Nocardioides opuntiae sp. nov., isolated from soil of a cactus

A novel high G+C actinobacterium, designated strain OS1-21(T), was isolated from the rhizosphere soil of a cactus (Opuntia fiscus-indica var. sanboten) and the taxonomic status was investigated using a polyphasic approach. Cells of strain OS1-21(T) were aerobic, Gram-stain-positive, non-endospore-forming, non-motile rods; colonies of the cells were circular, translucent, smooth and moderate yellow in colour. LL-Diaminopimelic acid was the diagnostic diamino acid in cell-wall peptidoglycan. The predominant menaquinone was MK-8(H4). The major fatty acids were iso-C(16 : 0), iso-C(16 : 0) 2-OH, 10-methyl C(17 : 0), 10-methyl C(18 : 0) and C(17 : 1)cis9. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and two unknown phospholipids. The DNA G+C content was 73.7 mol%. Based on 16S rRNA gene sequence analysis, the closest phylogenetic neighbours were Nocardioides panacihumi Gsoil 616(T) (98.7% sequence similarity) and Nocardioides terrae VA15(T) (97.8%), followed by Nocardioides marinus CL-DD14(T) (97.1%). DNA-DNA relatedness values of strain OS1-21(T) with the type strains of the closest phylogenetic neighbours were low (<16.0%). Combined data of polyphasic taxonomic analyses revealed that the organism could be assigned to a novel species of the genus Nocardioides, for which the name Nocardioides opuntiae sp. nov. is proposed. The type strain is OS1-21(T) ( = KCTC 19804(T) = NBRC 107915(T)).