Nocardioides alpinus sp. nov., a psychrophilic actinomycete isolated from alpine glacier cryoconite

Abstract

A Gram-positive, non-motile, rod-shaped, psychrophilic actinomycete, designated strain Cr7-14T, was isolated from alpine glacier cryoconite. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Cr7-14T was related to members of the genus Nocardioides and shared highest 16S rRNA gene sequence similarities with the type strains of Nocardioides furvisabuli (98.6 %), Nocardioides ganghwensis (98.2 %), Nocardioides oleivorans (98.1 %) and Nocardioides exalbidus (97.6 %). The predominant cellular fatty acids of strain Cr7-14T were C17 : 1ω8c (39.5 %) and iso-C16 : 0 (32.4 %). The major menaquinone was MK-8(H4). The diagnostic diamino acid in the cell-wall peptidoglycan was ll-2,6-diaminopimelic acid. The predominant cell-wall sugars were galactose and rhamnose. The polar lipid pattern contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, four unknown glycolipids and two unknown polar lipids. The genomic DNA G+C content was 71.9 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA–DNA relatedness data, a novel species, Nocardioides alpinus sp. nov., is proposed, with Cr7-14T ( = DSM 23325T = LMG 26053T = CGMCC 1.10697T) as the type strain.