【摘要】 以酸部分水解聚丙烯腈纤维为载体 ,以戊二醛为交联剂 ,共价键结合制备了固定化胞外青霉素G酰化酶。当水解后的载体中 NH2 基含量为 690 μmol g和含水量为 64%时 ,对酶蛋白的固定量达 1 0 0mg g以上 ,固定化酶的活力达 2 30 0IU g ,酶活力总产率为 30 % ,固定化效率为 56%。酶活力的总产率和固定化率随加酶量的增加而降低。该酶可以将浓度为 2 5%～1 2 5%的青霉素G钾盐水解 98%以上。批投青霉素G钾盐为 1 0g,酶负荷为 1 50IU g(PGK) ,经2 0批水解反应后 ,剩余酶活力为 80 %。用二硫基苏醣醇处理固定化酶 ,对水解青霉素G钾盐的操作稳定性有促进作用。固定化酶的室温保存半衰期为 1 30d。用戊二醛和硼氢化钠溶液处理固定化酶后 ,酶活力的室温保存稳定性有所降低。更多还原

【Abstract】 The immobilization of Penicillin G Acylase from Bacillus megaterium by glutaraldehyde crosslinking on the partially acid\|hydrolyed polyacrylonitrile fiber was studied.When the amount of \|NH 2 on fiber were 690μmol/g and the moisture in the fiber was 64%,and the content of enzyme protein immobilized on fiber was more than 100mg/g.The activity of 2300IU/g was obtained with 30% of overall yield and 56% of binding efficiency.The immobilization yield was markedly influenced by ratio of the amount of free enzyme used to the weight of the fiber.The half\|life of storage stability of immobilized PGA at room temperature was 130 days.The immobilized PGA kept 80% of the initial activity after 20 cycles of operation in 10% of PGK(W/V)in 0.05mol/L phosphate buffer,pH8.0,at 37℃ and an enzyme load of 150IU/g(PGK)and 10g(PGK)for per cycle of operation.The hydrolysis conversion of PGK in the range of 2.5%～12.5%(W/V)were over 98% for the immobilized PGA.The operation stability of immobilized PGA treated with DTT was better than that of immobilized PGA untreated.更多还原