Abstract

• Peroxidase (PODs, E.C.1.11.1.7) catalyzes the oxidation of H2O2 and guaiacol forming the product tetraguaiacol and water. In this study partially purified peroxidase enzyme was extracted from fresh bitter gourd by ammonium sulphate precipitation method. Guaiacol was used as a substrate for peroxidase activity determination by using UV-visible spectrophotometer. Protein content of enzyme solution was determined by Biuret method. The specific activity of peroxidase was 0.6361 U mL-1 and the enzyme was purified 1.99 fold over its crude extract. The optimum pH of peroxidase was 6.0 in phosphate buffer and optimum temperature was 40 ˚C. The values of Km and Vmax treated statistically using the linear regression method were compared with various graphical methods (Michaelis-Menten, Lineweaver-Burk, Eadie-Hofstee and Hanes-Wilkinson). The Km and Vmax values of peroxidase were found to be 0.514 x10-2 M and 26.853 M min-1 , respectively, from Lineweaver-Burk plot. The reaction order for peroxidase-catalyzed reaction of conversion of guaiacol to tetraguaiacol was found to be first order. The activation energy (Ea) of peroxidasecatalyzed reaction was calculated to be 3.592 kcal mol-1 . The decolourisation of methyl orange (MO) by crude peroxidase from bitter gourd was studied by using spectrophotometric method.