Cryobacterium melibiosiphilum sp. nov., a psychrophilic bacterium isolated from glacier ice.

Abstract

A psychrophilic, Gram-stain-positive, rod-shaped bacterium, designated Hh39T, was isolated from Xinjiang No. 1 glacier in PR China. Strain Hh39T was catalase-positive, oxidase-negative and could grow at 0-18 °C, pH 6.0-11.0 and in the presence of 0-2.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Hh39T belonged to the genus Cryobacterium. The highest level of 16S rRNA gene sequence similarities were found to the type strains of Cryobacterium levicorallinum (99.01 %), Cryobacterium luteum (98.90 %), Cryobacterium aureum (98.90 %) and Cryobacterium roopkundense (98.75 %). However, the low average nucleotide identity (80.65-81.89 %) and digital DNA-DNA hybridization values (22.1-23.8 %) between strain Hh39T and its four closest relatives indicated that it represents a novel species of the genus Cryobacterium. The predominant fatty acids were anteiso-C15:0, anteiso-C15:1, iso-C16:0 and anteiso-C17:0. The major menaquinone was MK-10. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, one unidentified lipid and one unidentified glycolipid. On the basis of results of phenotypic, genotypic and phylogenetic analyses, a novel species, Cryobacterium melibiosiphilum sp. nov., is proposed, with Hh39T (=NBRC 107884T=CGMCC 1.11212T) as the type strain.