深海热液区发酵型铁还原细菌 Anoxybacter fermentans的铁还原机制研究

微生物铁还原过程,是深海热液系统非常重要的生物地球化学循环。发酵型铁还原细菌普遍存在于深海热液区，可利用丰富的含铁化合物为电子受体，目前可培养菌株少，研究匮乏。已知铁还原机制均依赖于细胞色素型蛋白。本研究将以来源于深海热液区的一株发酵型铁还原细菌Anoxybacter fermentans DY22613为研究对象，结合生物化学、电化学和分子生物学的研究方法，分析该菌株的胞外电子传递过程，包括可利用的外源和内生的电子穿梭体/螯合剂；分析菌株的基因转录表达调控差异，构建基因共表达网络；分析胞内氧化还原蛋白/分子的活性；构建突变菌株库确证与铁还原直接相关的基因；本项目将模拟不同电子受体（无铁，可溶性铁，不可溶铁（硫铁矿，水铁矿））的深海热液环境，确定其胞外/胞内铁还原机制和电子传递过程，将阐明这类微生物在深海热液区的特殊生存机制，有助于进一步完善环境微生物铁还原机制和电子传递的理论和应用基础。

Microbial iron reducing in the hydrothermal vent fields is an important biogeochemical process. Limited study on the fermentative iron reduing bacteria in the hydrothermal fields was done to isolate them and elucidate their iron reducing mechanisms. The known microbial iron reducing mechanism was based on c-type cytochrome. In this study, based on biochemical, electrochemical and molecular (transcriptome, proteome, mutant library construction) methods, we aim to analyze the iron reducing process of a fermentative iron reducer Anoxybacter fermentans DY22613 isolated from hydrothermal sulfides, including electron shuttle/chelator analysis, differential gene regulation and expression, further mutant confirmation to elucidate the molecular mechanism of iron reducing and electron transfer. The analysis of the strain grown in the different electron acceptors (no iron，dissolved iron, iron mineral）will provide novel insights into the iron reducing mechanisms of fermentative iron reducer and their adaptation in hydrothermal vents. The research will improve our understanding of microbial iron-reducing and electron transfer mechanisms.