PURIFICATION AND CHARACTERIZATION OF RECOMBINANT PHYTASE

Abstract

Phytate is the major storage form of phosphorus. It accounts for more than 80% of the total phosphorus in some plant. Phytate acts as -an anti-nutrient factor by forming insoluble complexes with protein and metal ions in the intestinal tract, thereby prevents mineral absorption of monogastric animals. Therefore, the addition of phytase to animal feed does not only enhance the efficiency of phosphate utilization but also reduce the phosphorus pollution in areas of intensive animal production. The phyC gene coding for phytase derived from B. subtilis B 1 was expressed successfully in E. coli BL21 cells. In this report, we studied the characteristics of recombinant phytase to use in animial feed. As a result, phytase, purified by Hig tag column chromatographies, had an estimated molecular weight of 47 kDa on SDS - polyacrylamide gel electrophoresis. Study on the effect of chelating agent and metal ions showed that the enzyme was strongly inhibited by EDTA, Cu2 ion. Addition of Ca2 ion to the PhyC helped increase its temperature stability