铁氧化菌细胞色素c蛋白与含铁矿物的电子传递机理研究

含铁矿物的微生物氧化在铁的地质循环，生物体新陈代谢以及污染物的转化与迁移中都起着重要的作用。本项目拟通过天然铁氧化菌Sideroxydans lithotrophicus ES-1中驱动电子转移的关键细胞色素c蛋白MtoA和不同含铁矿物纳米颗粒之间的反应动力学研究，结合先进的纳米技术、分子生物学技术以及现代矿物学表征方法，揭示细胞色素c 蛋白在铁细菌-矿物界面电子转移中的作用。比较在溶解态、吸附态和结构态三种赋存状态下，Fe(II)和MtoA之间氧化还原速度的差异；系统分析水体的pH值、离子强度、有机质浓度等化学性质对离子的表面吸附以及电子转移效率的影响；阐述含铁矿物的晶相、粒径、形态、聚集状态等矿物学特征与其微生物氧化速度之间的关系。从分子水平上探讨铁细菌氧化含铁矿物的反应机理，为揭示铁细菌在生物地球化学过程中的作用和开发铁细菌在水环境修复中的应用提供科学依据。

Microbial oxidation of Fe(II)-bearing minerals plays a key role in Fe cycle,cell metabolism,as well as the transformation and transport of contaminants in natural environment. In this project, the mechanisms of electron transfer on microbe-mineral interface will be studied through the oxidation kinetics of Fe(II)-bearing minerals by MtoA, a c-type cytochrome of natural iron-oxidizing bacterium, Sideroxydans lithotrophicus ES-1.Advanced nanotechniques,molecular biological techniques, and mineral characterization methods will also be applied to investigate the changes of minerals and proteins in the microbial redox reactions. The oxidation rates of dissolved Fe(II), absorbed Fe(II), and structural Fe(II) by MtoA will be compared. The influence of chemical properties of solution, such as pH values, ionic strength, natural organic matter (NOM), on the reactivity of MtoA will be investigated. The relationship between mineralogical properties of Fe(II)-bearing minerals, including crystal phase, size, aggregation,etc., and the oxidation rates with MtoA will be studied. This study aims to provide molecular insights to the mechanisms of the microbial oxidation of Fe(II)-bearing minerals with iron-oxidizing bacteria. It will be helpful for understanding the influence of microbe-mineral interactions on biogeochemical processes,and also important for utilizing iron-oxidizing bacteria in environmental purification.