Actinomadura hankyongense sp. nov. Isolated From Soil of Ginseng Cultivating Field.

A Gram-positive, rod-shaped, non-spore-forming, and aerobic bacterium (Gsoil 556) was isolated from soil of a ginseng field and subjected to its taxonomic position. Based on 16S rRNA gene sequence similarity, strain Gsoil 556 was shown to belong to the genus Actinomadura of the family Thermomonosporaceae and was closely related to A. montaniterrae CYP1-1B (99.3%), A. nitritigenes DSM 44137 (98.7%), and A. rudentiformis HMC1 (98.5%), while it showed less than 98.4% sequence similarity to the other species of this genus. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that it is most closely related to A. rudentiformis HMC1 and A. nitritigenes DSM 44137. The DNA G+C content was 73.1 mol%. The peptidoglycan was meso-diaminopimelic acid and the whole-cell sugar contained fucose, galactose, glucose, mannose, and ribose. The predominant menaquinone (KK) was MK-9(H) [55%] and MK-9(H) [45%]. The major cellular fatty acids were C, C, C ω9c and summed feature 3 (C ω6c/C ω7c). All these data supported the affiliation of strain Gsoil 556 to the genus Actinomadura. The DNA-DNA hybridization between strain Gsoil 556 and its phylogenetically closest relatives were less than 40%. Furthermore, the results of physiological and biochemical tests enabled strain Gsoil 556 to be differentiated genotypically and phenotypically from currently known Actinomadura species. Therefore, strain Gsoil 556 represents a novel species of the genus Actinomadura, for which the name Actinomadura hankyongense sp. nov. is proposed. The type strain Gsoil 556 (=KACC 19438=LMG 30327).