Immobilization of Phytase from Rice Bean (Vigna umbellata Thunb.) on Glutaraldehyde Activated Chitosan Microspheres
Journal of scientific research
The immobilization of phytase from rice bean was optimized on the glutaraldehyde-activated chitosan microsphere, and characterized. The optimum percent immobilization was 77.48%, when microspheres were prepared with 1.5% chitosan, activated with glutaraldehyde (0.5%, for 4 h) and with the enzyme protein (0.2 mg/mL, and coupling time 4 h). The immobilized phytase exhibited elongated fibres and pores. FTIR results suggest the formation of a Schiff base with a band at 1638 cm -1 . The pH and
... . The pH and temperature optimum of immobilized phytase was 4.0 and 40 °C, respectively. The energy of activation was 34.5 kJ/mol. The Km and Vmax values of immobilized phytase were 0.62 mM and 3.42 μmol/min. The immobilized enzyme when incubated at 50 °C, retained 59% activity after 75 min. The immobilized phytase showed 80% activity retention, after 14 days, when stored at 4 °C. The immobilized phytase could be reused for 4 cycles with 58% activity retention. The immobilized phytase, when incubated for 60 min in the presence trypsin and pepsin, showed 92.9 and 95% activity retention, respectively. The properties of immobilized phytase did not alter with respect to pH, and temperature optima. Immobilized phytase exhibited proteolytic resistance when incubated with pepsin for 1 h, and this can find application in animal feed.