Nocardioides flavescens sp. nov., isolated from soil of Gaoligong Mountain, PR China.

ABSTRACT

A Gram-stain-positive, non-motile, aerobic, rod-shaped, golden yellow-pigmented actinobacterium, designated strain YIM 123512T, was isolated from soil sampled at Gaoligong Mountain, Yunnan Province, PR China. The strain grew at 10-40 °C (optimum, 28 °C), with 0-3.0 % (w/v) NaCl (optimum, 0-1.0 %) and at pH 5.0-11.0 (optimum, pH 7.0). The major menaquinone was MK-8(H4) and the major cellular fatty acids (>10 %) were identified as iso-C16  0 and C17  1 ω8c. Strain YIM 123512T had ll-2, 6-diaminopimelic acid as the diagnostic cell-wall diamino acid. The major polar lipids were found to be diphosphatidylglycerol, phosphatidylglycerol, two unknown phospholipids and one unknown lipid. The genomic DNA G+C content of strain YIM 123512T was 72.7 mol% based on its draft genome sequence. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain YIM 123512T appeared to be most closely related to Nocardioides halotolerans KCTC 19274T (97.7 % sequence similarity) and to belong to the genus Nocardioides. The sequence similarity values of strain YIM 123512T to other currently described type strains of the genus Nocardioides were less than 97.0 %. Based on the draft genome sequence, the novel strain showed an average nucleotide identity value of 80.2 % and a digital DNA-DNA hybridization value of 23.1 % with the reference strain N. halotolerans KCTC 19274T. The results of the polyphasic taxonomic study including phenotypic, chemotaxonomic and phylogenetic analyses show that strain YIM 123512T represents a novel species of the genus Nocardioides, for which the name Nocardioides flavescens sp. nov. is proposed. The type strain is YIM 123512T (=KCTC 49303T=CGMCC 4.7628T).