Immobilized glucose oxidase on different supports for biotransformation removal of glucose from oligosaccharide mixtures

Four immobilized forms of glucose oxidase (GOD) were used for biotransformation removal of glucose from its mixture with dextran oligosaccharides. GOD was biospecifically bound to Concanavalin A-bead cellulose (GOD-ConA-TBC) and covalently to triazine-bead cellulose (GOD-TBC). Eupergit C and Eupergit CM were used for preparation of other two forms of immobilized GOD: GOD-EupC and GOD-EupCM. GOD-ConA-TBC and GOD-EupC exhibited the best operational and storage stabilities. pH and temperature optima of these two immobilized enzyme forms were broadened and shifted to higher values (pH 7 and 35 °C) in comparison with those of free GOD. The decrease of Vmax values after immobilization was observed, from 256.8 ± 7.0 μmol min−1 mgGOD−1 for free enzyme to 63.8 ± 4.2 μmol min−1 mgGOD−1 for GOD-ConA-TBC and 45 ± 2.7 μmol min−1 mgGOD−1 for GOD-EupC, respectively. Depending on the immobilization mode, the immobilized GODs were able to decrease the glucose content in solution to 3.8–15.6% of its initial amount The best glucose conversion, was achieved by an action of GOD-EupCM on a mixture of 100 g dextran with 9 g of glucose (i.e. 98.7% removal of glucose).