Taxonomic evaluation of putative Streptomyces scabiei strains held in the ARS Culture Collection (NRRL) using multi-locus sequence analysis

Multi-locus sequence analysis has been demonstrated to be a useful tool for identification of Streptomyces species and was previously applied to phylogenetically differentiate the type strains of species pathogenic on potatoes (Solanum tuberosum L.). The ARS Culture Collection (NRRL) contains 43 strains identified as Streptomyces scabiei deposited at various times since the 1950s and these were subjected to multi-locus sequence analysis utilising partial sequences of the house-keeping genes atpD, gyrB, recA, rpoB and trpB. Phylogenetic analyses confirmed the identity of 17 of these strains as Streptomyces scabiei, 9 of the strains as the potato-pathogenic species Streptomyces europaeiscabiei and 6 strains as potentially new phytopathogenic species. Of the 16 other strains, 12 were identified as members of previously described non-pathogenic Streptomyces species while the remaining 4 strains may represent heretofore unrecognised non-pathogenic species. This study demonstrated the value of this technique for the relatively rapid, simple and sensitive molecular identification of Streptomyces strains held in culture collections.