The enzyme phytase has broad biotechnological applications, especially in the reduction of phytate, antinutritional factors that chelate essential minerals, in human and animal food. We investigated the enzymatic properties of 尾-propeller phytase (BPP) from
Bacillus amyloliquefaciens DS11. Thermal refolding analysis demonstrated that BPP can remarkably restore its enzymatic activity in the presence of 5 mM Ca
2+ to 87% of its original activity after heating to 100 掳C and subsequent cooling, indicating that the enzyme requires Ca
2+ for appropriate refolding. Furthermore, pH-dependent kinetic studies showed that BPP required excess Ca
2+ for its enzymatic activity as the pH decreased, suggesting that the optimal Ca
2+鈥損hytate ratio for enzymatic catalysis depends on the pH value of the environment. Finally, we verified the practical application of BPP at two different pH鈥檚 using soybean meal as a natural source of phytate. As compared to a commercial phytase, BPP efficiently hydrolyzed food phytate over neutral pH ranges.
Keywords:
尾-propeller phytase; Ca2+鈭抪hytate salts; thermal refolding