谷氨酰胺高效酶法转化条件研究

Study on High-efficient Enzymatic Conversion Conditions of Glutamine

[目的]研究不同影响因素及工艺条件对酶法生产L-谷氨酰胺的影响。[方法]以安琪酵母为试验菌种,在YEPD培养基中28℃培养24 h后进行气流干燥处理,然后进行谷氨酰胺的合成反应,之后测定与计算葡萄糖(谷氨酸)的量、谷氨酸的消耗量以及谷氨酰胺的生成量。[结果]在磷酸盐浓度为0.15 mol/L,酶液浓度在80 U/m l时,谷氨酸加入量为25 g/L,谷氨酰胺的产量最大,提高葡萄糖加入量会增加谷氨酰胺的转化,但利用率明显降低。通过正交试验发现,优化条件与单因素试验结果一致,谷氨酸添加量是最显著的因素,在优化条件下,谷氨酰胺产量达26.8 g/L,转化率为91.2%。采用葡萄糖、谷氨酸的分批补料工艺,得到谷氨酰胺的最高产量为33.8g/L。[结论]优化酶法合成谷氨酰胺的工艺条件能够有效降低生产成本。

[ Objective ] The purpose was to study the impact of different factors and processing conditions on the enzymatic production of L-glutamine. [ Method ] With angel yeast as experimental culture, it was treated with pneumatic drying after culturing in YEPD medium at 28℃ for 24 h, and then went on to the synthesis of glutamine, followed by the determination and calculation of the amount of glucose （Glu）, glutamyl acid consumption and the formation amount of glutamine. [Result] When the conditions were： phosphate at 0.15 mol/L M, enzyme at 80 U/ml and the adding amount of glutamic acid at 25 g/L, the yield of glutamine reached the maximal. The yield of glutamine was improved with the higher glucose adding amount, but the utilization rate was decreased significantly. The optimum condition was obtained through the orthogonal experiment, which was consistent with the result of single-factor experiment. The adding amount of glutamic acid was the most significant factor. Under the optimum conditions the yield of glutamine reached 26.8 g/L and the conversion rate was 91.2%. With fed-batch process of glucose and glutamic acid, the maximum output of glutamine was 33.8 g/L. [Conclusion] Optimizing processing conditions on the enzymatic production of L-glutamine could reduce production costs.