Actinomycetospora rishiriensis sp. nov., isolated from a lichen

Abstract

An actinomycete, strain RI109-Li102T, was isolated from a lichen sample obtained from Rishiri Island in Japan. Cells of strain RI109-Li102T 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 °C (optimum 30 °C). The whole-cell hydrolysate contained meso-diaminopimelic acid, arabinose and galactose. The predominant menaquinone was MK-8(H4) and the diagnostic phospholipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol and diphosphatidylglycerol. The major cellular fatty acids were iso-C16 : 0 and iso-C16 : 1 H. Comparative 16S rRNA gene sequence analysis revealed that strain RI109-Li102T was most closely related to Actinomycetospora corticicola 014-5T (99.0 % rRNA gene sequence similarity) and Actinomycetospora chiangmaiensis YIM 0006T (98.4 %). However, DNA–DNA hybridization assays, as well as physiological and biochemical analyses, showed that strain RI109-Li102T could be differentiated from its closest phylogenetic relatives. It is proposed that strain RI109-Li102T ( = NBRC 106356T  = KCTC 19782T) be classified as the type strain of a novel species, with the name Actinomycetospora rishiriensis sp. nov.