title: The source of inoculum plays a defining role in the development of MEC microbial consortia fed with acetic and propionic acid mixtures.
abstract: Microbial electrolysis cells (MECs) can be used as a downstream process to dark fermentation to further capture electron in volatile fatty acids that remain after fermentation, improving this way the viability of the overall process. Acetic and propionic acid are common products of dark fermentation. The main objective of this work was to investigate the effect of different initial concentrations of a mixture of acetic and propionic acids on MECs microbial ecology and hydrogen production performance. To link microbial structure and function, we characterized the anode respiring biofilm communities using pyrosequencing and quantitative-PCR. The best hydrogen production rates (265mL/d/Lreactor) were obtained in the first block of experiments by MEC fed with 1500mg/L acetic acid and 250mg/L propionic acid. This reactor presents in the anode biofilm an even distribution of Proteobacteria, Firmicutes and Bacteroidetes and Arcobacter was the dominant genera. The above fact also correlated to the highest electron load among all the reactors. It was evidenced that although defined acetic and propionic acid concentrations fed affected the structure of the microbial consortia that developed at the anode, the initial inoculum played a major role in the development of MEC microbial consortia.
authors.affiliation: Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, 76230 Queretaro, Mexico.
authors.forename: Vianey
authors.initials: V
authors.lastname: Ruiz
authors.affiliation: Swette Center for Environmental Biotechnology at Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA.
authors.forename: Zehra Esra
authors.initials: ZE
authors.lastname: Ilhan
authors.affiliation: Swette Center for Environmental Biotechnology at Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA.
authors.forename: Dae-Wook
authors.initials: DW
authors.lastname: Kang
authors.affiliation: Swette Center for Environmental Biotechnology at Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA; School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5701, USA.
authors.forename: Rosa
authors.initials: R
authors.lastname: Krajmalnik-Brown
authors.affiliation: Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, 76230 Queretaro, Mexico. Electronic address: Gbuitronm@ii.unam.mx.
authors.forename: Germán
authors.initials: G
authors.lastname: Buitrón
mesh_terms: D019342:Acetic Acid / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D004566:Electrodes; D004572:Electrolysis; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation; D006859:Hydrogen / Q000378:metabolism; D059013:Microbial Consortia / Q000502:physiology*; D011422:Propionates / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D005232:Fatty Acids, Volatile; D011422:Propionates; D006859:Hydrogen; C029658:propionic acid; D019342:Acetic Acid
keywords: Hydrogen production; Microbial ecology; Microbial electrolysis cells; Pyrosequencing; Volatile fatty acids