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

Sporulation of bacilli in a homogeneous batch culture began immediatel y after exhaustion of glucose. In a dialysis culture the bacillary cel ls changed to a state of maintenance in which both growth and sporulat ion were absent. The stale of maintenance was characterized by low met abolic activity of the cells; after the supply of the substrate was cu t off the cells underwent lysis without spore formation. The growth an d sporulation of bacilli in batch and dialysis cultures, and spore ger mination on a full-value medium were described well enough by a modifi ed synthetic chemostatic model. The results of simulation allowed the conclusion that the change of bacilli to a state of maintenance was as sociated 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.