Purification and Characterization of Sweet Potato

Peroxidase (POX), a biotechnologically important enzyme was purified from bulb of Ipomoea batatas and characterized for use in the bioconversion of phenolic compounds from industrial wastewater. Purified peroxidase (POXp) was obtained using the gel-filtration chromatography and anion exchange chromatography. A final yield of 18 % was obtained with 20.5 as purification fold. Electrophoresis on SDS-PAGE and native-PAGE showed that POXp is monomeric with a molecular weight of 44 kDa. The optimum pH and optimum temperature were respectively 6.0 and 45 ° C. All enzyme activity was retained for 2 hours at pH values between 4.0 to 9.0. While the enzyme was partially inhibited by SDS, PCMB and sodium disulfide, it was completely inhibited by ascorbic acid, citric acid, sodium azide and sodium thiosulfate. The presence of Calcium (Ca2+), Copper (Cu2+), Barium (Ba2+), Manganese (Mn2+) and polyethylene glycol increased POXp activity but it was reduced by Magnesium (Mg2+), Sodium (Na+), Potassium (K+) and EDTA. However, Zinc (Zn2+) had no effect on POXp. The enzyme oxidized a wide range of phenolic substrates, the greatest rate of oxidation being obtained with guaiacol. These properties may allow the use of these enzymes fo