Nocardia bhagyanesis sp. nov., a novel actinomycete isolated from the rhizosphere of Callistemon citrinus (Curtis), India

A novel actinomycete strain, designated VRC07^T, was isolated from a Callistemon citrinus rhizosphere sample collected from Hyderabad, India. Its taxonomic status was determined by using polyphasic approach. It is a Gram-positive, aerobic, non-motile, weakly acid-fast strain. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain VRC07^T is a member of the genus Nocardia. The highest levels of 16S rRNA gene sequence similarity was found between the strains Nocardia niwae W9241^T (99.6 %), Nocardia amikacinitolerans W9988^T (99.3 %) and Nocardia arthritidis IFM 10035^T (98.9 %); similarity to other type strains of the genus Nocardia was below 98.7 %. The organism had chemical and morphological features consistent with its classification in the genus Nocardia such as meso-diaminopimelic acid as the diagnostic diamino acid in the cell wall peptidoglycan. Arabinose and galactose as the diagnostic sugars. Diagnostic polar lipids were phosphatidylinositol, diphosphatidylglycerol, and phosphatidylglycerol. The predominant menaquinone was MK-8(H_{4, ω-cycl}). The major fatty acids were C_16:0, C_18:0, C_{18:1 w9c}, C_{18:0 10-methyl TBSA} and sum in feature 3 (16:1 w7c/16:1 w6c). The G+C content of the genomic DNA was 68.5 mol%. The DNA–DNA relatedness data, together with phenotypic differences clearly distinguished the isolate from its closest relatives. On the basis of these phenotypic and genotypic data, the isolate represents a novel species, for which the name Nocardia bhagyanesis sp. nov., is proposed. The type strain is VRC07^T (=KCTC 29209^T = MTCC 11725^T = ATCC BAA-2548).