黄素介导的胞外电子转移研究与工程改造  

Research and Strategies of Flavins-mediated Extracellular Electron Transfer

作　　者：李媛媛 李妍[1] 曹英秀 宋浩[1] LI Yuan-yuan;LI Yan;CAO Ying-xiu;SONG Hao(School of Chemical Engineering and Technology,Tianjin University,Frontier Science Center for Synthetic Biology,Key Laboratory of Systems Bioengineering(Ministry of Education),Tianjin 300072,China)

机构地区：[1]天津大学化工学院/合成生物学前沿科学中心系统生物工程教育部重点实验室,天津300072

出　　处：《中国生物工程杂志》2021年第10期89-99,共11页China Biotechnology

基　　金：国家重点研发计划(2018YFA0901300);天津市青年人才托举工程(TJSQNTJ-2018-16)资助项目。

摘　　要：产电微生物的胞外电子转移在能源、环境等诸多领域有着非常重要的应用价值。希瓦氏菌(Shewanella oneidensis)作为模式产电微生物,其电催化系统引起了广泛的研究。黄素作为S.oneidensis重要的电子载体,其介导的胞外电子转移是电子传递过程中的一个限速步骤。然而自然环境中野生型S.oneidensis的黄素分泌量极低,对其工程改造也存在一定的局限性,因而严重阻碍了胞外电子的传递过程,这已成为限制其电子转移的主要瓶颈。基于S.oneidensis黄素介导的电子转移机制,系统地从黄素的合成路径及转录调控的角度阐明了黄素合成的调控因素,并综述近年来利用代谢工程、合成生物学以及电极材料修饰等方法来提高黄素介导电子转移的工程化策略,未来可利用一些系统的研究方法和表达工具来加速产电微生物黄素介导的胞外电子转移。Extracellular electron transfer is the process that electroactive microorganisms(EAMs)acquire energy from the environment by extending respiratory chains to external electron acceptors.Organism Shewanella oneidensis is widely used as a model to study emerging bioelectrochemical technologies,including microbial fuel cell(MFC),microbial electrosynthesis,as well as pollutant degradation in bioremediation.A previous study reported that almost all electrons generated by S.oneidensis were transmitted into acceptors relying on flavins,including flavin mononucleotide(FMN)and riboflavin(RF).What’s more,flavins-mediated extracellular electron transfer is the rate-limiting step in the process of electron transmission.However,flavins secreted by wild-type S.oneidensis are negligible,and the engineering modifications for S.oneidensis are limited,both of which seriously hinder the electrons transfer process,and enable the main bottleneck of restricting the electrons transmission.In this study,the regulatory factors of flavin synthesis were systematically demonstrated from the perspective of flavin biosynthesis and transcriptional regulation relying on the mechanisms of flavins-mediated electron transfer in S.oneidensis.Besides,the strategies utilizing metabolic engineering,synthetic biology and modification of electrode materials for improving flavins-mediated electron transfer in recent years were summarized.Further,it can be proposed that in the future,systematic research and expression tools can be utilized to accelerate the flavins-mediated extracellular electron transfer in EAMs.

关 键 词：S.oneidensis 核黄素 细胞色素 胞外电子转移 代谢工程 

分 类 号：Q819[生物学—生物工程]