Facing the problem of phosphorus deficiency in animal feed and the problem of phosphorus pollution in areas of intensive livestock production, Phytase seems destined to become increasingly important. Phytase activity was measured at 55 °C in a buffer containing 200 mM sodium acetate, pH 5.5 and 1 mM CaCl2. The activity of phytase was calculated as release of inorganic phosphate (Pi) per minute. Activity response to pH was examined at 55 °C using a 0.1 M glycine buffer in the pH ranges of 2-4 and 9-10, 0.1 M sodium acetate buffer in the pH range of 4-6.5, and a 0.1 M Tris buffer in the pH range of 6-9. The optimum temperature was determined in 200 mM sodium acetate, 1 mM CaCl2 at pH 5.5 and 1.5 mM phytic acid as substrate in the range from 25 to 75 °C with 10 °C increments. Kinetic properties were estimated with sodium phytate as substrate. Initial velocity was determined at substrate concentrations ranging from 1.0–25.0 mM sodium phytate and double reciprocal plot of the data were constructed. The optimum temperature of phytate degrading activity of the extract was 55 °C and the Arrhenius energy of activation for the hydrolysis of sodium phytate by the phytase was 27.5 kJ.mol-1. The extract exhibits maximum activity at pH =5.5 with two other lower peaks of activity at pH =3 and pH= 8. This Result suggests that there are at least three isozymes for phytate degrading activity in this extract. When phytate were used as substrate, Km was 152 μM.
