sp. nov., a novel actinobacterium with antimicrobial activity isolated from the rhizospheric soil of D. Don.

A novel actinobacterium, designated strain CWNU-1, was isolated from the rhizospheric soil of D. Don and examined using a polyphasic taxonomic approach. The organism developed pale blue aerial mycelia that was simply branched and terminated in open or closed coils of three or more volutions on International Project 3 agar. Spores were ellipsoidal to cylindrical with wrinkled surfaces. The strain showed high 16S rRNA gene sequence similarity to NBRC 13192 (98.8 %), NBRC 13354 (98.7 %) and JCM 9920 (98.6 %). The phylogenetic result based on 16S rRNA gene and genome sequences clearly demonstrated that strain CWNU-1 formed an independent phylogenetic lineage. On the basis of orthologous average nucleotide identity, CWNU-1 was most closely related to NBRC 13601 with 79.3 % identity. The results of the digital DNA-DNA hybridization analysis also indicated low levels of relatedness with other species, as the highest value was observed with NBRC 13601 (25.3 %). With reference to phenotypic characteristics, phylogenetic data, orthologous average nucleotide identity and digital DNA-DNA hybridization results, strain CWNU-1 was readily distinguished from its most closely related strains and classified as representing a novel species, for which the name sp. nov. is proposed. The type strain is CWNU-1 (=CGMCC 4.7758=MCCC 1K07402=JCM 35391).