title: Microbe-assisted sulfide oxidation in the anode of a microbial fuel cell.
abstract: Sulfide oxidation is coupled with electricity generation in a sulfide-fed microbial fuel cell (MFC). This study demonstrated that both electrochemical reactions and microbial catalysis were involved in such a complex sulfide oxidation process in the anode of an MFC. The microbe-assisted sulfide oxidation generated a higher persistent current density than the sulfide oxidation via single electrochemical reactions only. Three valence states of S (-II), S (0), and S (+VI) were discovered from the sulfide oxidation, and So, Sx(2-), S4O6(2-), S2O3(2-), and SO4(2-) were detected as the intermediates. Based on the sulfur speciation and microbial community analysis, the sulfide oxidation pathways in the MFC were proposed. The oxidation of sulfide to So/Sx(2-) and further to S4O6(2-)/S2O3(2-) occurred spontaneously as electrochemical reactions, and electricity was generated. The formation of So/Sx(2-) and S2O3(2-) was accelerated by the bacteria in the MFC anode, and SO4(2-) was generated because of a microbial catalysis. The microbe-assisted production of S2O3(2-) and SO4(2-) resulted in a persistent current from the MFC.
authors.affiliation: Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China.
authors.forename: Min
authors.initials: M
authors.lastname: Sun
authors.forename: Zhe-Xuan
authors.initials: ZX
authors.lastname: Mu
authors.forename: You-Peng
authors.initials: YP
authors.lastname: Chen
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Sheng
authors.forename: Xian-Wei
authors.initials: XW
authors.lastname: Liu
authors.forename: Yong-Zhen
authors.initials: YZ
authors.lastname: Chen
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhao
authors.forename: Hua-Lin
authors.initials: HL
authors.lastname: Wang
authors.forename: Han-Qing
authors.initials: HQ
authors.lastname: Yu
authors.forename: Li
authors.initials: L
authors.lastname: Wei
authors.forename: Fang
authors.initials: F
authors.lastname: Ma
mesh_terms: D001674:Bioelectric Energy Sources / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology; D004560:Electricity; D004566:Electrodes / Q000382:microbiology; D010084:Oxidation-Reduction; D012996:Solutions; D013057:Spectrum Analysis; D013440:Sulfides / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism; D016999:Sulfur-Reducing Bacteria / Q000378:metabolism*
chemical_list: D012996:Solutions; D013440:Sulfides; D013455:Sulfur