天冬氨酸酶基因工程菌固定化细胞制备L-天冬氨酸合成条件优化

Optimization synthesis conditions of L-aspartic acid by immobilized cells of aspartase engineering bacteria

摘要:

以反丁烯二酸和氨水为原料，采用天冬氨酸酶基因工程菌固定化细胞生物催化法合成L-天冬氨酸。考察反丁烯二酸浓度、温度、pH对合成L-天冬氨酸的影响，固定化天冬氨酸酶基因工程菌合成L-天冬氨酸最佳条件为：底物反丁稀二酸的浓度为300 g/L，反应温度为37℃，底物pH为7.5，L-天冬氨酸的产率为96.7%。固定化细胞可连续使用10批次。通过电镜观察天冬氨酸酶基因工程菌均匀分布于载体，天冬氨酸酶基因工程菌固定化细胞具有良好的稳定性。

Abstract:

With fumaric acid and ammonium hydroxide as raw materials, synthesis of L-aspartic acid by immobilized cells of aspartase engineering bacteria was carried out. The effect of fumaric acid concentration, pH and reaction temperature was investigated. The optimized preparation conditions were as follows: 300 g/L fumaric acid, 37oC, pH7.5, the yield of L-aspartic acid is 96.7%. The immobilized bacteria could be used continuously for 10 times. The aspartase engineering bacterias were distributed evenly over the carrier by electron microscope.The immobilized cells of aspartase engineering bacterias have good stability.