生物地球化学锰循环中的微生物胞外电子传递机制

Mechanisms of extracellular electron transfer in the biogeochemical manganese cycle

摘要:

微生物是生物地球化学元素循环的重要驱动者，在锰等变价金属元素的氧化还原过程中起着至关重要的作用。近年来，Mn（Ⅲ）的发现以及在一些环境中的广泛存在，丰富了人们对Mn（Ⅲ）以及自然界锰循环过程的认识。研究发现，锰的生物地球化学循环，尤其是锰还原过程，与微生物胞外电子传递紧密相关，且目前已知的5种胞外电子传递机制均与锰还原有关联。因此，本文综述了锰的生物地球化学循环及其意义，并从微生物胞外电子传递的机制、微生物介导锰氧化、微生物介导锰还原等3个方面来介绍参与锰循环的微生物多样性；以及微生物地球化学锰循环的环境意义。对微生物参与锰循环过程的研究不仅可以进一步丰富相关理论，同时也能推动生物除锰、污染物原位修复及生物冶金等应用领域的发展。

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.