Blastococcus jejuensis sp. nov., an actinomycete from beach sediment, and emended description of the genus Blastococcus Ahrens and Moll 1970

Abstract

A novel actinomycete, strain KST3-10(T), was isolated from sand sediment of a beach in Jeju, Korea, and was subjected to polyphasic taxonomic characterization. The organism produced circular, smooth, translucent, apricot-coloured colonies comprising coccoid- or rod-shaped cells. Phylogenetic analyses based on 16S rRNA gene sequences showed that the organism belonged to the family Geodermatophilaceae and consistently formed a distinct sub-branch outside the radiation of the genus Blastococcus. The organism showed 16S rRNA gene sequence similarity values of 98.2 % with respect to Blastococcus aggregatus DSM 4725(T) and 98.1 % with respect to Blastococcus saxobsidens BC444(T). The type strains of the two Blastococcus species shared 98.2 % sequence similarity with respect to each other, whereas the levels of sequence similarity between the novel organism and the type strains of the less closely related neighbours, Modestobacter multiseptatus and Geodermatophilus obscurus, were in the range 96.2-96.9 %. The physiological, biochemical and chemotaxonomic data revealed that the novel organism can be readily differentiated from members of the genus Blastococcus and that it merits separate species status. On the basis of the phenotypic and genotypic evidence, strain KST3-10(T) represents a novel species of the genus Blastococcus, for which the name Blastococcus jejuensis sp. nov. is proposed. The type strain is KST3-10(T) (=NRRL B-24440(T)=KCCM 42251(T)).