In situ role of extracellular polymeric substances in microbial electron transfer by Methylomonas sp.LW13  

作　　者：Huan Wang Yue Zheng Baoli Zhu Feng Zhao 

机构地区：[1]CAS Key Laboratory of Urban Pollutant Conversion,Institute of Urban Environment,Chinese Academy of Sciences,1799 Jimei Road,Xiamen 361021,China [2]Key Laboratory of Agro-ecological Processes in Subtropical Regions,Taoyuan Agroecosystem Research Station,Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China

出　　处：《Fundamental Research》2021年第6期735-741,共7页自然科学基础研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grants No.41907027,22025603 and 41471260)。

摘　　要：Extracellular polymeric substances(EPS),produced by microorganisms,establish the functional and structural integrity of microbial biofilms.In biological wastewater treatments,the transformation of pollutants largely relies on microbial electron transfer.As a bridge between the microbial cytomembrane/cytoderm and terminal electron acceptors,the role of EPS in microbial electron transfer cannot be ignored.However,due to the complexity of its composition,the in situ function of EPS in extracellular electron transfer is still unclear.In this work,we constructed an epsH gene knockout mutant of Methylomonas sp.LW13 with significantly reduced EPS formation.The content of protein and polysaccharide,two major components of EPS,of theΔepsH mutant and wild-type during different growth stages were compared.The redox signal and in situ Au reduction of theΔepsH mutant were obviously stronger than those of the wild-type,which suggested that EPS can hinder extracellular electron transfer in this system.Although redox activity was detected in EPS,high faradaic resistance of EPS was demonstrated.Our results enlighten the in situ role of EPS in extracellular electron transfer with the help of molecular manipulations and provide insights into how to regulate the microbial process of wastewater treatments.

关 键 词：Extracellular electron transfer Extracellular polymeric substances Gene knockout Au reduction METHANOTROPHS 

分 类 号：X703[环境科学与工程—环境工程]