Nocardioides gilvus sp. nov., isolated from Namtso Lake.

Abstract

A Gram-stain positive, facultatively anaerobic, non-motile and rod to coccoid-shaped bacterium, designated XZ17(T), was isolated from Namtso Lake of Tibet, China. Strain XZ17(T) grew optimally at pH 8.0-9.0, at 30-33°C and in the presence of 0-1.0% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain XZ17(T) belongs to the genus Nocardioides in the family Nocardioidaceae. Strain XZ17(T) shared pairwise 16S rRNA gene sequence similarities of 97.2, 96.8, 96.5, 96.4 and <96.0% to Nocardioides solisilvae KCTC 39528(T), Nocardioides daejeonensis JCM 16922(T), Nocardioides jensenii NCIB 9770(T), Nocardioides dubius KCTC 9992(T) and other Nocardioides species, respectively. It contained MK-8 (H4) as the predominant menaquinone and C17:1 ω8c, C15:0, C17:0 and C18:1 ω9c as the major fatty acid. The strain had cell wall peptidoglycan based on LL-2,6-diaminopimelic acid. The polar lipids of strain XZ17(T) comprised diphosphatidylglycerol, phosphatidylglycerol, three unidentified phospholipids, three unidentified glycolipids and two unidentified lipids. The DNA G+C content of strain XZ17(T) was 68.9mol%. Based on distinctive phenotypic characteristics, phylogenetic analysis and chemotaxonomic data, it can be concluded that strain XZ17(T) represents a novel species within the genus Nocardioides, for which the name Nocardioides gilvus sp. nov. is proposed. The type strain is strain XZ17(T) (=KCTC 39561(T)=MCCC 1H00114(T)).