Co-imobilização das enzimas dextrana-sacarase e dextranase em suporte agarose-epóxido

Abstract

Enzymes are widely applied in the food industry. Among them, the enzyme dextransucrase has the ability to produce dextran in the presence of sucrose, while it synthesizes prebiotic oligosaccharides in the presence of an acceptor, examples being, glucose, maltose and fructose. Its immobilized form is useful for a more economical and efficient synthesis of these products. However, as it may not be immobilized easily, it can become an obstacle to its large-scale implementation. The co-immobilization with the enzyme dextranase is an alternative to improve its stability. The co-immobilization will form a multifunctional catalyst, which exhibits not only the desired catalytic activities of each enzyme individually, but also other functions due to their synergistic effect. This work aimed to co-immobilize dextransucrase and dextranase in epoxy-agarose support and to synthesize prebiotic oligosaccharides. The amount of epoxy-agarose support which was going to be used and the storage conditions were determined. Immobilization parameters such as yield, efficiency and recovered activity were analyzed, which presented the test with 1 mL of DS (26.16 UI) and 0.5 μL DN (2.76 UI) as being the best for these parameters. In the analysis of optimum temperature and pH, it was observed that the co-immobilized enzyme was able to expand the range of optimum activity in comparison with the free enzyme. The oligosaccharides produced by the synthesis were quantified by thin layer chromatography. The results showed that the co-immobilization was carried out successfully and allowed to produce oligosaccharides with degrees of polymerization up to 5, similarly to what was obtained by using the free enzymes.