深海冷泉古菌厌氧甲烷氧化研究进展

在富含甲烷水合物的海相冷泉沉积物中, 古菌厌氧甲烷氧化作用(anaerobic oxidation of methane, AOM)越来越受到人们的重视。目前普遍认为, AOM是由嗜甲烷古菌和硫酸盐还原菌共同调节的生物地球化学过程。16S rRNA基因分析表明, 包括AEME-1、AEME-2和AEME-3在内的多种甲烷古菌参与了AOM的过程, 它们广泛分布于全球大洋海底缺氧带。AOM过程与全球环境变化密切相关, 从深海底部冷泉区向上渗漏的甲烷气体, 绝大部分在穿透缺氧带沉积层过程中被甲烷氧化古菌所消耗, 有效减少了具有强烈温室效应的甲烷气体向大气的释放。对AOM生物地球化学过程的研究, 在认识冷泉系统碳酸盐的形成机理、控制强温室气体甲烷从海底的渗漏和开发可燃冰新能源等方面具有重要意义。

Progress of anaerobic oxidation of methane by archaea in the cold seep of deep Sea

Anaerobic oxidation of methane (AOM) by archaea in marine sediments is gradually recognized by scientists and is regarded as an important biogeochemical process performed by both methanotrophic archaea and sulfate-reducing bacteria. Our analysis of 16S rRNA showed that multiple kinds of Methanoarchaea including AEME-1, AEME-2 and AEME-3 were the players in the AOM process, and these Methanoarchaea were distributed widely in the oxygen minimum zone of the open ocean. Furthermore, AOM process is related to the global environmental change closely. Most methane leaked from cold seeps of deep sea was consummated by Methanoarchaea in the course of penetrating the deposition layer of anoxic zone; so emission of strong greenhouse methane was reduced greatly. The studies of AOM biogeochemical process should be significant for understanding the formation mechanism of clod seep carbonate, controlling the leaking methane from seafloor, exploitation of combustible ice, and so on.