Biology of a widespread uncultivated archaeon that contributes to carbon fixation in the subsurface
Biology of a widespread uncultivated archaeon that contributes to carbon fixation in the subsurface
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DOI：
10.1038/ncomms6497
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发表时间：
2014-11-01
影响因子：
16.6
通讯作者：
Moissl-Eichinger, Christine
中科院分区：
文献类型：
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作者：
Probst, Alexander J.;Weinmaier, Thomas;Moissl-Eichinger, Christine
地下微生物生命对地球化学循环有重要贡献，但它在很大程度上仍然没有被描述，特别是它的古细菌成员。这种“微生物暗物质”已经被最近的研究所探索，然而，这些研究大多仅基于DNA序列信息。在这里，我们使用不同的技术，包括超微结构分析，将基因组学与SM1 Euryarchaeon谱系的生物学联系起来，SM1 Euryarchaeon谱系是一组未培养的地下古菌。系统基因组学分析表明，这一谱系属于一个广泛的组古菌，我们建议分类为一个新的euryarchaeal命令（'alphidatus Altiarchaeales'）。具有代表性的双膜物种“Alpidatus Altiarchaeum hamiconexum”具有使用尚未报道的无因子（420）还原乙酰辅酶A途径的自养代谢，这通过古细菌脂质的稳定碳同位素测量证实。我们的研究结果表明，这种谱系已经进化出特定的代谢和结构特征，如纳米抓钩，使这种广泛分布的古细菌能够主导厌氧地下水，在那里它可能代表一个重要的二氧化碳汇。
Subsurface microbial life contributes significantly to biogeochemical cycling, yet it remains largely uncharacterized, especially its archaeal members. This 'microbial dark matter' has been explored by recent studies that were, however, mostly based on DNA sequence information only. Here, we use diverse techniques including ultrastuctural analyses to link genomics to biology for the SM1 Euryarchaeon lineage, an uncultivated group of subsurface archaea. Phylogenomic analyses reveal this lineage to belong to a widespread group of archaea that we propose to classify as a new euryarchaeal order ('Candidatus Altiarchaeales'). The representative, double-membraned species 'Candidatus Altiarchaeum hamiconexum' has an autotrophic metabolism that uses a not-yet-reported Factor(420)-free reductive acetyl-CoA pathway, confirmed by stable carbon isotopic measurements of archaeal lipids. Our results indicate that this lineage has evolved specific metabolic and structural features like nano-grappling hooks empowering this widely distributed archaeon to predominate anaerobic groundwater, where it may represent an important carbon dioxide sink.