Streptosporangium jiaoheense sp nov and Streptosporangium taraxaci sp nov., actinobacteria isolated from soil and dandelion root (Taraxacum mongolicum Hand.-Mazz.)

Two novel actinobacteria, designated strains NEAU-Jh1-4(T) and NEAU-Wp2-0(T), were isolated from muddy soil collected from a riverbank in Jiaohe and a dandelion root collected from Harbin, respectively. A polyphasic study was carried out to establish the taxonomic positions of these two strains. The phylogenetic analysis based on the 16S rRNA gene sequences of strains NEAU-Jh1-4(T) and NEAU-Wp2-0(T) indicated that strain NEAU-Jh1-4(T) clustered with Streptosporangium nanhuense NEAU-NH11(T) (99.32% 16S rRNA gene sequence similarity), Streptosporangium purpuratum CY-15110(T) (98.30%) and Streptosporangium yunnanense CY-11007(T) (97.95%) and strain NEAU-Wp2-0(T) clustered with 'Streptosporangium sonchi' NEAU-QS7 (99.39%), 'Streptosporangium kronopolitis' NEAU-ML10 (99.26%), 'Streptosporangium shengliense' NEAU-GH7 (98.85%) and Streptosporangium longisporum DSM 43180(T) (98.69%). Moreover, morphological and chemotaxonomic properties of the two isolates also confirmed their affiliation to the genus Streptosporangium. However, the low level of DNA DNA hybridization and some phenotypic characteristics allowed the isolates to be differentiated from the most closely related species. Therefore, it is proposed that strains NEAU-Jh1-4(T) and NEAU-Wp2-0(T) represent two novel species of the genus Streptosporangium, for which the name Streptosporangium jiaoheense sp. nov. and Streptosporangium taraxaci sp. nov. are proposed. The type strains are NEAU-Jh1-4(T) (=CGMCC 4.72131=JCM 303481) and NEAU-Wp2-0(T) (=CGMCC 4.7217(T)=JCM 303491), respectively.