Mechanisms of extracellular electron transfer in the biogeochemical manganese cycle

Abstract:

Microorganisms are important driver for the circulation of biogeochemical elements and play a vital role in the redox of metal elements possessing variable valence such as manganese. In recent years, the discovery and wide distribution of Mn(Ⅲ) in certain environment enrich our knowledge of natural manganese cycle. Some reports showed that geochemical cycling of manganese, especially dissimilatory manganese reduction, was closely related to microbial extracellular electron transfer, and dissimilatory manganese reduction involves five mechanisms of extracellular electron transfer. In this review, we discuss geochemical cycling and significance of manganese; microbial diversity of manganese cycle involving three aspects:mechanisms of microbial extracellular electron transfer, manganese oxidation mediated by microorganisms and manganese reduction mediated by microorganisms; The environmental significance of microbial geochemical manganese cycle. The research on the process of manganese cycle not only enriches related theories, but also stimulates the development of application including biological manganese removal, in-situ remediation of contaminants and bioleaching.