Performance of immobilized pectinex ultra SP-L on magnetic duolite-polystyrene composite particles. Part II: A magnetic fluidized bed reactor study Original Research Article

Pectinex Ultra SP-L immobilized magnetic duolite-polystyrene particles were used in a magnetic fluidized bed reactor. Enzyme activity was determined by the refractive method. The maximum activity of the enzyme in immobilized form was observed at 55 °C and pH 5. It was found that an increase of the flow rate of the substrate caused a decrease in the enzyme activity. Michaelis–Menten constant and maximal reaction rate were found as 0.439 g L−1 and 44.8 g L−1 s−1, respectively for the free enzyme. The apparent values of these terms for the immobilized enzyme were calculated as 4.416 g L−1 and 5.5 × 10-5 g s−1 g particles−1, respectively. Although the activity of the immobilized enzyme was increased by the increase of the reaction temperature up to 55 °C, the reaction stability was found poor at 55 °C.