Department of Molecular Biology, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan; Japan Collection of Microorganisms, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074, Japan.
Environ Microbiol. 2015 May;17(5):1817-35. doi: 10.1111/1462-2920.12648. Epub 2014 Dec 17.
Seafloor massive sulfides are a potential energy source for the support of chemosynthetic ecosystems in dark, deep-sea environments; however, little is known about microbial communities in these ecosystems, especially below the seafloor. In the present study, we performed culture-independent molecular analyses of sub-seafloor sulfide samples collected in the Southern Mariana Trough by drilling. The depth for the samples ranged from 0.52 m to 2.67 m below the seafloor. A combination of 16S rRNA and functional gene analyses suggested the presence of chemoautotrophs, sulfur-oxidizers, sulfate-reducers, iron-oxidizers and iron-reducers. In addition, mineralogical and thermodynamic analyses are consistent with chemosynthetic microbial communities sustained by sulfide minerals below the seafloor. Although distinct bacterial community compositions were found among the sub-seafloor sulfide samples and hydrothermally inactive sulfide chimneys on the seafloor collected from various areas, we also found common bacterial members at species level including the sulfur-oxidizers and sulfate-reducers, suggesting that the common members are widely distributed within massive sulfide deposits on and below the seafloor and play a key role in the ecosystem function.
海底块状硫化物是支持黑暗深海环境中化能合成生态系统的潜在能源；然而，对于这些生态系统中的微生物群落，特别是海底以下的微生物群落，人们知之甚少。在本研究中，我们通过钻探对马里亚纳海槽采集的海底以下硫化物样本进行了无培养的分子分析。样本的深度范围从海底以下 0.52 米到 2.67 米。16S rRNA 和功能基因分析的组合表明存在化能自养生物、硫氧化菌、硫酸盐还原菌、铁氧化菌和铁还原菌。此外，矿物学和热力学分析与海底以下硫化物矿物维持的化能合成微生物群落一致。尽管在海底以下硫化物样本和从不同区域采集的海底热液不活动硫化物烟囱中发现了不同的细菌群落组成，但我们也在种水平上发现了常见的细菌成员，包括硫氧化菌和硫酸盐还原菌，这表明这些常见的成员在海底和海底以下的块状硫化物矿床中广泛分布，并在生态系统功能中发挥关键作用。
