title: Analysis of alkane-dependent methanogenic community derived from production water of a high-temperature petroleum reservoir.
abstract: Microbial assemblage in an n-alkanes-dependent thermophilic methanogenic enrichment cultures derived from production waters of a high-temperature petroleum reservoir was investigated in this study. Substantially higher amounts of methane were generated from the enrichment cultures incubated at 55 °C for 528 days with a mixture of long-chain n-alkanes (C(15)-C(20)). Stoichiometric estimation showed that alkanes-dependent methanogenesis accounted for about 19.8% of the total amount of methane expected. Hydrogen was occasionally detected together with methane in the gas phase of the cultures. Chemical analysis of the liquid cultures resulted only in low concentrations of acetate and formate. Phylogenetic analysis of the enrichment revealed the presence of several bacterial taxa related to Firmicutes, Thermodesulfobiaceae, Thermotogaceae, Nitrospiraceae, Dictyoglomaceae, Candidate division OP8 and others without close cultured representatives, and Archaea predominantly related to uncultured members in the order Archaeoglobales and CO(2)-reducing methanogens. Screening of genomic DNA retrieved from the alkanes-amended enrichment cultures also suggested the presence of new alkylsuccinate synthase alpha-subunit (assA) homologues. These findings suggest the presence of poorly characterized (putative) anaerobic n-alkanes degraders in the thermophilic methanogenic enrichment cultures. Our results indicate that methanogenesis of alkanes under thermophilic condition is likely to proceed via syntrophic acetate and/or formate oxidation linked with hydrogenotrophic methanogenesis.
authors.affiliation: State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai, 200237, China.
authors.forename: Serge Maurice
authors.initials: SM
authors.lastname: Mbadinga
authors.forename: Kai-Ping
authors.initials: KP
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Zhou
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Wang
authors.forename: Shi-Zhong
authors.initials: SZ
authors.lastname: Yang
authors.forename: Jin-Feng
authors.initials: JF
authors.lastname: Liu
authors.forename: Ji-Dong
authors.initials: JD
authors.lastname: Gu
authors.forename: Bo-Zhong
authors.initials: BZ
authors.lastname: Mu
mesh_terms: D000473:Alkanes / Q000378:metabolism*; D001105:Archaea / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D044822:Biodiversity; D005618:Fresh Water / Q000737:chemistry / Q000382:microbiology*; D006358:Hot Temperature; D006859:Hydrogen / Q000378:metabolism; D008697:Methane / Q000378:metabolism*; D008969:Molecular Sequence Data; D010578:Petroleum / Q000032:analysis*; D010802:Phylogeny
chemical_list: D000473:Alkanes; D010578:Petroleum; D006859:Hydrogen; D008697:Methane