title: Modifying the endogenous electron fluxes of Rhodobacter sphaeroides 2.4.1 for improved electricity generation.
abstract: The purple bacteria Rhodobacter sphaeroides serve as a promising biocatalyst in the photo-microbial fuel cell system (photo-MFC). This gram-negative species performs highly efficient anoxygenic photosynthesis that ensures an anaerobic environment in the anode compartment. Previous studies incorporating R. sphaeroides into photo-MFC were conducted using platinum as the anode electrode. In this study, we detected a steady current generation of R. sphaeroides in a bioelectrochemical system where glassy carbon was the working electrode and a typical growth medium was the electrolyte. The bioelectricity generation synchronized with the supplementation of reduced carbon source and showed immediate response to illumination, which strongly indicated the correlation between the observed current and the cytoplasmic quinone activity. Modifications of the endogenous electron flows mediated by quinone pool are shown to have significantly enhanced the bioelectricity generation. We anticipate that the findings in this study would advance future optimization of R. sphaeroides as an anode strain, as well as facilitate the study of bioenergetics in photosynthetic bacteria.
authors.affiliation: Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Man Tung
authors.initials: MT
authors.lastname: Wong
authors.affiliation: Bioengineering Graduate Program, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Danhui
authors.initials: D
authors.lastname: Cheng
authors.affiliation: Bioengineering Graduate Program, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Ri
authors.initials: R
authors.lastname: Wang
authors.affiliation: Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; Bioengineering Graduate Program, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong. Electronic address: kehsing@ust.hk.
authors.forename: I-Ming
authors.initials: IM
authors.lastname: Hsing
mesh_terms: D055162:Biocatalysis; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D004560:Electricity; D004579:Electron Transport; D008954:Models, Biological; D009154:Mutation; D010788:Photosynthesis; D011809:Quinones / Q000378:metabolism; D012242:Rhodobacter sphaeroides / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D019802:Succinic Acid / Q000378:metabolism
chemical_list: D011809:Quinones; D019802:Succinic Acid
keywords: Anode strain optimization; Bioelectricity generation; Bioelectrochemical system; Microbial fuel cell; Rhodobacter sphaeroides; Ubiquinone pool