title: Microbial communities from 20 different hydrogen-producing reactors studied by 454 pyrosequencing.
abstract: To provide new insight into the dark fermentation process, a multi-lateral study was performed to study the microbiology of 20 different lab-scale bioreactors operated in four different countries (Brazil, Chile, Mexico, and Uruguay). Samples (29) were collected from bioreactors with different configurations, operation conditions, and performances. The microbial communities were analyzed using 16S rRNA genes 454 pyrosequencing. The results showed notably uneven communities with a high predominance of a particular genus. The phylum Firmicutes predominated in most of the samples, but the phyla Thermotogae or Proteobacteria dominated in a few samples. Genera from three physiological groups were detected: high-yield hydrogen producers (Clostridium, Kosmotoga, Enterobacter), fermenters with low-hydrogen yield (mostly from Veillonelaceae), and competitors (Lactobacillus). Inocula, reactor configurations, and substrates influence the microbial communities. This is the first joint effort that evaluates hydrogen-producing reactors and operational conditions from different countries and contributes to understand the dark fermentation process.
authors.affiliation: Microbial Ecology Laboratory, BioGem Department, Biological Research Institute Clemente Estable, Ministery of Education, Av. Italia, 3318, Montevideo, Uruguay. cetchebehere@iibce.edu.uy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Etchebehere
authors.affiliation: BioProA Laboratory, Chemical Engineering Institute, Engineering Faculty, University of the Republic, Herrera y Reissing, 565, Montevideo, Uruguay.
authors.forename: Elena
authors.initials: E
authors.lastname: Castelló
authors.affiliation: Microbial Ecology Laboratory, BioGem Department, Biological Research Institute Clemente Estable, Ministery of Education, Av. Italia, 3318, Montevideo, Uruguay.
authors.forename: Jorge
authors.initials: J
authors.lastname: Wenzel
authors.affiliation: Biological Processes Laboratory, Center for Research, Development and Innovation in Environmental Engineering, São Carlos School of Engineering (EESC), University of São Paulo (USP), Engenharia Ambiental-Bloco 4-F, Av. João Dagnone, 1100-Santa Angelina 13.563-120, São Carlos, SP, Brazil.
authors.forename: Mélida
authors.initials: M
authors.lastname: del Pilar Anzola-Rojas
authors.affiliation: BioProA Laboratory, Chemical Engineering Institute, Engineering Faculty, University of the Republic, Herrera y Reissing, 565, Montevideo, Uruguay.
authors.forename: Liliana
authors.initials: L
authors.lastname: Borzacconi
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, 76320, Querétaro, Mexico.
authors.forename: Germán
authors.initials: G
authors.lastname: Buitrón
authors.affiliation: Environmental Biotechnology Laboratory, Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Chile, Avenida Brasil, 2085, Valparaíso, Chile.
authors.forename: Lea
authors.initials: L
authors.lastname: Cabrol
authors.affiliation: Biological Processes Laboratory, Center for Research, Development and Innovation in Environmental Engineering, São Carlos School of Engineering (EESC), University of São Paulo (USP), Engenharia Ambiental-Bloco 4-F, Av. João Dagnone, 1100-Santa Angelina 13.563-120, São Carlos, SP, Brazil.
authors.forename: Vivian María
authors.initials: VM
authors.lastname: Carminato
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, 76320, Querétaro, Mexico.|División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica A.C. (IPICYT), Camino a la Presa San José 2055, Lomas 4ª. Sección, 78216, San Luis Potosí, SLP, Mexico.
authors.forename: Julian
authors.initials: J
authors.lastname: Carrillo-Reyes
authors.affiliation: División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica A.C. (IPICYT), Camino a la Presa San José 2055, Lomas 4ª. Sección, 78216, San Luis Potosí, SLP, Mexico.
authors.forename: Crhistian
authors.initials: C
authors.lastname: Cisneros-Pérez
authors.affiliation: Microbial Ecology Laboratory, BioGem Department, Biological Research Institute Clemente Estable, Ministery of Education, Av. Italia, 3318, Montevideo, Uruguay.
authors.forename: Laura
authors.initials: L
authors.lastname: Fuentes
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, 76320, Querétaro, Mexico.
authors.forename: Iván
authors.initials: I
authors.lastname: Moreno-Andrade
authors.affiliation: División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica A.C. (IPICYT), Camino a la Presa San José 2055, Lomas 4ª. Sección, 78216, San Luis Potosí, SLP, Mexico.
authors.forename: Elías
authors.initials: E
authors.lastname: Razo-Flores
authors.affiliation: Environmental Biotechnology Laboratory, Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Chile, Avenida Brasil, 2085, Valparaíso, Chile.
authors.forename: Gonzalo Ruiz
authors.initials: GR
authors.lastname: Filippi
authors.affiliation: Environmental Biotechnology Laboratory, Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Chile, Avenida Brasil, 2085, Valparaíso, Chile.
authors.forename: Estela
authors.initials: E
authors.lastname: Tapia-Venegas
authors.affiliation: Environmental Biotechnology Laboratory, Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Chile, Avenida Brasil, 2085, Valparaíso, Chile.
authors.forename: Javiera
authors.initials: J
authors.lastname: Toledo-Alarcón
authors.affiliation: Biological Processes Laboratory, Center for Research, Development and Innovation in Environmental Engineering, São Carlos School of Engineering (EESC), University of São Paulo (USP), Engenharia Ambiental-Bloco 4-F, Av. João Dagnone, 1100-Santa Angelina 13.563-120, São Carlos, SP, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Zaiat
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors / Q000592:standards*; D003013:Clostridium / Q000145:classification / Q000235:genetics / Q000378:metabolism; D004754:Enterobacter / Q000145:classification / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D000068536:Bacillota / Q000145:classification / Q000235:genetics / Q000378:metabolism; D059014:High-Throughput Nucleotide Sequencing; D006859:Hydrogen / Q000378:metabolism*; D007778:Lactobacillus / Q000145:classification / Q000235:genetics / Q000378:metabolism; D007843:Latin America; D059013:Microbial Consortia / Q000235:genetics*; D020560:Proteobacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D020124:Thermotoga maritima / Q000145:classification / Q000235:genetics / Q000378:metabolism; D045854:Veillonellaceae / Q000145:classification / Q000235:genetics / Q000378:metabolism
chemical_list: D012336:RNA, Ribosomal, 16S; D006859:Hydrogen
keywords: 454 pyrosequencing; Biohydrogen; Dark fermentation; Microbial community; Reactor