title: Comparison of metabolomic profiles of microbial communities between stable and deteriorated methanogenic processes.
abstract: Central metabolite profiles from glucose in microbial communities during methanogenic process were compared between a stable methanogenic reactor (MR) and a deteriorated reactor (DR). The concentrations of intracellular metabolites related to the Embden-Meyerhof and pentose phosphate pathways, with the exception of pyruvate, remained high in the MR, showing increased carbon flux in the glycolysis pathway during stable methanogenesis. Extracellular acetate temporarily accumulated in the MR, consistent with higher ATP level in the MR. Intracellular concentrations of the intermediates in the reductive branch of tricarboxylic acid cycle, malate, fumarate, and succinate were higher in the DR. Low NADH/NAD(+) ratio both in the MR and DR would suggest NADH consumption during acetate and lactate/succinate production in the MR and DR, respectively. Intracellular glutamate levels were higher in the MR, correlating with lower NADPH/NADP(+) ratio concentrations in the MR. These findings contribute to a better understanding of the metabolic state during stable methanogenesis.
authors.affiliation: Graduate School of Engineering, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sasaki
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
authors.forename: Yota
authors.initials: Y
authors.lastname: Tsuge
authors.affiliation: Bioengineering Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko-shi, Chiba 270-1194, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Morita
authors.affiliation: Graduate School of Engineering, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan; Biomass Engineering Program, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. Electronic address: akondo@kobe-u.ac.jp.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D002264:Carboxylic Acids / Q000032:analysis; D002952:Citric Acid Cycle; D003067:Coenzymes / Q000378:metabolism; D005110:Extracellular Space / Q000737:chemistry; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis; D006863:Hydrogen-Ion Concentration; D055442:Metabolome; D055432:Metabolomics; D008697:Methane / Q000378:metabolism*; D013997:Time Factors
chemical_list: D002264:Carboxylic Acids; D003067:Coenzymes; D005947:Glucose; D008697:Methane
keywords: Central metabolism; Intracellular metabolites; Metabolomic analysis; Methanogenic process; Microbial community