Streptomyces shinuiensis sp. nov., a Salternamides-Producing Bacterium Isolated from Saltern Sediment

Strain HK10^T, previously isolated from saltern sediment and identified as a salternamides-producing bacterium, was taxonomically characterized in the present study. The strain is a Gram-stain-positive, aerobic, and filamentous actinobacterium. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HK10^T belongs to the genus Streptomyces and is most closely related to Streptomyces radiopugnans R97^T (99.4% sequence similarity), followed by other Streptomyces species with sequence similarities of ≤98.9%. The draft genome sequence of strain HK10^T was 6.69 Mbp and a DNA G+C content of 72.7%. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain HK10^T and type strains of the genus Streptomyces were ≤92.7% and ≤53.0%, respectively, which are below the thresholds for species delineation, indicating that strain HK10^T represents a novel species. The major cellular fatty acids were iso-C_16:0, anteiso-C_15:0, anteiso-C_17:0, and iso-C_14:0. The predominant menaquinone was menaquinone-9 (MK-9). The polar lipid profile included phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylinositol dimannoside. Whole-cell hydrolysates of strain HK10^T contained _L,L-diaminopimelic acid and glycine. Based on phylogenetic, genomic, chemotaxonomic, and physiological evidence, strain HK10^T is considered to represent a novel species of the genus Streptomyces, for which the name Streptomyces shinuiensis sp. nov. is proposed. The type of strain is HK10^T (= NBRC 114904^T = KACC 22137^T).