Immobilization of avocado phytase on epoxy-activated Sepabead EC-EP and its application in soymilk phytate hydrolysis

There is a great demand for using phytases to reduce phytate content in animal feed stuffs and food for human consumption. Industrial application of phytase requires efficient methods to immobilize the enzyme, yielding a biocatalyst with high activity and stability compared to the free enzyme. In the present study, phytase was immobilized on Sepabead EC-EP and then used in the biodegradation of soymilk phytate. The immobilized enzyme exhibited an activity of 0.1 U per g of carrier and activity yield of 70.83%. Optimum temperature and pH for the immobilized enzyme were 55 degrees C and 5.5, respectively. Both the enzymes were stable between pH 3.0-8.0 and below 70 degrees C. Kinetic parameters(K(m) and V(max)) and the usability of the immobilized enzyme were determined. The immobilized enzyme hydrolyzed 65% of soymilk phytate in 8 h at 60 degrees C, as compared with 56% hydrolysis observed for the native enzyme over the same period of time.