摘要
脱胶蚕丝用稀碱溶液处理后制成多孔的碱化丝素 ,经物理吸附方法固定 α-淀粉酶 ,制得碱化丝素固定化酶 .每克碱化丝素固定化酶的总活力为 4 39.81U,固定化酶活力回收率为 4 8.33% ,活力表现率为 74 .18% .同样 ,蚕丝经高浓度氯化钙溶液溶解、脱盐等处理后制成丝素粉末 ,经吸附后用戊二醛为交联剂固定了 α-淀粉酶 ,制成粉末状丝素固定化酶 .每克粉末状丝素固定化酶的总活力为 5 0 9.0 9U,活力回收率为 5 8.33% ,活力表现率为 83.4 5 % .经对固定化酶性质的研究表明 :碱化丝素和丝素粉末均能较好地固定α-淀粉酶 ;最适温度比游离酶升高了 10℃ ;最适 p H降低了 0 .8～ 1.0个单位 ,固定化酶具有较长的操作半衰期 (2 6～ 38d)、较强的抗蛋白质变性剂 (8mol/ L尿素溶液中的活力在 80 %以上 )和贮存稳定性 (贮存 60 d后 ,其活力大于 5 0 % ) ;实验还发现 :在制备固定化淀粉酶时 ,酶的最适浓度为 2 .8～ 3.2 g/ L ,戊二醛的最适浓度为 0 .2 5 % .
Cavernous basified fibroin was prepared from degumed silk which pretreated with dilute alkali solution and served as supporter for immobilization of α amylase to form the basified fibroin immobilized α amylase, BFIA. The BFIA has a total activity of 439.81 U/g, a recovery rate of 48.33%, and an activity express ratio of 74.18%. Fibroin powder prepared by dissolving fibroin in CaCl 2 solution, desalting and subsegment treatment, was used as supporter for immobilization of α amylase, the so called fibroin powder immobilized α amylase, FPIA when the adsorbed α amylase was immobilized by the cross linking agent glutaraldehyde. The activity, the activity recovery ratio and the activity express ratio of FPIA were 509.09 U/g, 58.33% and 83.454% respectively. Our research showed that both basified fibroin and fibroin powder immobilize α amylase satisfactorily, their optimum temperature being 10 ℃ high and optimum pH 0.8 1.0 units lower as compared to the free α amylase. Experiment showed that the immobilized α amylase had longer work half life (26 38 d), high assistance to the action of resisting protein denaturing agent (over 80% of enzyme activity was retained in 8 mol/L urea solution) and improved stability for storage more than 50% of enzyme active remained after being stored for 60 days. It was found that the optimum enzyme concentration for preparation of immobilized α amylase was 2.8 3.2 g/L, and the optimum glutaraldehyde concentration was 0.25%.
出处
《浙江大学学报（农业与生命科学版）》
CAS
CSCD
北大核心
2002年第1期64-69,共6页
Journal of Zhejiang University:Agriculture and Life Sciences
基金
浙江省自然科学基金资助项目 ( 3 93 116)
