Kitasatospora camelliae sp. nov., isolated from rhizosphere soil of Camellia oleifera.

Abstract

Strain HUAS MG31^T was isolated from the rhizosphere soil of Camellia oleifera collected from Taoyuan County, China. This strain produced white substrate mycelium and hair brown aerial mycelium without diffusible pigment on the Gause's synthetic No. 1 medium. Aerial mycelia differentiated into rectiflexible spore chains consisting of spherical or cylindrical spores with smooth surfaces. Cell wall peptidoglycan of strain HUAS MG31^T contained meso-diaminopimelic acid, and whole-cell sugars were galactose and mannose. The menaquinones of strain HUAS MG31^T were MK-9(H₆), MK-9(H₈) and MK-9(H₄). The major cellular fatty acids consisted of Summed Feature 9 (iso-C_17 : 1 ω9c/10-methyl C_16 : 0), iso-C_16 : 0, iso-C_15 : 0, anteiso-C_15 : 0, iso-C_17 : 0, anteiso-C_17 : 0, Summed Feature 3 (iso H-C_16 : 1 /_C16 : 1 ω6c) and cyclo C_17 : 0. Sequence analysis based on the full-length 16S rRNA gene of strain HUAS MG31^T showed that it shared highest sequence similarities to Kitasatospora paranensis HKI 0190^T (99.5%) and Kitasatospora terrestris HKI 0186^T (99.4%). The phylogenomic tree shows that strain HUAS MG31^T forms an independent subclade, indicating that it might belong to a potential novel species. The results from phylogenetic trees based on 16S rRNA gene sequences showed that strain HUAS MG31^T was most closely related to K. paranensis HKI 0190^T. However, the average nucleotide identity and the digital DNA-DNA hybridization between strain HUAS MG31^T and K. paranensis JCM 13005^T were 87.0 %/81.2% and 25.8 %, respectively, below the 95%-96% and 70 % threshold that defined a new species. Meanwhile, phenotypic, chemotaxonomic characteristics and MALDI-TOF MS results further confirmed that strain HUAS MG31^T was significantly different from K. paranensis JCM 13005^T. Therefore, these results reveal that strain HUAS MG31^T represents a novel species of the genus Kitasatospora, for which the name Kitasatospora camelliae sp. nov. is proposed. The type strain is HUAS MG31^T (=MCCC 1K09225^T= JCM 37022^T).