Sphaerisporangium aureirubrum sp. nov., an actinomycete isolated from soil

Abstract

A novel actinomycete, designated strain NEAU-GQTH1-3T, was isolated from muddy soil collected from a stream in Qitaihe, Heilongjiang Province, north-east China and characterized using a polyphasic approach. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the organism should be assigned to the genus Sphaerisporangium and forms a stable clade with its closest relative Sphaerisporangium rubeum JCM 13067T (98.2 % 16S rRNA gene sequence similarity). Moreover, morphological and chemotaxonomic properties of strain NEAU-GQTH1-3T also confirmed the affiliation of the isolate to the genus Sphaerisporangium. The cell wall contained meso-diaminopimelic acid and the whole-cell sugars were glucose, galactose, madurose, mannose and ribose. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylinositol, two phosphatidylinositol mannosides, phosphoglycolipid, an unidentified phospholipid and an unidentified glycolipid. The major menaquinones were MK-9(H4), MK-9(H6) and MK-9(H2). The predominant cellular fatty acids were iso-C16 : 0 and 10-methyl C17 : 0. Mycolic acids were absent. The DNA G+C content was 70.4 mol%. However, the low level of DNA–DNA relatedness and some phenotypic characteristics allowed the isolate to be differentiated from its closest relative. Therefore, it is concluded that strain NEAU-GQTH1-3T represents a novel species of the genus Sphaerisporangium, for which the name Sphaerisporangium aureirubrum sp. nov. is proposed. The type strain is NEAU-GQTH1-3T ( = CGMCC 4.7199T = JCM 30346T).