title: Activity and distribution of thermophilic prokaryotes in hydrothermal fluid, sulfidic structures, and sheaths of alvinellids (East Pacific Rise, 13°N).
abstract: Processes of inorganic carbon assimilation, methanogenesis, sulfate reduction, and acetate oxidation to CO(2) occurring in samples from the East Pacific Rise at 13°N were traced, using radioisotopically labeled substrates, at temperatures ranging from 65 to 100°C. Molecular hydrogen stimulated lithotrophic methanogenesis and sulfate reduction but inhibited inorganic carbon assimilation. Active mineralization of acetate was observed in an organic-rich Alvinella-associated system at 80°C. Members of the Thermococcales were the most numerous hyperthermophilic archaea in these samples, their density achieving 10(8) cells per cm(3), while the numbers of cultured hydrogen-utilizing thermophilic lithotrophs were several orders of magnitude lower.
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospekt 60-letiya Oktyabrya 7/2, 117312 Moscow, Russia.
authors.forename: Elizaveta A
authors.initials: EA
authors.lastname: Bonch-Osmolovskaya
authors.forename: Anna A
authors.initials: AA
authors.lastname: Perevalova
authors.forename: Tatiana V
authors.initials: TV
authors.lastname: Kolganova
authors.forename: Igor I
authors.initials: II
authors.lastname: Rusanov
authors.forename: Christian
authors.initials: C
authors.lastname: Jeanthon
authors.forename: Nikolay V
authors.initials: NV
authors.lastname: Pimenov
mesh_terms: D000085:Acetates / Q000378:metabolism; D017554:Carbon Compounds, Inorganic / Q000378:metabolism; D006358:Hot Temperature; D006859:Hydrogen / Q000737:chemistry / Q000378:metabolism; D008697:Methane / Q000096:biosynthesis; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010140:Pacific Ocean; D010802:Phylogeny; D011387:Prokaryotic Cells / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater; D013440:Sulfides / Q000378:metabolism*; D019709:Thermococcales / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000085:Acetates; D017554:Carbon Compounds, Inorganic; D012336:RNA, Ribosomal, 16S; D013440:Sulfides; D006859:Hydrogen; D008697:Methane