Identification and taxonomy of strain RA-WS2: a novel setomimycin producing actinobacterium.

Unlabelled: The taxonomic position of novel bianthraquinone antibiotic producer  strain RA-WS2, a soil isolate from Shivalik region of NW Himalayas, India, has been described. The isolate produces Setomimycin as a major secondary metabolite under defined submerged fermentation conditions. 16S rRNA partial gene sequencing of the isolate indicated its closest similarity (99.4%) with , followed by  However the morphological characteristics i.e. colony colour, mycelium and spore chain arrangement were found to be close to Therefore, a polyphasic approach was used for taxonomic positioning of the isolate. The Whole genome based similarity with 88.4% dDDH value, 98.65% ANI and 96.99% AAI value indicated its closest identity with . The taxonomic characteristics such as white colony with smooth surface, cylindrical spores arranged in straight chain, diffusible melanin production, high salt tolerance, 16S rRNA gene sequencing and phylogenomic studies, led to the identification of the strain as  RA-WS2. The predicted biosynthetic gene clusters further confirmed the presence of the BGC for setomimycin biosynthesis in strain RA-WS2.

Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03459-5.