Comparative Research on Immobilization of Glucoamylase with Globe α-chitosan
張劍(Jian Zhang)；王又容(You-Rong Wang)；陳進(Jin Chen)；羅瑜(Yu Luo)
球形α-殼聚糖 ； 脫乙酰度 ； 固定化酶 ； 糖化酶 ； globle α-chitosan ； degree of deacetylation ； immobilized enzyme ； glucoamylase
|Volume or Term/Year and Month of Publication||
2005卷12期（2005 / 12 / 20）
15 - 18
After being dissolved in the high concentration of NaOH, a-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 free enzyme. The optimal temperature was 50℃. The Michaelis constant of the immobilized glucoamylase was 22.63mg/L. Compared to the free enzyme (34.62mg/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 6d to the free 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 free enzyme.