Microbiology and Computational Biology Laboratory, Department of Botany, Raiganj University, Raiganj, India.
Mycology and Plant Pathology Laboratory, Department of Botany, Raiganj University, Raiganj, India.
Crit Rev Microbiol. 2022 May;48(3):327-355. doi: 10.1080/1040841X.2021.1970512. Epub 2021 Sep 2.
Heavy metals bring long-term hazardous consequences and pose a serious threat to all life forms. Being non-biodegradable, they can remain in the food webs for a long period of time. Metal ions are essential for life and indispensable for almost all aspects of metabolism but can be toxic beyond threshold level to all living beings including microbes. Heavy metals are generally present in the environment, but many geogenic and anthropogenic activities has led to excess metal ion accumulation in the environment. To survive in harsh metal contaminated environments, bacteria have certain resistance mechanisms to metabolize and transform heavy metals into less hazardous forms. This also gives rise to different species of heavy metal resistant bacteria. Herein, we have tried to incorporate the different aspects of heavy metal toxicity in bacteria and provide an up-to-date and across-the-board review. The various aspects of heavy metal biology of bacteria encompassed in this review includes the biological notion of heavy metals, toxic effect of heavy metals on bacteria, the factors regulating bacterial heavy metal resistance, the diverse mechanisms governing bacterial heavy metal resistance, bacterial responses to heavy metal stress, and a brief overview of gene regulation under heavy metal stress.
重金属会带来长期的有害后果，对所有生命形式构成严重威胁。由于它们不可生物降解，因此可以在食物网中长时间存在。金属离子对生命是必需的，几乎在新陈代谢的各个方面都是不可或缺的，但超过阈值水平对包括微生物在内的所有生物都是有毒的。重金属通常存在于环境中，但许多地球成因和人为活动导致环境中金属离子过度积累。为了在恶劣的金属污染环境中生存，细菌具有一定的代谢和转化重金属为危害较小形式的抵抗机制。这也导致了不同种类的重金属抗性细菌的产生。在此，我们尝试将细菌中重金属毒性的不同方面纳入其中，并提供最新的全面综述。本综述涵盖了细菌中重金属生物学的各个方面，包括重金属的生物学概念、重金属对细菌的毒性作用、调节细菌重金属抗性的因素、控制细菌重金属抗性的多种机制、细菌对重金属胁迫的反应以及重金属胁迫下基因调控的简要概述。
