Simultaneous enzymatic synthesis of gluconic acid and sorbitol. Continuous process development using glucose-fructose oxidoreductase from Zymomonas mobilis.

The production of sorbitol and gluconic acid by isolated glucose-fructose oxidoreductase (GFOR) from Zymomonas mobilis has been studied in a convective, 100-mL loop reactor with tangential ultrafiltration. Using a dilution rate of 0.04/h and 5 kU/L GFOR, substrate conversion (3 M sugar) in a single stage was >85%, and productivities of 126 g sorbitol/(L x d) were obtained.