Saccharothrix camelliae sp. nov., isolated from rhizosphere soil of Camellia oleifera Abel and proposal of Saccharothrixyanglingensis as a later heterotypic synonym of Saccharothrix longispora

A novel actinobacterial strain, designated HUAS TT1 T , was isolated from the rhizosphere soil of Camellia oleifera collected from Changde City, Hunan Province, China. Sequence analysis of the full-length 16S rRNA gene revealed that strain HUAS TT1 T belonged to the genus Saccharothrix and shared the highest sequence similarities with Saccharothrix yanglingensis Hhs.015 T (99.30%), Saccharothrix carnea NEAU-yn17 T (98.89%), Saccharothrix hoggarensis SA181 T (98.89%), Saccharothrix saharensis SA152 T (98.82%), and Saccharothrix longispora NRRL B-16116 T (98.75%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain HUAS TT1 T was related to Saccharothrix yanglingensis Hhs.015 T and Saccharothrix longispora NRRL B-16116 T . Phylogenetic analysis based on whole-genome sequences and 120 core gene sequences showed that the evolutionary neighbors of strain HUAS TT1 T were Saccharothrix hoggarensis SA181 T and Saccharothrix saharensis SA152 T . However, the ANIb/m and dDDH values between the whole-genome sequences of strain HUAS TT1 T and Saccharothrix hoggarensis SA181 T / Saccharothrix saharensis SA152 T were 85.82%/88.80 and 32.90%, 86.42%/89.43, and 34.40%, respectively, well below the 95–96 and 70% cut-off points recommended for delineating species, suggesting that strain HUAS TT1 T is a novel Saccharothrix species. This result was further verified by the phenotypic and chemotaxonomic differences between them. Therefore, according to the above data, strain HUAS TT1 T represents a novel species of the genus Saccharothrix , for which the name Saccharothrix camelliae sp. nov. is proposed. The type strain used was HUAS TT1 T (=MCCC 1K09364 T = JCM 37292 T ). In addition, the phenotypic, chemotaxonomic, and genotypic characteristics, as well as the phylogenetic information, indicated that S. yanglingensis CGMCC 4.5627 T and S. longispora CGMCC 4.1357 T belong to the same species. Therefore, on the basis of these results and Rule 42 of the Bacteriological Code, we propose that Saccharothrix yanglingensis is a later heterotypic synonym of Saccharothrix longispora , for which an emended description is given.