Enhanced Stability of Lactobacillus paracasei Aspartate Ammonia-Lyase via Electrospinning for Enzyme Immobilization

This study investigates the immobilization of Lactobacillus paracasei AAL (LpAAL) protein onto polyvinyl alcohol/nylon 6/chitosan nanofiber membranes using dextran polyaldehyde as a biodegradable cross-linker. Immobilization enhanced the enzyme's stability, shifting its optimal reaction conditions from 40 °C to 45 °C and pH from 8.0 to 8.5. While immobilization slightly reduced its catalytic efficiency, it significantly improved enzyme stability and reusability. The immobilized enzyme retained 85% of its initial activity after 7 days of storage at room temperature, compared to 55% for the free enzyme. Reusability tests demonstrated that immobilized LpAAL protein maintained approximately 50% of its activity after six consecutive reaction cycles, highlighting its robustness over repeated use. These results underscore the advantages of nanofiber-based immobilization in enhancing enzyme stability and utility for industrial applications, offering a practical approach to overcoming the limitations associated with free enzyme systems.