KINETICS OF GROWTH AND PRODUCT FORMATION IN CULTURES FROM STREPTOCOCCI OF GROUP-A AND GROUP-C

During growth of streptococci of Lancefield groups A and C in a cultur e medium containing glucose, yeast extract and peptone, two main growt h phases occur: growth phase I and growth phase II (diauxic growth). T hey are separated by a short stationary phase (1st stationary phase). The diauxic growth is caused by transient limitations as well as the a vailability of new sources of the amino acids L-serine and L-arginine. Growth phase I consists of an exponential and a nearly linear part. T hese growth kinetics are reflected by the kinetics of gas metabolism a s well as by product formation. Hyaluronic acid is formed during the n early linear phase whereas the enzyme alkaline phosphatase, is exclusi vely excreted in the 1(st) stationary phase. Also carbon dioxide and L -lactate are mainly produced in a growth phase-dependent mode. In the late stationary phase (2(nd) stationary phase) more oxygen is consumed whereas the demand for oxygen in the 1(st) stationary phase is nearly zero.