Saccharopolyspora indica sp. nov., an actinomycete isolated from the rhizosphere of Callistemon citrinus (Curtis)

Abstract

A novel actinomycete strain, designated VRC122T, was isolated from a Callistemon citrinus rhizosphere sample collected from New Delhi, India, and its taxonomic status was determined by using a polyphasic approach. Strain VRC122T was a Gram-stain-positive, aerobic, non-motile, non-acid-alcohol-fast strain. Phylogenetic analysis based on 16S rRNA gene sequences showed the strain was placed in a well-separated sub-branch within the genus Saccharopolyspora. The highest levels of 16S rRNA gene sequence similarity were found with Saccharopolyspora hirsuta subsp. kobensis JCM 9109T (98.71%), Saccharopolyspora antimicrobica I05-00074T (98.69%) and Saccharopolyspora jiangxiensis W12T (98.66%); 16S rRNA gene sequence similarities with type strains of all other species of the genus Saccharopolyspora were below 98%. Chemosystematic studies revealed that it contained meso-diaminopimelic acid. Arabinose and galactose were the predominant whole-cell sugars. Diagnostic polar lipids were diphosphatidylglycerol, phosphatidylinositol and phosphatidylcholine. MK-9(H6) was the predominant menaquinone. C14:0, C16:0, iso-C15:0, iso-C16:0, iso-C17:0, anteiso-C15:0, anteiso-C17:0, C17:0 cyclo and summed feature 3 (C16:1ω7c and/or C16:1ω6c) were the major cellular fatty acids. The G+C content of the genomic DNA was 69.5 mol%. The results of DNA-DNA hybridization (30%, 22% and 25%, respectively) with type strains of the above-mentioned species, in combination with differences in physiological and biochemical data supported that strain VRC122T represents a novel species of the genus Saccharopolyspora, for which the name Saccharopolyspora indica sp. nov., is proposed. The type strain is VRC122T (=KCTC 29208T=MTCC 11564T=MCC 2206T=ATCC BAA-2551T).