Actinomycetospora rishiriensis sp nov., isolated from a lichen

An actinomycete, strain RI109-Li102(T), was isolated from a lichen sample obtained from Rishiri Island in Japan. Cells of strain RI109-Li102(T) were Gram-positive, aerobic and non-motile and formed bud-like spore chains. The isolate grew with 0-3% (w/v) NaCl, at pH 5-9 and at 10-30 degrees C (optimum 30 degrees C). The whole-cell hydrolysate contained meso-diaminopimelic acid, arabinose and galactose. The predominant menaquinone was MK-8(H-4) and the diagnostic phospholipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol and diphosphatidylglycerol. The major cellular fatty acids were iso-C-16:0 and iso-C-16:1 H. Comparative 16S rRNA gene sequence analysis revealed that strain RI109-Li102(T) was most closely related to Actinomycetospora corticicola 014-5(T) (99.0% rRNA gene sequence similarity) and Actinomycetospora chiangmaiensis YIM 0006(T) (98.4%). However, DNA-DNA hybridization assays, as well as physiological and biochemical analyses, showed that strain RI109-Li102(T) could be differentiated from its closest phylogenetic relatives. It is proposed that strain RI109-Li102(T) (=NBRC 106356(T) =KCTC 19782(T)) be classified as the type strain of a novel species, with the name Actinomycetospora rishiriensis sp. nov.