Streptomyces fenghuangensis sp. nov., isolated from seawater.

An actinomycete, designated strain GIMN4.003(T), was isolated from seawater collected in Sanya, China. It produced white aerial mycelium and yellow substrate mycelium on Gause's synthetic agar medium no. 1. The substrate mycelium colour was not sensitive to pH. Scanning electron microscopy observations revealed that GIMN4.003(T) produced straight to flexuous spore chains of rough to warty spores. ll-Diaminopimelic acid was present in the cell-wall hydrolysate. Based on chemotaxonomy and morphological features, strain GIMN4.003(T) was identified as a member of the genus Streptomyces. Melanin was not produced. No antimicrobial activity was detected against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Penicillium citrinum or Candida albicans. Analysis of the 16S rRNA gene sequence revealed that the highest sequence similarity was to Streptomyces radiopugnans R97(T) (99.0%). However, DNA relatedness between GIMN4.003(T) and S. radiopugnans DSM 41901(T) was low (41.24±1.47%). Furthermore, the morphological, physiological and biochemical characteristics of strain GIMN4.003(T) were different from those of S. radiopugnans DSM 41901(T) and the type strains of other closely related Streptomyces species. On the basis of its physiological and molecular properties, it is evident that strain GIMN4.003(T) (=CCTCCM 208215(T) =NRRL B-24801(T)) represents the type strain of a novel species within the genus Streptomyces, for which the name Streptomyces fenghuangensis sp. nov. is proposed.