title: Biogas production using anaerobic groundwater containing a subterranean microbial community associated with the accretionary prism.
abstract: In a deep aquifer associated with an accretionary prism, significant methane (CH₄) is produced by a subterranean microbial community. Here, we developed bioreactors for producing CH₄ and hydrogen (H₂) using anaerobic groundwater collected from the deep aquifer. To generate CH₄, the anaerobic groundwater amended with organic substrates was incubated in the bioreactor. At first, H₂ was detected and accumulated in the gas phase of the bioreactor. After the H₂ decreased, rapid CH₄ production was observed. Phylogenetic analysis targeting 16S rRNA genes revealed that the H₂ -producing fermentative bacterium and hydrogenotrophic methanogen were predominant in the reactor. The results suggested that syntrophic biodegradation of organic substrates by the H₂ -producing fermentative bacterium and the hydrogenotrophic methanogen contributed to the CH₄ production. For H₂ production, the anaerobic groundwater, amended with organic substrates and an inhibitor of methanogens (2-bromoethanesulfonate), was incubated in a bioreactor. After incubation for 24 h, H₂ was detected from the gas phase of the bioreactor and accumulated. Bacterial 16S rRNA gene analysis suggested the dominance of the H₂ -producing fermentative bacterium in the reactor. Our study demonstrated a simple and rapid CH4 and H2 production utilizing anaerobic groundwater containing an active subterranean microbial community.
authors.affiliation: Department of Geosciences, Graduate School of Science, Shizuoka University, Shizuoka, Japan.
authors.forename: Kyohei
authors.initials: K
authors.lastname: Baito
authors.affiliation: Department of Geosciences, Graduate School of Science, Shizuoka University, Shizuoka, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Imai
authors.affiliation: Department of Geosciences, Graduate School of Science, Shizuoka University, Shizuoka, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Matsushita
authors.affiliation: Department of Geosciences, Graduate School of Science, Shizuoka University, Shizuoka, Japan.
authors.forename: Miku
authors.initials: M
authors.lastname: Otani
authors.affiliation: Department of Geosciences, Graduate School of Science, Shizuoka University, Shizuoka, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Geosciences, Graduate School of Science, Shizuoka University, Shizuoka, Japan.|Center for Integrated Research and Education of Natural Hazards, Shizuoka University, Shizuoka, Japan.|PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kimura
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D056804:Biofuels; D019149:Bioreactors / Q000382:microbiology*; D016000:Cluster Analysis; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D060587:Groundwater / Q000382:microbiology*; D006859:Hydrogen / Q000378:metabolism; D008697:Methane / Q000378:metabolism; D059013:Microbial Consortia; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D009930:Organic Chemicals / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D056804:Biofuels; D004275:DNA, Ribosomal; D009930:Organic Chemicals; D012336:RNA, Ribosomal, 16S; D006859:Hydrogen; D008697:Methane