Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, No. 174, Shapingba Street, Chongqing, 400045, China.
Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
Appl Microbiol Biotechnol. 2024 Feb 26;108(1):235. doi: 10.1007/s00253-023-12967-6.
Methylmercury formation is mainly driven by microbial-mediated process. The mechanism of microbial mercury methylation has become a crucial research topic for understanding methylation in the environment. Pioneering studies of microbial mercury methylation are focusing on functional strain isolation, microbial community composition characterization, and mechanism elucidation in various environments. Therefore, the functional genes of microbial mercury methylation, global isolations of Hg methylation strains, and their methylation potential were systematically analyzed, and methylators in typical environments were extensively reviewed. The main drivers (key physicochemical factors and microbiota) of microbial mercury methylation were summarized and discussed. Though significant progress on the mechanism of the Hg microbial methylation has been explored in recent decade, it is still limited in several aspects, including (1) molecular biology techniques for identifying methylators; (2) characterization methods for mercury methylation potential; and (3) complex environmental properties (environmental factors, complex communities, etc.). Accordingly, strategies for studying the Hg microbial methylation mechanism were proposed. These strategies include the following: (1) the development of new molecular biology methods to characterize methylation potential; (2) treating the environment as a micro-ecosystem and studying them from a holistic perspective to clearly understand mercury methylation; (3) a more reasonable and sensitive inhibition test needs to be considered. KEY POINTS: • Global Hg microbial methylation is phylogenetically and functionally discussed. • The main drivers of microbial methylation are compared in various condition. • Future study of Hg microbial methylation is proposed.
甲基汞的形成主要受微生物介导的过程驱动。微生物汞甲基化的机制已成为理解环境中甲基化作用的关键研究课题。微生物汞甲基化的开创性研究主要集中在功能菌株的分离、微生物群落组成的特征描述以及各种环境中的机制阐明上。因此，对微生物汞甲基化的功能基因、Hg 甲基化菌株的全球分离及其甲基化潜能进行了系统分析，并对典型环境中的甲基化剂进行了广泛的综述。总结和讨论了微生物汞甲基化的主要驱动因素（关键理化因素和微生物群落）。尽管近十年来在微生物汞甲基化机制方面取得了重大进展，但仍存在几个方面的局限性，包括：（1）鉴定甲基化剂的分子生物学技术；（2）汞甲基化潜能的表征方法；（3）复杂的环境特性（环境因素、复杂群落等）。因此，提出了研究 Hg 微生物甲基化机制的策略。这些策略包括：（1）开发新的分子生物学方法来表征甲基化潜能；（2）将环境视为一个微生态系统，并从整体角度进行研究，以清楚地了解汞甲基化；（3）需要考虑更合理和敏感的抑制试验。
• 从系统发生和功能角度讨论了全球 Hg 微生物甲基化作用。
• 比较了各种条件下微生物甲基化的主要驱动因素。
• 提出了 Hg 微生物甲基化的未来研究方向。
