[Conditions for formation of heteromorphic forms of Bacillus brevis and their cytology]

The conditions of formation of Bacillus brevis var. GB heteromorphous forms were studied both under natural conditions and in the course of action of various factors. Natural polymorphism of the culture is low. It increases as the temperature of cultivation is lowered down to 28 degrees C or when the culture is kept at 5--6 degrees C in a refigerator. The P- and S forms of dissociation display higher polymorphism than than P+ and R variants. Cytological investigation has shown that heteromorphous forms are very large and contain gigantic nuclear formations in the form of solid bodies or bands. The sharp increase in the size of the nucleoids, their aggregation and splitting (breaking down of a band into sepraate units, transverse division of large nucleoids), as well as the data of biochemical analysis suggest the polygenomic or polyenergid nature of the giant heteromorphous forms of Bacillus brevis var. GB.