Improving the recycling and storage stability of enzyme by encapsulation in mesoporous CaCO3–alginate composite gel

Mesoporous CaCO3 microparticle-doped alginate composite gels were prepared and studied as efficient carriers for enzyme immobilization. β-Glucuronidase (GUS) was immobilized by first pre-adsorption on CaCO3 microparticles and then encapsulation in alginate beads. In this hybrid composite, alginate matrix effectively prevented the desorption of enzyme and inhibited the recrystallization of CaCO3, while the impregnated CaCO3 particles remarkably reduced the swelling of alginate hydrogel from 130% to 20%. As a result, GUS loading efficiency, recycling and storage stability were all significantly improved. Immobilized GUS retained 80% of its initial activity after seven recycles and 67% after storage for 27 days.