Reclassification of Streptomyces fulvissimus as a later heterotypic synonym of Streptomyces microflavus

Abstract

We investigated the taxonomic relationships among Streptomyces fulvissimus , Streptomyces fulvorobeus and Streptomyces microflavus . These type strains shared the same 16S rRNA gene sequence. Digital DNA–DNA relatedness and average nucleotide identity analyses using whole genome sequences suggested that S. fulvissimus and S. microflavus belong to the same genomospecies, whereas S. fulvorobeus does not. In addition to previously reported phenotypic data, the presence of almost the same set of secondary metabolite-biosynthetic gene clusters for polyketides and nonribosomal peptides also supported the synonymy between S. fulvissimus and S. microflavus . Therefore, S. fulvissimus should be reclassified as a later heterotypic synonym of S. microflavus .

Reclassification of Streptomyces costaricanus and Streptomyces phaeogriseichromatogenes as later heterotypic synonyms of Streptomyces murinus

“…Polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) gene clusters encoded in genomes were surveyed using the antiSMASH bacterial version (https://antismash.secondarymetabolites.org/#!/start). The outputs were manually analysed, mainly based on gene and domain organisations and on similarities with product-identified biosynthetic genes, as previously reported [11].…”

“…org/#!/ start). The outputs were manually analysed, mainly based on gene and domain organisations and on similarities with product-identified biosynthetic genes, as previously reported [11]. The 16S rRNA gene sequences of the type strains of S. costaricanus, S. graminearus, S. murinus and S. phaeogriseichromatogenes were identical and formed an independent clade in the phylogenetic trees ( Fig.…”

“…Conventionally, 16S rRNA gene sequence analysis has been employed for bacterial classification; however, owing to the high similarities among Streptomyces species, their classification is considerably complicated and still needs to be extensively studied [1][2][3][4][5][6][7][8][9]. Previous studies have often reported that species of the genus Streptomyces are overclassified [10][11][12][13][14][15][16]. DNA-DNA relatedness is presently used as the ultimate means to define bacterial species [17,18].…”

Reclassification of 15 Streptomyces species as synonyms of Streptomyces albogriseolus, Streptomyces althioticus, Streptomyces anthocyanicus, Streptomyces calvus, Streptomyces griseoincarnatus, Streptomyces mutabilis, Streptomyces pilosus or Streptomyces rochei

“…But their morphologies and products are so diverse that they seem to be overclassified. It is often reported that distinct species sharing the same 16S rRNA gene sequence should be reclassified as synonyms [1–9]. Nowadays, in addition to 16S rRNA gene sequence analysis, molecular-based classification such as multilocus sequence analysis (MLSA) and digital DNA–DNA hybridization using whole genome sequences can be commonly employed for classification of bacterial species [10–13], which makes the bacterial identification clearer than before [14, 15].…”

“…Nowadays, in addition to 16S rRNA gene sequence analysis, molecular-based classification such as multilocus sequence analysis (MLSA) and digital DNA–DNA hybridization using whole genome sequences can be commonly employed for classification of bacterial species [10–13], which makes the bacterial identification clearer than before [14, 15]. During our continuous 16S rRNA gene sequence analysis [1–7, 16, 17], it is noticed that eight sets of species in the genus Streptomyces share completely identical 16S rRNA gene sequences as described below. This research aimed to clarify the taxonomic relationship among these species.…”