Li Sicong, Wang Jiahua, Liu Jie, Zhang Hongcai, Bao Tianqiang, Sun Chengwen, Fang Jiasong, Cao Junwei
Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China.
Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
Microorganisms. 2023 Mar 21;11(3):798. doi: 10.3390/microorganisms11030798.
species are widely distributed in various environments, especially deep-sea sediments, due to their remarkable ability to utilize multiple electron receptors and versatile metabolic capabilities. In this study, a novel facultatively anaerobic, psychrophilic, and piezotolerant bacterium, sp. MTB7, was isolated from the Mariana Trench at a depth of 5900 m. Here, we report its complete genome sequence and adaptation strategies for survival in deep-sea environments. MTB7 contains what is currently the third-largest genome among all isolated strains and shows higher coding density than neighboring strains. Metabolically, MTB7 is predicted to utilize various carbon and nitrogen sources. D-amino acid utilization and HGT-derived purine-degrading genes could contribute to its oligotrophic adaptation. For respiration, the cytochrome ubiquinol oxidase genes typically expressed at high oxygen concentrations, are missing. Conversely, a series of anaerobic respiratory genes are employed, including fumarate reductase, polysulfide reductase, trimethylamine-N-oxide reductase, crotonobetaine reductase, and Mtr subunits. The glycine reductase genes and the triplication of dimethyl sulfoxide reductase genes absent in neighboring strains could also help MTB7 survive in low-oxygen environments. Many genes encoding cold-shock proteins, glycine betaine transporters and biosynthetic enzymes, and reactive oxygen species-scavenging proteins could contribute to its low-temperature adaptation. The genomic analysis of MTB7 will deepen our understanding of microbial adaptation strategies in deep-sea environments.
由于其利用多种电子受体的卓越能力和多样的代谢能力，该物种广泛分布于各种环境中，尤其是深海沉积物。在本研究中，从深度为5900米的马里亚纳海沟分离出一种新型兼性厌氧、嗜冷且耐压的细菌——MTB7菌。在此，我们报告其完整的基因组序列以及在深海环境中生存的适应策略。MTB7拥有目前所有已分离菌株中第三大的基因组，且编码密度高于邻近菌株。在代谢方面，预计MTB7能利用多种碳源和氮源。D - 氨基酸利用和水平基因转移衍生的嘌呤降解基因可能有助于其在贫营养环境中的适应。在呼吸作用方面，通常在高氧浓度下表达的细胞色素泛醇氧化酶基因缺失。相反，它采用了一系列厌氧呼吸基因，包括延胡索酸还原酶、多硫化物还原酶、三甲胺 - N - 氧化物还原酶、巴豆甜菜碱还原酶和Mtr亚基。邻近菌株中不存在的甘氨酸还原酶基因以及二甲基亚砜还原酶基因的三倍体也可能有助于MTB7在低氧环境中生存。许多编码冷休克蛋白、甘氨酸甜菜碱转运蛋白和生物合成酶以及活性氧清除蛋白的基因可能有助于其低温适应。对MTB7的基因组分析将加深我们对深海环境中微生物适应策略的理解。
