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

Abstract

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

Keywords: Streptomyces albosporeus subsp. labilomyceticus; Streptomyces antimycoticus subsp. sporoclivatus; Streptomyces asiaticus subsp. ignotus; Streptomyces lavendulae subsp. grasserius; reclassification; synonym.