Cyclic 3′;5′ adenosine monophosphate-phosphodiesterase and the release of catabolite repression of β-galactosidase by exogenous cyclic 3′;5′ adenosine monophosphate in escherichia coli

The level of cAMP-phosphodiesterase was much lower in cells of E. coli K-12 grown in glucose-containing medium than in glycerol-containing medium. When in addition to glucose the growth medium contained also cAMP, the level of this enzyme increased to that observed in the glycerol-grown cells or even higher. This enzyme reduced the efficiency of exogenous cAMP in releasing catabolite repression.