1. An experimental system suitable for the study of enzyme formation has been described.
2. The formation of ß-galastosidase in E. coli B could be induced by lactose, melibiose, D-galactose and ß-methyl-D-galactoside.
3. Lactose-induced ß-galactosidase formation was found to be inhibited by D-glucose, D-mannose, D-fructose, D-arabinose, and raffinose.
4. The utilizable structural analogue, D-glucose, was found to either stimulate or inhibit ß-galactosidase formation depending upon its concentration. D-Arabinose, on the other hand, a non-utilizable structural analogue, is only capable of inhibiting, whereas succinic acid, a structurally unrelated energy source, is only capable of stimulating ß-galactosidase formation.
5. D-Arabinose inhibition of lactose-induced ß-galactosidase formation was found to be of the competitive type.
6. Some of the implications of these findings have been discussed.
