Elevated Cyclic Adenosine 3′, 5′ Monophosphate Enhances Lactic Acid Production by Streptococcus lactis

Abstract

Elevation of cyclic adenosine 3′, 5′ monophosphate levels induced by prostaglandin E1 enhanced growth of Streptococcus lactis C2 in a medium supplemented with lactose. The prostaglandin E1-induced enhancement of growth did not appear to result from stimulation of the phosphoenolpyruvate phosphotransferase system because o-nitrophenol-β-D-galactopyranoside phosphorylation was not elevated by prostaglandin E1, treatment. Measurement of the extracellular proteolytic activity revealed increased activity in prostaglandin E1-treated cultures suggesting that an increase in the organic nitrogen source contributed to increased growth rate. Moreover, elevations in intracellular cyclic adenosine 3’, 5’ monophosphate induced by prostaglandin E1 treatment increased lactic acid production at the cellular level.