National Collection of Industrial Microorganisms (NCIM), Biochemical Sciences Division, CSIR-National Chemical Laboratory (NCL), Pune, India.
National Collection of Industrial Microorganisms (NCIM), Biochemical Sciences Division, CSIR-National Chemical Laboratory (NCL), Pune, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
Chemosphere. 2021 Feb;264(Pt 2):128574. doi: 10.1016/j.chemosphere.2020.128574. Epub 2020 Oct 9.
Lonar Lake, India; a hypersaline and hyperalkaline extremophilic ecosystem having a unique microbial population has been rarely explored for bioremediation aspects. MinION-based shotgun sequencing was used to comprehensively compare the microbial diversity and functional potential of xenobiotic degradation pathways with seasonal changes. Proteobacteria and Firmicutes were prevalent bacterial phyla in the pre-monsoon and post-monsoon samples. Functional analysis from SEED-subsystem and KEGG database revealed 28 subsystems and 18 metabolic pathways for the metabolism of aromatic compounds and xenobiotic biodegradation respectively. Occurrence of N-phenyl alkanoic, benzoate, biphenyl, chloroaromatic, naphthalene, and phenol degradation genes depicted varied abundance in the pre-monsoon and post-monsoon samples. Further, KEGG analysis indicated nitrotoluene degradation pathway (ko00633) abundant in post-monsoon samples, and the benzoate degradation pathway (ko00362) predominant in 19LN4S (pre-monsoon) than 18LN7S (post-monsoon) samples. The abundant genes for benzoate degradation were pcaI: 3-oxoadipate CoA-transferase, alpha subunit, pcaH: protocatechuate 3,4-dioxygenase, beta subunit, and pcaB: 3-carboxy-cis, cis-muconate cycloisomerase, and 4-oxalocrotonate tautomerase. This metagenomic study provides a unique blueprint of hitherto unexplored xenobiotic biodegradation genes/pathways in terms of seasonal variations in the Lonar Lake, and warrants active exploitation of microbes for bioremediation purposes.
印度 Lonar 湖是一个高盐度和高碱性的极端生态系统，拥有独特的微生物种群，但其生物修复方面的研究很少。本研究采用 MinION 高通量测序技术，全面比较了在季节变化条件下，潜在的外来化合物降解途径的微生物多样性和功能潜力。在旱季和雨季前、后样本中，变形菌门和厚壁菌门是主要的细菌门。从 SEED 亚系统和 KEGG 数据库的功能分析中，分别发现了 28 个亚系统和 18 个代谢途径，用于芳香族化合物的代谢和外来化合物的生物降解。N-苯烷酸、苯甲酸、联苯、氯代芳烃、萘和苯酚降解基因的出现表明，在旱季和雨季前、后样本中丰度不同。此外，KEGG 分析表明，在后季样本中存在大量的硝甲苯降解途径（ko00633），而在 19LN4S（旱季）样本中，苯甲酸降解途径（ko00362）比 18LN7S（雨季）样本更为丰富。苯甲酸降解的丰富基因有 pcaI：3-氧代己二酸辅酶 A 转移酶，α 亚基，pcaH：原儿茶酸 3,4-加双氧酶，β 亚基和 pcaB：3-羧基-顺式，顺式-粘康酸环异构酶和 4-氧代戊烯二酸互变异构酶。本宏基因组研究提供了 Lonar 湖迄今为止尚未探索的外来化合物生物降解基因/途径的独特蓝图，为生物修复目的微生物的积极开发提供了依据。
