铁循环微生物对环境中重金属的影响研究进展

铁循环微生物包括铁氧化菌(Fe(Ⅱ)-oxidizing bacteria,FeOB)和铁还原菌(Fe(Ⅲ)-reducing bacteria,FeRB),在由它们介导Fe²⁺(Fe³⁺)氧化(还原)的过程中,往往也伴随着一系列重金属元素的迁移转化,对重金属在环境中的生物有效性和迁移性方面有重要作用.本文综述了环境中的铁循环微生物,针对铁循环微生物驱动重金属迁移转化的作用机制,分别从铁氧化菌氧化亚铁生成铁矿物对重金属的固定,铁还原菌介导铁矿物还原溶解及次生矿物生成,以及铁循环微生物代谢耦合重金属形态转化方面进行阐述;进一步通过研究实例综述了铁循环微生物对环境中砷、镉、铬、铜、铅等重金属的作用及修复潜力;未来的研究可关注特定微生物的成矿机制,生物成矿对重金属固定的调控,以及重金属复合污染场地的铁循环微生物修复应用等方面.本文以期为基于铁循环微生物的重金属污染修复提供理论指导和应用依据.

Study on the influence of iron redox cycling microorganisms on heavy metals in the environment

Iron redox cycling microorganisms include Fe(Ⅱ)-oxidizing bacteria and Fe(Ⅲ)-reducing bacteria.The oxidation(or reduction)of Fe²⁺(or Fe³⁺)mediated by these microorganisms is usually accompanied by the migration and transformation of a series of heavy metal elements,which plays an important role in influencing the bioavailability and mobility of heavy metals in the environment.This paper reviewed the iron redox cycling microorganisms in the environment,and discussed the mechanism of iron redox cycling microorganisms driving heavy metal migration and transformation from the following aspects:immobilization of heavy metals by iron minerals produced by iron oxidizing bacteria;reduction and dissolution of iron minerals and formation of secondary minerals mediate by iron-reducing bacteria;and microbial metabolism of iron redox cycling microorganisms coupled with heavy metal speciation transformation.Furthermore,the remediation potential of iron redox cycling microorganisms on heavy metals such as arsenic,cadmium,chromium,copper and lead in the environment were summarized through research examples.Future research can focus on the biomineralization mechanism of specific microorganisms,regulation of heavy metal remediation by biomineralization,and the application of iron redox cycling microorganisms in remediation of heavy metal contaminated sites.This paper aims to provide theoretical and application basis for remediation of heavy metal pollution based on iron redox cycling microorganisms.