Effects of Calcium and Vanadium Ions on the Epoxidation of Cyclohexene with H2O2 Catalyzed by Vanadium Bromoperoxidase

Vanadium bromoperoxidase (v-bpo) from a marine macro-alga corallina officinalis can catalyze the epoxidation of cyclohexene in the presence of kbr to form epoxycyclohexane using h2o2 as the oxidant. a process intensification strategy has been developed by the integration of v-bpo pretreatment, continuous feeding of h2o2, and optimizing reaction conditions in order to improve the epoxidation productivity. the bpo activity and thermostability increased significantly when the v-bpo solution was dialyzed with a buffer containing 1.0 mmol/l vanadium ion and 1.0 mmol/l calcium ion. the apparent enzyme activity was improved when the h2o2 was fed continuously using a constant flow pump. when combined with the optimal reaction conditions (including buffer, ph, temperature, enzyme concentration, and kbr and h2o2 concentrations), the space-time yield of epoxycyclohexane and its yield to hydrogen peroxide reached 4.79 g/(l.h) and 74%, respectively. these values are 78% increasing than the highest values reported previously.