title: Enhanced Shewanella biofilm promotes bioelectricity generation.
abstract: Electroactive biofilms play essential roles in determining the power output of microbial fuel cells (MFCs). To engineer the electroactive biofilm formation of Shewanella oneidensis MR-1, a model exoelectrogen, we herein heterologously overexpressed a c-di-GMP biosynthesis gene ydeH in S. oneidensis MR-1, constructing a mutant strain in which the expression of ydeH is under the control of IPTG-inducible promoter, and a strain in which ydeH is under the control of a constitutive promoter. Such engineered Shewanella strains had significantly enhanced biofilm formation and bioelectricity generation. The MFCs inoculated with these engineered strains accomplished a maximum power density of 167.6 ± 3.6 mW/m(2) , which was ∼ 2.8 times of that achieved by the wild-type MR-1 (61.0 ± 1.9 mW/m(2) ). In addition, the engineered strains in the bioelectrochemical system at poised potential of 0.2 V vs. saturated calomel electrode (SCE) generated a stable current density of 1100 mA/m(2) , ∼ 3.4 times of that by wild-type MR-1 (320 mA/m(2) ).
authors.affiliation: School of Chemical & Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore.
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
authors.affiliation: School of Chemical & Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore.
authors.forename: Yang-Yang
authors.initials: YY
authors.lastname: Yu
authors.affiliation: School of Chemical & Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore.
authors.forename: Xiao-Peng
authors.initials: XP
authors.lastname: Deng
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore.
authors.forename: Chun Kiat
authors.initials: CK
authors.lastname: Ng
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore.|School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore.
authors.forename: Bin
authors.initials: B
authors.lastname: Cao
authors.affiliation: School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore.
authors.forename: Jing-Yuan
authors.initials: JY
authors.lastname: Wang
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Rice
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore.
authors.forename: Staffan
authors.initials: S
authors.lastname: Kjelleberg
authors.affiliation: Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China. hsong@tju.edu.cn.
authors.forename: Hao
authors.initials: H
authors.lastname: Song
mesh_terms: D001674:Bioelectric Energy Sources; D018441:Biofilms / Q000254:growth & development*; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism; D004560:Electricity; D015870:Gene Expression; D007544:Isopropyl Thiogalactoside / Q000378:metabolism; D019761:Phosphorus-Oxygen Lyases / Q000096:biosynthesis / Q000235:genetics; D020592:Shewanella / Q000254:growth & development / Q000502:physiology*; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D007544:Isopropyl Thiogalactoside; C062025:bis(3',5')-cyclic diguanylic acid; D019761:Phosphorus-Oxygen Lyases; D006152:Cyclic GMP
keywords: Shewanella; bioelectrochemical systems; biofilm; c-di-GMP; extracellular electron transfer; microbial fuel cells