Brazelton William J, Thornton Christopher N, Hyer Alex, Twing Katrina I, Longino August A, Lang Susan Q, Lilley Marvin D, Früh-Green Gretchen L, Schrenk Matthew O
Department of Biology, University of Utah , Salt Lake City , UT , United States.
Department of Earth and Environmental Sciences, Michigan State University , East Lansing , MI , United States.
PeerJ. 2017 Jan 26;5:e2945. doi: 10.7717/peerj.2945. eCollection 2017.
The production of hydrogen and methane by geochemical reactions associated with the serpentinization of ultramafic rocks can potentially support subsurface microbial ecosystems independent of the photosynthetic biosphere. Methanogenic and methanotrophic microorganisms are abundant in marine hydrothermal systems heavily influenced by serpentinization, but evidence for methane-cycling archaea and bacteria in continental serpentinite springs has been limited. This report provides metagenomic and experimental evidence for active methanogenesis and methanotrophy by microbial communities in serpentinite springs of the Voltri Massif, Italy. Methanogens belonging to family Methanobacteriaceae and methanotrophic bacteria belonging to family Methylococcaceae were heavily enriched in three ultrabasic springs (pH 12). Metagenomic data also suggest the potential for hydrogen oxidation, hydrogen production, carbon fixation, fermentation, and organic acid metabolism in the ultrabasic springs. The predicted metabolic capabilities are consistent with an active subsurface ecosystem supported by energy and carbon liberated by geochemical reactions within the serpentinite rocks of the Voltri Massif.
与超镁铁质岩石蛇纹石化相关的地球化学反应产生氢气和甲烷，这有可能维持独立于光合生物圈的地下微生物生态系统。在受蛇纹石化严重影响的海洋热液系统中，产甲烷和甲烷营养微生物大量存在，但大陆蛇纹岩泉中甲烷循环古菌和细菌的证据一直有限。本报告提供了宏基因组学和实验证据，证明意大利沃尔特里山地块蛇纹岩泉中的微生物群落存在活跃的产甲烷作用和甲烷营养作用。属于甲烷杆菌科的产甲烷菌和属于甲基球菌科的甲烷营养细菌在三个超基性泉（pH值为12）中大量富集。宏基因组数据还表明，超基性泉具有氢氧化、产氢、固碳、发酵和有机酸代谢的潜力。预测出的代谢能力与由沃尔特里山地块蛇纹岩岩石内地球化学反应释放的能量和碳所支持的活跃地下生态系统相一致。
