title: Diversity of Archaea in marine sediments from Skan Bay, Alaska, including cultivated methanogens, and description of Methanogenium boonei sp. nov.
abstract: Methanogenesis in cold marine sediments is a globally important process leading to methane hydrate deposits, cold seeps, physical instability of sediment, and atmospheric methane emissions. We employed a multidisciplinary approach that combined culture-dependent and -independent analyses with geochemical measurements in the sediments of Skan Bay, Alaska (53 degrees N, 167 degrees W), to investigate methanogenesis there. Cultivation-independent analyses of the archaeal community revealed that uncultivated microbes of the kingdoms Euryarchaeota and Crenarchaeota are present at Skan Bay and that methanogens constituted a small proportion of the archaeal community. Methanogens were cultivated from depths of 0 to 60 cm in the sediments, and several strains related to the orders Methanomicrobiales and Methanosarcinales were isolated. Isolates were psychrotolerant marine-adapted strains and included an aceticlastic methanogen, strain AK-6, as well as three strains of CO(2)-reducing methanogens: AK-3, AK7, and AK-8. The phylogenetic positions and physiological characteristics of these strains are described. We propose a new species, Methanogenium boonei, with strain AK-7 as the type strain.
authors.affiliation: Biology Department, Portland State University, PO Box 751, Portland, Oregon 97207-0751, USA. melissa.kendall@utsouthwestern.edu
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Kendall
authors.forename: George D
authors.initials: GD
authors.lastname: Wardlaw
authors.forename: Chin F
authors.initials: CF
authors.lastname: Tang
authors.forename: Adam S
authors.initials: AS
authors.lastname: Bonin
authors.forename: Yitai
authors.initials: Y
authors.lastname: Liu
authors.forename: David L
authors.initials: DL
authors.lastname: Valentine
mesh_terms: D000085:Acetates / Q000378:metabolism; D000413:Alaska; D002245:Carbon Dioxide / Q000378:metabolism; D019615:Crenarchaeota / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D003470:Culture Media; D019641:DNA, Archaeal / Q000032:analysis; D019605:Euryarchaeota / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D019015:Geologic Sediments / Q000382:microbiology*; D008697:Methane / Q000378:metabolism*; D019638:Methanomicrobiaceae / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D019640:Methanosarcinales / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D000085:Acetates; D003470:Culture Media; D019641:DNA, Archaeal; D012336:RNA, Ribosomal, 16S; D002245:Carbon Dioxide; D008697:Methane