Pseudonocardia carboxydivorans sp. nov., a carbon monoxide-oxidizing actinomycete, and an emended description of the genus Pseudonocardia.

A bacterial strain, Y8(T), capable of oxidizing carbon monoxide, was isolated from a soil sample collected from a roadside in Seoul, Korea. On the basis of 16S rRNA gene sequence similarity analyses, strain Y8(T) was shown to belong to the genus Pseudonocardia and was related most closely to the type strain of Pseudonocardia alni (99.6 % similarity). The cells were aerobic and stained Gram-positive, with white aerial mycelium and brown substrate mycelium. The predominant fatty acids were 16 : 0 iso and 16 : 1 iso. The cell-wall peptidoglycan of strain Y8(T) contained meso-diaminopimelic acid. The DNA G+C content was 77 mol%. Strain Y8(T) contained MK-9 as the major menaquinone, which is different from the major menaquinone reported previously in the genus Pseudonocardia, MK-8(H(4)). DNA-DNA relatedness between strain Y8(T) and the type strains of P. alni and Pseudonocardia antarctica was respectively 10 and 63 %. Based on phylogenetic, morphological and chemotaxonomic evidence, it is proposed that strain Y8(T) (=KCCM 42678(T) =JCM 14827(T)) be classified as the type strain of a novel species, Pseudonocardia carboxydivorans sp. nov. An emended description of the genus Pseudonocardia is also presented.