Nanobiotechnology Laboratory, Department of Studies in Biotechnology, University of Mysore, Manasagangotri, Mysuru, Karnataka, 570006, India.
Laboratory of Plant Healthcare and Diagnostics, PG Department of Biotechnology and Microbiology, Karnatak University, Dharward, Karnataka, 580003, India.
Arch Microbiol. 2022 Feb 14;204(3):172. doi: 10.1007/s00203-022-02756-6.
In the recent years, yeasts have evolved as potent bioremediative candidates for the detoxification of xenobiotic compounds found in the natural environment. Candida sp. are well-studied apart from Saccharomyces sp. in heavy metal detoxification mechanisms. In the current study, Candida parapsilosis strain ODBG2, Candida sp. strain BANG3, and Candida viswanathii strain ODBG4 were isolated from industrial effluents and contaminated ground water, and were studied for their metal tolerance. Among these three isolates, the metal tolerance was found to be more towards Lead (Pb 2 mM), followed by Cadmium (Cd 1.5 mM) and Chromium [Cr(VI), 1 mM]. On further exploring the involvement of primary defensive enzymes in these isolates towards metal tolerance, the anti-oxidative enzyme superoxide dismutase was found to be prominently high (25% with respect to the control) during first 24 h of metal-isolate interaction. The Catalase enzyme assay was observed to have increased enzyme activity at 48 h. It also triggered the activity of peroxidases, which lead to the increase in reduced glutathione in the organism by 0.87-1.9-fold as a metal chelator and also as a second-line defensive molecule. The exoproteome profile showed the early involvement (exponential growth phase) of secreted proteins (low-molecular-weight) of about ~ 40-45 kDa under Cd and Pb stress (0.5 mM). The exoproteome profiling under heavy metal stress in Candida parapsilosis strain ODBG2 and Candida viswanathii strain ODBG4 is the first report.
近年来，酵母已成为从自然环境中发现的异生物质化合物解毒的有效生物修复候选物。在重金属解毒机制方面，除了酿酒酵母外，对假丝酵母属的研究也很多。在本研究中，从工业废水和受污染的地下水分离出了两株近平滑假丝酵母（Candida parapsilosis）菌株 ODBG2、一株毕赤酵母（Candida sp.）菌株 BANG3 和一株威氏假丝酵母（Candida viswanathii）菌株 ODBG4，并对它们的金属耐受性进行了研究。在这三个分离株中，对铅（Pb 2 mM）的耐受性最高，其次是镉（Cd 1.5 mM）和铬[Cr(VI)，1 mM]。在进一步探讨这些分离株中主要防御酶对金属耐受性的参与情况时，发现超氧化物歧化酶等抗氧化酶在金属-分离株相互作用的前 24 小时内显著升高（相对于对照增加了 25%）。48 小时后观察到过氧化氢酶的酶活性增加。它还触发了过氧化物酶的活性，导致还原型谷胱甘肽在生物体中的含量增加了 0.87-1.9 倍，作为金属螯合剂和二线防御分子。外蛋白质组图谱显示，在 Cd 和 Pb 胁迫（0.5 mM）下，分泌蛋白（低分子量）的早期参与（指数生长阶段）约为 40-45 kDa。这是首次报道近平滑假丝酵母（Candida parapsilosis）菌株 ODBG2 和威氏假丝酵母（Candida viswanathii）菌株 ODBG4 在重金属胁迫下的外蛋白质组图谱。
