Actinomadura rayongensis sp. nov., isolated from peat swamp forest soil

A novel actinomycete strain RY35-68(T), isolated from a peat swamp forest soil sample in Rayong Province, Thailand, was characterized using a polyphasic approach. The strain belonged to the genus Actinomadura based on morphological and chemotaxonomic characteristics. Cell-wall analysis revealed the presence of meso-diaminopimelic acid and N-acetylmuramic acid in the peptidoglycan layer. The diagnostic sugar in whole-cell hydrolysates was identified as madurose. The predominant menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). The major cellular fatty acids were C16 : 0 and iso-C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The genomic DNA G+C content was 73.7 mol%. On the basis of 16S rRNA gene sequence similarity analysis, strain RY35-68(T) was closely related to the species Actinomadura atramentaria JCM 6250(T) (97.5 %). The value of DNA-DNA relatedness between strain RY35-68(T) and A. atramentaria JCM 6250(T) was 37.6-42.6 %. On the basis of its phenotypic characteristics and these results mentioned, this strain could be distinguished from the closely related type strain and represents a novel species of the genus Actinomadura, for which the name Actinomadura rayongensis sp. nov. (type strain RY35-68(T) = JCM 19830(T) = TISTR 2211(T) = PCU 332(T)) is proposed.