title: Performance of microbial electrolysis cells with bioanodes grown at different external resistances.
abstract: Bioelectrochemical systems need an anode with a high abundance of exoelectrogenic bacteria for an optimal performance. Among all possible operational parameters for an efficient enrichment, the role of external resistance in microbial fuel cell (MFC) has gained a lot of interest since it indirectly poises an anode potential, a key parameter for biofilm distribution and morphology. Thus, this work aims at investigating and discussing whether bioanodes selected at different external resistances under MFC operation present different responses under both MFC and microbial electrolysis cell (MEC) operation. A better MEC performance (i.e. shorter start-up time, higher current intensity and higher H2 production rate) was obtained with an anode from an MFC developed under low external resistance. Quantitative real-time polymerase chain reaction (qPCR) confirmed that a low external resistance provides an MFC anodic biofilm with the highest content of Geobacter because it allows higher current intensity, which is correlated to exoelectrogenic activity. High external resistances such as 1,000 Ω led to a slower start-up time under MEC operation.
authors.affiliation: GENOCOV, Departament d'Enginyeria Química, Biològica i Ambiental, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain E-mail: juanantonio.baeza@uab.cat.
authors.forename: Laura
authors.initials: L
authors.lastname: Rago
authors.affiliation: GENOCOV, Departament d'Enginyeria Química, Biològica i Ambiental, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain E-mail: juanantonio.baeza@uab.cat.
authors.forename: Nuria
authors.initials: N
authors.lastname: Monpart
authors.affiliation: Departament de Genètica i de Microbiologia, Facultat de BioCiències, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Cortés
authors.affiliation: GENOCOV, Departament d'Enginyeria Química, Biològica i Ambiental, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain E-mail: juanantonio.baeza@uab.cat.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Baeza
authors.affiliation: GENOCOV, Departament d'Enginyeria Química, Biològica i Ambiental, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain E-mail: juanantonio.baeza@uab.cat.
authors.forename: Albert
authors.initials: A
authors.lastname: Guisasola
mesh_terms: D001419:Bacteria / Q000254:growth & development*; D018407:Bacterial Physiological Phenomena; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D018441:Biofilms / Q000254:growth & development; D004566:Electrodes; D004572:Electrolysis; D045302:Geobacter / Q000502:physiology*; D060888:Real-Time Polymerase Chain Reaction