Characterization of Extracellular Phytase Produced from Bacillus subtilis

Introduction: Phytase enzyme catalyzes the hydrolysis of phytate, an anti-nutrient compound present in cereals and grains, to release orthophosphate and myo-inositol hexakisphosphate with lower degrees of phosphorylation, with metal ions, proteins, and starch chelated to phytate naturally. The study aimed to screen potential phytase-producing bacterial isolates and characterize the extracellular phytase of the bacterial isolate with the best phytase activity. Methods: A promising isolate (R5-C2-C4) out of thirty tested bacterial strains, which showed the best hydrolysis efficiency on Phytase Selective Medium (PSM) plates, was selected to investigate phytase production in Liquid Phytase Selective Medium (LPSM) under constant conditions of 37°C and pH 7.0 during a 72-hour incubation period, with measurements taken at 24-hour intervals using phytase production activity assay. Results: The local isolate Bacillus subtilis (C4) was found to produce significantly the highest phytase activity of 0.818 Unit/ml out of the tested isolates during 72 h of incubation at 37°C with the pH of 7.0 as a characterization of crude phytase. Discussion: Enzyme activity and stability under varying pH and temperature conditions are always a significant challenge during food and feed processing. Most studies indicate that bacterial phytase and especially Bacillus sp. phytase had a pH optimum of (6.5-7.5), and optimum temperature of (35-60)°C, where the phytase parameters of this study isolate, Bacillus subtilis found to be in the same range. Conclusion: The local isolated Bacillus subtilis produces its significant amount of phytase with ideal production parameters, which would considerably make it useful for applications in feed and food.