By using transmission electron microscopy (TEM), it was found that under the influence of the minimum inhibitory concentration Cry proteins (δ-endotoxins) parasporal crystals of Bacillus thuringiensis subsp. kurstaki is a change of the ultrastructure of cells E. coli: a violation of the homogeneity of the cytoplasm (the appearance of grain) a significant number of cells in the population (35±7,5 %), the destruction of the cell walls of varying degrees, uneven increase from different sides and enlightenment periplasmic space. Varying degrees of disruption of the structure of E. coli cells in the microbial population is an example of the phenomenon of dissociation morphological and physiological heterogeneity of the cells of bacteria and is the result of their adaptation to the adverse factors. This indicates the plasticity of microorganisms and their capacity to adapt to non-optimal living conditions, in particular under the action of δ-endotoxins produced by B. thuringiensis.
