The Identification Of A Novel Specie Of Soil Actinomycete Isolated From Loess Plateau

The taxonomic position of strain F22T was determined by using a polyphasic approach. F22T was isolated from a soil sample collected from Fu County, Loess Plateau in Shaanxi Province, China.The isolates exhibit antibacterial and antifungal activity, especially to Staphyloccocus aureus Rosenbach, Bacillus subtilis (Ehrenberg) Cohn and Cylindrocarpon destructans (Zinssn) Scholten. The strain was assigned to the genus Streptomyces on the basis of 16S rDNA analysis, where it formed a separate clade. The strain is characterized by light pink aerial cell mass, spiral spore chains and a smooth spore surface. The cell wall of it contained LL-diaminopimelic acid, arabinose, galactose and ribose as the diagnostic diaminoacid indicating that the cell wall was of chemotype-I. The major polar lipids of the isolate were phosphatidylinositol mannosides, isoprenologues, phosphatidylinositol and phosphatidylethanolamine. It belongs to phospholipid type II. The major menaquinones of the isolate were octahydrogenated, hexahydrogenated, and tetrahydrogenated with nine isoprene units recorded as [MK-9 (H8, H6 and H4)]. The major fatty acid components analysis showed that the organism mainly contained branched-chain, anteiso- and iso-, and a proportion of unsaturated fatty acids. The DNA G+C mol% of the strain was 70.6%. The strain was most similar to the type strains of Streptomyces resistomycificus(98.28%) NRRL 2290,Streptomyces ciscaucasicus(98.13%) NRRL B-51078,Streptomyces chartreusis (98.13%)NRRL 2287 and Streptomyces canus (98.13%). Furthermore, DNA–DNA hybridization with these four Streptomyces species showed 48.7%,45.2%,39.2% and 40.6% relatedness, respectively.All of these could illustrate that F22T can be classified as the type strain of a novel specie in the genus Streptomyces, Streptomyces sp. nov.