title: Microbial community analysis in a long-term membrane-less microbial electrolysis cell with hydrogen and methane production.
abstract: A single-chamber microbial electrolysis cell (MEC) aiming at hydrogen production with acetate as sole carbon source failed due to methanogenesis build-up despite the significant amount of 2-bromoethanesulfonate (BES) dosage, 50 mM. Specific batch experiments and a thorough microbial community analysis, pyrosequencing and qPCR, of cathode, anode and medium were performed to understand these observations. The experimental data rebuts different hypothesis and shows that methanogenesis at high BES concentration was likely due to the capacity of some Archaea (hydrogen-oxidizing genus Methanobrevibacter) to resist high BES concentration up to 200 mM. Methanobrevibacter, of the Methanobacteriales order, represented almost the 98% of the total Archaea in the cathode whereas Geobacter was highly abundant in the anode (72% of bacteria). Moreover, at higher BES concentration (up to 200 mM), methanogenesis activity decreased resulting in an increase of homoacetogenic activity, which challenged the performance of the MEC for H2 production.
authors.affiliation: GENOCOV, Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Rago
authors.affiliation: GENOCOV, Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Ruiz
authors.affiliation: GENOCOV, Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Baeza
authors.affiliation: GENOCOV, Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. Electronic address: albert.guisasola@uab.cat.
authors.forename: Albert
authors.initials: A
authors.lastname: Guisasola
authors.affiliation: Departament de Genètica i de Microbiologia, Facultat de BioCiències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Cortés
mesh_terms: D017738:Alkanesulfonic Acids / Q000378:metabolism / Q000494:pharmacology; D001105:Archaea / Q000235:genetics / Q000502:physiology; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D056804:Biofuels; D004275:DNA, Ribosomal; D004566:Electrodes; D004572:Electrolysis; D045302:Geobacter / Q000235:genetics / Q000502:physiology; D006859:Hydrogen / Q000378:metabolism*; D008697:Methane / Q000096:biosynthesis*; D059013:Microbial Consortia / Q000187:drug effects / Q000502:physiology*; D008855:Microscopy, Electron, Scanning; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D017738:Alkanesulfonic Acids; D056804:Biofuels; D004275:DNA, Ribosomal; C018853:2-bromoethanesulfonic acid; D006859:Hydrogen; D008697:Methane
keywords: 2-Bromoethanesulfonate (BES); Hydrogen; Methane; Microbial electrolysis cell (MEC); Pyrosequencing; qPCR