Five new combinations and emended descriptions of two species related to subspecies in the genus Streptomyces

Taxonomic positions of <i>Streptomyces albosporeus</i> subsp. <i>labilomyceticus</i>, <i>Streptomyces lavendulae</i> subsp. <i>grasserius</i>, <i>Streptomyces asiaticus</i> subsp. <i>ignotus</i>, <i>Streptomyces antimycoticus</i> subsp. <i>sporoclivatus</i> and <i>Streptomyces althioticus</i> subsp. <i>attaecolombicae</i> were reviewed according to analyses of 16S rRNA gene and whole-genome sequences and phenotypic comparisons. The rank of <i>S. albosporeus</i> subsp. <i>labilomyceticus</i> was elevated to an independent species, for which <i>Streptomyces labilomyceticus</i> comb. nov. was proposed. <i>S. lavendulae</i> subsp. <i>grasserius</i> was considered a later heterotypic synonym of <i>Streptomyces colombiensis. S. colombiensis</i> and <i>Streptomyces lavendulae</i> can be united under one species as subspecies. Therefore, <i>S. colombiensis</i> was reclassified as a subspecies of <i>S. lavendulae</i>, for which <i>Streptomyces lavendulae</i> subsp. <i>colombiensis</i> comb. nov. was proposed. <i>S. asiaticus</i> subsp. <i>ignotus</i> was closely related to <i>Streptomyces rhizosphaericus. Streptomyces asiaticus</i> was reclassified as a later heterotypic synonym of <i>S. rhizosphaericus</i>. According to the reclassification of the parent taxa, the scientific name of <i>S. asiaticus</i> subsp. <i>ignotus</i> was updated to <i>Streptomyces rhizosphaericus</i> subsp. <i>ignotus</i> comb. nov. <i>S. antimycoticus</i> subsp. <i>sporoclivatus</i> NBRC 100767^T showed 88.6% DNA-DNA relatedness to <i>Streptomyces antimycoticus</i> subsp. <i>antimycoticus</i> NBRC 12839^T, suggesting that they belong to the same subspecies. In contrast, <i>Streptomyces mordarskii</i> JCM 5052^T showed DNA-DNA relatedness of 75.6% to <i>Streptomyces antimycoticus</i> NBRC 12839^T, suggesting that they are two subspecies of the same species. Therefore, <i>S. mordarskii</i> was considered as a subspecies of <i>S. antimycoticus</i>, for which <i>Streptomyces antimycoticus</i> subsp. <i>mordarskii</i> comb. nov. was proposed. Although the genus <i>Streptomyces</i> included inappropriate scientific names of subspecies, they were correctly updated through these reclassifications. Additionally, <i>Streptomyces labedae</i>, <i>Streptomyces gancidicus</i> and <i>Streptomyces albaduncus</i> were reclassified as later heterotypic synonyms of <i>Streptomyces griseoincarnatus</i>, <i>Streptomyces pseudogriseolus</i> and <i>Streptomyces griseoloalbus</i>, respectively.