title: Methanolobus profundi sp. nov., a methylotrophic methanogen isolated from deep subsurface sediments in a natural gas field.
abstract: A mesophilic, methylotrophic methanogen, strain MobM(T), was isolated from a natural gas field in Japan. Strain MobM(T) grew on methanol and methylamines, but not on H(2)/CO(2), formate, acetate or dimethyl sulfide. The cells were motile, irregular cocci (diameter, 0.9-1.2 microm) and occurred singly, in pairs, as tetracocci or (occasionally) as aggregates. Strain MobM(T) grew at 9-37 degrees C (optimally at 30 degrees C) and at pH 6.1-7.8 (optimally at pH 6.5). Sodium and magnesium were required for growth, at 0.1-1.0 M Na(+) (optimally at 0.35 M) and 10-400 mM Mg(2+) (optimally at 15-25 mM). The G+C content of the genomic DNA was 42.4 mol%. 16S rRNA gene sequencing revealed that the isolate is a member of the genus Methanolobus, but distinct from its closest neighbours, Methanolobus tindarius DSM 2278(T) (sequence similarity, 98.0 %) and Methanolobus vulcani DSM 3029(T) (98.1 %). On the basis of phenotypic and phylogenetic features of MobM(T), it is clear that this strain represents a novel species of the genus Methanolobus, for which the name Methanolobus profundi sp. nov. is proposed. The type strain is MobM(T) (=DSM 21213(T)=NBRC 104158(T)).
authors.affiliation: Institute for Geo-Resources and Environment, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8567, Japan.
authors.forename: Hanako
authors.initials: H
authors.lastname: Mochimaru
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tamaki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hanada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Imachi
authors.forename: Kohei
authors.initials: K
authors.lastname: Nakamura
authors.forename: Susumu
authors.initials: S
authors.lastname: Sakata
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Kamagata