[Physiologo-biochemical properties of a chemostatic culture of Bacillus megaterium at different pH values].

Properties of the chemostat culture of Bacillus megaterium were studied during its growth in the state of stress caused by unfavourable acid and alkaline values of pH. The effect of pH is not specific since changes occur in both energy exchange and constructive metabolism. The common action of hydrogen and hydroxyl ions is a decrease in the economic coefficient as greater amounts of the energy substrate are being used, the repression of oxidative enzymes, a decrease in the pool of ATP, and an increase in the respiration quotient. Protein synthesis is inhibited and synthesis of nitrogenless reserve substances is stimulated. Acid and alkaline conditions have also a specific action in the cells of Bac. megaterium. In the alkaline medium, metabolites are liberated into the medium, the cells are enriched with carbohydrates, and acetate is accumulated in the medium. In the acid medium, the cells are enriched with acid insoluble polyphosphates. Idle consumption of the energy substrate takes place.