Cyclic AMP phosphodiesterase activities in growing cells of baker's yeast (Saccharomyces cerevisiae).

The activities of two cyclic AMP phosphodiesterases of baker's yeast (Saccharomyces cerevisiae) were measured during diauxic batch growth on 2% glucose. The specific activity (units/mg of yeast protein) of the Mg-independent, high Km phosphodiesterase increased 20-fold throughout the 108 h cultivation. The specific activity of the Mg-dependent, low Km phosphodiesterase about doubled during glucose utilization and fell back to the initial level as the cells entered stationary phase.