Catalase (CAT; EC 1.11.1.6)
Catalase activity was determined as H2O2 consumption measured by the decrease in absorbance at 240 nm according to the method of Aebi (1983). The assay buffer contained 50 mM KH2PO4/K2HPO4 (pH 7.0), 10 mM H2O2. Extinction coefficient of 39.4 mM-1cm-3 was used to calculate activity. Enzyme activity was expressed in μM H2O2 hydrolyzed per min.