State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China.
Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou, Fujian 350002, PR China.
J Hazard Mater. 2022 Jan 5;421:126684. doi: 10.1016/j.jhazmat.2021.126684. Epub 2021 Jul 20.
Selenium is an essential trace element for humans, animals and microorganisms. Microbial transformations, in particular, selenium dissimilatory reduction and bioremediation applications have received increasing attention in recent years. This review focuses on multiple Se-reducing pathways under anaerobic and aerobic conditions, and the phylogenetic clustering of selenium reducing enzymes that are involved in these processes. It is emphasized that a selenium reductase may have more than one metabolic function, meanwhile, there are several Se(VI) and/or Se(IV) reduction pathways in a bacterial strain. It is noted that Se(IV)-reducing efficiency is inconsistent with Se(IV) resistance in bacteria. Moreover, we discussed the links of selenium transformations to biogeochemical cycling of other elements, roles of Se-reducing bacteria in soil, plant and digestion system, and the possibility of using functional genes involved in Se transformation as biomarker in different environments. In addition, we point out the gaps and perspectives both on Se transformation mechanisms and applications in terms of bioremediation, Se fortification or dietary supplementation.
硒是人类、动物和微生物的必需微量元素。近年来，微生物转化，特别是硒的异化还原和生物修复应用受到了越来越多的关注。本综述重点介绍了在厌氧和有氧条件下的多种硒还原途径，以及参与这些过程的硒还原酶的系统发育聚类。强调了一种硒还原酶可能具有多种代谢功能，同时，在一个细菌菌株中存在多种 Se(VI)和/或 Se(IV)还原途径。值得注意的是，细菌中硒(IV)的还原效率与硒(IV)的抗性不一致。此外，我们还讨论了硒转化与其他元素生物地球化学循环的联系、硒还原菌在土壤、植物和消化系统中的作用，以及将参与硒转化的功能基因作为不同环境中的生物标志物的可能性。此外，我们还指出了在生物修复、硒强化或饮食补充方面，硒转化机制和应用方面的差距和展望。
