Preparation and properties of α-amylase immobilized on silk fibroin

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 acti...

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Bibliographic Details
Main Authors: ZHU Xiang-rui, XU Jun-liang
Format: Article
Language:English
Published: Zhejiang University Press 2002-01-01
Series:浙江大学学报. 农业与生命科学版
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Online Access:https://www.academax.com/doi/10.3785/1008-9209.2002.01.0064
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Summary: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<sub>2</sub> solution, desalting and subsegment treatment, was used as supporter for immobilization of α-amylase, the socalled 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 C 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%.
ISSN:1008-9209
2097-5155