Decolorization of direct dyes using peroxidase from raphanus sativus (F04 SL)

An acidic peroxidase was isolated and partially purified from raphanus sativus. the purified enzyme was characterized in terms of kinetics and thermodynamic aspects. finally the enzyme was assessed to see its potential for decolorization of direct dyes. the specific activity of raphanus sativus peroxidase increased from 44.77 to 65.20 u/mg of protein using 80 % ammonium sulphate precipitation. the optimum ph and temperature of the enzyme was 4 and 55 °c respectively. the activation energy of raphanus sativus peroxidase was 25.44 kj/mol and average value of k m was 0.25 mm. the activation energy of thermal denaturation of raphanus sativus peroxidase was 17.79 kj/mol. it was observed that with an increase in temperature,there was decrease in a half life and enthalpy,which showed that the enzyme was unstable at higher temperature. a maximum decolorization of 97 and 77 % was observed for solar blue a and solar flavine 5g at ph 4 and temperature 50 °c respectively. it was observed that % decolorization of both the dyes increased with an increase in enzyme units and incubation time. h2o2 dose of 0.8 mm for solar blue a and 0.7 mm for solar flavine 5g was sufficient for the maximum dye degradation.