Mardanov Andrey V, Beletsky Alexey V, Kadnikov Vitaly V, Slobodkin Alexander I, Ravin Nikolai V
Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia.
Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences Moscow, Russia.
Front Microbiol. 2016 Jun 17;7:950. doi: 10.3389/fmicb.2016.00950. eCollection 2016.
Thermosulfurimonas dismutans S95(T), isolated from a deep-sea hydrothermal vent is the first bacterium of the phylum Thermodesulfobacteria reported to grow by the disproportionation of elemental sulfur, sulfite, or thiosulfate with carbon dioxide as the sole carbon source. In contrast to its phylogenetically close relatives, which are dissimilatory sulfate-reducers, T. dismutans is unable to grow by sulfate respiration. The features of this organism and its 2,1 Mb draft genome sequence are described in this report. Genome analysis revealed that the T. dismutans genome contains the set of genes for dissimilatory sulfate reduction including ATP sulfurylase, the AprA and B subunits of adenosine-5'-phosphosulfate reductase, and dissimilatory sulfite reductase. The oxidation of elemental sulfur to sulfite could be enabled by APS reductase-associated electron transfer complex QmoABC and heterodisulfide reductase. The genome also contains several membrane-linked molybdopterin oxidoreductases that are thought to be involved in sulfur metabolism as subunits of thiosulfate, polysulfide, or tetrathionate reductases. Nitrate could be used as an electron acceptor and reduced to ammonium, as indicated by the presence of periplasmic nitrate and nitrite reductases. Autotrophic carbon fixation is enabled by the Wood-Ljungdahl pathway, and the complete set of genes that is required for nitrogen fixation is also present in T. dismutans. Overall, our results provide genomic insights into energy and carbon metabolism of chemolithoautotrophic sulfur-disproportionating bacterium that could be important primary producer in microbial communities of deep-sea hydrothermal vents.
从深海热液喷口分离出的歧化嗜热硫单胞菌S95(T)是嗜热脱硫杆菌门中首个被报道能以元素硫、亚硫酸盐或硫代硫酸盐歧化作用生长且以二氧化碳作为唯一碳源的细菌。与其在系统发育上亲缘关系较近的异化硫酸盐还原菌不同，歧化嗜热硫单胞菌无法通过硫酸盐呼吸生长。本报告描述了该微生物的特征及其2.1 Mb的基因组草图序列。基因组分析表明，歧化嗜热硫单胞菌基因组包含异化硫酸盐还原所需的一组基因，包括ATP硫酸化酶、腺苷-5'-磷酸硫酸还原酶的AprA和B亚基以及异化亚硫酸盐还原酶。APS还原酶相关电子传递复合体QmoABC和异二硫化物还原酶可使元素硫氧化为亚硫酸盐。该基因组还包含几种与膜相连的钼蝶呤氧化还原酶，据认为它们作为硫代硫酸盐、多硫化物或连四硫酸盐还原酶的亚基参与硫代谢。如周质硝酸盐和亚硝酸盐还原酶的存在所示，硝酸盐可作为电子受体并被还原为铵。自养型碳固定通过伍德-Ljungdahl途径实现，歧化嗜热硫单胞菌中也存在固氮所需的全套基因。总体而言，我们的结果为化能自养硫歧化细菌的能量和碳代谢提供了基因组层面的见解，这类细菌可能是深海热液喷口微生物群落中重要的初级生产者。
