用于修饰淀粉的碳水化合物酶

Carbohydrate Enzymes for Structured and Modified Starch

用各种碳水化合物酶处理的被修饰淀粉的功能特性在食品科技界被广泛关注。酶被用于修饰淀粉,改变其结构特性,以便在食品和其它工业中应用。水解直链淀粉的酶如环糊精降解酶能用于生产各种直链淀粉。当去比例酶与淀粉反应,支链淀粉的支链将被改变,得到的被修饰淀粉在冻融过程中很稳定,在食品工业中有极大的应用前景。作者试图将地衣芽孢杆菌(bacilluslicheniformis)中的麦芽基因淀粉酶(maltogenicamylase)基因引入土豆基因组来改造土豆淀粉,生产新型碳水化合物。在该转基因土豆淀粉中,支链淀粉的支链长度有重新分配。

The functional properties of modified starch produced by treatment of various carbohydrate enzymes are of great interest in food biotechnology. For new applications in food and any other industries, many biotechnological attempts have been made to modify starch and to change its structural properties by enzymes. An amylose-varied starch can be produced by amylose-hydrolyzing enzyme such as cyclodextrin-degrading enzyme. When a disproportionating enzyme reacts with starch, the side chains of amylopectin can be altered. The resulting modified starch is freeze-thaw stable and shows a great potentials for being utilized in food industry. We also attempted to engineer potato tuber to produce novel carbohydrate by introducing the gene corresponding to maltogenic amylase from Bacillus licheniformis into the potato chromosome. The redistribution of side chain length of amylopectin were observed in transgenic starch.