携带污染物降解基因的可移动基因元件及其介导的生物修复

Degradative mobile genetic elements(MGEs) and their potential use in MGE-mediated biodegradation

可移动基因元件(mobile genetic elements,MGEs)在环境微生物群落中的水平转移是细菌基因组进化和适应特定环境压力的重要机制.在污染土壤和水体中接种携带具有降解基因MGEs的菌株后,随着MGEs的水平基因转移,可使降解基因转移至具有竞争性的土著微生物中并在其中表达,从而不必考虑供体菌在环境中是否能够长期存活.这种由可移动降解基因元件水平转移介导的生物修复为探索新的生物修复途径提供了可行性.本文重点综述了环境样品中携带降解基因MGEs的多样性及其在促进污染物降解过程中的重要作用,介绍了从环境样品中分离代谢MGEs的方法,并列举了在污染土壤、活性污泥、其他生物反应器等生态系统中MGEs水平转移的几个实例.

The horizontal transfer of mobile genetic elements（MGEs） in environmental microbial communities plays an important role in the evolution of bacterial genomes and the adaption of microbial populations to specific environmental stress.Inoculation of the bacterial strains with MGEs with pollutant-degrading gene and the subsequent horizontal transfer of the MGEs to one or various well-established and competitive indigenous bacterial populations in an ecosystem will allow the catabolic gene to be transferred and expressed in indigenous microbial populations,and hence,the survival of the introduced donor strains is no longer needed to be considered.The MGE-mediated bioremediation provides the feasibility for developing new bioremediation strategies.This paper summarized the diversity of MGEs with pollutant-degrading gene in the environment and the important roles of these MGEs in promoting pollutant degradation,introduced the methodological approaches for the isolation of the MGEs from environmental samples,and listed several studies that monitored the horizontal transfer of the MGEs in polluted soil,activated sludge,and other bioreactors.