【摘要】 糖化酶（ＥＣ．３．２．１．３，ＧＡ）是工业上应用规模最大的３种酶制剂之一［１］．目前，工业生产中大多采用游离ＧＡ，这给产物的分离和纯化带来诸多不便．因此，采用固定化糖化酶（ＩＧＡ）是酶制剂工业发展的必然趋势．人们已对糖化酶的固定化进行了大量研究［２～...更多还原

【Abstract】 Glucoamylase from Aspergillus niger(EC 3.2.1.3) was immobilized on porous starch graft copolymer beads (PSGC) which were synthesized in our laboratory. Some of the factors which influence the activity of the immobilized enzyme and the stability of the immobilized enzyme were investigated. The activity and special activity is 1 340 IU per gram dry gel and 58.1 IU per millgram protein respectively when GA was immobilized under best condition found by ourselves. The optimium pH of the immobilized glucoamylase shifted 1.2 unit towards basic direction as compared to that of soluble enzyme. The thermostability of immobilized glucoamylase is longer than that of soluble enzyme, the operational half life of immobilized glucoamylase was 28 d and 8 d with 20% dextrin as substrate at 55 ℃ and 60 ℃, respectively.更多还原