GROWTH AND SPORULATION OF BACILLUS-SUBTILIS IN BATCH AND DIALYSIS CULTURES - EXPERIMENT AND SIMULATION

Sporulation of bacilli in a homogeneous batch culture began immediately after exhaustion of glucose. In a dialysis culture the bacillary cells changed to a state of maintenance in which both growth and sporulation were absent. The stale of maintenance was characterized by low metabolic activity of the cells; after the supply of the substrate was cut off the cells underwent lysis without spore formation. The growth and sporulation of bacilli in batch and dialysis cultures, and spore germination on a full-value medium were described well enough by a modified synthetic chemostatic model. The results of simulation allowed the conclusion that the change of bacilli to a state of maintenance was associated with synthesis of an autoinhibitor reducing the effectiveness of growth and with the initiation of the early stage of sporulation. The possible ecological significance of the revealed peculiarities of the behavior of bacilli under conditions of deep growth limitation is discussed.