Pseudonocardia kongjuensis sp. nov., isolated from a gold mine cave.

The taxonomic position of an isolate that was recovered from a gold mine cave near Kongju, Republic of Korea, was determined by 16S rDNA sequence studies and chemotaxonomic characterization. Comparative studies of 16S rDNA sequences indicated that this organism was phylogenetically related to members of the genus Pseudonocardia, branching outside a cluster encompassing Pseudonocardia autotrophica and Pseudonocardia compacta. The affiliation to the genus was also supported by the cell chemistry, which was represented by a type IV cell wall, MK-8(H4) as the major menaquinone, a phospholipid type PIII pattern (phosphatidylcholine as a diagnostic phospholipid) and a DNA G+C content of 71 mol%. The fatty acid profile contained saturated, unsaturated and 10-methyl branched fatty acids, but tuberculostearic acid and hydroxy fatty acids were not present. The isolate differed from its phylogenetic neighbours in the presence of phosphatidylethanolamine, dodecanoate, 16-methylheptadecenoate and 16-methylheptadecanoate and the absence of phosphatidylinositol mannoside and phosphatidylmethylethanolamine. The unique combination of physiological properties, the cellular fatty acid profile and DNA-DNA hybridization data indicates that this organism is readily differentiated from the type strains of all of the validly published species of the genus Pseudonocardia. The name Pseudonocardia kongjuensis sp. nov. is proposed for the type strain, LM 157T (= IMSNU 50583T = KCTC 9990T = DSM 44525T).