ANALYSIS OF OSMOTIC STABILITY OF BACTERIAL PROTOPLASTS IN FREE AND IMMOBILIZED STATES
The paper considers the resistance of protoplasts to osmolysis in a free and immobilized agar state by light scattering, biocalorimetry and bioluminescence methods in order to determine the possibility of using protoplasts for biosensory analysis of aqueous media. The study of changes in the light scattering of protoplasts of В. subtilis bacteria in physiological medium and from the sucrose concentration in the range of 0-30% showed that it is associated with both an increase in the size of protoplasts and a decrease in their concentration. Three stages of light scattering changes during protoplasts formation of В. subtilis bacteria were noted and discussed. The analysis of the osmotic stability of protoplasts in the immobilized state, carried out by the method of biocalorimetry, showed a 2-stage character of the change in their heat release when placed in physiological medium. This is explained from the standpoint of Selye's stress theory as the stress and distress states of protoplasts. The analysis of osmolysis of protoplasts by biocalorimetry and bioluminescence showed similar results. Immobilization of protoplasts in agar showed that their osmotic stability increases, however, 0.7% agar did not provide sufficient osmotic stability and only 2% agar allows replacing the hypertonic medium with a gel environment, which allows the use of protoplasts as part of biosensor devices.