Induction of GalK. (A) Growth of L. casei 64H cultures. At time zero, carbohydrates were added to the cultures. (B) Specific activity of GalK at different points after induction. The curve is representative for five independent experiments, which all showed the drastic drop of activity for the 4-h value. ▴, LCM; ▪, LCM plus galactose; ○, LCM plus lactose.