Cryobacterium aureum sp. nov., a psychrophilic bacterium isolated from glacier ice collected from the ice tongue surface

A psychrophilic, Gram-stain-positive, rod-shaped bacterium, designated strain Hh31T, was isolated from Xinjiang No. 1 Glacier in China. Strain Hh31T was catalase-positive, oxidase-negative and able to grow at between 0-18 °C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Hh31T belonged to the genus Cryobacterium and was most closely related to the type strains of Cryobacterium levicorallinum, Cryobacterium luteum and Cryobacterium flavum. DNA-DNA hybridization, calculation of average nucleotide identity and digital DNA-DNA hybridization revealed that strain Hh31T was distinct from its closest phylogenetic neighbours. The major cellular fatty acids of strain Hh31T were anteiso-C15 : 0, anteiso-C15 : 1, iso-C15:0, iso-C16 : 0 and anteiso-C17 : 0. The predominant menaquinones of strain Hh31T were MK-9 and MK-10. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid, one unidentified glycolipid and another unidentified lipid. Physiological tests such as carbon source utilization, showed phenotypic differentiation of strain Hh31T from the closest related phylogenetic neighbours. Based on a polyphasic approach, a novel species, Cryobacterium aureum sp. nov., is proposed, with Hh31T (=NBRC 107882T=CGMCC 1.11213T) as the type strain.