Evidence for phylogenetically and catabolically diverse active diazotrophs in deep-sea sediment
Evidence for phylogenetically and catabolically diverse active diazotrophs in deep-sea sediment
复制标题
深海沉积物中具有系统发育和分解代谢多样性的活性重氮菌的证据
DOI：
10.1038/s41396-019-0584-8
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发表时间：
2020-01-06
期刊：
影响因子：
11
通讯作者：
Dekas, Anne E.
中科院分区：
文献类型：
--
作者：
Kapili, Bennett J.;Barnett, Samuel E.;Dekas, Anne E.
固氮微生物通过缓解氮限制来调节海洋生产力。然而，我们对深海沉积物中固氮生物的身份和活动知之甚少，深海沉积物是一个覆盖地球近三分之二的栖息地。在这里，我们确定候选固氮生物从太平洋沉积物中收集在2893米水深使用N-15-DNA稳定同位素探测和nifH序列分析的一种新的管道。总之，这些方法检测到一个意想不到的多样性的活性固氮生物，包括成员的酸细菌，厚壁菌门，硝化螺菌，γ-变形菌，和δ-变形菌。Deltaproteobacteria主要是Desulfobacterales和Desulfuronadales的成员，是检测到的最丰富的固氮生物，并显示出最微多样性的相关nifH序列。一些检测到的谱系，包括酸杆菌中的那些，以前没有被证明可以固氮。固氮菌表现出多样的分解代谢，具有使用氧、氮、铁、硫和碳作为末端电子受体的潜力。因此，底栖重氮营养可能在一系列地球化学条件下持续存在，并在地质时间尺度上提供稳定的固定氮来源。我们的研究结果表明，在深海沉积物中的固氮群落是生物遗传和分解代谢多样性，并开辟了一条新的调查路线的生态和生物地球化学的影响深海微生物。
Diazotrophic microorganisms regulate marine productivity by alleviating nitrogen limitation. However, we know little about the identity and activity of diazotrophs in deep-sea sediments, a habitat covering nearly two-thirds of the planet. Here, we identify candidate diazotrophs from Pacific Ocean sediments collected at 2893 m water depth using N-15-DNA stable isotope probing and a novel pipeline for nifH sequence analysis. Together, these approaches detect an unexpectedly diverse assemblage of active diazotrophs, including members of the Acidobacteria, Firmicutes, Nitrospirae, Gammaproteobacteria, and Deltaproteobacteria. Deltaproteobacteria, predominately members of the Desulfobacterales and Desulfuromonadales, are the most abundant diazotrophs detected, and display the most microdiversity of associated nifH sequences. Some of the detected lineages, including those within the Acidobacteria, have not previously been shown to fix nitrogen. The diazotrophs appear catabolically diverse, with the potential for using oxygen, nitrogen, iron, sulfur, and carbon as terminal electron acceptors. Therefore, benthic diazotrophy may persist throughout a range of geochemical conditions and provide a stable source of fixed nitrogen over geologic timescales. Our results suggest that nitrogen-fixing communities in deep-sea sediments are phylogenetically and catabolically diverse, and open a new line of inquiry into the ecology and biogeochemical impacts of deep-sea microorganisms.