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

Abstract

An actinomycete strain, designated KLBMP S0039T, 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(H4ω-cycl). The diagnostic phospholipids were found to be diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and unknown lipids. The predominant cellular fatty acids were identified as C16 : 0, C18 : 0, C18 : 1ω9c, and 10-methyl C18 : 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 S0039T was most closely related to Nocardia neocaledoniensis NBRC 108232T (99.4 % 16S rRNA gene sequence similarity) and Nocardia asteroides NBRC 15531T (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 S0039T 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 S0039T represents a novel species of the genus Nocardia, for which the name Nocardiarhizosphaerihabitans sp. nov. is proposed. The type strain is KLBMP S0039T (=KCTC 39693T=CGMCC 4.7329T).