Kumar Vijay, Kashyap Prakriti, Kumar Subhash, Thakur Vikas, Kumar Sanjay, Singh Dharam
Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India.
Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre (CSIR-HRDC), Ghaziabad, India.
Front Microbiol. 2022 Jul 6;13:881873. doi: 10.3389/fmicb.2022.881873. eCollection 2022.
Bacterial adaption to the multiple stressed environments of high-altitude niches in the Himalayas is intriguing and is of considerable interest to biotechnologists. Previously, we studied the culturable and unculturable metagenome microbial diversity from glacial and kettle lakes in the Western Himalayas. In this study, we explored the adaptive strategies of a unique Himalayan eurypsychrophile sp. PCH194, which can synthesize polyhydroxybutyrate (PHB) and violacein pigment. Whole-genome sequencing and analysis of sp. PCH194 (4.58 Mb chromosome and three plasmids) revealed genetic traits associated with adaptive strategies for cold/freeze, nutritional fluctuation, defense against UV, acidic pH, and the kettle lake's competitive environment. Differential proteome analysis suggested the adaptive role of chaperones, ribonucleases, secretion systems, and antifreeze proteins under cold stress. Antifreeze activity inhibiting the ice recrystallization at -9°C demonstrated the bacterium's survival at subzero temperature. The bacterium stores carbon in the form of PHB under stress conditions responding to nutritional fluctuations. However, violacein pigment protects the cells from UV radiation. Concisely, genomic, proteomic, and physiological studies revealed the multiple adaptive strategies of Himalayan to survive the high-altitude stresses.
细菌对喜马拉雅山脉高海拔生态位多种应激环境的适应性十分有趣,并且引起了生物技术学家的极大兴趣。此前,我们研究了西喜马拉雅地区冰川湖和锅穴湖可培养和不可培养的宏基因组微生物多样性。在本研究中,我们探索了一种独特的喜马拉雅广适嗜冷菌PCH194菌株的适应策略,该菌株能够合成聚羟基丁酸酯(PHB)和紫色杆菌素。对PCH194菌株(4.58 Mb染色体和三个质粒)进行全基因组测序和分析,揭示了与冷/冻、营养波动、紫外线防御、酸性pH值以及锅穴湖竞争环境的适应策略相关的遗传特征。差异蛋白质组分析表明,伴侣蛋白、核糖核酸酶、分泌系统和抗冻蛋白在冷应激下具有适应性作用。在-9°C抑制冰重结晶的抗冻活性证明了该细菌在零下温度下的生存能力。该细菌在应激条件下以PHB的形式储存碳,以应对营养波动。然而,紫色杆菌素可保护细胞免受紫外线辐射。简而言之,基因组、蛋白质组和生理学研究揭示了喜马拉雅菌株在高海拔应激下生存的多种适应策略。