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Electron transfer from a solid-state electrode assisted by methyl viologen sustains efficient microbial reductive dechlorination of TCE

TitoloElectron transfer from a solid-state electrode assisted by methyl viologen sustains efficient microbial reductive dechlorination of TCE
Tipo di pubblicazioneArticolo su Rivista peer-reviewed
Anno di Pubblicazione2007
AutoriAulenta, F., Catervi A., Majone M., Panero S., Reale P., and Rossetti S.
RivistaEnvironmental Science and Technology
Volume41
Paginazione2554-2559
ISSN0013936X
Parole chiaveAnaerobic, article, Bacteria, Bacteria (microorganisms), Biodegradation, Bioremediation, Chemical, contamination, dechlorination, Electrochemistry, electrode, Electrodes, electron, Electron donors, Electron transitions, electron transport, Environmental, ethane, Ethylene, fluorescence, fuel cell, ground water, Groundwater pollution, In Situ Hybridization, methyl chloride, microbial activity, microbial degradation, Microbial respirations, Microorganisms, oxidation reduction reaction, Oxidation-Reduction, paraquat, Reaction analysis, respiration, Solid-state electrodes, Trichloroethylene, water contamination, Water Pollutants, Water pollution control
Abstract

The ability to transfer electrons, via an extracellular path, to solid surfaces is typically exploited by microorganisms which use insoluble electron acceptors, such as iron-or manganese-oxides or inert electrodes in microbial fuel cells. The reverse process, i.e., the use of solid surfaces or electrodes as electron donors in microbial respirations, although largely unexplored, could potentially have important environmental applications, particularly for the removal of oxidized pollutants from contaminated groundwater or waste streams. Here we show, for the first time, that an electrochemical cell with a solid-state electrode polarized at -500 mV (vs standard hydrogen electrode), in combination with a low-potential redox mediator (methyl viologen), can efficiently transfer electrochemical reducing equivalents to microorganisms which respire using chlorinated solvents. By this approach, the reductive transformation of trichloroethene, a toxic yet common groundwater contaminant, to harmless end-products such as ethene and ethane could be performed. Furthermore, using a methyl-viologen-modified electrode we could even demonstrate that dechlorinating bacteria were able to accept reducing equivalents directly from the modified electrode surface. The innovative concept, based on the stimulation of dechlorination reactions through the use of solid-state electrodes (we propose for this process the acronym BEARD: Bio-Electrochemically Assisted Reductive Dechlorination), holds promise for in situ bioremediation of chlorinated-solvent-contaminated groundwater, and has several potential advantages over traditional approaches based on the subsurface injection of organic compounds. The results of this study raise the possibility that immobilization of selected redox mediators may be a general strategy for stimulating and controlling a range of microbial reactions using insoluble electrodes as electron donors. © 2007 American Chemical Society.

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cited By 94

URLhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-34247098528&doi=10.1021%2fes0624321&partnerID=40&md5=916c3137443d9faa147363501b982c05
DOI10.1021/es0624321
Citation KeyAulenta20072554