Pseudonocardia lutea sp. nov., a novel actinobacterium isolated from soil in Chad.

Abstract

A novel actinomycete, designated strain NEAU-G57T was isolated from a soil sample collected from the bottom of a river in Chad. A polyphasic approach was employed to determine the status of strain NEAU-G57T. Phylogenetic analysis based on its 16S rRNA gene sequence indicated that the organism should be assigned to the genus Pseudonocardia and formed a monophyletic clade with its closest relatives Pseudonocardia yuanmoensis YIM 75926T (98.8 %), Pseudonocardia halophobica DSM 43089T (98.2 %) and Pseudonocardia kujensis A 4038T (97.6 %). Moreover, morphological and chemotaxonomic properties of strain NEAU-G57T also confirmed the affiliation of the isolate to the genus Pseudonocardia. The cell wall contained meso-diaminopimelic acid and whole-cell sugars were glucose, xylose, arabinose and galactose. The predominant menaquinone was MK-8(H4). The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxyphosphatidylmethylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol mannosides, one unidentified glycolipid and one unidentified lipid. The major fatty acids were C16 : 0 and C16 : 1ω7c. The DNA G+C content was 73.3 mol%. However, the low level of DNA-DNA relatedness and some phenotypic characteristics allowed the isolate to be differentiated from its closely related species. Therefore, it is concluded that strain NEAU-G57T can be classified as representing a novel species of the genus Pseudonocardia, for which the name Pseudonocardia lutea sp. nov. is proposed. The type strain is NEAU-G57T (=JCM 32387T=CGMCC 4.7397T).