Development of a novel ultrasound- and biocrosslinking-enhanced immobilization strategy with application to food enzymes.

The increasing demand for greener food production makes biocatalysts more desirable than traditional production approaches. One limiting factor for biocatalyst efficiency is the immobilization strategy. In this work, a novel immobilization method was developed with the tyrosine-tag crosslinking mechanism. The immobilization efficiency was further enhanced with ultrasound treatment. Such a strategy was proven to be efficient with food enzyme lipase, d-amino acid oxidase and glucose dehydrogenase when they were immobilized on macroporous resins, amino resins, epoxy resins, and multiwalled carbon nanotubes. For lipase, glucose dehydrogenase and d-amino acid oxidase, the immobilization yield on macroporous resins increased by 20.4%, 21.1% and 24.1%, respectively. In addition, the immobilized enzymes had enhanced reusability, with a high degree of activity (more than 85%) detected after six cycles. Furthermore, the enzyme electrochemical sensors constructed by enzyme crosslinking have higher sensitivity, with peak currents 4-8 times those of sensors with uncrosslinked enzymes. The enzyme immobilization strategy developed in this study paves the way for better application of biocatalysts in the food industry.