Nocardioides potassii sp. nov., isolated from weathered potash tailings soil

Abstract

A Gram-positive, aerobic actinomycete, designated strain KLBMP 9356T, was isolated from weathered potash tailings soil sampled in Xuzhou, Jiangsu Province, PR China. The colonies were cream-coloured, convex and rounded. The optimal growth conditions of strain KLBMP 9356T were 1 % (w/v) NaCl, 28 °C and pH 7. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain KLBMP 9356T showed the highest similarity to Nocardioides zhouii CGMCC 1.11084T (98.9 %) and Nocardioides glacieisoli CGMCC 1.11097T (98.7 %). Results from two tree-making algorithms supported the position that strain KLBMP 9356T forms a stable clade with N. zhouii CGMCC 1.11084T and N. glacieisoli CGMCC 1.11097T. Strain KLBMP 9356T exhibited low digital DNA-DNA hybridization values with N. zhouii CGMCC 1.11084T (27.6 %) and N. glacieisoli CGMCC 1.11097T (31.4 %). The average nucleotide identity values between strain KLBMP 9356T and N. zhouii CGMCC 1.11084T and N. glacieisoli CGMCC 1.11097T were 83.8% and 85.9%, respectively. The peptidoglycan in the cell wall of the novel strain was ll-2,6-diaminopimelic acid and the predominant menaquinone was MK-8(H4). The major fatty acids (>10 %) were C17:1ω8c and C18:1ω9c. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, lyso-phospatidylglycerol and phosphatidylinositol. The genomic DNA G+C content was 71.6 mol%. Based on its morphological, chemotaxonomic and phylogenetic characteristics, strain KLBMP 9356T represents a novel species of the genus Nocardioides , for which the name Nocardioides potassii sp. nov. is proposed. The type strain is KLBMP 9356T (=CGMCC 4.7738T=NBRC 115493T).