Department of Biological Science and Engineering, Korea Advanced Institute of Science and Technology, Cheongyang, Seoul 130-650, Korea.
Biotechnol Bioeng. 1992 Feb 5;39(3):336-42. doi: 10.1002/bit.260390312.
Gluconic acid and sorbitol were simultaneously produced from glucose and Jerusalem artichoke using a glucose-fructose oxidoreductase of Zymomonas mobilis and inulinase. Inulinase was immobilized on chitin by cross-linking with glutaraldehyde. Cells of Z. mobilis permeabilized with toluene were coimmobilized with chitin-immobilized inulinase in alginate beads. The optimum amounts of both chitin-immobilized inulinase and permeabilized cells for coimmobilization were determined, and operational conditions were optimized. In a continuous stirred tank reactor operation, the maximum productivities for gluconic acid and sorbitol were about 19.2 and 21.3 g/L/h, respectively, at the dilution rate of 0.23 h(-1) and the substrate concentration of 20%, but operational stability was low because of the abrasion of the beads. As an approach to increase the operational stability, a recycle packed-bed reactor (RPBR) was employed. In RPBR operation, the maximum productivities for gluconic acid and sorbitol were found to be 23.4 and 26.0 g/L/h, respectively, at the dilution rate of 0.35 h(-1) and the substrate concentration of 20% when the recirculation rate was fixed at 900 mL/h. Coimmobilized enzymes were stable for 250 h in a recycle packed-bed reactor without any loss of activity, while half-life in a continuous stirred tank reactor (CSTR) was observed to be about 150 h.
葡萄糖和菊芋使用运动发酵单胞菌的葡萄糖-果糖氧化还原酶和菊粉酶同时生产葡萄糖酸和山梨糖醇。菊粉酶通过与戊二醛交联固定在几丁质上。用甲苯透化的运动发酵单胞菌细胞与固定在几丁质上的菊粉酶一起共固定在藻酸盐珠中。确定了共固定化所需的几丁质固定化菊粉酶和透化细胞的最佳量，并优化了操作条件。在连续搅拌槽式反应器操作中，在稀释率为 0.23 h(-1)和底物浓度为 20%的条件下，最大葡萄糖酸和山梨糖醇产率分别约为 19.2 和 21.3 g/L/h，但由于珠粒的磨损，操作稳定性较低。为了提高操作稳定性，采用了循环填充床反应器 (RPBR)。在 RPBR 操作中，当循环速率固定在 900 mL/h 时，在稀释率为 0.35 h(-1)和底物浓度为 20%的条件下，最大葡萄糖酸和山梨糖醇产率分别为 23.4 和 26.0 g/L/h。共固定化酶在循环填充床反应器中稳定 250 小时，没有任何活性损失，而在连续搅拌槽式反应器 (CSTR) 中的半衰期约为 150 小时。
