Inhibition, Repression and Induction of Phosphatase Activity in a Salt Lake Sediment

The inhibitory/repressive effect of the final reaction product (inorganic o-phosphate) and the inducing effect of a substrate (β-glycerophosphate) on the phosphatase activity and synthesis in a salt lake sediment were studied. The determinations have been differentially carried out, for acid, neutral and alkaline phosphatase, and in reaction mixtures without buffering. The acid phosphatase activity was the most intense, and the alkaline phosphatase activity was the lowest. The inhibitory effect was obvious at 0.2 and especially at 2 mg PO4 3––P/ml concentration, without significant differences between the four types of activities. A significantly negative correlation has been established between the concentration of added inorganic o-phosphate and the intensity of phosphatase activity. Both the repressive effect of inorganic o-phosphate and the inducing effect of β-glycerophospate were stronger in the case of acid phosphatase synthesis. In the case of acid phosphatase, the inducing effect of β-glycerophosphate prevailed over the repressive effect of inorganic ophosphate. In the other three cases, the repressive effect of the final reaction product was dominant.