Preparation and application of immobilized plant-esterase

The wheat straw is modified by using epichlorohydrin,ethanediamine and glutaraldehyde to prepare the immobilized material. The optimum immobilization conditions and characterizations of the immobilized esterase are investigated. The results show that the good immobilization effect can be achieved under the following conditions: 20 m L /g of crude enzyme( with respect to modified wheat straw),6 hours of immobilized time,35℃ of immobilization temperature and 7. 0 of p H. The recovery rate of the enzyme activity is 46%. The p H,thermal and storage stability of the immobilized enzyme are greatly improved. The Michaelis constant of the immobilized esterase is 41 mmol / L. The standard curve and method to determination of dichlorvos by enzyme inhibition are established. The linear ranges for the determination of dichlorvos are 1. 0 × 10- 4- 6. 25 × 10- 4mg / L. The detection limit is 0. 06 μg / L.