[Relationship between the ultrastructure and biochemical composition of spores and their resistance to high temperature exposure and chemical agents].

The author used the spores of B. cereus and of its two mutants (10id -- defective by spore coats, and No. 3 -- DPA-deficient). The mentioned microbes were subjected to the action of vapour (99 degrees), 5% sodium hydroxide solution at a temperature of 50 degreeC, and of 0.25% sodium hypochlorite solution. On the basis of the survival curves it was revealed that a mutant with defective coats possessed the least resistance to the factors under study. On these grounds a conclusion was drawn on the important portective function of the spore coat, and not simply of the presence of DPA, in the mechanism of thermo- and chemical resistance of spores.