Miyata Naoyuki, Tani Yukinori, Sakata Masahiro, Iwahori Keisuke
Institute for Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga, Shizuoka, Japan.
J Biosci Bioeng. 2007 Jul;104(1):1-8. doi: 10.1263/jbb.104.1.
Diverse bacteria and fungi oxidize Mn(II) enzymatically and produce insoluble Mn(III, IV) oxides, and these organisms are considered to be the primal agents for the occurrence of natural Mn oxide phases in most environments. Biogenic Mn oxides have a high sorption capacity for metal cations and an ability to oxidize numerous inorganic and organic compounds, owing to their structural and redox features. Thus, the microbial process is of significance in both biogeochemical and biotechnological contexts. In this article we summarize the enzymatic Mn(II) oxidation and interactions of biogenic Mn oxides with toxic metal and metalloid ions. Although Mn oxide formation by fungi has not been fully characterized yet, recent researches with ascomycetes emphasize the similarity between the bacterial and fungal Mn(II) oxidation with respect to the involved catalyst (i.e., multicopper oxidase-type enzymes) and the reaction product [i.e., layer-type Mn(IV) oxides]. Laboratory cultures of bacterial and fungal Mn oxidizers are expected to provide fundamental knowledge in their potential use for remediation of environments and effluents contaminated with toxic metal(loid) ions.
多种细菌和真菌可通过酶促作用氧化二价锰（Mn(II)）并产生不溶性的三价锰和四价锰（Mn(III,IV)）氧化物，在大多数环境中，这些生物被认为是天然锰氧化物形成的主要因素。由于其结构和氧化还原特性，生物源锰氧化物对金属阳离子具有高吸附能力，并且能够氧化多种无机和有机化合物。因此，微生物过程在生物地球化学和生物技术领域都具有重要意义。在本文中，我们总结了酶促氧化Mn(II)以及生物源锰氧化物与有毒金属和类金属离子的相互作用。尽管真菌形成锰氧化物的过程尚未完全明确，但最近针对子囊菌的研究强调了细菌和真菌氧化Mn(II)在相关催化剂（即多铜氧化酶类酶）和反应产物（即层状四价锰氧化物）方面的相似性。细菌和真菌锰氧化剂的实验室培养有望为它们在修复被有毒金属（类金属）离子污染的环境和废水方面的潜在应用提供基础知识。
