ABSTRACT
Invertase from Saccharomyces cerevisiae was immobilized on agarose beads, activated with various groups (glyoxyl, MANAE or glutaraldehyde), and on some commercial epoxy supports (Eupergit and Sepabeads). Very active and stable invertase derivatives were produced by the adsorption of the enzyme on MANAE-agarose, MANAE-agarose treated with glutaraldhyde and glutaraldehyde-agarose supports. At pH 5.0, these derivatives retained full activity after 24h at 40 ºC and 50 ºC. When assayed at 40 °C and 50 °C, with the pH adjusted to 7.0, the invertase-MANAE-agarose derivative treated with glutaraldehyde retained 80% of the initial activity. Recovered activities of the derivatives produced with MANAE, MANAE treated with glutaraldehyde and glutaraldehyde alone were 73.5%, 44.4% and 36.8%, respectively. These three preparations were successfully employed to produce glucose and fructose in 3 cycles of sucrose hydrolysis.
Invertase de Saccharomyces cerevisiae foi imobilizada em agarose ativada com diferentes grupos (glioxil, MANAE ou glutaraldeído) e suportes epóxidos comerciais (Eupergit e Sepabeads). Derivados de invertase ativos e estabilizados foram produzidos pela adsorção da enzima em suportes MANAE-agarose, MANAE-agarose tratado com glutaraldeído e glutaraldeído-agarose. Em pH 5,0 estes derivados retiveram total atividade até 24h a 40 ºC e 50 ºC. Quando os ensaios foram a 40 °C e 50 °C com o pH alterado para 7,0, o derivado invertase-MANAE-agarose tratado com glutaraldeído apresentou 80% da atividade inicial. As atividades recuperadas dos derivados foram 73,5%, 44,4% e 36,8%, respectivamente para MANAE, MANAE tratado com glutaraldeído e glutaraldeído. Essas três preparações foram empregadas com sucesso em 3 ciclos de hidrólise da sacarose para produzir glicose e frutose.