Schouw Anders, Vulcano Francesca, Roalkvam Irene, Hocking William Peter, Reeves Eoghan, Stokke Runar, Bødtker Gunhild, Steen Ida Helene
Department of Biological Sciences and KG Jebsen Centre for Deep Sea Research, University of Bergen, N-5020 Bergen, Norway.
Department of Earth Science and KG Jebsen Centre for Deep Sea Research, University of Bergen, N-5020 Bergen, Norway.
Microorganisms. 2018 Jul 4;6(3):63. doi: 10.3390/microorganisms6030063.
strain L81, recently isolated from a black smoker biofilm at the Loki’s Castle hydrothermal vent field, was previously described as a mesophilic, obligately anaerobic heterotroph able to ferment carbohydrates, peptides, and aliphatic hydrocarbons. The strain was classified as a new genus within the family . Herein, its genome is analyzed and is reassigned to the genus as a new strain of , designated strain L81. The 6.4 Mbp genome contained 5651 protein encoding genes, whereof 4043 were given a functional prediction. Pathways for fermentation of mono-saccharides, di-saccharides, peptides, and amino acids were identified whereas a complete pathway for the fermentation of -alkanes was not found. Growth on carbohydrates and proteinous compounds supported methane production in co-cultures with . Multiple confurcating hydrogen-producing hydrogenases, a putative bifurcating electron-transferring flavoprotein—butyryl-CoA dehydrogenase complex, and a Rnf-complex form a basis for the observed hydrogen-production and a putative reverse electron-transport in strain L81. Combined with the observation that -alkanes did not support growth in co-cultures with , it seemed more plausible that the previously observed degradation patterns of crude-oil in strain L81 are explained by unspecific activation and may represent a detoxification mechanism, representing an interesting ecological function. Genes encoding a capacity for polyketide synthesis, prophages, and resistance to antibiotics shows interactions with the co-occurring microorganisms. This study enlightens the function of the fermentative microorganisms from hydrothermal vents systems and adds valuable information on the bioprospecting potential emerging in deep-sea hydrothermal systems.
L81菌株最近从洛基城堡热液喷口场的一个黑烟菌生物膜中分离出来，此前被描述为一种嗜温、专性厌氧异养菌，能够发酵碳水化合物、肽和脂肪烃。该菌株被归类为该科内的一个新属。在此，对其基因组进行了分析，并将其重新归类为新的菌株，指定为菌株L81。6.4 Mbp的基因组包含5651个蛋白质编码基因，其中4043个基因有功能预测。确定了单糖、双糖、肽和氨基酸的发酵途径，但未发现完整的正构烷烃发酵途径。在与……的共培养中，碳水化合物和蛋白质化合物上的生长支持甲烷产生。多个分叉的产氢氢化酶、一种假定的分叉电子传递黄素蛋白 - 丁酰辅酶A脱氢酶复合物和一个Rnf复合物构成了菌株L81中观察到的产氢和假定的逆向电子传递的基础。结合正构烷烃在与……的共培养中不支持生长的观察结果，似乎更合理的是，菌株L81中先前观察到的原油降解模式是由非特异性激活解释的，可能代表一种解毒机制，这代表了一种有趣的生态功能。编码聚酮化合物合成能力、原噬菌体和抗生素抗性的基因显示出与同时存在的微生物的相互作用。这项研究揭示了热液喷口系统中发酵微生物的功能，并为深海热液系统中出现的生物勘探潜力增加了有价值的信息。
