Activity of magnetite-immobilized catalase in hydrogen peroxide decomposition

The present work analyzes the activity in decomposition of H₂O₂ using magnetite-immobilized catalase. The support of catalase is a glutaraldehyde-treated magnetite (Fe₃O₄). The data obtained in the H₂O₂ decomposition are analyzed. The fitting of the initial rate of the H₂O₂ decomposition versus hydrogen peroxide concentration data is discussed using a specific program for enzyme kinetics modeling (Leonora). The free catalase from Aspergillus niger (3.5 or 10 U/mL) does not show substrate inactivation up to 0.4 M H₂O₂. The immobilized catalase at low catalyst concentration shows substrate inhibition. Using 1 mg/mL of supported catalase the predicted maximum activity is higher than in the case of the free catalase at similar catalase concentration, although the optimum temperature is lower (40 °C versus 60 °C).