重金属胁迫下的细菌适应性进化研究进展

Advances in Bacterial Adaptive Evolution under Heavy Metal Ion Stress

细菌进化的本质是碱基突变、基因重排或水平基因转移,在适应性进化过程中,主要受生物和非生物因素的影响,其中重金属胁迫也是细菌适应性进化的主要因素之一。重金属胁迫促使细菌适应性地强化与金属输入和转化有关的代谢途径,而过量的金属则诱导金属积累和外排过程。在重金属胁迫下,基于重金属抗性(HMR)基因和酶蛋白的适应,细菌抗性机制亦发生适应性进化,整理和总结了包括隔离机制适应、金属调控蛋白调控机制适应及酶解毒机制适应方面的研究。目前,重金属离子已对环境造成严重污染,威胁人类健康和生态系统的稳定,因此,阐明重金属胁迫下的细菌适应性进化,不仅丰富了细菌进化研究的内容,而且为在复杂环境条件下实现重金属离子污染的微生物的修复提供了理论基础。

Base mutation,gene re-arrangement or horizontal gene transfer are the fundamental mechanisms involved in bacterial evolution.During adaptive evolution,they are mainly affected by biological and abiological factors.Among them,heavy metal ion stress is also one of the main reasons during bacterial adaptive evolution,and it drives bacteria to adaptively strengthen the metabolic pathways related to metal input and/or transformation.On the other hand,excessive metal ion also can induce metal accumulation and efflux.Under heavy metal stress,heavy metal resistance(HMR)gene and enzyme protein play an important role involved in mechanisms of bacterial adaptive evolution.The mechanisms include the adaptation of isolation,the regulatory adaptation of metal regulatory protein and the adaptation of enzyme detoxification.The current research status and progress were summarized in this paper.Heavy metal ions have polluted the environment and threatened human health and ecosystem stability.Therefore,to elucidate the molecular mechanisms of adaptive evolution of bacteria under heavy metal stress,this paper not only enriches the content of bacterial evolutionism,but also provides a theoretical basis for the biological remediation of environmental pollution by heavy metal ions.