We studied the taxonomic relationship between Streptomyces cinnamonensis and Streptomyces virginiae. These type strains shared the same 16S rRNA gene sequence. Phylogenomic analysis supported them being closely related. Digital DNA-DNA relatedness and average nucleotide identity using whole genome sequences indicated that the two species represent the same genomospecies. They shared similar phenotypic characteristics and harboured the same set of secondary metabolite-biosynthetic gene clusters for polyketides and nonribosomal peptides in the genomes. Therefore, according to Rule 24b of the Bacteriological Code, S. cinnamonensis Okami 1952, 572AL (Approved Lists 1980) should be reclassified as a later heterotypic synonym of S. virginiae Grundy et al. 1952, 399AL (Approved Lists 1980) emend. Nouioui et al. 2018. Although 16S rRNA gene sequences were identical among type strains of Streptomyces xanthophaeus, Streptomyces spororaveus and Streptomyces nojiriensis and between those of Streptomyces vinaceus and Streptomyces cirratus, respectively, digital DNA-DNA relatedness indicated that these species are not synonymous.
Keywords: Streptomyces; Streptomyces cinnamonensis; Streptomyces virginiae; genome sequence; reclassification; synonym.