title: Specific and efficient electrochemical selection of Geoalkalibacter subterraneus and Desulfuromonas acetoxidans in high current-producing biofilms.
abstract: Two different saline sediments were used to inoculate potentiostatically controlled reactors (a type of microbial bioelectrochemical system, BES) operated in saline conditions (35 gNaCl l(-1)). Reactors were fed with acetate or a mixture of acetate and butyrate at two pH values: 7.0 or 5.5. Electroactive biofilm formation lag-phase, maximum current density production and coulombic efficiency were used to evaluate the overall performance of reactors. High current densities up to 8.5 A m(-2) were obtained using well-defined planar graphite electrodes. Additionally, biofilm microbial communities were characterized by CE-SSCP and 454 pyrosequencing. As a result of this procedure, two anode-respiring bacteria (ARB) always dominated the anodic biofilms: Geoalkalibacter subterraneus and/or Desulfuromonas acetoxidans. This suggests that a strong electrochemically driven selection process imposed by the applied potential occurs in the BES system. Moreover, the emergence of Glk. subterraneus in anodic biofilms significantly contributes to broaden the spectrum of high current producing microorganisms electrochemically isolated from environmental samples.
authors.affiliation: INRA, UR 0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Pierra
authors.affiliation: INRA, UR 0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: Alessandro A
authors.initials: AA
authors.lastname: Carmona-Martínez
authors.affiliation: INRA, UR 0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Trably
authors.affiliation: INRA, UR 0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Godon
authors.affiliation: INRA, UR 0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France. Electronic address: nicolas.bernet@supagro.inra.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bernet
mesh_terms: D000085:Acetates / Q000378:metabolism; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D018441:Biofilms / Q000254:growth & development; D020148:Butyric Acid / Q000378:metabolism; D045287:Desulfuromonas / Q000378:metabolism* / Q000502:physiology; D004553:Electric Conductivity; D004563:Electrochemistry; D004579:Electron Transport; D006863:Hydrogen-Ion Concentration
chemical_list: D000085:Acetates; D020148:Butyric Acid
keywords: 454 pyrosequencing; Desulfuromonas acetoxidans; Geoalkalibacter subterraneus; Microbial bioelectrochemical systems; Saline wastewater