α-淀粉酶及其复合酶体系对淀粉酶解性能研究

Study on the Starch Enzymolysis Performance ofα-Amylase and Its Complex Enzyme System

研究了单一α-淀粉酶体系及α-淀粉酶与β-淀粉酶、普鲁兰酶、糖化酶组成的二元、三元、四元复合酶体系,对3种造纸常用变性淀粉(氧化淀粉、酶解淀粉、阳离子淀粉)的酶解性能,探究不同α-淀粉酶用量对淀粉分解率和DE值的影响。结果表明,在单一α-淀粉酶体系中,淀粉分解率达到90%时,阳离子淀粉酶解所需α-淀粉酶用量约为其他2种淀粉的4倍;酶解淀粉加入柠檬酸抑制Zn2+后,其淀粉分解率最大可提高37.4%;二元复合酶体系中,α-淀粉酶/β-淀粉酶对阳离子淀粉的分解率比α-淀粉酶/糖化酶及α-淀粉酶/普鲁兰酶分别高5.3%和8.7%;三元复合酶体系中,α-淀粉酶/糖化酶/β-淀粉酶对阳离子淀粉的分解率比α-淀粉酶/糖化酶/普鲁兰酶高1.2%。在将α-淀粉酶/糖化酶/β-淀粉酶/普鲁兰酶的四元复合酶体系应用于阳离子淀粉、酶解淀粉、氧化淀粉的酶解反应时,达到淀粉分解率80%所需α-淀粉酶用量分别为单一α-淀粉酶体系的56%、38%和17%。

This study investigated the enzymatic performance of singleα-amylase and binary,ternary,and quaternary complex enzyme systems consisting ofα-amylase withβ-amylase,pullulanase and glucoamylase for three commonly used modified starches(oxidized starch,enzymatically hydrolyzed starch,and cationic starch).The effect of differentα-amylase dosages on starch enzymatic rate and DE value was explored.The results indicated that when the starch enzymatic rate reached 90%in singleα-amylase system,the required amount ofα-amylase for cationic starch enzymolysis was about 4 times than that of the other two kinds of starches.The enzymatic rate of enzymatically hydrolyzed starch could be increased by up to 37.4%when citric acid was added to inhibit zinc ions.In the binary complex enzyme system,the enzymatic rate of cationic starch byα-amylase/β-amylase was 5.3%and 8.7%higher than that byα-amylase/glucoamylase andα-amylase/pullulanase,respectively.In the ternary complex enzyme system,the enzymatic rate of cationic starch byα-amylase/glucoamylase/β-amylase was 1.2%higher than that byα-amylase/glucoamylase/pullulanase.In the application ofα-amylase/glucoamylase/β-amylase/pullulanase tetrameric complex enzyme system to the enzymatic reactions of cationic starch,enzymatically hydrolyzed starch and oxidized starch,when the enzymatic rate of starch reached 80%,the required amount ofα-amylase was 56%,38%and 17%of that by singleα-amylase system,respectively.