A novel endophytic actinomycete, designated A301T, was isolated from the root of Geranium carolinianum Linn collected from Mount Emei in China and characterized using a polyphasic approach. Growth occurred at 10-37 °C, pH 6-11 and in the presence of 0-5 % NaCl (w/v). Strain A301T contained ll-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan. The whole-cell hydrolysates included galactose and ribose. The predominant menaquinones were MK-9(H6) and MK-9(H8). The major cellular fatty acids were C15 : 0, C16 : 0, anteiso-C15 : 0 and iso-C16 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, two unidentified phospholipids, three unidentified lipids and two unidentified aminophospholipids. Strain A301T shared the highest 16S rRNA gene sequence similarity to Streptomyces cinereorubersubsp. fructofermentans NBRC 15396T (98.1 %) and Streptomyces turgidiscabies ATCC 700248T (98.1 %). The DNA-DNA relatedness values between strain A301T and the two above-mentioned members of the genus Streptomyces were 42.6 % and 47.2 %, respectively. The G+C content of the DNA was 70.5 mol%. On the basis of the polyphasic approach and DNA-DNA hybridization data, strain A301T represents a novel species within the genus Streptomyces, for which the name Streptomyces geranii sp. nov. is proposed. The type strain is A301T (=CGMCC 4.7422T=JCM 32177T).
Keywords: Streptomyces geranii; endophytic actinomycete; polyphasic approach.