and the exact roles. Here, we studied the glycogen metabolism in "Ca. Brocadia sinica" growing in continuous retentostat cultures with bicarbonate as a carbon source. The effect of the culture growth phase was investigated. During the growing phase, intracellular glycogen content increased up to 32.6 mg-glucose (g-biomass dry wt)-1 while the specific growth rate and ATP/ADP ratio decreased. The accumulated glycogen begun to decrease at the onset of entering the near-zero growth phase and was consumed rapidly when substrates were depleted. This clearly indicates that glycogen was synthesized and utilized as an energy storage. The proteomic analysis revealed that "Ca. B. sinica" synthesized glycogen via three known glycogen biosynthesis pathways and simultaneously degraded during the progress of active anammox, implying that glycogen is being continuously recycled. When cells were starved, a part of stored glycogen was converted to trehalose, a potential stress protectant. This suggests that glycogen serves at least as a primary carbon source of trehalose synthesis for survival. This study provides the first physiological evidence of glycogen metabolism in anammox bacteria and its significance in survival under natural substrate-limited habitat.
  • Kentaro Miyazaki, Hikaru Suenaga, Mamoru Oshiki, Shuichi Kawano, Toshikazu Fukushima
    Microbiology Resource Announcements 10 7 2021年02月18日 [査読有り]
     
    ABSTRACT A thiocyanate-degrading bacterium, Thiohalobacter sp. strain COW1, was isolated from activated sludge treating coke oven wastewater, and the complete genome sequence was determined. COW1 contained a single circular chromosome (3.23 Mb; G+C content, 63.4%) in which 2,788 protein-coding genes, 39 tRNA genes, and 3 rRNA genes were identified.
  • 海洋に流出した窒素除去を目的とした海洋性anammox細菌の研究
    田中考国, 押木守, 金田一智規, 新田見匡
    分離技術 51 1 32 - 41 2021年02月 [査読有り]
  • Masataka Aoki, Mamoru Oshiki, Mizuki Iwagaki, Masashi Hatamoto, Takashi Yamaguchi, Nobuo Araki
    Microbiology Resource Announcements 10 2 2021年01月14日 [査読有り]
     
    ABSTRACT We report the draft genome sequence of Cytophagales sp. strain WSM2-2, isolated from garden soil. A 5.5-Mb genome sequence comprising four contigs was successfully obtained using Illumina NovaSeq and MinION sequencers. This draft genome sequence will contribute to the genomic knowledge of the bacterial order Cytophagales.
  • Yuki Iwasaki, Yuya Itoiri, Sota Ihara, Hironaga Akita, Mamoru Oshiki, Zen-ichiro Kimura
    Journal of Genomics 9 6 - 9 2021年 [査読有り]
  • 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 ME20086  2020年08月 [査読有り][通常論文]
  • N2O production using native nos-deficient denitrifying bacterial strains screened by a genome mining approach
    Mamoru Oshiki, Miho Ishimaru, Masashi Hatamoto, Takashi Yamaguchi, Nobuo Araki, Satoshi Okabe
    Bioresource Technology Reports 11 100529  2020年08月 [査読有り][通常論文]
  • Takahiro Watari, Wilasinee Kotcharoen, Takanori Omine, Masashi Hatamoto, Nobuo Araki, Mamoru Oshiki, Kazuhisa Mimura, Akihiro Nagano, Takashi Yamaguchi
    Environmental Technology & Innovation 19 100861 - 100861 2020年08月 [査読有り][通常論文]
  • 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 136928  2020年05月01日 [査読有り][通常論文]
     
    © 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.
  • Yuga Hirakata, Masashi Hatamoto, Mamoru Oshiki, Takahiro Watari, Nobuo Araki, Takashi Yamaguchi
    The ISME journal 14 7 1873 - 1885 2020年04月27日 [査読有り][通常論文]
     
    Anaerobic protists are major predators of prokaryotes in anaerobic ecosystems. However, little is known about the predation behavior of anaerobic protists because almost none have been cultured. In particular, these characteristics of anaerobic protists in the phyla Metamonada and Cercozoa have not been reported previously. In this study, we isolated three anaerobic protists, Cyclidium sp., Trichomitus sp., and Paracercomonas sp., from anaerobic granular sludge in an up-flow anaerobic sludge blanket reactor used to treat domestic sewage. Ingestion and digestion of food bacteria by anaerobic protists with or without endosymbiotic methanogens were demonstrated using tracer experiments with green fluorescent protein and a stable carbon isotope. These tracer experiments also demonstrated that Cyclidium sp. supplied CO2 and hydrogen to endosymbiotic methanogens. While Cyclidium sp. and Trichomitus sp. ingested both Gram-negative and -positive bacteria, Paracercomonas sp. could only take up Gram-negative bacteria. Archaeal cells such as Methanobacterium beijingense and Methanospirillum hungatei did not support the growth of these protists. Metabolite patterns of all three protists differed and were influenced by food bacterial species. These reported growth rates, ingestion rates, food selectivity, and metabolite patterns provide important insights into the ecological roles of these protists in anaerobic ecosystems.
  • Biosynthesis of hydrazine from ammonium and hydroxylamine using an anaerobic ammonium oxidizing bacterium
    Mamoru Oshiki Koshiro Yamada, Itsuki Kato, Kento Okoshi, Toshiro Imai, Takashi Yamaguchi & Nobuo Araki
    Biotechnology letters 42 979 - 985 2020年03月 [査読有り][通常論文]
  • Total ammonia nitrogen (TAN) removal performance of a recirculating down-hanging sponge (DHS) reactor operated at 10 to 20ºC with activated carbon
    Mamoru Oshiki, Takashi Aizuka, Hirotoshi Netsu, Satoshi Oomori, Akihiro Nagano, Takashi Yamaguchi, Nobuo Araki
    Aquaculture 520 734963  2020年01月 [査読有り][通常論文]
  • Hironaga Akita, Yuya Itoiri, Akio Kumagai, Noriyo Takeda, Akinori Matsushika, Mamoru Oshiki, Zen-ichiro Kimura
    J. Genomics 8 21 - 24 2020年01月 [査読有り][通常論文]
  • Yuga Hirakata, Masashi Hatamoto, Mamoru Oshiki, Takahiro Watari, Kyohei Kuroda, Nobuo Araki, Takashi Yamaguchi
    Scientific Reports 9 1 12783 - 12783 2019年12月01日 [査読有り][通常論文]
     
    © 2019, The Author(s). Eukaryotes are important components of ecosystems in wastewater treatment processes. However, little is known about eukaryotic community in anaerobic wastewater treatment systems. In this study, eukaryotic communities in an up flow anaerobic sludge blanket (UASB) reactor treating domestic sewage during two years of operation were investigated using V4 and V9 regions of 18S rRNA gene for amplicon sequencing. In addition, activated sludge and influent sewage samples were also analyzed and used as the references for aerobic eukaryotic community to characterize anaerobic eukaryotes. The amplicon sequence V4 and V9 libraries detected different taxonomic groups, especially from the UASB samples, suggesting that commonly used V4 and V9 primer pairs could produce a bias for eukaryotic communities analysis. Eukaryotic community structures in the UASB reactor were influenced by the immigration of eukaryotes via influent sewage but were clearly different from the influent sewage and activated sludge. Multivariate statistics indicated that protist genera Cyclidium, Platyophrya and Subulatomonas correlated with chemical oxygen demand and suspended solid concentration, and could be used as bioindicators of treatment performance. Uncultured eukaryotes groups were dominant in the UASB reactor, and their physiological roles need to be examined to understand their contributions to anaerobic processes in future studies.
  • Draft Genome Sequence of the Plant Growth-Promoting Streptomyces sp. Strain 6-11-2
    A. Ztouti, N. Saito, J. Sasaki, T. Yamaguchi, N. Araki, M. Oshiki
    Microbiol. Resour. Announc. 8 e00877-19  2019年11月 [査読有り][通常論文]
  • Oshiki M, Fukushima T, Kawano S, Kasahara Y, Nakagawa J
    Microbes and environments 34 4 402 - 412 2019年10月 [査読有り][通常論文]
  • Kanae Kobayashi, Akiko Makabe, Midori Yano, Mamoru Oshiki, Tomonori Kindaichi, Karen L. Casciotti, Satoshi Okabe
    The ISME Journal 13 10 2426 - 2436 2019年10月 [査読有り][通常論文]
  • Kobayashi Kanae, Makabe Akiko, Yano Midori, Oshiki Mamoru, Kindaichi Tomonori, Casciotti Karen L, Okabe Satoshi
    The ISME Journal 13 10 2426 - 2436 2019年10月 [査読有り][通常論文]
  • 田中 孝国, 半田 佳幹, フーレイチア, 田中 昭雄, 押木 守, 金田一 智規, 新田見 匡
    工業用水 = Journal of industrial water 656 656 77 - 84 日本工業用水協会 2019年09月 [査読有り][通常論文]
  • Nittami, T, Shoji, T, Koshiba, Y, Noguchi, M, Oshiki, M, Kuroda, M, Kindaichi, T, Fukuda, J, Kurisu F
    Process Saf. Environ. 124 137 - 142 2019年04月 [査読有り][通常論文]
     
    © 2019 Institution of Chemical Engineers Kouleothrix (Type 1851) filamentous bacteria associated with bulking incidents were investigated for their quantitative correlations with sludge settleability in municipal wastewater treatment plants (WWTPs) around Japan. Factors affecting their abundance were also explored by statistical analyses with the aim of controlling bulking by suppressing their growth. Real-time quantitative PCR assays showed Kouleothrix spp. mainly ranged from 104−105 copies ng-DNA−1 in WWTPs. They were not always abundant in every WWTP, but their abundance (>105 copies ng-DNA−1) almost always coincided with low activated sludge settleability. Their abundance in nitrogen removal processes was always low (1.08 − 3.83 × 104 copies ng-DNA−1). Denitrification process at the feeding stage may be a useful selection pressure for Kouleothrix spp., leading to their suppression. A stepwise multiple regression analysis revealed that the increase of dissolved oxygen (DO) and pH in an aeration tank have a negative influence, while NH4+ increase in the influent has a positive influence on the Kouleothrix spp. abundance. The three-variable model was significant and accounted for approximately 45% of the variance in the dependent variable (i.e., Kouleothrix spp.). The DO increase had the greatest influence on the Kouleothrix spp. decrease, and thus, the DO control may be a promising way to suppress their growth in WWTPs.
  • 吉田 力, 佐藤 剛, 押木 守, 荒木 信夫, 平片 悠河, 幡本 将史, 山口 隆司
    土木学会論文集G(環境) 75 7 III_19 - III_24 公益社団法人 土木学会 2019年 [査読有り][通常論文]
     

    本研究では実都市下水を供給したUASBリアクター内の上昇線流速を段階的に変化させ, 槽内に出現する嫌気性原生動物の細胞数と原生動物叢への影響を解析した. 原生動物の細胞数は槽内の上昇線流速が2.4-14.4m/dayの範囲では0-3970cells/mLで変化し,上昇線流速の増加に伴って増加する傾向が見られた.22.4m/dayの上昇線流速では原生動物が汚泥床外へ流亡し,細胞数は100cells/mLまで急激に減少した.UASB内に存在した嫌気性原生動物はMetopus palaeformis,Metopus contortus,Chaenomorpha sp.,Plagiopyla sp.が優占種であり,平均して全18SrRNA遺伝子の約7割を占めた.線流速が大きい条件でUASB内の原生動物の優占種は短期間で変化し,その変化は同一条件の運転期間においても観察された.

  • Health impact of agricultural drainage water for farmers in the West Nile Delta
    Okubo, T, Iguchi, A, Tanaka, S, Uchida, S, Tagawa, T, Oshiki, M, Araki, A, Tawfik, A, Takahashi, M, Kubota, K, Harada, H, Uemura, S
    Int. J. Environ. Res 13 319 - 325 2019年 [査読有り][通常論文]
  • Oshiki M, Masuda Y, Yamaguchi T, Araki N
    Chemosphere 213 498 - 506 2018年12月 [査読有り][通常論文]
  • Kobayashi S, Hira D, Yoshida K, Toyofuku M, Shida Y, Ogasawara W, Yamaguchi T, Araki N, Oshiki M
    Microbes and environments 33 4 428 - 434 2018年10月 [査読有り][通常論文]
  • 押木守
    生物工学会誌 96 7 408  2018年07月25日 [査読無し][通常論文]
  • Mamoru Oshiki, Mitsuru Araki, Yuga Hirakata, Masashi Hatamoto, Takashi Yamaguchi, Nobuo Araki
    MICROBES AND ENVIRONMENTS 33 2 230 - 233 2018年07月 [査読有り][通常論文]
     
    Although the turnover of urea is a crucial process in nitrogen transformation in soil, limited information is currently available on the abundance and diversity of ureolytic prokaryotes. The abundance and diversity of the soil 16S rRNA gene and ureC (encoding a urease catalytic subunit) were examined in seven soil types using quantitative PCR and amplicon sequencing with Illumina MiSeq. The amplicon sequencing of ureC revealed that the ureolytic community was composed of phylogenctically varied prokaryotes, and we detected 363 to 1,685 species-level ureC operational taxonomic units (OTUs) per soil sample, whereas 5,984 OTUs were site-specific OTUs found in only one of the seven soil types.
  • 田中 孝国, フーレイチア, 田中 昭雄, 押木 守, 金田一 智規, 新田見 匡
    工業用水 = Journal of industrial water 648 648 39 - 43 日本工業用水協会 2018年05月 [査読有り][通常論文]
  • Rathnayake, Rathnayake M. L. D., Oshiki, Mamoru, Ishii, Satoshi, Segawa, Takahiro, Satoh, Hisashi, Okabe, Satoshi
    ENVIRONMENTAL SCIENCE & TECHNOLOGY 52 10 5744 - 5752 2018年05月 [査読有り][通常論文]
     
    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.
  • Mamoru Oshiki, Takayuki Miura, Shinobu Kazama, Takahiro Segawa, Satoshi Ishii, Masashi Hatamoto, Takashi Yamaguchi, Kengo Kubota, Akinori Iguchi, Tadashi Tagawa, Tsutomu Okubo, Shigeki Uemura, Hideki Harada, Naohiro Kobayashi, Nobuo Araki, Daisuke Sano
    Frontiers in Microbiology 9 830  2018年04月27日 [査読有り][通常論文]
     
    Detection and genotyping of pathogenic RNA viruses in human and environmental samples are useful for monitoring the circulation and prevalence of these pathogens, whereas a conventional PCR assay followed by Sanger sequencing is time-consuming and laborious. The present study aimed to develop a high-throughput detection-and-genotyping tool for 11 human RNA viruses [Aichi virus astrovirus enterovirus norovirus genogroup I (GI), GII, and GIV hepatitis A virus hepatitis E virus rotavirus sapovirus and human parechovirus] using a microfluidic device and next-generation sequencer. Microfluidic nested PCR was carried out on a 48.48 Access Array chip, and the amplicons were recovered and used for MiSeq sequencing (Illumina, Tokyo, Japan) genotyping was conducted by homology searching and phylogenetic analysis of the obtained sequence reads. The detection limit of the 11 tested viruses ranged from 100 to 103 copies/μL in cDNA sample, corresponding to 101-104 copies/mL-sewage, 105-108 copies/g-human feces, and 102-105 copies/g-digestive tissues of oyster. The developed assay was successfully applied for simultaneous detection and genotyping of RNA viruses to samples of human feces, sewage, and artificially contaminated oysters. Microfluidic nested PCR followed by MiSeq sequencing enables efficient tracking of the fate of multiple RNA viruses in various environments, which is essential for a better understanding of the circulation of human pathogenic RNA viruses in the human population.
  • Mamoru Oshiki, Takahiro Segawa, Satoshi Ishii
    Applied and Environmental Microbiology 84 8 e02615-17  2018年04月01日 [査読有り][通常論文]
     
    Various microorganisms play key roles in the nitrogen (N) cycle. Quantitative PCR (qPCR) and PCR amplicon sequencing of N cycle functional genes allow us to analyze the abundance and diversity of microbes responsible for N-transforming reactions in various environmental samples. However, analysis of multiple target genes can be cumbersome and expensive. PCR-independent analysis, such as metagenomics and metatranscriptomics, is useful but expensive, especially when we analyze multiple samples and try to detect N cycle functional genes present at a relatively low abundance. Here, we present the application of microfluidic qPCR chip technology to simultaneously quantify and prepare amplicon sequence libraries for multiple N cycle functional genes as well as taxon-specific 16S rRNA gene markers for many samples. This approach, named the nitrogen cycle evaluation (NiCE) chip, was evaluated by using DNA from pure and artificially mixed bacterial cultures and by comparing the results with those obtained by conventional qPCR and amplicon sequencing methods. Quantitative results obtained by the NiCE chip were comparable to those obtained by conventional qPCR. In addition, the NiCE chip was successfully applied to examine the abundance and diversity of N cycle functional genes in wastewater samples. Although nonspecific amplification was detected on the NiCE chip, this can be overcome by optimizing the primer sequences in the future. As the NiCE chip can provide a high-throughput format to quantify and prepare sequence libraries for multiple N cycle functional genes, this tool should advance our ability to explore N cycling in various samples.
  • 大久保 努, 上村 繁樹, 井口 晃徳, 多川 正, 押木 守, 久保田 健吾, 荒木 信夫, 原田 秀樹, Tawfik Ahmed, 市村 禎二郎
    下水道協会誌 = Journal of Japan Sewage Works Association 55 665 76 - 82 日本下水道協会 2018年03月 [査読有り][通常論文]
  • 伊藤 司, 金田一 智則, 押木 守, 岡部 聡
    EICA : journal of EICA : 環境システム計測制御学会誌 22 4 21 - 26 環境システム計測制御学会 2018年 [査読有り][通常論文]
  • 最初沈殿池+DHSシステムに付加する下水処理水の灌漑利用のための消毒システムの開発
    景政 柊蘭, 長町 晃宏, 井口 晃徳, 久保田 健吾, 高橋 優信, 原田秀樹, 押木守, 荒木信夫, 大久保努, 上村 繁樹, 多川 正
    土木学会論文集G 74 7 333 - 340 2018年 [査読有り][通常論文]
  • Lei Zhang, Yuko Narita, Lin Gao, Muhammad Ali, Mamoru Oshiki, Satoshi Ishii, Satoshi Okabe
    WATER RESEARCH 125 249 - 258 2017年11月 [査読有り][通常論文]
     
    Phylogenetically diverse anammox bacteria have been detected in most of anoxic natural and engineered ecosystems and thus regarded as key players in the global nitrogen cycle. However, ecological niche differentiation of anammox bacteria remains unresolved despite its ecological and practical importance. In this study, the microbial competitions for a common substrate (nitrite) among three anammox species (Le. "Candidatus Brocadia sinica", "Candidatus Jettenia caeni" and "Candidatus Kuenenia stuttgartiensis") were systematically investigated in nitrite-limited gel-immobilized column reactors (GICR) and membrane bioreactors (MBRs) under different nitrogen loading rates (NLRs). 16 S rRNA gene-based population dynamics revealed that "Ca. J. caeni" could proliferate only at low NLRs, whereas "Ca. B. sinica" out competed other two species at higher NLRs in both types of reactors. Furthermore, FISH analysis revealed that "Ca. J. caeni" was mainly present as spherical microclusters at the inner part (low NO2- environment), whereas "Ca. B. sinica" was present throughout the gel beads and granules. This spatial distribution supports the outcomes of the competition experiments. However, the successful competition of "Ca. J. caeni" at low NLR could not be explained with the Monod model probably due to inaccuracy of kinetic parameters such as half saturation constant (K-s) for nitrite and a difference in the maintenance rate (m). In addition, the growth of "Ca. K. stuttgartiensis" could not be observed in any experimental conditions, suggesting possible unknown factor(s) is missing. Taken together, NLR was one of factors determining ecological niche differentiation of "Ca. B. sinica" and "Ca. J. caeni". (C) 2017 Elsevier Ltd. All rights reserved.
  • Mamoru Oshiki, Keisuke Mizuto, Zen-ichiro Kimura, Tomonori Kindaichi, Hisashi Satoh, Satoshi Okabe
    ENVIRONMENTAL MICROBIOLOGY REPORTS 9 5 550 - 561 2017年10月 [査読有り][通常論文]
     
    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'.
  • Mamoru Oshiki, Toshikazu Fukushima, Shuichi Kawano, Junichi Nakagawa
    Genome Announcements 5 32 e00799-17  2017年08月01日 [査読有り][通常論文]
     
    A draft genome sequence of a neutrophilic halophile capable of thiocyanate degradation, Thiohalobacter thiocyanaticus FOKN1, was determined using a PacBio RSII sequencer. A 3.23-Mb circular genome sequence was assembled, in which 3,026 gene-coding sequences, 45 tRNAs, and 1 rrn operon were annotated.
  • Hisashi Satoh, Yuji Miyazaki, Shou Taniuchi, Mamoru Oshiki, Rathnayake M. L. D. Rathnayake, Masahiro Takahashi, Satoshi Okabe
    ANALYTICAL SCIENCES 33 7 825 - 830 2017年07月 [査読有り][通常論文]
     
    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.
  • Lei Zhang, Yuko Narita, Lin Gao, Muhammad Ali, Mamoru Oshiki, Satoshi Okabe
    WATER RESEARCH 116 296 - 303 2017年06月 [査読有り][通常論文]
     
    Anammox bacteria have long been considered to be slow-growing bacteria. However, it has recently been reported that they could grow much faster than previously thought when they were cultivated in a membrane bioreactor (MBR) with a step-wise decrease in the solid retention time (SRT). Here, we reevaluated the maximum specific growth rates (mu(max)) of three phylogenetically distant anammox bacterial species (i.e. "Ca. Brocadia sinica", "Ca. Jettenia caeni" and "Ca. Scalindua sp.") by directly measuring 16S rRNA gene copy numbers using newly developed quantitative polymerase chain reaction (qPCR) assays. When free-living planktonic "Ca. B. sinica" and "Ca. J. caeni" cells were immobilized in polyvinyl alcohol (PVA) and sodium alginate (SA) gel beads and cultivated in an up-flow column reactor with high substrate loading rates at 37 degrees C, the mu(max) were determined to be 033 +/- 0.02 d(-1) and 0.18 d(-1) (corresponding doubling time of 2.1 day and 3.9 day) from the exponential increases in 16S rRNA genes copy numbers, respectively. These values were faster than the fastest growth rates reported for these species so far. The cultivation of anammox bacteria in gel beads was achieved less than one month without special cultivation method and selection pressure, and the exponential increase in 16S rRNA gene numbers was directly measured by qPCR with high reproducibility; therefore, the resulting mu(max) values were considered accurate. Taken together, the fast growth is, therefore, considered to be an intrinsic kinetic property of anammox bacteria. (C) 2017 Elsevier Ltd. All rights reserved.
  • Naohiro Kobayashi, Mamoru Oshiki, Toshihiro Ito, Takahiro Segawa, Masashi Hatamoto, Tsuyoshi Kato, Takashi Yamaguchi, Kengo Kubota, Masanobu Takahashi, Akinori Iguchi, Tadashi Tagawa, Tsutomu Okubo, Shigeki Uemura, Hideki Harada, Toshiki Motoyama, Nobuo Araki, Daisuke Sano
    WATER RESEARCH 110 389 - 398 2017年03月 [査読有り][通常論文]
     
    A down-flow hanging sponge (DHS) reactor has been developed as a cost-effective wastewater treatment system that is adaptable to local conditions in low-income countries. A pilot-scale DHS reactor previously demonstrated stable reduction efficiencies for chemical oxygen demand (COD) and ammonium nitrogen over a year at ambient temperature, but the pathogen reduction efficiency of the DHS reactor has yet to be investigated. In the present study, the reduction efficiency of a pilot-scale DHS reactor fed with municipal wastewater was investigated for 10 types of human pathogenic viruses (norovirus GI, GII and GIV, aichivirus, astrovirus, enterovirus, hepatitis A and E viruses, rotavirus, and sapovirus). DHS influent and effluent were collected weekly or biweekly for 337 days, and concentrations of viral genomes were determined by microfluidic quantitative PCR. Aichivirus, norovirus GI and GII, enterovirus, and sapovirus were frequently detected in DHS influent, and the logio reduction (LR) of these viruses ranged from 1.5 to 3.7. The LR values for aichivirus and norovirus Gil were also calculated using a Bayesian estimation model, and the average LR (standard deviation) values for aichivirus and norovirus GII were estimated to be 1.4 (1.5) and 1.8 (2.5), respectively. Quantitative microbial risk assessment was conducted to calculate a threshold reduction level for norovirus Gil that would be required for the use of DHS effluent for agricultural irrigation, and it was found that LRs of 2.6 and 3.7 for norovirus GII in the DHS effluent were required in order to not exceed the tolerable burden of disease at 10(-4) and 10(-6) disability-adjusted life years loss per person per year, respectively, for 95% of the exposed population during wastewater reuse for irrigation. (C) 2016 Elsevier Ltd. All rights reserved.
  • Y. Hirakata, M. Hatamoto, M. Oshiki, N. Araki, T. Yamaguchi
    Lecture Notes in Civil Engineering 4 218 - 224 2017年 [査読有り][通常論文]
     
    © Springer International Publishing AG 2017. Microbial eukaryotes play important roles in sewage treatment systems. In an up-flow anaerobic sludge blanket (UASB) reactor fed with domestic sewage, anaerobic bacteria, archaea, and microbial eukaryotes (protist and fungi) coexist. To date, bacterial and archaeal communities in the UASB reactor have been widely studied. However, little is known about the eukaryotic community structure and function in most of anaerobic treatment systems. In this study, we analyzed eukaryotic community in the UASB reactor treating domestic sewage over 2 years operational period based on 18S rRNA gene sequences. In addition, multivariate statistics were applied to elucidate the correlation between eukaryotic community and operational conditions of the UASB reactor. The dominant protist groups observed were from phylum Ciliophora, Apicomplexa, Perkisea and Amoebozoa in the UASB reactor. Followings were flagellate protist such as Cercozoa, Sulcozoa, Bicosoecida, Choanomonada, Dinoflagellata and Metamonada. The result showed protist phylum and water temperature were not correlated. Only phylum Sulcozoa positively correlated with COD and suspended solid (SS), whereas other protist showed low correlation. The dominant fungi groups were LKM11, LKM15 and phylum Ascomycota. Uncultured LKM15 correlated with sulfide whereas phylum Discicristoidea and Chytridiomycota showed negative correlation. Phylum Ascomycota seemed most abundant when sulfide was low, but their association with environmental variables remained unclear. These results suggested that some protist and fungi groups could be used as indicator of environmental parameters in the UASB reactor.
  • Mamoru Oshiki, Hisashi Satoh, Satoshi Okabe
    ENVIRONMENTAL MICROBIOLOGY 18 9 2784 - 2796 2016年09月 [査読有り][通常論文]
     
    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.
  • Mamoru Oshiki, Muhammad Ali, Kaori Shinyako-Hata, Hisashi Satoh, Satoshi Okabe
    ENVIRONMENTAL MICROBIOLOGY 18 9 3133 - 3143 2016年09月 [査読有り][通常論文]
     
    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.
  • Yuga Hirakata, Mamoru Oshiki, Kyohei Kuroda, Masashi Hatamoto, Kengo Kubota, Takashi Yamaguchi, Hideki Harada, Nobuo Araki
    MICROBES AND ENVIRONMENTS 31 3 279 - 287 2016年09月 [査読有り][通常論文]
     
    Predation by protists is top-down pressure that regulates prokaryotic abundance, community function, structure, and diversity in natural and artificial ecosystems. Although the effects of predation by protists have been studied in aerobic ecosystems, they are poorly understood in anoxic environments. We herein studied the influence of predation by Metopus and Caenomorpha ciliates-ciliates frequently found in anoxic ecosystems-on prokaryotic community function, structure, and diversity. Metopus and Caenomorpha ciliates were cocultivated with prokaryotic assemblages (i.e., anaerobic granular sludge) in an up-flow anaerobic sludge blanket (UASB) reactor for 171 d. Predation by these ciliates increased the methanogenic activities of granular sludge, which constituted 155% of those found in a UASB reactor without the ciliates (i.e., control reactor). Sequencing of 16S rRNA gene amplicons using Illumina MiSeq revealed that the prokaryotic community in the UASB reactor with the ciliates was more diverse than that in the control reactor; 2,885-3,190 and 2,387-2,426 operational taxonomic units (>97% sequence similarities), respectively. The effects of predation by protists in anaerobic engineered systems have mostly been overlooked, and our results show that the influence of predation by protists needs to be examined and considered in the future for a better understanding of prokaryotic community structure and function.
  • 長町 晃宏, 井口 晃徳, 瀬戸 雄太, 久保田 健吾, 押木 守, 荒木 信夫, 大久保 努, 上村 繁樹, 高橋 優信, 原田 秀樹, 多川 正
    土木学会論文集G(環境) 72 7 III_187 - III_195 公益社団法人 土木学会 2016年 [査読有り][通常論文]
     
    活性汚泥法の代替下水処理技術として一次沈殿処理の後段処理にDown-flow Hanging Sponge (DHS)を組み合わせた低コスト・低エネルギー消費型下水処理システム(一次沈殿+DHSシステム)を考案し,1,000日以上に及ぶ連続通水実験を実施した.その結果,衛生指標微生物としての大腸菌群及び糞便性大腸菌群の対数除去率は,DHSのHRTが0.8時間の時にはそれぞれ1.45 log,1.88 logと低かった.この時のBOD,SSの除去率は80%以下で,硝化反応も見られなかった.しかしDHSのHRTを3.2時間とすることで,大腸菌群及び糞便性大腸菌群の対数除去率は,2.73 log,3.15 logを示し,BOD,SSの除去率もそれぞれ90%以上を達成した.同一下水を処理している活性汚泥法による大腸菌群及び糞便性大腸菌群の対数除去率がそれぞれ2.55 log,2.19 logであり,BOD,SS除去率もほぼ同等だった.以上より,一次沈殿+DHSシステムは,HRTを管理することで活性汚泥法とほぼ同等の衛生指標微生物除去性能を得ることができる.
  • 伊藤寿宏, 押木守, 小林直央, 加藤毅, 瀬川高弘, 幡本将史, 山口隆司, 原田秀樹, 北島正章, 岡部聡, 佐野大輔
    土木学会論文集 G(環境)(Web) 72 7 III_305‐III_313(J‐STAGE) - III_313 公益社団法人 土木学会 2016年 [査読有り][通常論文]
     
    本研究では、流入下水中のヒト腸管系ウイルス濃度分布、及びWHOが推奨する許容年間疾病負荷(10<sup>-6</sup> disability-adjusted life years per person per year)に基づいて、定量的微生物リスク評価(quantitative microbial risk assessment: QMRA)の手法を用いて下水再生水の利用用途ごとにウイルス除去効率の目標値を算出する手法を構築・提案する。代表的なヒト腸管系ウイルスとしてノロウイルスに着目し、流入下水中のノロウイルス濃度モニタリングデータを使用することで、6種類の下水再生水利用シナリオにおけるノロウイルスの下水再生水中許容濃度及び除去効率の目標値を試算した。本研究で提案した方法により算出したヒト腸管系ウイルス除去効率目標値を使用する際には、下水再生システム稼動後においても未処理下水中のヒト腸管系ウイルス濃度をモニタリングすることが求められる。また、用量反応モデル情報の更新と、下水再生利用が行われる地域の状況に基づいた曝露シナリオとパラメータの更新についても継続して取り組むことが重要である。
  • Mamoru Oshiki, Kaori Shinyako-Hata, Hisashi Satoh, Satoshi Okabe
    Genome Announcements 3 2 2016年 [査読有り][通常論文]
     
    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.
  • Mamoru Oshiki, Ryota Takagi, Masashi Hatamoto, Takashi Yamaguchi, Nobuo Araki
    JOURNAL OF GENERAL AND APPLIED MICROBIOLOGY 62 6 330 - 333 2016年 [査読有り][通常論文]
  • Rathnayake M. L. D. Rathnayake, Mamoru Oshiki, Satoshi Ishii, Takahiro Segawa, Hisashi Satoh, Satoshi Okabe
    BIORESOURCE TECHNOLOGY 197 15 - 22 2015年12月 [査読有り][通常論文]
     
    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.
  • Yuga Hirakata, Mamoru Oshiki, Kyohei Kuroda, Masashi Hatamoto, Kengo Kubota, Takashi Yamaguchi, Hideki Harada, Nobuo Araki
    MICROBES AND ENVIRONMENTS 30 4 335 - 338 2015年12月 [査読有り][通常論文]
     
    The aim of the present study was to investigate the prokaryotic community structure of the anaerobic ciliate, Metopus sp. using rRNA sequencing, fluorescence in situ hybridization ( FISH), and transmission electron microscopy (TEM). Metopus sp. was physically separated from anaerobic granular sludge in a domestic wastewater treatment plant and anoxically cultivated for 7 d. 16S rRNA gene sequences from the prokaryotes Methanoregula boonei and Clostridium aminobutyricum were abundantly detected in Metopus ciliates. The FISH analysis using the oligonucleotide probes Mg1200b and Cla568 demonstrated that these prokaryotes were localized within Metopus cells. These results identify M. boonei- and C. aminobutyricum-like prokaryotes as novel endosymbionts of Metopus ciliates.
  • Muhammad Ali, Mamoru Oshiki, Lashitha Rathnayake, Satoshi Ishii, Hisashi Satoh, Satoshi Okabe
    WATER RESEARCH 79 147 - 157 2015年08月 [査読有り][通常論文]
     
    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.
  • Ali M, Oshiki M, Awata T, Isobe K, Kimura Z, Yoshikawa H, Hira D, Kindaichi T, Satoh H, Fujii T, Okabe S
    Environmental microbiology 17 6 2172 - 2189 2015年06月 [査読有り][通常論文]
     
    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.
  • 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][通常論文]
  • Muhammad Ali, Mamoru Oshiki, Satoshi Okabe
    WATER RESEARCH 57 215 - 222 2014年06月 [査読有り][通常論文]
     
    It is still the biggest challenge to secure enough seeding biomass for rapid start-up of fullscale (anaerobic ammonium oxidation) anammox processes due to slow growth. Preservation of active anammox biomass could be one of the solutions. In this study, biomass of anammox bacterium, "Candidatus Brocadia sinica", immersed in various nutrient media were preserved at 80 C, 4 C and room temperature. After 45, 90 and 150 days of preservation, specific anammox activity (SAA) of the preserved anammox biomass was determined by measuring (29)N2 production rate and transcription levels of hzsA gene encoding hydrazine synthase alpha subunit. Storage in nutrient medium containing 3 mM of molybdate at room temperature with periodical (every 45 days) supply of Nlit and NO2- was proved to be the most effective storage technique for "Ca. Brocadia sinica" biomass. Using this preservation condition, 96, 92 and 65% of the initial SAA was sustained after 45, 90 and 150 days of storage, respectively. Transcription levels of hzsA gene in biomass correlated with the SAA (R-2 = 0.83), indicating it can be used as a genetic marker to evaluate the anammox activity of preserved biomass. Furthermore, the 90-day-stored biomass was successfully reactivated by immobilizing in polyvinyl alcohol (6%, w/v) and sodium alginate (2%, w/v) gel and then inoculated to up-flow column reactors. Total nitrogen removal rates rapidly increased to 7 kg-N m(-3) d(-1) within 35 days of operation. Based on these results, the room temperature preservation with molybdate addition is simple, cost-effective and feasible at a practical scale, which will accelerate the practical use of anammox process for wastewater treatment. (C) 2014 Elsevier Ltd. All rights reserved.
  • 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 2013年12月 [査読有り][通常論文]
     
    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.
  • Oshiki, Mamoru, Awata, Takanori, Kindaichi, Tomonori, Satoh, Hisashi, Okabe, Satoshi
    MICROBES AND ENVIRONMENTS 28 4 436 - 443 2013年12月 [査読有り][通常論文]
     
    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.
  • 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][通常論文]
     
    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.
  • Takanori Awata, Mamoru Oshiki, Tomonori Kindaichi, Noriatsu Ozaki, Akiyoshi Ohashi, Satoshi Okabe
    APPLIED AND ENVIRONMENTAL MICROBIOLOGY 79 13 4145 - 4148 2013年07月 [査読有り][通常論文]
     
    The phylogenetic affiliation and physiological characteristics (e.g., K-s and maximum specific growth rate [mu(max)]) of an anaerobic ammonium oxidation (anammox) bacterium, "Candidatus Scalindua sp.," enriched from the marine sediment of Hiroshima Bay, Japan, were investigated. "Candidatus Scalindua sp." exhibits higher affinity for nitrite and a lower growth rate and yield than the known anammox species.
  • Mamoru Oshiki, Motoharu Onuki, Hiroyasu Satoh, Takashi Mino
    MICROBES AND ENVIRONMENTS 28 1 96 - 104 2013年03月 [査読有り][通常論文]
     
    The removal of biodegradable organic matter is one of the most important objectives in biological wastewater treatments. Polyhydroxyalkanoate (PHA)-accumulating organisms (PHAAOs) significantly contribute to the removal of biodegradable organic matter; however, their microbial community composition is mostly unknown. In the present study, the microbial community composition of PHAAOs was investigated at 8 full-scale wastewater treatment plants (WWTPs), operated in fully aerobic mode, by fluorescence in situ hybridization (FISH) analysis and post-FISH Nile blue A (NBA) staining techniques. Our results demonstrated that 1) PHAAOs were in the range of 11-18% in the total number of cells, and 2) the microbial community composition of PHAAOs was similar at the bacterial domain/phylum/class/order level among the 8 full-scale WWTPs, and dominant PHAAOs were members of the class Alphaproteobacteria and Betaproteobacteria. The microbial community composition of alpha- and beta-proteobacterial PHAAOs was examined by 16S rRNA gene clone library analysis and further by applying a set of newly designed oligonucleotide probes targeting 16S rRNA gene sequences of alpha- or beta-proteobacterial PHAAOs. The results demonstrated that the microbial community composition of PHAAOs differed in the class Alphaproteobacteria and Betaproteobacteria, which possibly resulted in a different PHA accumulation capacity among the WWTPs (8.5-38.2 mg-C g-VSS-1 h(-1)). The present study extended the knowledge of the microbial diversity of PHAAOs in full-scale WWTPs operated in fully aerobic mode.
  • Purnika Damindi Ranasinghe, Hiroyasu Satoh, Mamoru Oshiki, Kenshiro Oshima, Wataru Suda, Masahira Hattori, Takashi Mino
    WATER SCIENCE AND TECHNOLOGY 66 10 2155 - 2161 2012年 [査読有り][通常論文]
     
    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.
  • Satoshi Okabe, Mamoru Oshiki, Yoshitaka Takahashi, Hisashi Satoh
    WATER RESEARCH 45 19 6461 - 6470 2011年12月 [査読有り][通常論文]
     
    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.
  • Satoshi Okabe, Mamoru Oshiki, Yoshitaka Takahashi, Hisashi Satoh
    Bioresource Technology 102 13 6801 - 6807 2011年07月 [査読有り][通常論文]
     
    The partial nitrification reactor was successfully started up and operated stably for more than 250days with a maximum nitrite production rate of 1.12kg-Nm-3day-1. The important factors for successful partial nitrification were high ammonium loading rate (> 1.0kg-Nm-3day-1) and relatively high pH (ca. 8.0), giving high free ammonia concentrations (> 10mg NH3-NL-1). In addition, the air flow rate must be controlled at the ratio of air flow rate to ammonium loading rate below 0.1 (mair3day-1)/(kg-Nm-3day-1). After the establishment of stable partial nitrification, the effluent NO2--N/NH4+-N ratio and effluent NO3--N concentration were 1.20±0.33 and 1.2±1.0mg-NL-1, respectively, which was then fed into an granular-sludge anammox reactor. Consistent nitrogen removal was achieved for more than 250days with a maximum nitrogen removal rate of 15.0kg-TNm-3day-1. © 2011 Elsevier Ltd.
  • Mamoru Oshiki, Masaki Shimokawa, Naoki Fujii, Hisashi Satohl, Satoshi Okabe
    MICROBIOLOGY-SGM 157 6 1706 - 1713 2011年06月 [査読有り][通常論文]
     
    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.
  • 押木守, 岡部聡
    生物の科学 遺伝 65 3 48 - 54 2011年05月01日 [査読無し][通常論文]
  • M. Oshiki, H. Satoh, T. Mino
    WATER SCIENCE AND TECHNOLOGY 64 3 747 - 753 2011年 [査読有り][通常論文]
     
    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.
  • Satoshi Okabe, Mamoru Oshiki, Yoichi Kamagata, Nobuyasu Yamaguchi, Masanori Toyofuku, Yutaka Yawata, Yosuke Tashiro, Nobuhiko Nomura, Hiroyuki Ohta, Moriya Ohkuma, Akira Hiraishi, Kiwamu Minamisawa
    MICROBES AND ENVIRONMENTS 25 4 230 - 240 2010年12月 [査読有り][通常論文]
     
    Ribosomal RNA (rRNA) sequence-based molecular techniques emerged in the late 1980s, which completely changed our general view of microbial life. Coincidentally, the Japanese Society of Microbial Ecology (JSME) was founded, and its official journal "Microbes and Environments (M&E)" was launched, in 1985. Thus, the past 25 years have been an exciting and fruitful period for M&E readers and microbiologists as demonstrated by the numerous excellent papers published in M&E. In this minireview, recent progress made in microbial ecology and related fields is summarized, with a special emphasis on 8 landmark areas; the cultivation of uncultured microbes, in situ methods for the assessment of microorganisms and their activities, biofilms, plant microbiology, chemolithotrophic bacteria in early volcanic environments, symbionts of animals and their ecology, wastewater treatment microbiology, and the biodegradation of hazardous organic compounds.
  • Mamoru Oshiki, Motoharu Onuki, Hiroyasu Satoh, Takashi Mino
    JOURNAL OF GENERAL AND APPLIED MICROBIOLOGY 56 2 163 - 167 2010年04月 [査読有り][通常論文]
  • M. Oshiki, H. Satoh, T. Mino
    WATER SCIENCE AND TECHNOLOGY 62 1 8 - 14 2010年 [査読有り][通常論文]
     
    The present study was conducted to evaluate the specific acetate uptake rates of microorganisms with and without polyhydroxyalkanoates (PHA) accumulation. Activated sludge was aerobically incubated with 75 mgCL(-1) radiolabeled or non-labeled acetate, and acetate consumption and PHA accumulation were monitored. Microorganisms were quantified as follows: all microbial cells by DAPI staining, whole acetate utilizing organisms by microautoradiography, and PHA-accumulating organisms by staining with Nile blue A. The abundance of acetate-utilizing organisms without PHA accumulation was also calculated from the outcomes. The estimate of acetate utilized by PHAAOs included both the acetate converted to PHA and that used to supply reducing power and ATP. Acetate utilized by PHAAOs and non-PHAAOs were divided by their respective abundances to obtain their respective specific acetate uptake rates: PHAAOs ranged between 5.3 and 8.0 x 10(-10) mgC cell(-1) h(-1), and non-PHAAOs ranged between 2.8 and 4.2 x 10(-10) mgC cell(-1) h(-1).
  • 押木 守, 佐藤 弘泰, 小貫 元治, 味埜 俊
    下水道協会誌 46 566 126 - 137 日本下水道協会 2009年12月15日 [査読有り][通常論文]
  • 微生物の持つ有機物貯蔵能力を利用した省エネルギー型廃水処理法の提案
    押木 守, 佐藤 弘泰, 味埜 俊
    用水と廃水 51 41 - 49 2009年 [査読有り][通常論文]
  • Occurrence of Polyhydroxyalkanoate as Temporal Carbon Storage Material in Activated Sludge during The Removal of Organic Pollutants.
    Oshiki, M, Yang, Y, Onuki, M, Satoh, H, Peng, Y.-Z, Mino, T
    J. Water Environ. Technol 6 77 - 83 2008年 [査読有り][通常論文]
  • Mamoru Oshiki, Motoharu Onuki, Hiroyasu Satoh, Takashi Mino
    WATER SCIENCE AND TECHNOLOGY 58 1 13 - 20 2008年 [査読有り][通常論文]
     
    A study was conducted to clarify phylogenetic affiliations of polyhydroxyalkanoate (PHA)-accumulating microorganisms in full-scale activated sludge processes. Activated sludge samples obtained from three full-scale activated sludge processes were aerobically incubated with excess acetate to increase their PHA content. The buoyant density separation method was applied to selectively collect PHA-accumulating cells, which were then analysed by the group-level FISH and the PCR-DGGE-sequencing methods, and possible PHA-accumulating microbial groups were screened. A set of oligonucleotide probes targeting the microbial groups suspected to accumulate PHA was introduced, and seven oligonucleotide probes were newly designed for this purpose. PHA accumulation of probe-positive cells was confirmed by the post-FISH PHA staining method, wherein PHA staining with Nile Blue A (NBA) was applied after FISH. As a result, the following seven bacterial groups were found to have PHA: Dechloromonas, Accumulibacter, Thauera, Zoogloea, Comamonas, Competibacter and a novel cluster in Beta-proteobacteria. Based on the results of the post-FISH PHA staining method, these seven bacterial groups were estimated to account for around four-tenths to two-thirds of total PHA-accumulating microorganisms.
  • 押木 守, 小貫 元治, 佐藤 弘泰, 味埜 俊
    環境工学研究論文集 43 195 - 203 Japan Society of Civil Engineers 2006年11月17日 [査読有り][通常論文]
     
    実下水処理場の活性汚泥を用いたバッチ試験を異なる電子受容体存在下で実施し, 活性汚泥による酢酸摂取へPHA蓄積細菌が寄与した割合を評価した. その際にNile blue Aで検出される細菌をPHA蓄積細菌とみなし, 存在割合をNile blue AとDAPIの二重染色法により定量評価した. 酢酸摂取にNile blue A陽性細菌が寄与した割合は2~10割であり, 好気条件で培養した活性汚泥でNile blue A陽性細菌は全菌の1~2割を占めた. さらにFISH法により<I>Candidatus</I> "Accumulibacter phosphatis"と<I>Candidatus</I> "Competibacter phosphatis"の存在割合を定量評価し, これらの細菌がNile blue A陽性細菌の中で1~9割を占めることを明らかにした.
  • 押木 守, 荒木 信夫, 竹林 賢, 長野 晃弘
    水環境学会誌 28 11 683 - 687 公益社団法人 日本水環境学会 2005年11月10日 [査読有り][通常論文]
     
    The transcription level of the nitrite reductase gene of denitrifying bacteria in a lab-scale denitrifying reactor was investigated by real-time reverse transcription (RT)-PCR technique as an indicator of in-situ microbial activity. Two types of batch experiment were conducted to clarify the effects of dissolved oxygen (DO) and carbon/nitrogen (C/N) ratio on the relative nirS mRNA level in denitrifying sludge. The reverse transcription of total RNA with the primer, nirS 6R, specific for the nirS gene was suitable for the subsequent quantification of the nirS gene by real-time PCR. The presence of DO and a low C/N ratio in the medium resulted in a rapid decrease in the relative transcription level of nirS mRNA from 105 to 103 copies·ng-1 total RNA within four hours of the batch experiments. The relative transcription remained at the same level after nitrate concentration decreased to a level low enough to reduce denitrification rate. Although there was no relationship between the denitrification rate of the reactor and the relative transcription level of nirS mRNA in the batch experiments, a quick response of transcriptional induction of nirS mRNA corresponding to the changes in DO and C/N ratio was detected.
  • 押木 守, 荒木 信夫, 山口 隆司, 山崎 慎一, 原田 秀樹
    環境工学研究論文集 40 63 - 70 Japan Society of Civil Engineers 2003年11月14日 [査読有り][通常論文]
     
    The relationship between ammonia-oxidizing activities and <I>amoA</I> mRNA (encoding ammonia monooxigenase) levels was investigated by batch experiments with nitrifying biofilms taken from a lab-scale bioreactor. RT-PCR technology was applied to determine copy numbers of <I>amoA</I> mRNA in total RNA extracted from the sludge sample. Ammonia oxidation rates and transcription levels of <I>amoA</I> mRNA were monitored throughout the experiment that ammonia was fed as the concentration rose abruptly up to 20 or 100 mg-N/L whenever ammonia was consumed completely. A large ammonia turnover rate occurred immediately after every ammonia shock load, although the <I>amoA</I> mRNA level was still low. The turnover rate gradually reduced with decreasing ammonia concentration, while the <I>amoA</I> mRNA level increased until several hours after every ammonia shock load. The tendency of the <I>amoA</I> mRNA transcription changed a decrease as ammonia concentration dropped as low as Km value of <I>Nitrosomonas</I>. The induction of <I>amoA</I> mRNA was detected under the presence of low ammonia less than 5 mg-N/L. However the <I>amoA</I> mRNA level was not correlated with the ammonia turnover rate in the range from 5 to 100mg-N/L. It was indicated that the <I>amoA</I> mRNA level in the nitrifying sludge was not directly connected to the <I>in-situ</I> activity of ammonia-oxidizing bacteria.

MISC

講演・口頭発表等

  • 嫌気性アンモニウム酸化(anammox)細菌クロニクル; 未知の代謝を解明する  [招待講演]
    押木守
    第四回北関東磐越地区化学技術フォーラム 2018年 郡山地域職業訓練センター
  • Candidatus Brocadia sinicaによる嫌気性アンモニウム酸化反応  [招待講演]
    Oshiki M
    The 8th Asian Symposium on Microbiology Ecology 2016年 台北
  • 未知転じて既知となる: 嫌気性アンモニア酸化細菌の発見がもたらした衝撃  [招待講演]
    押木守
    48回GRL浜松セミナー 2014年 静岡大学
  • 嫌気性アンモニウム酸化細菌による亜硝酸還元  [招待講演]
    押木守
    平成25年度日本水環境学会北海道支部学術講演会 2013年 北海道大学
  • 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  [招待講演]
    押木守
    第65回日本生物工学会大会 2013年 広島国際会議場
  • 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  [招待講演]
    押木守
    第15回水環境学会シンポジウム 2012年 佐賀大学
  • 省エネ・創エネ型下水処理技術の提案  [招待講演]
    Oshiki M
    International Workshop on Water and Wastewater Treatment 2009年 台湾
  • 活性汚泥による有機物除去へのPHA蓄積細菌の寄与  [招待講演]
    第11回水環境学会シンポジウム 2008年 関西大学

所属学協会

  • 土木学会   日本水環境学会   日本農芸化学会   日本ゲノム微生物学会   日本微生物生態学会   

共同研究・競争的資金等の研究課題

  • 水処理微生物のバイオインフォマティクス
    日本製鉄株式会社・電気通信大学:
    研究期間 : 2019年07月 - 現在 
    代表者 : 福島寿和
  • 新規好気性アンモニア酸化反応の分子メカニズム解明に向けた触媒分子の分離と機能解明
    日本学術振興会:日本学術振興会科学研究費補助金 基盤研究C
    研究期間 : 2019年04月 - 現在 
    代表者 : 押木守
  • 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
    日本学術振興会:日本学術振興会科学研究費補助金 基盤研究(A)
    研究期間 : 2019年04月 -2023年03月 
    代表者 : 岡部聡
  • ゲノムマイニングおよび培養試験から存在が見いだされた新規な亜硝酸還元酵素の正体と機能をつきとめる
    公益財団法人発酵研究所一般研究助成:
    研究期間 : 2018年04月 -2020年03月 
    代表者 : 押木守
  • プロテオーム解析による有機ハロゲン呼吸細菌の網羅的機能タイピング
    日本学術振興会:日本学術振興会科学研究費補助金 基盤研究(B)
    研究期間 : 2017年04月 -2020年03月 
    代表者 : 吉田奈央子
  • 硫黄サイクルを基幹とした高度水資源循環システムの構築
    日本学術振興会:日本学術振興会科学研究費補助金 基盤研究(A)
    研究期間 : 2016年04月 -2020年03月 
    代表者 : 山口隆司
  • 嫌気性原生動物による都市下水処理UASB内の捕捉SS成分の分解・メタン化の促進
    日本学術振興会:日本学術振興会科学研究費補助金 基盤研究(B)
    研究期間 : 2016年04月 -2020年03月 
    代表者 : 荒木信夫
  • 水処理微生物のバイオインフォマティクス
    日本製鉄株式会社(旧 新日鐵住金株式会社)・電気通信大学:
    研究期間 : 2016年07月 -2019年06月 
    代表者 : 福島寿和
  • 分子・物質合成プラットフォーム利用促進事業: 嫌気性アンモニウム酸化(anammox)細菌におけるヒドラジンN2H4分子の細胞イメージング
    千歳科学技術大学:
    研究期間 : 2018年04月 -2019年03月 
    代表者 : 押木守
  • 窒素循環に新たな1ページを加える第三の窒素ガス生成経路を担う微生物群の同定
    日本学術振興会:日本学術振興会科学研究費補助金 若手(B)
    研究期間 : 2017年04月 -2019年03月 
    代表者 : 押木守
  • エネルギー資源を生み出す排水処理技術の開発:液体燃料ヒドラジンN2H4の生産
    公益財団法人インテリジェント・コスモス学術振興財団:
    研究期間 : 2017年09月 -2018年03月 
    代表者 : 押木守
  • ヒドラジンをエネルギーとして生産する新規な窒素含有排水処理法の開発
    イムラ・ジャパン株式会社:第一回イムラ・ジャパン賞
    研究期間 : 2017年04月 -2018年03月 
    代表者 : 押木守
  • 極域生態系における元素循環関連遺伝子群の網羅的検出手法の開発
    国立極地研究所:一般共同研究助成
    研究期間 : 2015年04月 -2018年03月 
    代表者 : 押木守
  • シアン分解菌の分離および廃水処理装置での利用
    高専−長岡技科大共同研究助成:育英奨学会研究助成金2014
    研究期間 : 2016年04月 -2017年03月 
    代表者 : 押木守
  • 膜分離技術を利用した脱塩素呼吸Dehalococcoides属細菌の高密度培養による超高速有機塩素嫌気分解リアクターの構築
    公益財団法人ユニオンツール:育英奨学会研究助成金
    研究期間 : 2016年04月 -2017年03月 
    代表者 : 押木守
  • マルチコピープラスミド含有ジオバクターによる有機塩素嫌気分解リアクターの開発
    日本学術振興会:日本学術振興会科学研究費補助金 挑戦的萌芽研究
    研究期間 : 2015年04月 -2017年03月 
    代表者 : 吉田奈央子
  • ナノ流路集積デバイスを用いた病原性微生物・ウイルスの迅速定量
    公益財団法人 内田エネルギー科学振興財団:
    研究期間 : 2015年04月 -2016年03月 
    代表者 : 押木守
  • 養殖・育種事業において甚大な経済被害をもたらす病原性微生物の一斉モニタリング技術の開発
    高専−長岡技科大共同研究助成:
    研究期間 : 2015年04月 -2016年03月 
    代表者 : 押木守
  • 超省エネ都市下水処理の安定性の強化にむけた嫌気性原生動物データベース(PD2)の整備
    公益財団法人 前田記念工学振興財団:
    研究期間 : 2015年04月 -2016年03月 
    代表者 : 押木守
  • 学生教育および教員研究の推進にむけた超遠心分離器の修理
    長岡工業高等専門学校重点施策経費:
    研究期間 : 2015年04月 -2016年03月 
    代表者 : 押木守
  • ナノ流路デバイスを用いた病原性微生物の迅速検査技術の開発
    独立行政法人国立高等専門学校機構:研究プロジェクト経費若手研究
    研究期間 : 2015年04月 -2016年03月 
    代表者 : 押木守
  • 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
    公益財団法人鉄鋼環境基金:若手研究助成
    研究期間 : 2014年04月 -2016年03月 
    代表者 : 押木守
  • 都市下水処理UASB内への嫌気性原生動物の高濃度培養技術の開発
    日本学術振興会:日本学術振興会科学研究費補助金 基盤研究(B)
    研究期間 : 2013年04月 -2016年03月 
    代表者 : 荒木信夫
  • 超省エネルギー型下水処理プロセスにおける病原性微生物の動態
    高専−長岡技科大共同研究助成:
    研究期間 : 2014年10月 -2015年03月 
    代表者 : 押木守
  • 水田土壌由来N2Oガスの生成経路および生成細菌の同定
    公益財団法人山口育英奨学会:
    研究期間 : 2014年07月 -2015年03月 
    代表者 : 押木守
  • アンモニア酸化細菌による亜酸化窒素(N2O)生成機構の解明
    公益財団法人ユニオンツール:育英奨学会研究助成金
    研究期間 : 2014年04月 -2015年03月 
    代表者 : 押木守
  • メタボローム解析に基づくANAMMOXプロセスの高効率・安定化技術の創出
    日本学術振興会:日本学術振興会科学研究費補助金 特別研究員奨励費
    研究期間 : 2011年04月 -2013年03月 
    代表者 : 押木守
  • 有機物の一時貯蔵によって減少する脱窒量の把握とその改善に向けた検討
    日本学術振興会:日本学術振興会科学研究費補助金 研究活動スタート支援
    研究期間 : 2009年04月 -2011年03月 
    代表者 : 押木守
  • 活性汚泥におけるPHA蓄積細菌群集の分子生物学的手法による解析
    日本学術振興会:日本学術振興会科学研究費補助金 特別研究員奨励費
    研究期間 : 2007年04月 -2008年03月 
    代表者 : 押木守

社会貢献活動

  • 日本酒醸造法に関する新規な醸造技術の提案
    期間 : 2018年11月17日 - 2018年11月17日
    役割 : 助言・指導
    主催者・発行元 : 発酵を科学するアイディアコンテスト
    イベント・番組・新聞雑誌名 : 第二回 発酵を科学するアイディアコンテスト

メディア報道

  • 廃棄物処理に関する啓蒙活動
    報道 : 2018年10月01日
    発行元・放送局 : ケーブル4K
    番組・新聞雑誌 : テレビ番組 テクノ探検隊「都市金山を掘り起こせ ~不要になった基盤から金を回収~」
     テレビ・ラジオ番組


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