STORAGE STABILIZATION OF ENZYME-ACTIVITY BY POLY(ETHYLENEIMINE)

The effect of mixing penicillin acylase with poly(ethyleneimine) is di scussed. The properties of the polymer-enzyme system were evaluated fo r a wide range of enzyme concentrations (0.3-45.5 mg/cm(3)) and poly(e thyleneimine) concentrations (0.0001-10 % wt.). It was shown that addi tion of poly(ethyleneimine) to crude enzyme preparation caused precipi tation of ballast protein and stabilization of the enzyme fraction rem aining in the supernatant. The soluble fraction had stable activity fo r 21 days storage at 37 degrees C while the native enzyme lost about 8 0 % of its initial activity. Additionally, it was ascertained that the polymer very slightly affected the properties of penicillin acylase i n the PEI-enzyme preparations. Finally, possible ways of using the pol ymer-enzyme preparations in a membrane reactor are suggested.