A novel Gram-stain-positive, non-motile, rod-shaped, non-spore-forming bacterium, designated HLT2-9T, was isolated from the ice tongue surface of Hailuogou Glacier in Sichuan Province, PR China. Colonies of cells were cream yellow, convex and round. Growth occurred at 0-27 °C (optimum, 20 °C), pH 7.0-10.0 (pH 7.0) and in the presence of 0-2.0 % (w/v) NaCl (0 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain HLT2-9T belonged to the genus Nocardioides. The highest level of sequence similarities were found to Nocardioides glacieisoli CGMCC1.11097T (99.24 %), Nocardioides oleivorans CGMCC 4.6882T (98.54 %) and Nocardioides ganghwensis CGMCC 4.6875T (98.54 %). However, the low average nucleotide identity (85.6-87.9 %) and digital DNA-DNA hybridization values (26.4-30.2 %) of strain HLT2-9T to its three closest relatives demonstrated that it represents a novel species of the genus Nocardioides. The major cellular fatty acids of strain HLT2-9T were C17 : 1ω8c and iso-C16 : 0. Strain HLT2-9T contained ll-2,6-diaminopimelic acid as the diamino acid in the cell-wall peptidoglycan. The predominant menaquinone is MK-8(H4). The G+C content of the genomic DNA was 70.65 mol%. Based on evidence collected from the phenotypic, genotypic and phylogenetic analyses, a novel species Nocardioideszhouii sp. nov. is proposed, with HLT2-9T (=CGMCC 1.11084T=NBRC 109783T) as the type strain.
Keywords: Nocardioides; Nocardioides zhouii; cold-adapted; glacier.