汞甲基化细菌研究进展  

Mercury methylation bacteria and methyl mercury producing: A review

作　　者：梁小兵[1] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550002

出　　处：《生态学杂志》2013年第3期755-761,共7页Chinese Journal of Ecology

基　　金：中国科学院国际合作局中俄合作项目(200923);国家重点基础研究计划项目(2006CB403200)资助

摘　　要：汞甲基化细菌在厌氧条件下将无机汞(Hg)转化成最高毒性的甲基汞(MeHg),通过生物富集以及在食物链中的生物放大造成人类甲基汞暴露。本文综述了水环境中汞甲基化细菌的种类、系统发生、甲基化机理、甲基汞生成的空间位置和影响因素。水环境中汞甲基化主要发生在海洋、海湾、河流和湖泊的厌氧沉积物中。硫酸盐还原菌和铁还原菌是主要的汞甲基化细菌,它们的种类、群落结构和分布制约了甲基汞的生成,从而影响人体健康。汞甲基化的生化机理的研究表明,甲基汞可能产生于不同的代谢途径,但是对于汞甲基化机理仍没有一致的认识。沉积物中汞甲基化细菌的分布影响甲基汞生成的空间位置和甲基化率。因此,水环境中的地球化学因素影响甲基化细菌的分布、甲基化率和甲基汞的生成。Mercury methylation bacteria change inorganic mercury to the highest toxic methylmer- cury （MeHg） under anaerobic conditions, which can result the human＇ s MeHg exposure by bio- accumulation and biomagnification. This article reviews the species and phylogeny of mercury methylation bacteria, methylation mechanism, spatial location of MeHg producing and the affect- ing factors in aquatic environments. In aquatic environments, mercury methylation occurs mainly in the anaerobic sediments of oceans, estuaries, rivers and lakes. Sulfate-reducing bacteria （SRB） and iron-reducing bacteria （IRB） are the main methylation bacteria. Their species, community structure and distribution control MeHg production and effects to human health. The studies on the biochemical mechanisms of mercury methylation show that MeHg may be produced from different metabolism pathways, but there still exist no consistent conclusions on mercury methylation mechanism. Spatial distribution of MeHg producing in sediments and the rate of mer- cury methylation are controlled by the distribution of mercury methylation bacteria, therefore the geochemical factors in aquatic environments affect the distribution of methylation bacteria, methy- lation rate and MeHg producing.

关 键 词：甲基化细菌 甲基汞 硫酸盐还原菌 铁还原菌 系统发生 

分 类 号：Q93[生物学—微生物学]