Synthesis, Modification, and Characterization of Fe3O4@SiO2-PEI-Dextranase Nanoparticles for Enzymatic Degradation of Dextran in Fermented Mash

During the sugar production process, undesirable compounds such as dextrans are produced and contaminate the flow of the sugar mill, reaching levels in the fluid of more than 10,000 ppm. Dextranase is an enzyme that has different industrial applications, since it catalyzes the hydrolysis of the bonds in random sites of the dextran. Therefore, the enzyme was immobilized using synthesized ferrite magnetic nanoparticles to degrade dextran in the fermented mash, because it is suitable to reuse and has a large surface area to bind dextranase on a solid carrier for easy magnetic separation. The synthesized bare and modified nanoparticles were characterized using SEM, EDS, FTIR, and XRD and confirmed the core–shell silica by increasing the silica composition from 0.2% of bare Fe3O4 NPs to 31.3% of modified Fe3O4 NPs. Ultrasonic treatment reduced the calculated crystal size with Scherer’s equation from 91.3 to 13.5 nm, providing more particles for immobilization. The solvothermal process synthesized ferrite nanoparticles (Fe3O4) and modified them with TEOS and PEI. The obtained immobilization efficiency was 28%. Perhaps it was lower; Fe3O4 degraded almost the same as the free enzyme. The percentage of dextran degradation with free enzymes and immobilized enzymes with Fe3O4 magnetic nanoparticles was 61 and 52%, respectively.