Blastococcus endophyticus sp. nov., an actinobacterium isolated from Camptotheca acuminata.

A novel endophytic actinobacterium, designated strain YIM 68236(T), was isolated from healthy leaves of Camptotheca acuminata. and characterized by using a polyphasic approach. Cells of this strain occurred singly, in pairs or in tetrads. It grew at 10-45 °C, at pH 5.0-8.0 (optimum pH 7.0) and in the presence of 0-3% (w/v) NaCl. The DNA G+C content was 71.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 68236(T) belongs to the genus Blastococcus. However, it differed from its closest relatives, Blastococcus aggregatus DSM 4725(T), Blastococcus saxobsidens DSM 44509(T) and Blastococcus jejuensis DSM 19597(T) in many phenotypic characteristics. Moreover, the DNA-DNA relatedness values between the novel isolate and the three above-mentioned type strains were 49.0 ± 1.6%, 46.1 ± 3.2% and 39.8 ± 1.5%, respectively. Based on comparative analysis of physiological and chemotaxonomic data, strain YIM 68236(T) represents a novel species of the genus Blastococcus, for which the name Blastococcus endophyticus sp. nov. is proposed. The type strain is YIM 68236(T) ( =CCTCC AA 209045(T) =DSM 45413(T) =KCTC 19998(T)).