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

Abstract

A novel high G+C actinobacterium, designated strain OS1-21T, 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 OS1-21T 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-C16 : 0, iso-C16 : 0 2-OH, 10-methyl C17 : 0, 10-methyl C18 : 0 and C17 : 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 616T (98.7 % sequence similarity) and Nocardioides terrae VA15T (97.8 %), followed by Nocardioides marinus CL-DD14T (97.1 %). DNA–DNA relatedness values of strain OS1-21T 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 OS1-21T ( = KCTC 19804T = NBRC 107915T).