Choline and betaine as inducer agents of Pseudomonas aeruginosa phospholipase C activity in high phosphate medium

In Pseudomonas aeruginosa, choline or betaine employed as the sole carbon and nitrogen source in a high phosphate medium induced a phopholipase C and an acid phosphatase activity but not an alkaline phosphatase activity. The P. aeruginosa strain utilized in this work does not possess a constitutive phospholipase C, since under culture conditions identical to those utilized by other authors (J. Bacteriol. 93, 670–674 (1967) and J. Bacteriol. 150, 730–738 (1982)), our phospholipase C proved to be an inorganic phosphate‐repressible enzyme. These findings enable us to conclude that although the phosphate control for the synthesis of phospholipase C may exist, it is expressed only under certain favorable culture conditions.