Nocardioides convexus sp. nov. and Nocardioides anomalus sp. nov., isolated from soil and mineral water.

Abstract

Two bacterial strains designated as W3-2-3T and HKS04T were isolated from mineral water and a soil sample, respectively, in the Republic of Korea. The 16S rRNA genes of the two strains shared a sequence similarity of 93.5 %. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains W3-2-3T and HKS04T formed a distinct lineage within the genus Nocardioides of the family Nocardioidaceae (order Propionibacteriales). The closely related species of strain W3-2-3T were Nocardioides albidus (98.9 %), Nocardioides caeni (98.8 %), Nocardioides kongjuensis (98.6 %), Nocardioides aromaticivorans (98.5 %), Nocardioides nitrophenolicus (98.4 %), Nocardioides flava (98.2 %) and Nocardioides ginsengisoli (98.1 %). The closest species of strain HKS04T was Nocardioides halotolerans (98.7 %). The genome sizes of strains W3-2-3T and HKS04T were 4741198 and 5 120341 bp, respectively. The genomic DNA G+C contents of strains W3-2-3T and HKS04T were 73.3 and 72.1 mol%, respectively. The main fatty acids of strain W3-2-3T were C17:1 ω6c and iso-C16:0 and those of strain HKS04T were iso-C16:0 and iso-C16:0 H. The main polar lipids of both strains were diphosphatidylglycerol and phosphatidylglycerol and the predominant respiratory quinone was MK-8(H4), supporting the affiliation of these strains with the genus Nocardioides. Based on the results of biochemical, chemotaxonomic and phylogenetic analyses, two novel species, Nocardioides convexus W3-2-3T (KACC 21211T=LMG 31251T) and Nocardioides anomalus HKS04T (KACC 18879T=LMG 31249T), are proposed.