AN AUTOMATED GLUCOSE-ISOMERASE REACTOR SYSTEM WITH ONLINE FLOW-INJECTION ANALYZERS FOR MONITORING OF PH, GLUCOSE AND FRUCTOSE CONCENTRATIONS

The literature on glucose isomerization with immobilized glucose isomerase has been reviewed with respect to thermodynamics and kinetics of the reaction and the industrial process layout. A laboratory scale fixed-bed reactor for isomerization of glucose with immobilized glucose isomerase has been constructed. A system for sample withdrawal and three flow injection analyzers-measuring glucose, fructose and pH-has been developed, automated and used to monitor the process. The equipment is controlled by a personal computer with interface expansion boards. The isomerization process has been monitored in steady-state operation as well as in pH transients. Using a commercial immobilized glucose isomerase (Sweetzyme Q from NOVO Industri A/S), the isomerization process has been studied with respect to equilibrium conversion, composition of the feed syrup, film diffusion resistance, enzyme deactivation and buffering effect of the immobilized enzyme. The experience from computerization of the equipment and the use of flow injection analyzers is summed up and the potential of such analyzers for monitoring biotechnological processes is discussed. © 1990.