Action of Urea on the Activity of Dehydrogenases and α-Glucosidase in Aerobacter aerogenes grown in Continuous Culture

Abstract

THE inhibition of enzymes by relatively high concentrations of urea and the protection afforded by various substances has been reported in some detail¹. In particular Sachar and Sadoff² have investigated the effect of glucose on the inactivation caused by 8 M urea on glucose dehydrogenase (EC 1.1.1.47 β-D-glucose : NAD(P) oxido-reductase) isolated from spores of Bacillus cereus. We have studied the action of urea on the activity of various dehydrogenases in intact cells of Aerobacter aerogenes grown in the chemostat. In this technique one of the constituents of the medium is kept in such short supply that the rate at which it is added controls the growth rate. If then the source of carbon is chosen as the limiting nutrient its protective action can be studied at low concentrations. Furthermore, in continuous culture true steady state levels of cellular properties are eventually obtained. The α-glucosidase (EC 3.2.1.20-α-D-glucoside glucohydrolase) activity has also been studied.