title: Sulfide-driven microbial electrosynthesis.
abstract: Microbial electrosynthesis, the conversion of carbon dioxide to organic molecules using electricity, has recently been demonstrated for acetogenic microorganisms, such as Sporomusa ovata. The energy for reduction of carbon dioxide originates from the hydrolysis of water on the anode, requiring a sufficiently low potential. Here we evaluate the use of sulfide as an electron source for microbial electrosynthesis. Abiotically oxidation of sulfide on the anode yields two electrons. The oxidation product, elemental sulfur, can be further oxidized to sulfate by Desulfobulbus propionicus, generating six additional electrons in the process. The eight electrons generated from the combined abiotic and biotic steps were used to reduce carbon dioxide to acetate on a graphite cathode by Sporomusa ovata at a rate of 24.8 mmol/day · m(2). Using a strain of Desulfuromonas as biocatalyst on the anode resulted in an acetate production rate of 49.9 mmol/day · m(2), with a Coulombic efficiency of over 90%. These results demonstrate that sulfide can serve effectively as an alternative electron donor for microbial electrosynthesis.
authors.affiliation: Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, United States.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Gong
authors.forename: Ali
authors.initials: A
authors.lastname: Ebrahim
authors.forename: Adam M
authors.initials: AM
authors.lastname: Feist
authors.forename: Mallory
authors.initials: M
authors.lastname: Embree
authors.forename: Tian
authors.initials: T
authors.lastname: Zhang
authors.forename: Derek
authors.initials: D
authors.lastname: Lovley
authors.forename: Karsten
authors.initials: K
authors.lastname: Zengler
mesh_terms: D000085:Acetates / Q000378:metabolism; D001674:Bioelectric Energy Sources; D019149:Bioreactors; D020564:Deltaproteobacteria / Q000378:metabolism; D004563:Electrochemistry; D004566:Electrodes; D010084:Oxidation-Reduction; D013431:Sulfates / Q000378:metabolism; D013440:Sulfides / Q000737:chemistry* / Q000378:metabolism; D013455:Sulfur / Q000737:chemistry / Q000378:metabolism; D045854:Veillonellaceae / Q000378:metabolism
chemical_list: D000085:Acetates; D013431:Sulfates; D013440:Sulfides; D013455:Sulfur