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An innovative method for immobilizing sucrose isomerase on ε-poly-l-lysine modified mesoporous TiO2

Author:
Wu, Lingtian, Liu, Yi, Chi, Bo, Xu, Zheng, Feng, Xiaohai, Li, Sha, Xu, Hong
Source:
Food chemistry 2015 v.187 pp. 182-188
ISSN:
0308-8146
Subject:
biocatalysts, catalytic activity, enzyme activity, food industry, half life, isomaltulose, methodology, pH, porous media, sucrose, temperature, titanium dioxide
Abstract:
Sucrose isomerase (SIase) is the key enzyme in the enzymatic synthesis of isomaltulose. Mesoporous titanium dioxide (M-TiO2) and ε-poly-l-lysine-functionalized M-TiO2 (EPL-M-TiO2) were prepared as carriers for immobilizing SIase. SIase was effectively immobilized on EPL-M-TiO2 (SI-EPL-M-TiO2) with an enzyme activity of 39.41U/g, and the enzymatic activity recovery rate up to 93.26%. The optimal pH and temperature of immobilized SIase were 6.0 and 30°C, respectively. SI-EPL-M-TiO2 was more stable in pH and thermal tests than SIase immobilized on M-TiO2 and free SIase. Km of SI-EPL-M-TiO2 was 204.92mmol/L, and vmax was 45.7μmol/L/s. Batch catalysis reaction of sucrose by SI-EPL-M-TiO2 was performed under the optimal conditions. The half-life period of SI-EPL-M-TiO2 under continuous reaction was 114h, and the conversion rate of sucrose after 16 batches consistently remained at around 95%, which indicates that SI-EPL-M-TiO2 has good operational stability. Thus, SI-EPL-M-TiO2 can be used as a biocatalyst in food industries.
Agid:
5424279