Streptomyces boninensis sp. Nov., isolated from soil from a limestone cave in the Ogasawara islands

Actinomycete strain K11-0400^T was isolated from a soil sample collected in the Ogasawara Islands (also known as the Bonin Islands), Tokyo, Japan. Mature spore chains of strain K11-0400^T had more than 20 spores per chain. The strain contained LL-diaminopimelic acid as the diamino acid in whole-cell hydrolysates, and MK-9(H₆) and MK-9(H₄) were the predominant menaquinones. The polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylinositol, and no diagnostic whole-cell sugar was detected. The G+C content of the genomic DNA was 72 mol%. These morphological and chemical features of strain K11-0400^T indicated that it belonged to the genus Streptomyces. Strain K11-0400^T showed the highest 16S rRNA gene sequence similarity to Streptomyces naganishii NBRC 12892^T (97.58 %). However, the DNA–DNA relatedness value between strain K11-0400^T and the related strain was below 70 %. Based on morphological, cultural and physiological characteristics, and DNA–DNA relatedness data, strain K11-0400^T should be classified as a new species of the genus Streptomyces, for which the name Streptomyces boninensis sp. nov. is proposed. The type strain of S. boninensis is K11-0400^T (=NBRC 113073^T, TBRC 7755^T).