Caldwell Sara L, Laidler James R, Brewer Elizabeth A, Eberly Jed O, Sandborgh Sean C, Colwell Frederick S
Department of Biology, Portland State University, Portland, Oregon 97201, USA.
Environ Sci Technol. 2008 Sep 15;42(18):6791-9. doi: 10.1021/es800120b.
Microbially mediated anaerobic oxidation of methane (AOM) moderates the input of methane, an important greenhouse gas, to the atmosphere by consuming methane produced in various marine, terrestrial, and subsurface environments. AOM coupled to sulfate reduction has been most extensively studied because of the abundance of sulfate in marine systems, but electron acceptors otherthan sulfate are more energetically favorable. Phylogenetic trees based on 16S rRNA gene clone libraries derived from microbial communities where AOM occurs show evidence of diverse, methanotrophic archaea (ANME) closely associated with sulfate-reducing bacteria, but these organisms have not yet been isolated as pure cultures. Several biochemical pathways for AOM have been proposed, including reverse methanogenesis, acetogenesis, and methylogenesis, and both culture-dependent and independent techniques have provided some clues to howthese communities function. Still, questions remain regarding the diversity, physiology, and metabolic restrictions of AOM-related organisms.
微生物介导的甲烷厌氧氧化（AOM）通过消耗在各种海洋、陆地和地下环境中产生的甲烷，减缓了重要温室气体甲烷向大气中的排放。由于海洋系统中硫酸盐含量丰富，与硫酸盐还原耦合的AOM得到了最广泛的研究，但除硫酸盐外的其他电子受体在能量上更有利。基于来自发生AOM的微生物群落的16S rRNA基因克隆文库构建的系统发育树显示，有证据表明多种与硫酸盐还原细菌密切相关的甲烷营养古菌（ANME）存在，但这些生物尚未作为纯培养物分离出来。已经提出了几种AOM的生化途径，包括反向产甲烷、产乙酸和甲基生成，并且依赖培养和不依赖培养的技术都为这些群落的功能提供了一些线索。然而，关于与AOM相关生物的多样性、生理学和代谢限制仍然存在问题。
