Journal ArticleDOI
Electron transfer from a solid-state electrode assisted by methyl viologen sustains efficient microbial reductive dechlorination of TCE.
Federico Aulenta,Alessandro Catervi,Mauro Majone,Stefania Panero,Priscilla Reale,Simona Rossetti +5 more
TLDR
It is shown, for the first time, that an electrochemical cell with a solid-state electrode polarized at -500 mV, in combination with a low-potential redox mediator (methyl viologen), can efficiently transfer electrochemical reducing equivalents to microorganisms which respire using chlorinated solvents.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.read more
Citations
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Journal ArticleDOI
Microbial electrosynthesis — revisiting the electrical route for microbial production
Korneel Rabaey,René A. Rozendal +1 more
TL;DR: This Review addresses the principles, challenges and opportunities of microbial electrosynthesis, an exciting new discipline at the nexus of microbiology and electrochemistry.
Journal ArticleDOI
The Microbe Electric: Conversion of Organic Matter to Electricity
TL;DR: Broad application of microbial fuel cells will require substantial increases in current density and a better understanding of the microbiology of these systems may help.
Journal ArticleDOI
Cathodes as electron donors for microbial metabolism: Which extracellular electron transfer mechanisms are involved?
TL;DR: This review illuminates extracellular electron transfer mechanisms that may be involved in microbial bioelectrochemical systems with biocathodes and predicts that in direct electron transfer reactions, c-type cytochromes often together with hydrogenases play a critical role and that, in mediated electronTransfer reactions, natural redox mediators, such as PQQ, will be involvement in the bioElectrochemical reaction.
Journal ArticleDOI
Bioelectrochemical systems (BES) for sustainable energy production and product recovery from organic wastes and industrial wastewaters
Deepak Pant,Anoop Singh,Gilbert Van Bogaert,Stig Irving Olsen,Poonam Singh Nee Nigam,Ludo Diels,Karolien Vanbroekhoven +6 more
TL;DR: Bioelectrochemical systems (BESs) as discussed by the authors are unique systems capable of converting the chemical energy of organic waste including low-strength wastewaters and lignocellulosic biomass into electricity or hydrogen/chemical products in microbial fuel cells or microbial electrolysis cells.
Journal ArticleDOI
Impact and application of electron shuttles on the redox (bio)transformation of contaminants: a review.
TL;DR: The aim of this review paper is to summarize the results of reductive (bio)transformation processes catalyzed by electron shuttles and to indicate which aspects should be further investigated to enhance the applicability of redox mediators on the (biotransformation of contaminants.
References
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Membrane and Morphological Changes in Apoptotic Cells Regulated by Caspase-Mediated Activation of PAK2
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Journal ArticleDOI
Graphite electrodes as electron donors for anaerobic respiration
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