摘要
α-甲壳素经高浓度NaOH溶液处理后,制成了3种不同脱乙酰度的壳聚糖载体,用戊二醛接枝,与游离酶偶联后便得到固定化酶。固定化酶性质和动力学参数的研究表明,脱乙酰度高的壳聚糖载体固定化糖化酶的性能最好:其酶回收率达75%;最适反应pH6.0～7.5,最适反应温度50℃;米氏常数22.63mg/L,与游离酶(34.62mg/L)相比,对底物的亲和力增强;室温时操作半衰期较游离酶延长6d以上;经过8次重复操作,酶活损失低于5%。由此可见,固定化酶提高了游离酶的贮藏和操作稳定性。
After being dissolved in the high concentration of NaOH, α-chitin could be prepared into α-chitosan of three different kinds of degree of deacetylation. Glucoamylase could be coupled into the carriers when the above-mentioned materials were grafted with glutaraldehyde, thus the immobilizations of glucoamylase were available. The research on the properties of the immobilized enzymes and dynamical constant indicated, the capability of the immobilized enzymes adopting α-chitosan with the highest degree of deacetylation as the carrier was best, whose enzyme recovery was 75%. The optimal pH value of the immobilized glucoamylase was 6.0-7.5, higher than that of the flee enzyme. The optimal temperature was 50℃. The Michaelis constant of the immobilized glucoamylase was 22.63 mg/L. Compared to the flee enzyme （34.62 mg/L）, the appetency of the immobilized enzymes to the substrate increased. The operation half-life of the immobilized enzymes in room temperature delayed more than 6 d to the flee enzyme .The enzyme activity of the immobilized enzymes lost less than 5% after 8 times＇ repeated operation. Thus it could be seen that the immobilized glucoamylase improved the store stability and operation stability of the flee enzyme.
出处
《中国酿造》
CAS
北大核心
2005年第12期15-18,共4页
China Brewing
基金
湖北省科技厅资助
武汉华润啤酒股份公司资助
武汉工业学院校级重大资助项目
关键词
球形α-壳聚糖
脱乙酰度
固定化酶
糖化酶
globle α-chitosan
degree of deacetylation
immobilized enzyme
glucoamylase
