A novel aerobic actinomycete, designated as HA15955T, was isolated from a mangrove mud sample collected in Sanya, China. Scanning electron microscopy revealed that HA15955T produced straight to spiral spore chains with smooth cylindrical spores. 16S rRNA gene sequence similarity showed that strain HA15955T belonged to the genus Streptomyces, was most closely related to Streptomyces speibonae NRRL B-24240T (98.7 % similarity) and formed a distinct subclade. The low relatedness value of DNA-DNA hybridization showed that it formed a distinct genomic species. Based on phenotypic, genotypic and phylogenetic data, strain HA15955T should be classified as a novel species of the genus Streptomyces, for which the name Streptomycescaeni sp. nov. is proposed. The type strain is HA15955T (=CGMCC 4.7426T=DSM 105693T).
Keywords: 16S rRNA; Streptomyces caeni sp. nov.; mangrove; polyphasic taxonomy.