Immobilization of lysozyme on layer-by-layer self-assembled electrospun films: Characterization and antibacterial activity in milk

Abstract

In this study, the electrospun cellulose acetate (CA) films were alternately deposited by lysozyme and sodium alginate (SA) on the nanofiber surface by layer-by-layer self-assembly technique. With the increasing number of layers, the films presented an increased average fiber diameter from 364 to 611 nm. The enhanced thermal stability was observed due to the layer-by-layer electrostatic deposition, as well as the formation of hydrogen bonds in the case of the CA(Lys-SA)9 film. The immobilized lysozyme exhibited the improved pH and temperature resistance, excellent storage stability, and retained over 70% of its initial activity after reusing 4 cycles. Moreover, these self-assembled films resulted in a substantial decrease in Staphylococcus aureus colonies in ultra-high temperature milk at 4 °C and 25 °C, respectively. The results suggested that the immobilization of lysozyme on layer-by-layer self-assembled electrospun films with antibacterial activity showed promising applications in milk and dairy products.