Cells of Aspergillus oryzae IPT-301 rich in fructosyltransferase (FTase) were successfully immobilized by crosslinking with glutaraldehyde and used for the transfructosylation reaction of sucrose. The glutaraldehyde concentration and pH used in the immobilization process were optimized for maximizing the transfructosylation activity (A_T) and minimizing the hydrolytic activity (A_H). Also, the operational stability and the influence of temperature, pH and sucrose concentration on the enzymatic activities of the free and crosslinked cells were evaluated. Both the maximum A_T and minimum A_H were obtained for cells immobilized with glutaraldehyde concentration of 2.1% (v/v) and pH 7.9. Crosslinked cells showed considerably higher A_T/A_H ratio than free cells at several temperatures, pH and sucrose concentrations in the reaction media. Kinetics data suggested that crosslinked cells present higher substrate-enzyme affinity and transfructosylation rate than free cells. Furthermore, after 12 batch reaction cycles the FTase present in the immobilized cell kept 88.9% of its initial A_T, demonstrating a considerably higher operational stability than the FTase present in the free cell, which showed 50.3% of its initial A_T. These results suggest the potential use of crosslinked cells of Aspergillus oryzae IPT-301 for the large-scale production of fructooligosaccharides (FOS).

通过与戊二醛交联成功地固定了富含果糖基转移酶（FTase）的米曲霉IPT-301细胞，并将其用于蔗糖的反果糖基化反应。对固定化过程中使用的戊二醛浓度和pH进行了优化，以最大程度地提高反果糖基化活性（A _T）和最小化水解活性（A _H）。此外，评估了操作稳定性以及温度，pH和蔗糖浓度对游离和交联细胞的酶活性的影响。最大A _T和最小A _H对于固定有戊二醛浓度为2.1％（v / v）和pH值为7.9的细胞，获得了这些化合物。在几种温度，pH和蔗糖浓度的反应介质中，交联细胞显示出比游离细胞更高的A _T / A _H比。动力学数据表明，交联细胞比游离细胞具有更高的底物酶亲和力和反果糖基化率。此外，12间歇反应循环之后存在于所述固定化细胞的FT酶保持其初始的A的88.9％_Ť，证明比FT酶存在于无细胞的，这表明它的初始A的50.3％相当高的操作稳定性_Ť。这些结果表明米曲霉交联细胞的潜在用途 IPT-301用于大规模生产低聚果糖（FOS）。