Sustained generation of electricity by the spore-forming, Gram-positive, Desulfitobacterium hafniense strain DCB2.
Desulfitobacterium hafniense strain DCB2 generates electricity in microbial fuel cells (MFCs) when humic acids or the humate analog anthraquinone-2,6-disulfonate (AQDS) is added as an electron-carrying mediator. When utilizing formate as fuel, the Gram-positive, spore-forming bacterium generated up to 400 mW/m2 of cathode surface area in a single-chamber MFC with a platinum-containing air-fed cathode. Hydrogen, lactate, pyruvate, and ethanol supported electricity generation, but acetate, propionate, and butyrate did not. Scanning electron microscopy indicated that strain DCB2 colonized the surface of a current-generating anode but not of an unconnected electrode. The electricity was recovered fully within minutes after the exchange of the medium in the anode chamber and within a week after an exposure of a colonized anode to 90 degrees C for 20 min. Of the six strains of Desulfitobacteria tested, all of which would reduce AQDS, only D. hafniense strain DCB2 continued to reduce AQDS and generate electricity for more than 24 h, indicating that reduction of the humate analog alone is insufficient to sustain electrode reduction.
Milliken
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Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Ave., 225 BSB, P.O. Box 250504, Charleston, SC 29425-2230, USA.
May
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D000880:Anthraquinones / Q000378:metabolism; D001674:Bioelectric Energy Sources; D045858:Desulfitobacterium / Q000502:physiology* / Q000648:ultrastructure; D004560:Electricity; D004566:Electrodes / Q000382:microbiology; D000431:Ethanol / Q000378:metabolism; D005561:Formates / Q000378:metabolism; D006859:Hydrogen / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D019289:Pyruvic Acid / Q000378:metabolism; D013997:Time Factors
D000880:Anthraquinones; D005561:Formates; C408124:anthraquinone-2,6-disulfonate; C030544:formic acid; D019344:Lactic Acid; D000431:Ethanol; D006859:Hydrogen; D019289:Pyruvic Acid