PURIFICATION AND CHARACTERIZATION OF PHYTASE FROM Bacillus licheniformis PFBL- 03

Abstract

Phytase from Bacillus licheniformis PFBL-03 was purified in three steps by using ammonium sulphate precipitation, ion exchange chromatography on DEAE Sephadex A-50 and gel filtration chromatography on Sephadex G-100. The single protein band on SDS-PAGE suggested that the enzyme was homogeneous. The molecular weight determined from SDS-PAGE was 36 kDa. The enzyme yield was 10% while the purification fold was 39. The optimum temperature of the purified phytase was 55oC and the enzyme was relatively stable up to 80oC by retaining 55% of its original activity after 1 hour of incubation at that temperature. The purified enzyme had optimum pH of 6.0 and was stable over pH range of 4.0 to 7.5.The kinetic parameters Km and Vmax of the purified phytase were 4.7 mM and 49.01 μmol/min. The activity of the enzyme was enhanced in the presence of Ca2+, but completely inhibited by Fe2+, Mn2+ and Cu2+