Feng Yongmei, Chang Xiulian, Wang Wenhua, Ma Runyu
College of Chemistry and Biology, Yantai University, Yantai, Shandong Province, PR China.
Artif Cells Blood Substit Immobil Biotechnol. 2010;38(1):43-51. doi: 10.3109/10731190903495777.
Beta-galactosidase of Aspergillus sp. AF crude homogenate was immobilized in Ca-alginate gel beads and used for the production of galactooligosaccharides (GOS) from lactose. Optimum pH and temperature, thermal and storage stability of the enzyme activity were investigated and compared with those of the free enzyme. The study on the improvement of mechanical strength of the alginate beads was carried out through various methods, which demonstrates that the hardening process, where the alginate beads were treated with 0.225 M CaCl(2) solution after three batches to compensate the lost of calcium in the beads, provided a high mechanical stability for repeated use in large-scale production. The experiment results show that GOS yield increased with the increase of lactose concentration, and also increased with excessive addition of lactose (exceeding its solubility) at the beginning of the reaction. The immobilization of beta-galactosidase of Aspergillus sp. AF crude homogenate is cheap in processing cost and easy to carry out, and the immobilized enzyme possesses high performance for industrial application.
将曲霉属AF粗匀浆中的β-半乳糖苷酶固定在海藻酸钙凝胶珠中，并用于从乳糖生产低聚半乳糖（GOS）。研究了该酶活性的最佳pH值和温度、热稳定性和储存稳定性，并与游离酶进行了比较。通过各种方法对海藻酸珠的机械强度改进进行了研究，结果表明，在经过三批反应后，用0.225 M氯化钙溶液处理海藻酸珠以补偿珠中钙的损失的硬化过程，为大规模生产中的重复使用提供了高机械稳定性。实验结果表明，GOS产量随乳糖浓度的增加而增加，并且在反应开始时，随着乳糖过量添加（超过其溶解度）也会增加。曲霉属AF粗匀浆中β-半乳糖苷酶的固定化加工成本低廉且易于实施，固定化酶在工业应用中具有高性能。
