title: [Comparative characteristics of spore-forming and asporogenic strains of Bacillus thuringiensis].
abstract: Comparative characteristics of sporogenous and asporogenous Bacillus thuringiensis strains is carried out. Asporogenous strains are found to differ from wild type strains in a number of criteria, including colony morphology, character of growth on rich and poor media and UV-sensitivity. Sporogenous strains form R colonies, they are more stable and more rare produce variants forming S colonies. S colonies are typical for asporogenous mutants, and under the cultivation in unfavourable conditions (elevated temperature, a shift of pH, a change of an incubation regime) asporogenous strains dissociate with a high frequency into R form. Initial strains, which are multiple auxotrophs, under certain conditions can form "prototrophic" revertants which are unstable when incubated on rich media. Suppressor mutation is supposed to be a possible mechanism of the origination of "prototrophs".
mesh_terms: D001413:Bacillus thuringiensis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D001435:Bacteriophages / Q000235:genetics; D002999:Clone Cells / Q000528:radiation effects; D003470:Culture Media; D014644:Genetic Variation / Q000528:radiation effects; D009154:Mutation / Q000528:radiation effects; D013171:Spores, Bacterial / Q000502:physiology; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D003470:Culture Media
vernacular_title: Sravnitel'naia kharakteristika sporoobrazuiushchikh i asporogennykh shtammov Bacillus thuringiensis.