Metabolic strategies of marine subseafloor Chloroflexi inferred from genome reconstructions
Metabolic strategies of marine subseafloor Chloroflexi inferred from genome reconstructions
复制标题
DOI：
10.1111/1462-2920.15061
复制
发表时间：
2020-06-04
影响因子：
5.1
通讯作者：
Spormann, Alfred M.
中科院分区：
文献类型：
--
作者：
Fincker, Maeva;Huber, Julie A.;Spormann, Alfred M.
绿柔菌门的未培养成员在许多海底环境中高度丰富。通过重建来自六个不同海底栖息地的 31 个 Chloroflexi 基因组来评估它们的代谢潜力。 Wood-Ljungdahl 途径、电子分叉和铁氧还蛋白依赖性转运耦合磷酸化酶几乎无处不在，表明厌氧产乙酸是其分解代谢的核心。大多数基因组同时包含复杂碳水化合物、碎屑蛋白、芳香化合物和氢的多种降解途径，表明化学多样化的有机底物的氧化与普遍存在的二氧化碳还原的耦合。这种途径组合可以通过使这些 Chloroflexi 能够在一种微生物中充当初级发酵剂和产乙酸菌而无需消耗互养 H-2，从而在海底环境中赋予适应性优势。虽然分解代谢氧呼吸的证据仅限于两个系统发育簇，但整个门中编码推定还原脱卤酶的基因的存在扩展了潜在有机卤化物呼吸的系统发育边界，超越了脱卤球菌纲。
Uncultured members of the Chloroflexi phylum are highly enriched in numerous subseafloor environments. Their metabolic potential was evaluated by reconstructing 31 Chloroflexi genomes from six different subseafloor habitats. The near ubiquitous presence of enzymes of the Wood-Ljungdahl pathway, electron bifurcation, and ferredoxin-dependent transport-coupled phosphorylation indicated anaerobic acetogenesis was central to their catabolism. Most of the genomes simultaneously contained multiple degradation pathways for complex carbohydrates, detrital protein, aromatic compounds, and hydrogen, indicating the coupling of oxidation of chemically diverse organic substrates to ubiquitous CO2 reduction. Such pathway combinations may confer a fitness advantage in subseafloor environments by enabling these Chloroflexi to act as primary fermenters and acetogens in one microorganism without the need for syntrophic H-2 consumption. While evidence for catabolic oxygen respiration was limited to two phylogenetic clusters, the presence of genes encoding putative reductive dehalogenases throughout the phylum expanded the phylogenetic boundary for potential organohalide respiration past the Dehalococcoidia class.