Enrichment of denitrifying anaerobic methane oxidizing microorganisms
Enrichment of denitrifying anaerobic methane oxidizing microorganisms
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DOI：
10.1111/j.1758-2229.2009.00083.x
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发表时间：
2009-10-01
影响因子：
3.3
通讯作者：
Yuan, Zhiguo
中科院分区：
文献类型：
--
作者：
Hu, Shihu;Zeng, Raymond J.;Yuan, Zhiguo
负责甲烷厌氧氧化（AOM）耦合反硝化的微生物尚未明确阐明。三个最近的出版物表明，它可以实现由厌氧甲烷古菌参与或不参与的分解细菌。限制这一研究领域进展的一个关键因素是缺乏富集培养物进行厌氧甲烷氧化（DAMO）。在这项研究中，DAMO文化丰富的混合接种物，包括沉积物从淡水湖，厌氧消化池污泥和回流活性污泥从污水处理厂。分别在35摄氏度和22摄氏度下运行的两个反应器在运行几个月后显示出同时的甲烷氧化和硝酸盐还原。来自35 ° C富集的16 S rRNA基因克隆文库的分析显示存在与其他DAMO古菌密切相关的古菌和属于尚未培养的NC 10门的优势细菌。这种培养物更喜欢亚硝酸盐而不是硝酸盐作为电子受体。目前的研究表明，古菌是甲烷氧化菌而不是产甲烷菌。达到的最高反硝化速率为2.35 mmol NO3--N gVSS-1天-1。在22 ℃富集的培养物含有与在35 ℃富集的培养物中观察到的相同的NC 10细菌，但不含古细菌。
P>The microorganisms responsible for anaerobic oxidation of methane (AOM) coupled to denitrification have not been clearly elucidated. Three recent publications suggested it can be achieved by a denitrifying bacterium with or without the involvement of anaerobic methanotrophic archaea. A key factor limiting the progress in this research field is the shortage of enrichment cultures performing denitrifying anaerobic methane oxidation (DAMO). In this study, DAMO cultures were enriched from mixed inoculum including sediment from a freshwater lake, anaerobic digester sludge and return activated sludge from a sewage treatment plant. Two reactors, operated at 35 degrees C and at 22 degrees C, respectively, showed simultaneous methane oxidation and nitrate reduction after several months of operation. Analysis of 16S rRNA gene clone libraries from the 35 degrees C enrichment showed the presence of an archaeon closely related to other DAMO archaea and a dominated bacterium belonging to the yet uncultivated NC10 phylum. This culture preferred nitrite to nitrate as the electron acceptor. The present study suggests that the archaea are rather methanotrophs than methanogens. The highest denitrification rate achieved was 2.35 mmol NO3--N gVSS-1 day-1. The culture enriched at 22 degrees C contained the same NC10 bacterium observed in the culture enriched at 35 degrees C but no archaea.