CATABOLITE REPRESSION OF ACONITATE HYDRATASE IN BACILLUS SUBTILIS

The synthesis of aconitate hydratase (citrate(isocitrate) hydro-lyase, EC 4.2.1.3) in Bacillus subtilis 168 is released from catabolite repression during nutrient-limited growth on media deficient in phosphate or nitrogen. Sulfate and tryptophan limitation lead to increased repression. The rate-limiting addition of adenosine increases the differential rate of aconitate hydratase synthesis in cultures of an adenine auxotroph of B. subtilis. The addition of adenosine to cultures gowing under nitrogen limitation causes a prolonged and complete repression of aconitate hydratase synthesis. It is concluded that restriction of anabolism itself does not cause an increase in catabolite repression in B. subtilis 168. The response of enzyme synthesis to nutrient deprivation depends on the nutrient limited. The data suggest that the effector of catabolite repression of aconitate hydratase is metabolically related to adenosine triphosphate. © 1968.