Insight into the function and evolution of the Wood-Ljungdahl pathway in Actinobacteria
Insight into the function and evolution of the Wood-Ljungdahl pathway in Actinobacteria
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深入了解放线菌中 Wood-Ljungdahl 途径的功能和进化
DOI：
10.1038/s41396-021-00935-9
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发表时间：
2021-05-05
期刊：
影响因子：
11
通讯作者：
Li, Wen-Jun
中科院分区：
文献类型：
--
作者：
Jiao, Jian-Yu;Fu, Li;Li, Wen-Jun
同质产氧菌等化能自养微生物的固碳作用对从无机世界向有机世界的过渡具有重要影响。最近的报道表明，放线菌门中存在与Wood-Ljungdahl通路（WLP）相关的关键酶基因，这增加了潜在自养生物的多样性。在这里，我们从新的和现有的宏基因组数据集中编译了42个放线菌宏基因组组装基因组（MAGs），并提出了三个新的分类，即Ca. Aquicultoria, Ca. Geothermincolia和Ca. Humimicrobiia。这些类别的大多数成员含有通过WLP编码丙酮生成的基因，以及各种氢化酶（NiFe组1a和3b-3d； FeFe组C； NiFe组4相关的氢化酶）。我们发现，这三个类别独立获得氢化酶，但一氧化碳脱氢酶/乙酰辅酶a合成酶复合物（CODH/ACS）显然存在于他们的最后一个共同祖先，并垂直遗传。此外，放线菌可能通过多个水平基因转移事件将CODH/ACS基因捐赠给硝化螺旋菌、Deltaproteobacteria （Desulfobacterota）和Thermodesulfobacteria中的多个谱系。最后，我们发现在有或没有甲烷生成抑制剂2-溴乙烷磺酸的温泉富集培养中，Ca.地热菌和h -2依赖性醋酸盐的产量明显增长，这与提出的同质产丙酮代谢一致。
Carbon fixation by chemoautotrophic microbes such as homoacetogens had a major impact on the transition from the inorganic to the organic world. Recent reports have shown the presence of genes for key enzymes associated with the Wood-Ljungdahl pathway (WLP) in the phylum Actinobacteria, which adds to the diversity of potential autotrophs. Here, we compiled 42 actinobacterial metagenome-assembled genomes (MAGs) from new and existing metagenomic datasets and propose three novel classes, Ca. Aquicultoria, Ca. Geothermincolia and Ca. Humimicrobiia. Most members of these classes contain genes coding for acetogenesis through the WLP, as well as a variety of hydrogenases (NiFe groups 1a and 3b-3d; FeFe group C; NiFe group 4-related hydrogenases). We show that the three classes acquired the hydrogenases independently, yet the carbon monoxide dehydrogenase/acetyl-CoA synthase complex (CODH/ACS) was apparently present in their last common ancestor and was inherited vertically. Furthermore, the Actinobacteria likely donated genes for CODH/ACS to multiple lineages within Nitrospirae, Deltaproteobacteria (Desulfobacterota), and Thermodesulfobacteria through multiple horizontal gene transfer events. Finally, we show the apparent growth of Ca. Geothermincolia and H-2-dependent acetate production in hot spring enrichment cultures with or without the methanogenesis inhibitor 2-bromoethanesulfonate, which is consistent with the proposed homoacetogenic metabolism.