Streptomyces phaeolivaceus sp. nov. and Streptomyces broussonetiae sp. nov., isolated from the leaves and rhizosphere soil of Broussonetia papyrifera

Two novel actinobacteria, designated strains GY16 T and T44 T , were isolated from the leaves and rhizosphere soil of Broussonetia papyrifera , respectively. A polyphasic approach was used for determining their taxonomic position. Results of 16S rRNA gene sequence analysis indicated that strain GY16 T exhibited highest similarities to Streptomyces cinereoruber subsp. fructofermentans CGMCC 4.1593 T (98.82 %), Streptomyces deccanensis KCTC 19241 T (98.76 %), Streptomyces scabiei NRRL B-16523 T (98.69 %), Streptomyces europaeiscabiei KACC 20186 T (98.69 %) and Streptomyces rishiriensis NBRC 13407 T (98.69 %), and strain T44 T showed 99.2, 99.1, 99.1 and <98.7 % sequence similarities to Streptomyces filipinensis CGMCC 4.1452 T , Streptomyces achromogenes subsp. achromogenes DSM 40028 T , Streptomyces durhamensis DSM 40539 T and other Streptomyces species, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain GY16 T formed an independent subclade, which indicated that strain GY16 T should belong to a potential novel species; and strain T44 T was closely related to S. filipinensis CGMCC 4.1452 T , S. achromogenes subsp. achromogenes DSM 40028 T , S. durhamensis DSM 40539 T and S. yokosukanensis DSM 40224 T . However, the multilocus sequence analysis evolutionary distance, average nucleotide identity and DNA–DNA hybridization values between closely related relatives were far from the species-level thresholds. In addition, phenotypic and chemotaxonomic characteristics further confirmed that strains GY16 T and T44 T belonged to two distinct species. Based on these results, it is concluded that the isolated strains represent novel species within the genus Streptomyces , for which the names Streptomyces phaeolivaceus sp. nov. (type strain GY16 T =CICC 24807 T =KCTC 49326 T ) and Streptomyces broussonetiae sp. nov. (type strain T44 T =CICC 24819 T =JCM 33918 T ) are proposed.