Purification and Characterization of Phytase from Novel Slated Bacillus cereus EME 48 and Study its Kinetic Properties

Phytase (myo-inositol-hexakisphosphate phosphohydrolase, (EC 3.1.3.8) has been purified from a novel isolated Bacillus cereus EME 48, from environmental samples based on their ability. The enzymes were purified and characterized, using a three-step purification procedure with 12.3-fold. The optimum pH for phytase activity was in the range of 4.0 to 5.0 and the optimum temperature was 40 to 60[degrees]C for 10 min. The metal ions Mg[Cl.sub.2], Co[Cl.sub.2], Ni[Cl.sub.2] and K[Cl.sub.2] did not show any inhibitory effect on the phytase activity of Bacillus cereus EME 48. Strongly inhibited by Fe[Cl.sub.2], Na Florida, EDTA, DTT, Al[Cl.sub.3] and Zn[Cl.sub.2] but significantly stimulated by Mg[Cl.sub.2], Ba[Cl.sub.2], Mn[Cl.sub.2] and Cu[Cl.sub.2]. The enzymes were active in the pH range of 5.0 to 6.5 with pH optima at 5.5. The enzyme from Bacillus cereus EME 48 retained about 80% activity up to 75[degrees]C. It was highly specific to sodium phytate as the substrate. Km for phytate was estimated to be 0.23 mmol and especially for penta- and tri-phosphate esters of myo-inositol. Due to their relatively high specific activity, substrate specificity, good pH profile and thermostability, the enzymes could be interesting candidate for agricultural and feed application. Keywords: Microbial phytase, Isolate, Bacillus cereus purified and characterized.