海藻酸钠复合载体固定化细胞拆分D,L-泛解酸内酯

Immobilization of fusarium oxysporum BU-11 cells by alginate composite for optical resolution of racemic DL-pantolactone

研究了海藻酸钠及其与聚丙烯酰胺(PAM)和聚乙烯醇(PVA)的复合载体对镰孢霉菌(Fusarium oxyspo-rumBU-11)细胞的固定,该固定化细胞被用于手性拆分D,L-泛解酸内酯的反应体系。实验表明,海藻酸钠固定化细胞具有较好的扩散性和强度,在水解试验中与游离细胞相比,酶活收率可达到80%以上,而且具有较好的温度和批次反应稳定性,在底物质量浓度为200 g/L的3 L搅拌式反应器中6 h水解反应20批,水解率可以保持在初始的80%左右。PVA和PAM的加入可增强固定化细胞的强度,前者对酶活影响不大,后者使酶活略有增加。

A processing of entrapping Fusarium oxysporum BU-Ⅱ in calcium alginate, alginate-PAM and alginate-PVA composite gel beads was investigated. The immobilized cells were applied in the optical resolution of racemic DL-pantolactone producing D-pantoic acid. It is shown that the alginate immobilized cells have good diffusivity and strength. Compared with the free cells, the enzyme activity of the immobilized cells reached to 80%. Further more, the alginate immobilized cells showed a good temperature and operation stability. A batched hydrolysis by the immobilized cells was carried out in a 200 g/L substrate solution every 6 hours in a 3 L stirred tank reactor. After 20 batches of the hydrolysis reaction, the enzyme activity reached 80 % of the original activity. It is shown that the addition of PVA enhances the strength of the immobilized cells, with little change in the enzyme activity, and while the addition of PAM induces the enhancement of not only the strength but also the enzyme activity of the immobilized cells.