微生物介导的甲烷厌氧氧化过程及其影响因子研究进展

Advances in microbial mediated anaerobic oxidation of methane and its influencing factors

温室气体甲烷减排是全球变化领域的研究热点,甲烷厌氧氧化(anaerobic methane oxidation,AOM)过程是一个以前被忽视的甲烷汇,在调控全球甲烷收支平衡及减缓温室效应等方面扮演着十分重要的角色。AOM微生物以甲烷为唯一电子供体,与硫酸盐(SO42-)、亚硝酸盐(NO2-)/硝酸盐(NO3-)、金属离子(Fe3+、Mn4+、Cr6+)等结合完成氧化还原过程,该过程是耦合碳、氮、硫循环的关键环节。本文系统整理分析了不同AOM类型、发生机理、相关功能微生物类群(ANME-1、ANME-2、ANME-3、NC10、MBG-D)及影响AOM过程的关键调控因子的最新研究进展。结果发现,目前80%以上研究都集中在对最常见电子受体类型(SO42-/NO3-/NO2-/Fe3+/Mn4+)的AOM相关过程,而忽视了潜在的新型电子受体(AQDS/HAs O42-/Cr6+/ClO4-等)的耦合作用过程和相对应的微生物类型及作用机理。对未来AOM研究方向提出展望,以期为研究甲烷厌氧氧化菌在不同生态系统中的生态分布及减缓全球温室气体排放提供新的思路。

Reduction of methane emission is a research hotspot in the field of climate change.The anaerobic methane oxidation(AOM)process has been neglected as a methane sink,but in fact plays an important role in regulating global methane balance and mitigating greenhouse effect.AOM microorganisms could utilize methane as electron donors to reduce sulfate(SO42-),nitrite(NO2-),nitrate(NO3-)and metal ions(Fe3+,Mn4+,Cr6+).AOM process is the key for the coupling of carbon,nitrogen,and sulfur cycles.We systematically analyzed the progress in research of AOM types,underlying mechanisms,related functional microbial groups(ANME-1,ANME-2,ANME-3,NC10,MBG-D)and key regulatory factors affecting the AOM process.We found that more than 80%of the studies focused on the AOM-related processes of the most common electron acceptor types(SO42-,NO3-,NO2-,Fe3+,Mn4+),ignoring the coupling process with potential new electron acceptors(AQDS,HAs O42-,Cr6+,ClO4-,etc.),the correspondingmicrobial types,and the underlying mechanism.We proposed future direction of AOM research with the aim to provide new ideas for finding out the ecological distribution of methane anaerobic oxidizing bacteria in different ecosystems and mitigating global greenhouse gas emissions.