Laboratory of Food Biochemistry, Department of Food Science, College of Food Engineering, State University of Campinas, Campinas, SP, Brazil.
J Biotechnol. 2012 Apr 15;158(3):137-43. doi: 10.1016/j.jbiotec.2012.01.012. Epub 2012 Jan 24.
Two different techniques of glucosyltransferase immobilization were studied for the conversion of sucrose into isomaltulose. The optimum conditions for immobilization of Erwinia sp. glucosyltransferase onto Celite 545, determined using response surface methodology, was pH 4.0 and 170 U of glucosyltransferase/g of Celite 545. Using this conditions more than 60% conversion of sucrose into isomaltulose can be obtained. The immobilization of glucosyltransferase was also studied by its entrapment in microcapsules of low-methoxyl pectin and fat (butter and oleic acid). The non-lyophilized microcapsules of pectin, containing the enzyme and fat, showed higher glucosyltransferase activity, compared with lyophilized microcapsules containing enzyme plus fat, and also lyophilized microcapsules containing enzyme without fat addition. The non-lyophilized microcapsules of pectin containing the glucosyltransferase and fat, converted 30% of sucrose into isomaltulose in the first batch. However the conversion decreased to 5% at the 10th batch, indicating inactivation of the enzyme.
两种不同的葡萄糖基转移酶固定化技术被用于将蔗糖转化为异麦芽酮糖。使用响应面法确定了将欧文氏菌属葡萄糖基转移酶固定到 Celite 545 上的最佳条件为 pH4.0 和 170U 葡萄糖基转移酶/g Celite 545。使用这些条件可以获得超过 60%的蔗糖转化率。还通过将葡萄糖基转移酶包埋在低甲氧基果胶和脂肪（黄油和油酸）的微胶囊中来研究其固定化。与含有酶和脂肪的冻干微胶囊相比，不含冻干的含有酶和脂肪的果胶微胶囊显示出更高的葡萄糖基转移酶活性，并且也与含有酶但未添加脂肪的冻干微胶囊相比。含有葡萄糖基转移酶和脂肪的非冻干果胶微胶囊在第一批中可将 30%的蔗糖转化为异麦芽酮糖。然而，在第 10 批时转化率下降到 5%，表明酶失活。
