Immobilized enzyme systems are widely used in industrial settings. Activity retention and storage stability of immobilized enzymes remains an important challenge in medical, diagnostics, and food applications. Immobilized enzymes are often incorporated into bioactive packaging and continuous processing systems in the food industry. Traditional immobilization methods are limited by the total protein attached to the modified surface, by restricted access between the enzyme and the substrate, and by denaturation resulting from immobilization processes. Using electrospun nanofibers as enzyme supports can overcome the difficulties that result from traditional immobilization by increasing the surface area available for material modification and allowing for easy access to enzymes due to the non-woven fiber's porosity, while remaining stable in long-term storage. In this study, lactase was electrospun into polyethylene oxide nanofibers with Pluronic F-127 (polyethylene oxide / polypropylene oxide copolymer nonionic surfactant). The nanofibers were characterized by electron microscopy to be cylindrical fibers, and had an average diameter of 305 nm with a minimum and maximum diameter of 114 nm and 562 nm respectively. The total protein loaded onto the nanofiber measured up to 8.832 �g. After electrospinning, enzymes retained 92% of their native (free, purified) activity. After 4 weeks storage, the immobilized enzyme fiber retained up to 63% of the activity of the original fiber.  These results suggest that immobilizing enzymes in a polymer nanofiber matrix can improve activity retention and storage stability compared to traditional immobilization methods.

Improving lactase stability by preparation of polymer nanofiber composites

247th National Meeting (2014)

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