甲烷厌氧氧化机理及其应用研究进展

Research progress on microbial mechanism and application of anaerobic oxidation of methane

甲烷是一种重要的温室气体,研究证明甲烷厌氧氧化(AOM)对于降低全球甲烷的排放有着重要意义。参与AOM反应的最终电子受体可分为三类,即SO2–4、NO_2~–/NO_3~–以及以Fe^(3+)、Cr^(5+)等为代表的金属离子。本文基于甲烷厌氧氧化过程所利用的电子受体的差别,结合不同类型AOM反应微生物的基因型分析,阐述了AOM过程的反应机理、相关的微生物种类及其代谢途径。其中对AAA(AOM-associated archaea,属于ANME-2d)的分离培养,以及其利用硝酸盐、Fe^(3+)、Cr^(5+)等离子氧化甲烷的研究对认识AOM反应机理和AOM的实际应用有很大推动作用。本文还介绍了AOM过程在环境污染控制领域实际应用中的最新研究进展,对AOM的实际应用及其在节能减排上的价值进行展望。AOM过程的进一步研究对拓宽该过程的工程应用以及对正确认识全球碳、氮、硫循环均有着重要意义。

Methane is a significant greenhouse gas, and anaerobic oxidation of methane（AOM） is important to mitigate the global methane emissions to atmosphere. There are three kinds of terminal electron acceptors involved in AOM processes： SO2–4, NO2^-/NO3^- and oxidized metals such as Fe^3＋, Cr^5＋. Based on microbial genotype analysis, the mechanisms, involved microorganisms and the intracellular metabolic pathway of three different kinds of AOM processes were summarized. Especially, the study of AAA（AOM-associated archaea, belonging to ANME-2 d）, which could couple the reduction of NO3^-, Fe^3＋ and Cr^5＋ to the oxidation of methane is critical for understanding the mechanisms of AOM, and researches on its separation and cultivation is important for the practical application of AOM. The latest research progresses of engineering applications of AOM in the field of environmental pollution control were also introduced, and the significance of AOM process in energy-saving and emission reduction was discussed. Further researches on the mechanisms of AOM are helpful for better understanding of the biogeochemical cycle of carbon, nitrogen and sulfur, and can promote more practical application of AOM.