Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/12/2010
Publication Date: 2/20/2011
Publication URL: http://handle.nal.usda.gov/10113/60391
Citation: Kim, B., Brown, R., Labeda, D.P., Goodfellow, M. 2011. Reclassification of "Dactylosporangium variesporum" as Saccharothrix variisporea corrig. (ex Tomita et al. 1977) sp. nov., nom. rev. International Journal of Systematic and Evolutionary Microbiology. 61(2):310-314. Interpretive Summary: The actinobacterial genus Dactylosporangium was described in 1967 by Thiemann et al. in Italy for novel strains isolated during the course of their antibiotic discovery program nd the invalid species 'Dactylosporangium variesporium' was isolated and described by Tomita et al. in 1977 in the course of a similar program in Japan. A thorough characterization of this strain was needed to validate the proposed species name and it was included in a study with other recent isolates of the genus Dactylosporangium. It was discovered that this strain represented a new species within the unrelated genus Saccharothrix, for which the name Saccharothrix variisporea was proposed. This was particularly significant because the only other microorganism reported to produce the same antibiotic, capreomycin, is also a similar species within the genus Saccharothrix. This study demonstrated the value of polyphasic studies that include a molecular phylogenetic component in clarifying the taxonomic status of novel antibiotic-producing actinobacteria and could be extremely useful to biotechnology researchers searching for novel microbial products. Key words: Pseudonocardineae, systematics.
Technical Abstract: In the course of a polyphasic study it was observed that “Dactylosporangium variesporum” NRRL B-16296 is misclassified as a member of the genus Dactylosporangium becasuse it exhibits properties consistent with its assignment to the genus Saccharothrix. Phylogenetic analyses based on 16S rRNA gene sequences show that the strain falls within the evolutionary radiation of Saccharothrix, a result which is supported by corresponding chemotaxonomic and morphological markers. The strain is phylogenetically most closely, albeit loosely, related to Saccharothrix espanaensis, but can be readily distinguished from this and other validly described Saccharothrix species by a range of phenotypic properties. The combined genotypic and phenotypic data demonstrate conclusively that this strain should be classified as a new species in the genus Saccharothrix for which the name Saccharothrix variisporea sp.nov. is proposed. The type strain is NRRL B-16296T(= ATCC 31203T = DSM 43911T = JCM 3273T = NBRC 14104T).