Polyphasic characterization and genomic insights into Nocardioides turkmenicus sp. nov. isolated from a desert soil.

Strain KC13, a novel desert-adapted, non-motile, Gram-stain-positive, rod-shaped, aerobic bacterium, was isolated from a soil sample collected from the Karakum Desert, Turkmenistan and characterised by a polyphasic approach. Phylogenetic analysis based on 16S rRNA sequences revealed that strain KC13 was a member of the genus Nocardioides, and formed a distinct cluster with Nocardioides luteus DSM 43366 (99.3% sequence identity), Nocardioides albus DSM 43109 (98.9%), Nocardioides panzhihuensis DSM 26487 (98.3%) and Nocardioides albertanoniae DSM 25218 (97.9%). The orthologous average nucleotide identity and digital DNA-DNA hybridization values were in the range of 85.8-91.0% and 30.2-35.9%, respectively, with the type strains of closely related species. The genome size of strain KC13 was 5.3 Mb with a DNA G + C content of 69.7%. Comprehensive genome analyses showed that strain KC13, unlike its close relatives, had many genes associated with environmental adaptation. Strain KC13 was found to have chemotaxonomic and phenotypic characteristics of members of the genus Nocardioides and some differences from phylogenetic neighbours. Based on the chemotaxonomic, genomic, phenotypic and phylogenetic data, strain KC13 represents a novel species of the genus Nocardioides, for which the name Nocardioides turkmenicus sp. nov. is proposed, and the type strain is KC13 (= JCM 33525 = CGMCC 4.7619).