title: Sustainable power production in a membrane-less and mediator-less synthetic wastewater microbial fuel cell.
abstract: Microbial fuel cells (MFCs) fed with wastewater are currently considered a feasible strategy for production of renewable electricity. A membrane-less MFC with biological cathode was built from a compact wastewater treatment reactor and fed with synthetic wastewater. When operated with an external resistance of 250 Omega, the MFC produced a long-term power of about 70 mW/m(2) for 10 months. Denaturing Gradient Gel Electrophoresis (DGGE) analysis of the cathode biomass when the MFC was closed on a 2100 Omega external resistance showed that the sequenced bands were affiliated with Firmicutes, alpha-Proteobacteria,beta-Proteobacteria, gamma-Proteobacteria, and Bacteroidetes groups. When the external resistance was varied between 250 and 2100 Omega, minimum sustainable resistance decreased from 900 to 750 Omega, while maximum sustainable power output decreased from 32 to 28 mW/m(2). It is likely that these effects were caused by changes in the microbial ecology of anodic and cathodic biomass attached to the electrodes. Results suggest that cathodic biomass enrichment in "electroactive" bacteria may improve MFCs power output in a similar fashion to what has been already observed for anodic biomass.
authors.affiliation: ENEA CR Bologna, ACS PROT IDR Section, Bologna, Italy.
authors.forename: Aba
authors.initials: A
authors.lastname: Aldrovandi
authors.forename: Enrico
authors.initials: E
authors.lastname: Marsili
authors.forename: Loredana
authors.initials: L
authors.lastname: Stante
authors.forename: Patrizia
authors.initials: P
authors.lastname: Paganin
authors.forename: Silvia
authors.initials: S
authors.lastname: Tabacchioni
authors.forename: Andrea
authors.initials: A
authors.lastname: Giordano
mesh_terms: D000641:Ammonia / Q000737:chemistry; D001673:Biodegradation, Environmental; D001674:Bioelectric Energy Sources / Q000382:microbiology; D018533:Biomass; D019149:Bioreactors; D003246:Conservation of Energy Resources; D004560:Electricity; D004566:Electrodes; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004735:Energy Transfer / Q000502:physiology; D004867:Equipment Design; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods
chemical_list: D012336:RNA, Ribosomal, 16S; D000641:Ammonia