Micromonospora lycii sp nov., a novel endophytic actinomycete isolated from wolfberry root (Lycium chinense Mill)

摘要

A novel actinomycete, designated strain NEAU-gq11(T), was isolated from wolfberry root (Lycium chinense Mill) and characterized using a polyphasic approach. Strain NEAU-gq11(T) was observed to form rough-surfaced spores that borne singly on the substrate hyphae but aerial mycelia were not developed. The organism showed closest 16S rRNA gene sequence similarity to Micromonospora saelicesensis Lupac 09(T) (99.4%), and phylogenetically clustered with M. chokoriensis 2-19/6(T) (99.3%), 'M. zeae' NEAU-gq9(T) (99.3%), M. violae NEAU-zh8(T) (99.1%), 'M. jinlongensis' NEAU-GRX11(T) (99.1%), M. zamorensis CR38(T) (99.0%), M. taraxaci NEAU-P5(T) (98.9%) and M. lupini Lupac 14N(T) (98.6%). Phylogenetic analysis based on the gyrB gene sequences also indicated that the isolate clustered with the above type strains except M. violae NEAU-zh8(T). The cell-wall peptidoglycan consisted of meso-diaminopimelic acid and glycine. The major menaquinones were MK-9(H-8), MK-10(H-6) and MK-10(H-2). The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acid was iso-C-16:0. Furthermore, some physiological and biochemical properties and low DNA-DNA relatedness values enabled the strain to be differentiated from members of closely related species. Therefore, it is proposed that strain NEAU-gq11(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora lycii sp. nov. is proposed. The type strain is NEAU-gq11(T) (=CGMCC 4.7149(T) = DSM 46703(T)).