Nocardioides mesophilus sp. nov., isolated from soil

Abstract

A short coccoid- to rod-shaped, motile, mesophilic actinobacterium, strain MSL-22T, was isolated from soil on Bigeum Island, Korea. A polyphasic study was undertaken to establish the taxonomic position of this strain. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain MSL-22T formed an evolutionary lineage within the radiation of the genus Nocardioides. In particular, it formed a monophyletic lineage with Nocardioides jensenii KCTC 9134T with which it shared the highest sequence similarity of about 97.3%. However, DNA–DNA relatedness demonstrated that strain MSL-22T was distinct from its closest phylogenetic neighbours. The cell-wall peptidoglycan of strain MSL-22T contained ll-diaminopimelic acid. The predominant menaquinone was MK-8(H4). Strain MSL-22T had a cellular fatty acid profile containing straight-chain, branched, unsaturated and 10-methyl fatty acids, with iso-C16 : 0 as the major fatty acid. The DNA G+C content of the strain was 68.7 mol%. On the basis of phenotypic and phylogenetic evidence, the strain is separate from previously described members of the genus Nocardioides and represents a novel species in this genus, for which the name Nocardioides mesophilus sp. nov. is proposed. The type strain is MSL-22T (=DSM 19432T=KCTC 19310T).