Research on Immobilization of Trehalose Synthase on Polyacrylonitrile

Abstract:

The crude trehalose synthase is immobilized on polyacrylonitrile membrane by adsorbtion. The optimal conditions of immobilization is research and the properties of immobilized enzyme by single factor method is analyzied. The results show that the optimum immobilization conditions are：pH 7.6，30 ℃ for 3 h with 0.1 mg trehalose synthase per square centimeter PAN membrane. The optimal reaction conditions of the immobilized trehalose synthase are 7.4，40 ℃ and initial substrate concentration 200 g/L. Compared with the free trehalose synthase，the thermal stability increases by 10 ℃，pH stability expande from pH 6.6 ~ 7.4 to pH 5.4 ~ 8.0. The max trehalose content is 50.9% when the reaction reached equilibrium，the by-product of glucose content is 9.1%，which reduced by 6 percentage points compared with the free enzyme and is the lowest byproduct content of the reported immobilization trehalose synthase. Under the optimum reaction conditions of pH 7.4，40 ℃，substrate concentration 200 g/L，the immobilized enzyme remains 64.4% of the initial enzyme activity after repeating used for 72 h.