Plasmid-associated sensitivity of Bacillus thuringiensis to UV light.
Spores and vegetative cells of Bacillus thuringiensis were more sensitive to UV light than were spores or cells of plasmid-cured B. thuringiensis strains or of the closely related Bacillus cereus. Introduction of B. thuringiensis plasmids into B. cereus by cell mating increased the UV sensitivity of the cells and spores. Protoxins encoded by one or more B. thuringiensis plasmids were not involved in spore sensitivity, since a B. thuringiensis strain conditional for protoxin accumulation was equally sensitive at the permissive and nonpermissive temperatures. In addition, introduction of either a cloned protoxin gene, the cloning vector, or another plasmid not containing a protoxin gene into a plasmid-cured strain of B. thuringiensis all increased the UV sensitivity of the spores. Although the variety of small, acid-soluble proteins was the same in the spores of all strains examined, the quantity of dipicolinic acid was about twice as high in the plasmid-containing strains, and this may account for the differences in UV sensitivity of the spores. The cells of some strains harboring only B. thuringiensis plasmids were much more sensitive than cells of any of the other strains, and the differences were much greater than observed with spores.
Benoit
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Food Animal Protection Research Laboratory, U.S. Department of Agriculture, College Station, Texas 77840.
Wilson
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Bull
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Aronson
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D001409:Bacillus cereus / Q000235:genetics / Q000528:radiation effects; D001413:Bacillus thuringiensis / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D001426:Bacterial Proteins / Q000378:metabolism; D010848:Picolinic Acids / Q000378:metabolism; D010957:Plasmids / Q000528:radiation effects*; D013045:Species Specificity; D013171:Spores, Bacterial / Q000235:genetics / Q000528:radiation effects; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D010848:Picolinic Acids; C004860:dipicolinic acid