CONTROL DYNAMICS OF BETA-GALACTOSIDASE IN RELATION TO BACTERIAL CELL CYCLE

The dynamic behaviour of β‐galactosidase was studied in chemostat cultures of Escherichia coli B synchronized with respect to cell division by periodic phosphate feeding. Stable oscillations in the enzyme were observed when lactose was present at 0.02%. Perturbation experiments were used to study the stability of these states, and transient high‐frequency oscillatory responses were observed. These results show that the lactose control circuit has different dynamic states, which may be due to differences in the degree of damping or in the frequency of autonomous oscillations. The results are interpreted in terms of the interactions between the lactose control circuit and the cyclic physiology of the cell during the growth and division cycle. Copyright © 1969, Wiley Blackwell. All rights reserved