环境生物膜中的汞甲基化

Mercury methylation in environmental biofilms

汞是严重危害食品安全及人体健康的全球性重金属污染物,揭示具有强生物毒性的甲基汞的生成和累积机制是汞污染研究领域的热点和难点.生物膜中无机汞的甲基化是环境中甲基汞污染的主要来源和甲基汞进入食物链的起点,但是目前学术界对汞甲基化机制的认知多基于浮游态纯菌实验,无法准确模拟生物膜中汞的甲基化过程.本文从生物膜中汞甲基化的生化分子路径、无机汞的化学形态和甲基化微生物的活性这三个决定汞甲基化过程的关键因素出发,详细阐述了目前生物膜中汞甲基化的研究现状、存在问题以及拟解决问题的技术手段,并对未来在该领域的研究工作进行了展望.生物膜中汞甲基化机制的研究可为深入理解甲基汞的环境累积过程,提高汞污染风险分析的准确性,开发有效的汞污染风险防控技术提供科学依据和数据支撑.

Mercury is a heavy metal contaminant that endangers food safety and human health globally.Understanding the mechanisms that control the production and accumulation of the potent toxin,methylmercury,has been the research focus of mercury pollution.Methylation of inorganic mercury in biofilms significantly contributes to methylmercury contamination in the natural environment,and serves as the entry point of methylmercury accumulation in the food web.However,current understanding of the mechanisms governing mercury methylation is mainly originated from experiments using planktonic cultures of pure strains,which do not properly simulate mercury methylation processes in biofilms.Here,we synthesized the current understanding and remaining challenges regarding the principal biochemical pathways responsible for mercury methylation,chemical speciation of inorganic mercury and the activity of microorganism in biofilms,the three key factors affecting microbial mercury methylation.Technical approaches for further solving the key questions of mercury methylation in environmental biofilms and future perspectives of this research area were also discussed.Research on mercury methylation in biofilms will help improve the mechanistic understanding of the methylmercury accumulation processes in the environment,and provide insights to accurate risk analysis and effective remediation strategies of mercury pollution.