Continuous enzyme-catalyzed production of 6-aminopenicillanic acid and product concentration by reverse osmosis

The efficiency of 6-aminopenicillanic acid (6-APA) production by enzyme-catalyzed hydrolysis of penicillin G using penicillin G amidase (E. C. 3.5.1.11) immobilized in polyacrylamide gel can be improved by using a lower substrate concentration and an optimized low buffer concentration. In a continuous process the combination of a stirred-tank reactor and a plug-flow reactor gives optimum productivity. Since precipitation of 6-APA is the crucial step in downstream processing, the product concentration has to be as high as possible. This can be achieved by concentrating the product solution by reverse osmosis.