Streptomyces hundungensis sp. nov., a novel actinomycete with antifungal activity and plant growth promoting traits

A novel actinobacterium MBRL 251T, isolated from a sample collected from a limestone quarry at Hundung, Manipur, India, was characterized using a polyphasic approach. The 16S ribosomal RNA gene sequence of strain MBRL 251T showed closest similarities with Streptomyces xanthochromogenes NRRL B-5410T (99.6%) and Streptomyces michiganensis NBRC 12797T (99.6%). The DNA relatedness between MBRL 251T and S. xanthochromogenes NBRC 12828T, and S. michiganensis NBRC 12797T was 46.6% and 40.7%, respectively. Strain MBRL 251T contained LL-diaminopimelic acid as the diagnostic diamino acid, with glucose and xylose as the main cell wall sugars, whereas small amounts of galactose, mannose, rhamnose and ribose were also detected in the whole-cell wall hydrolysates. The major fatty acids identified were anteiso-C15:0 (35.1%), iso-C16:0 (21.1%) and anteiso-C17:1 (13.2%). The predominant menaquinones detected were MK-9(H6) and MK-9(H8), whereas the polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositolmannosides. The G+C content of the genomic DNA was 72.3%. The phenotypic and genotypic data showed that strain MBRL 251T merits the recognition as a representative of a novel species of the genus Streptomyces. It is proposed that the isolate should be classified in the genus Streptomyces as a novel species, Streptomyces hundungensis sp. nov. The type strain is MBRL 251T (=JCM 17577T=KCTC 29124T).