Streptomyces caviscabies sp nov, from deep-pitted lesions in potatoes in Quebec, Canada

Eight deep-pitted-scab-inducing streptomycetes isolated from potato lesions in Quebec (Canada) were phenotypically compared with representative strains of the principal plant-pathogenic Streptomyces species. These eight strains could be distinguished from representatives of Streptomyces scabies, Streptomyces aureofaciens, Streptomyces ipomoeae, and Streptomyces acidiscabies on the basis of their morphological or physiological properties. They were characterized by a gold mycelium on yeast-malt extract medium and a white mass of spores borne in flexuous chains. The spores of these organisms were cylindrical and smooth. Their cell walls contained the LL-diaminopimelic acid isomer, and their DNA guanine-plus-cytosine content was 71 mol%. The strains which we studied did not produce melanin. All of the strains grew on proline or methionine as a sole nitrogen source and utilized raffinose as a sole carbon source. Bacterial growth was inhibited at pH 4.5. The levels of DNA relatedness between the deep-pitted-scab-inducing strains and strains of the other plant-pathogenic Streptomyces species were low. We place these deep-pitted-scab-inducing strains in a new bacterial species, for which we propose the name Streptomyces caviscabies. The type strain of this species is strain ATCC 51928.