Distribution of anaerobic carbon monoxide dehydrogenase genes in deep subseafloor sediments
Distribution of anaerobic carbon monoxide dehydrogenase genes in deep subseafloor sediments
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DOI：
10.1111/lam.12727
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发表时间：
2017-05-01
影响因子：
2.4
通讯作者：
Inagaki, F.
中科院分区：
文献类型：
--
作者：
Hoshino, T.;Inagaki, F.
一氧化碳(CO)是有机化合物分解产生的最简单的氧化碳，预计在海洋沉积物中存在大量。然而，尽管CO的厌氧氧化是一个热力学上有利的反应，可能会发生硫酸盐还原、甲烷生成、乙酰化和生氢反应，但在深海海底沉积生物圈中CO的有效性在很大程度上是未知的。在这项研究中，我们首次调查了编码厌氧一氧化碳脱氢酶催化β亚基的一氧化碳脱氢酶基因(Cos)在日本熊野盆地胡安德富卡海脊东侧、火星-乌尔萨盆地和岛下半岛的海底沉积物岩心样品中的分布，分别在综合大洋钻探计划(IODP)301、308和315以及D/V Chikyu试航CK06-06期间进行了调查。我们的结果表明，从海底到海底以下约390米处，存在着不同的COOS基因，这表明在海底以下缺氧微生物生态系统中，微生物群落具有利用CO的代谢功能，并且可能负责厌氧CO氧化的微生物群落根据海底深部沉积生物圈中可能产生能量的代谢反应而有所不同。这项研究是对编码厌氧一氧化碳脱氢酶(CODH)的功能基因的首次调查。以前未发现的CO脱氢酶基因(COOS)的广泛存在表明，在深海海底沉积生物圈中，各种微生物都能够厌氧氧化CO。
Carbon monoxide (CO) is the simplest oxocarbon generated by the decomposition of organic compounds, and it is expected to be in marine sediments in substantial amounts. However, the availability of CO in the deep subseafloor sedimentary biosphere is largely unknown even though anaerobic oxidation of CO is a thermodynamically favourable reaction that possibly occurs with sulphate reduction, methanogenesis, acetogenesis and hydrogenesis. In this study, we surveyed for the first time the distribution of the CO dehydrogenase gene (cooS), which encodes the catalytic beta subunit of anaerobic CO dehydrogenase (CODH), in subseafloor sediment-core samples from the eastern flank of the Juan de Fuca Ridge, Mars-Ursa Basin, Kumano Basin, and off the Shimokita Peninsula, Japan, during Integrated Ocean Drilling Program (IODP) Expeditions 301, 308 and 315 and the D/V Chikyu shakedown cruise CK06-06, respectively. Our results show the occurrence of diverse cooS genes from the seafloor down to about 390m below the seafloor, suggesting that microbial communities have metabolic functions to utilize CO in anoxic microbial ecosystems beneath the ocean floor, and that the microbial community potentially responsible for anaerobic CO oxidation differs in accordance with possible energy-yielding metabolic reactions in the deep subseafloor sedimentary biosphere.Significance and Impact of the StudyLittle is known about the microbial community associated with carbon monoxide (CO) in the deep subseafloor. This study is the first survey of a functional gene encoding anaerobic carbon monoxide dehydrogenase (CODH). The widespread occurrence of previously undiscovered CO dehydrogenase genes (cooS) suggests that diverse micro-organisms are capable of anaerobic oxidation of CO in the deep subseafloor sedimentary biosphere.