SiO ₂ -CS Nanocomposite Carriers Immobilized Phospholipase D

Synthesis of rare phospholipids using phospholipase D is phosphatidyl transfer reaction catalyzed in order to improve the reuse of the number of free phospholipase D, to reduce macro carrier in the immobilized enzyme system in the dual-phase mass transfer resistance object. In this paper, different nano-size SiO2and chitosan composite materials for the preparation of nano-carrier, and then using adsorption, absorption-aggregation method and adsorption-gathering-crosslinking method different types of immobilized enzyme. By measuring the immobilized phospholipase D enzyme activity and reaction rate, the conditions for its preparation optimized. Finally Kinetic immobilized phospholipase D to explore, build relevant physical models.The use of acid-base neutralization of acid precipitation SiO2to evenly cover the surface of the SiO2different size. Particle size were successfully prepared25nm,50nm, three different sizes of100nm nano SiO2-CS composite carrier, by measuring the carrier chitosan nanocomposite loading and surface amino content, optimizing its preparation conditions access to the most good raw material is: SiO2mass ratio of chitosan and0.1, the alkali concentration4mol/L. Characterization of the composite carrier and its stability studies Description: chitosan wrapped in SiO2surface without destroying the relevant functional groups, and nano-SiO2-CS composite carrier stable structure. Comparison of different size composite carrier that: the smaller the particle size, the better the performance of nano-composite carrier.With different size SiO2-CS as a carrier, respectively, using adsorption, absorption-crosslinking, adsorption-gather-prepared by crosslinking the immobilized enzyme, and by measuring the enzyme activity of the immobilized enzyme catalyzed reaction rate derived: adsorption-aggregation-crosslinked immobilized enzyme prepared the best performance, it combines adsorption, cross-linking method advantages, while avoiding their disadvantages as far as possible. Its catalytic activity is adsorption-crosslinking of3.25times,1.44times the adsorption method. Process for preparing the optimal conditions are:adsorption time is2h, the solution concentration of5%glutaraldehyde, as crosslinking time2h, ethanol and the enzyme solution volume ratio of0.5. Finally, the preparation of the immobilized enzyme activity up to1.30U/g.Ping-pong mechanism with phospholipase D reaction is catalyzed bisubstrate principle Kinetic nanocomposite carrier for immobilized phospholipase D were analyzed to establish the relevant kinetic equations. The results showed that: nano-composite carrier particle is small, therefore, pass in catalysis small transfer resistance, when the speed reaches200rpm, the impact is negligible diffusion resistance. After dynamics simulation Matlab language, intuitive dynamics equations can be analyzed. Immobilized phospholipase D efficient catalytic activity and stability are well represented. The results can be used as reference for industrial applications.