John Jojy, Siva Vinu, Richa Kumari, Arya Aditya, Kumar Amit
International Research Centre for Climate Change Studies, Sathyabama Institute of Science and Technology, Old Mahabalipuram Road, Chennai 600119, India.
Amazing Biotech Private Limited, Marakkanam, Tamil Nadu 604303, India.
Microorganisms. 2019 Nov 19;7(11):577. doi: 10.3390/microorganisms7110577.
Life in salt pans with varying chemical compositions require special adaptation strategies at both the physiological and molecular level. The Marakkanam salt pan in South India is characterized with a high fluctuation in salinity (19-490 ppt), Ultravioletradiation, and heavy metal concentrations. Several bacterial species have been isolated and identified in the view of phylogenetic analysis and for the subsequent production of industrially important enzymes. However, limited information exists on the genomic basis of their survival under variable environmental conditions. To this extent, we sequenced the whole genome of the sp. HTSP, a moderately halophilic bacterium. We analysed the physiological and genomic attributes of sp. HTSP to elucidate the strategies of adaptation under various abiotic stresses. The genome size is estimated to be 3.39 Mbp with a mean G + C content of 50.6%, including 3150 coding sequences. The genome possessed osmotic stress-related coding sequences, and genes involved in different pathways of DNA repair mechanisms and genes related to the resistance to toxic metals were identified. The periplasmic stress response genes and genes of different oxidative stress mechanisms were also identified. The tolerance capacity of the bacterial isolates to heavy metals, UV-radiation, and salinity was also confirmed through appropriate laboratory experiments under controlled conditions.
生活在化学成分各异的盐田中需要在生理和分子水平上采取特殊的适应策略。印度南部的马勒卡纳姆盐田的特点是盐度（19 - 490 ppt）、紫外线辐射和重金属浓度波动很大。从系统发育分析以及后续生产具有工业重要性的酶的角度出发，已经分离并鉴定了几种细菌物种。然而，关于它们在可变环境条件下生存的基因组基础的信息有限。在此范围内，我们对中度嗜盐细菌HTSP菌进行了全基因组测序。我们分析了HTSP菌的生理和基因组特征，以阐明其在各种非生物胁迫下的适应策略。基因组大小估计为3.39 Mbp，平均G + C含量为50.6%，包括3150个编码序列。该基因组拥有与渗透胁迫相关的编码序列，鉴定出了参与DNA修复机制不同途径的基因以及与抗有毒金属相关的基因。还鉴定了周质应激反应基因和不同氧化应激机制的基因。通过在受控条件下进行适当的实验室实验，也证实了细菌分离株对重金属、紫外线辐射和盐度的耐受能力。
