[The nature of the interrelations of different Bacillus thuringiensis serotypes between themselves and other species of the genus Bacillus].

Intraspecies interrelations between representatives of 7 serotypes of Bacillus thuringiensis, as well as antagonistic interrelations between B. thuringiensis and 130 strains of 16 species of Bacillus bacteria were studied. Antagonistic activity was determined for 18 strains, representatives of genus Bacillus, with respect to B.

[The choice of the optimal aeration conditions for the stab cultivation of Bacillus thuringiensis H14 266/2-1].

Optimal conditions of aeration with depth regime of cultivation of Bacillus thuringiensis H14 266/2-1, their effect on the output of biomass, endotoxin and activity of bacteria have been studied. The aeration conditions are optimized using the mathematical method of experiment planning. It is established that the air supply favours an increase of the bacillary biomass and insecticide activity for the whole cultivation period.

[Intensification of the growth and development of Bacillus thuringiensis H14 266/2-1 by optimizing the nutrient medium].

The mathematical method of experimental design was used to develop a new enzymic medium for cultivation of Bacillus thuringiensis H14 266/2-1, a bactoculicide producer. The optimized medium based on corn flour enzyme lysate as a carbon source and fodder yeast enzyme lysate as a source of nitrogen amine made it possible to increase twice the titre biomass yield for 24 h cultivation as compared to the initial medium. The above medium does not yield to the initial production medium in the insecticide activity.