Immobilization of tropizyme-P on amino-functionalized magnetic nanoparticles for fruit juice clarification

Nowadays nanoparticles are widely used as a key tool for enzyme immobilization. Tropizyme-P, a pectolytic enzyme was successfully immobilized on amino functionalized magnetic nanoparticles (AMNPs) using glutaraldehyde as a cross-linking agent at 15 mM concentration and 4h cross-linking time. The average size of the synthesized AMNPs was found below 80 nm by particle size analyzer. The binding of tropizyme-P on nanoparticles was confirmed by FTIR spectroscopy. SEM analysis revealed that there was no significance difference in the size of nanoparticles after tropizyme-P immobilization. XRD results showed no phase change in nanoparticles after enzyme immobilization. Physical parameters viz. pH and temperature were optimized. The pH was found to be same and there was shift in optimum temperature of immobilized tropizyme-P by 5oC. Immobilized tropizyme-P had more thermal stability than free one. The kinetic studies revealed an increase in V max of the immobilized enzyme. Reusability of immobilized tropizyme-P was found to retain upto 85% of initial activity after sixth cycles of reuse.