Kadnikov Vitaly V, Mardanov Andrey V, Beletsky Alexey V, Karnachuk Olga V, Ravin Nikolai V
Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prosp 33-2, Moscow, 119071, Russia.
Laboratory of Biochemistry and Molecular Biology, Tomsk State University, 634050, Tomsk, Russia.
Extremophiles. 2019 Mar;23(2):189-200. doi: 10.1007/s00792-018-01073-5. Epub 2019 Jan 1.
Bacteria of candidate phylum OP8 (Aminicenantes) have been identified in various terrestrial and marine ecosystems as a result of molecular analysis of microbial communities. So far, none of the representatives of Aminicenantes have been isolated in a pure culture. We assembled the near-complete genome of a member of Aminicenantes from the metagenome of the 2-km-deep subsurface thermal aquifer in Western Siberia and used genomic data to analyze the metabolic pathways of this bacterium and its ecological role. This bacterium, designated BY38, was predicted to be rod shaped, it lacks flagellar machinery but twitching motility is encoded. Analysis of the BY38 genome revealed a variety of glycosyl hydrolases that can enable utilization of carbohydrates, including chitin, cellulose, starch, mannose, galactose, fructose, fucose, rhamnose, maltose and arabinose. The reconstructed central metabolic pathways suggested that Aminicenantes bacterium BY38 is an anaerobic organotroph capable of fermenting carbohydrates and proteinaceous substrates and performing anaerobic respiration with nitrite. In the deep subsurface aquifer Aminicenantes probably act as destructors of buried organic matter and produce hydrogen and acetate. Based on phylogenetic and genomic analyses, the novel bacterium is proposed to be classified as Candidatus Saccharicenans subterraneum.
通过对微生物群落的分子分析，在各种陆地和海洋生态系统中已鉴定出候选门类OP8（氨基辛那菌门）的细菌。到目前为止，氨基辛那菌门的代表菌株均未在纯培养物中分离出来。我们从西西伯利亚2公里深处的地下热含水层宏基因组中组装了氨基辛那菌门一个成员的近完整基因组，并利用基因组数据分析了该细菌的代谢途径及其生态作用。这种细菌被命名为BY38，预计呈杆状，它缺乏鞭毛机制，但编码了颤动运动。对BY38基因组的分析揭示了多种糖基水解酶，这些酶能够利用包括几丁质、纤维素、淀粉、甘露糖、半乳糖、果糖、岩藻糖、鼠李糖、麦芽糖和阿拉伯糖在内的碳水化合物。重建的中心代谢途径表明，氨基辛那菌BY38是一种厌氧有机营养菌，能够发酵碳水化合物和蛋白质底物，并利用亚硝酸盐进行厌氧呼吸。在深层地下含水层中，氨基辛那菌可能作为埋藏有机物的分解者，产生氢气和乙酸盐。基于系统发育和基因组分析，这种新细菌被提议归类为“地下糖辛那菌”。
