Encapsulation of β-galactosidase from Aspergillus oryzae based on “fish-in-net” approach with molecular imprinting technique

By using tetraethylorthosilicate as a silica resource and triblock copolymer P123 as a template, the encapsulations of β-galactosidase with three different models of without protection, protection of protective agent and molecular imprinting technique pretreatment were accomplished through modified “fish-in-net” route at pH 5.0. The highest enzymatic activity of β-galactosidase was gained by using pretreatment of molecular imprinting technique. Scanning electron microscopy (SEM) images showed that the matrix of encapsulated β-galactosidase was made of an aggregation of uniform microspheres of 200–300 nm, and N2 adsorption/desorption isotherms demonstrated that the matrix of encapsulated β-galactosidase possessed average Brunauer–Emmett–Teller (BET) pore size of 27 Å and narrow pore size distribution. More importantly, compared with encapsulated β-galactosidase without protection, the hydrolytic activity of encapsulated β-galactosidase pretreated by molecular imprinting technique was about 3 times and 1.8 times, while the enzymatic activity of encapsulated β-galactosidase with the protection of protective agent increased only 1.3-fold when lactose and o-nitrophenyl-β-d-galactopyranoside (ONPG) were used as substrates, respectively. The protective effect of molecular imprinting technique pretreatment on the enzymatic activity after encapsulation was better than that by protective agent.