Ferraz H C, Borges C P, Alves T L
Chemical Engineering Program--COPPE, Federal University of Rio de Janeiro, RJ, Brazil.
Appl Biochem Biotechnol. 2000 Oct;89(1):43-53. doi: 10.1385/abab:89:1:43.
Immobilization of Zymomonas mobilis by different methods was investigated. Experiments were performed in order to choose the most appropriate support for the immobilization of the cells. The most advantageous option was to use permeabilized cells in the bore of microporous hollow fibers. Whereas the reaction rate was about 33 g of gluconate/(g of protein x h) using hollow fibers, which is comparable to that observed by using free cells, the calcium alginate immobilized cells presented a reaction rate of 4 g of gluconate/(g of protein x h). These results can be explained by the mass transfer resistance effect, which, indeed, was much lower in the case of hollow-fiber membranes than in the alginate gel beads. A loss of enzymatic activity during the reaction was observed in all experiments, which was attributed to the lactone produced as an intermediate of the reaction.
研究了用不同方法固定化运动发酵单胞菌。进行实验以选择最适合固定化细胞的载体。最有利的选择是在微孔中空纤维的孔中使用透化细胞。使用中空纤维时反应速率约为33克葡萄糖酸盐/（克蛋白质×小时），这与使用游离细胞时观察到的反应速率相当，而海藻酸钙固定化细胞的反应速率为4克葡萄糖酸盐/（克蛋白质×小时）。这些结果可以用传质阻力效应来解释，实际上，中空纤维膜的传质阻力效应比海藻酸盐凝胶珠的传质阻力效应低得多。在所有实验中都观察到反应过程中酶活性的损失，这归因于作为反应中间体产生的内酯。
