Control Mechanisms Operative in a Natural Microbial Population Selected for Its Ability to Degrade L-Lysine. II. Effects of Fructose and Ribose in Batch Systems

A natural microbial population was acclimated to L-lysine as the sole carbon source when ammonia nitrogen was provided in the medium. Fructose exerted a slight retarding effect upon the metabolic removal of lysine. The response was due to catabolite repression of the inducible enzyme system responsible for lysine degradation. Inhibition of activity of preformed enzymes played no part in the response. Ribose caused a slight increase in the rate of synthesis of lysine-degrading enzymes.