Nocardia rhizosphaerihabitans sp nov., a novel actinomycete isolated from a coastal soil

An actinomycete strain, designated KLBMP S0039(T), was isolated from the rhizosphere soil of Lycium Linn., collected from the coastal region in Lianyungang, Jiangsu Province, eastern PR China, and was studied to determine its taxonomic position. The isolate showed a combination of morphological and chemotaxonomic properties typical of the members of the genus Nocardia. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid and the whole-cell sugars were galactose, arabinose, glucose and ribose. The predominant menaquinone was identified as MK-8(H-4 omega-cycl). The diagnostic phospholipids were found to be diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and unknown lipids. The predominant cellular fatty acids were identified as C-16:0, C-18:0, C-18:1 omega 9c, and 10-methyl C-18:0 [tuberculostearic acid (TBSA)]. The G+C content of the genomic DNA was determined to be 68.2 mol%. The 16S rRNA gene sequence similarity indicated that KLBMP S0039(T) was most closely related to Nocardia neocaledoniensis NBRC 108232(T) (99.4% 16S rRNA gene sequence similarity) and Nocardia asteroides NBRC 15531(T) (99.2 %), similarities to other type strains of species of the genus Nocardia were found to be less than 98.6 %. However, DNA-DNA relatedness values and phenotypic data indicated that KLBMP S0039(T) could be clearly distinguished from the closely related species of the genus Nocardia. On the basis of polyphasic taxonomic data, it is concluded that KLBMP S0039(T) represents a novel species of the genus Nocardia, for which the name Nocardia rhizosphaerihabitans sp. nov. is proposed. The type strain is KLBMP S0039(T) (=KCTC 39693(T) =CGMCC 4.7329(T)).