Nocardioides aquiterrae sp. nov., isolated from groundwater in Korea

A bacterial strain, GW-9T, which was isolated from groundwater in Korea, was subjected to a polyphasic taxonomic study using phenotypic characterization and phylogenetic and genetic methods. Phylogenetic analysis based on 16S rDNA sequences showed that strain GW-9T forms an evolutionary lineage within the radiation enclosing Nocardioides species and, in particular, a coherent cluster with Nocardioides pyridinolyticus. The cell-wall peptidoglycan type of strain GW-9T was based on LL-diaminopimelic acid as the diamino acid, indicating wall chemotype I. The predominant menaquinone was MK-8(H4). Strain GW-9T had a cellular fatty acid profile containing straight-chain, branched, unsaturated and 10-methyl fatty acids. The major fatty acid was iso-C(16:0). The DNA G+C content of strain GW-9T was 73 mol%. The 16S rDNA of strain GW-9T was 99.2% similar to that of the type strain of Nocardioides pyridinolyticus and 94.9-96.0% similar to sequences of the type strains of other Nocardioides species. Differences in phenotypic characteristics and genetic distinctiveness indicate that strain GW-9T is separate from previously described Nocardioides species. Therefore, on the basis of the data presented, a novel species of the genus Nocardioides, Nocardioides aquiterrae sp. nov., is proposed. The type strain is strain GW-9T (=KCCM 41647T=JCM 11813T).