Hydrothermal activity can generate numerous and diverse hydrocarbon compounds. However, little is known about the influence of such hydrocarbons on deep-sea hydrothermal microbial ecology. We hypothesize that certain bacteria live on these hydrocarbons. Therefore, in this study, the distribution of hydrocarbons and their associated hydrocarbon-degrading bacteria were investigated at deep-sea hydrothermal vents at the Southern Mid-Atlantic Ridge, the Southwest Indian Ridge, and the East Pacific Rise. A variety of hydrocarbon-degrading consortia were obtained from hydrothermal samples collected at the aforementioned sites after low-temperature enrichment under high hydrostatic pressures, and the bacteria responsible for the degradation of hydrocarbons were investigated by DNA-based stable-isotope probing with uniformly 13C-labeled hydrocarbons. Unusually, we identified several previously recognized sulfur-oxidizing chemoautotrophs as hydrocarbon-degrading bacteria, e.g., the SAR324 group, the SUP05 clade, and Sulfurimonas, and for the first time confirmed their ability to degrade hydrocarbons. In addition, Erythrobacter, Pusillimonas, and SAR202 clade were shown to degrade polycyclic aromatic hydrocarbons for the first time. These results together with relatively high abundance in situ of most of the above-described bacteria highlight the potential influence of hydrocarbons in configuring the vent microbial community, and have made the importance of mixotrophs in hydrothermal vent ecosystems evident.

中文翻译：

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居住在深海热液生态系统中的各种异养和混养细菌对碳氢化合物的氧化。

水热活动会产生大量多样的碳氢化合物。但是，关于这类烃对深海热液微生物生态学的影响知之甚少。我们假设某些细菌生活在这些碳氢化合物上。因此，在这项研究中，在南部中大西洋海岭，西南印第安海岭和东太平洋上升带的深海热液喷口处研究了碳氢化合物及其相关的降解碳氢化合物的细菌的分布。在高静水压力下进行低温富集后，从上述位置收集的水热样品中获得了多种降解烃类的财团，并通过基于DNA的稳定同位素探针（以13C-标记的碳氢化合物。不寻常的是，我们鉴定了几种先前公认的硫氧化性化学自养生物作为降解碳氢化合物的细菌，例如SAR324组，SUP05进化枝和硫酸单胞菌，并首次证实了它们降解碳氢化合物的能力。此外，显示出红杆菌，脓杆菌和SAR202进化枝首次降解多环芳烃。这些结果以及大多数上述细菌的相对较高的原位丰度突出了碳氢化合物在构造通风口微生物群落中的潜在影响，并使混合营养菌在热液通风口生态系统中的重要性显而易见。并首次证实了它们具有降解碳氢化合物的能力。此外，显示出红杆菌，脓毒杆菌和SAR202进化枝首次降解多环芳烃。这些结果以及大多数上述细菌的相对较高的原位丰度突出了碳氢化合物在构造通风口微生物群落中的潜在影响，并使混合营养菌在热液通风口生态系统中的重要性显而易见。并首次证实了它们具有降解碳氢化合物的能力。此外，显示出红杆菌，脓杆菌和SAR202进化枝首次降解多环芳烃。这些结果以及大多数上述细菌的相对较高的原位丰度突出了碳氢化合物在构造通风口微生物群落中的潜在影响，并使混合营养菌在热液通风口生态系统中的重要性显而易见。