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ID 20778
本文ファイル
著者
Tsushima, Ikuo
Ogasawara, Yuji
Shimokawa, Masaki
Satoh, Hisashi
Okabe, Satoshi
NDC
建設工学・土木工学
抄録(英)
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 phylogenetic 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 ?m) of the biofilm, where high anammox activity was mainly detected with microelectrodes. The relative abundance of anammox bacteria decreased along the flow 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 ?mol cm?2 h?1 at P2 (the second port, 170 mm from the inlet port) to 0.30 and 0.35 ?mol cm?2 h?1 at P3 (the third port, 205 mm 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 O2 or organic compounds, which consequently established suitable microenvironments for anammox bacteria.
掲載誌名
Applied and Environmental Microbiology
73巻
15号
開始ページ
4931
終了ページ
4939
出版年月日
2007-08
出版者
American Society for Microbiology
ISSN
0099-2240
NCID
出版者DOI
言語
英語
NII資源タイプ
学術雑誌論文
広大資料タイプ
学術雑誌論文
DCMIタイプ
text
フォーマット
application/pdf
著者版フラグ
publisher
権利情報
Copyright (c) American Society for Microbiology
関連情報URL
部局名
工学研究科