互营氧化产甲烷微生物种间电子传递研究进展

A review of interspecies electron transfer in syntrophic-methanogenic associations

摘要:

甲烷是重要的温室气体，也是典型的可再生性生物质能源。目前约70%的大气甲烷排放来源于产甲烷微生物过程。在产甲烷环境中，产甲烷菌与互营细菌形成互营关系，从而克服有机质厌氧分解反应的热力学能垒，实现短链脂肪酸和醇类物质的互营氧化产甲烷过程。该过程中，种间电子传递是关键步骤。本文首先概述了甲烷的研究意义及微生物互营降解有机质产甲烷的过程，然后分别综述了种间H2转移、种间甲酸转移和种间直接电子传递这3种种间电子传递机制的起源、发展、研究现状和未来所需要解决的研究问题。

Abstract:

Methane is a crucial green-house gas as well as a typical renewable biomass energy. About 70% of the current CH4 emission into the atmosphere is originated from methanogenic microbial processes. In methanogenic environments, the close coupling of methanogens with syntrophic bacteria overcomes the energetic barriers for the anaerobic oxidation of short-chain fatty acids and alcohols with CH4 and CO2 as end products. Interspecies electron transfer is a critical step of this process. Here we firstly overviewed the research significance of methane and the microbial processes of syntrophic methanogenesis by degrading organic matters. And secondly summarized the origins, developments, research status and questions to be solved of the three interspecies electron transfer mechanisms, which is interspecies hydrogen transfer (IHT), interspecies formate transfer (IFT) and direct interspecies electron transfer (DIET).