Evaluation of a Beta-propeller Phytase for its Application in Aquaculture (original) (raw)

The beta-propeller phytases are structurally different from the commercially available phytases, possess high thermal stability, an optimal temperature of 55 to 70°C, unique Ca2+-dependent catalytic properties, a pH optimum close to 7, and exhibit activity within a range of pHs that is broader than those of the histidine acid phytases. In this work, the performance of FTEII, a new beta-propeller phytase, was compared with those of three commercial phytases in terms of thermostability at 99°C, resistance to proteolysis by digestive enzymes, and their effectiveness for phosphorus (P) release from two feed ingredients. FTEII showed the highest thermostability with residual activity of 82±3 after 1.5 min treatment at 90°C. All phytases were resistant to shrimp digestive enzymes and to porcine trypsin, residual activities showed values higher than 60% in all cases. Total phosphorus released from each phytase-treated ingredient was time, temperature and type of ingredient dependent. FTEII...