利用廉价原料生产聚谷氨酸的研究

Study on Production of Polyglutamic Acid from Cheap Raw Materials

目的降低聚谷氨酸的生产成本。方法从聚谷氨酸发酵所需的氮源和碳源出发,分别研究了小麦水解蛋白、豆饼粉、豆粕粉、玉米蛋白、玉米浆等有机氮源和甘蔗糖蜜、甜菜糖蜜、葡萄糖蜜、玉米糖蜜等碳源对聚谷氨酸发酵产量的影响,在此基础上通过单因素实验优化了玉米浆、硫酸铵、甜菜蜜、谷氨酸钠的添加量,最后通过发酵罐发酵比较了优化后的工艺与使用蛋白胨和葡萄糖作为氮源和碳源的工艺。结果使用玉米浆40 g/L、硫酸铵5 g/L、甜菜蜜350 g/L、谷氨酸钠70 g/L时聚谷氨酸的产量最高,达45.34 g/L,高于使用蛋白胨、葡萄糖作为氮源和碳源的发酵水平(40.46 g/L)。结论通过使用廉价的氮源玉米浆、硫酸铵和碳源甜菜蜜,可实现聚谷氨酸的低成本化生产,产量提高了12%,生产成本降低了20%以上。

Objective To reduce the production cost of γ-polyglutamic acid.Methods Based on the nitrogen and carbon sources for polyglutamic acid fermentation,in this paper,the effects of organic nitrogen sources(such as wheat hydrolyzed protein,soybean cake powder,soybean meal powder,corn protein,corn pulp)and carbon sources(such as sugarcane molasses,beet molasses,grape molasses and corn molasses)on polyglutamic acid fermentation yield were studied respectively.On this basis,the addition amounts of corn pulp,ammonium sulfate,beet honey and monosodium glutamate were optimized by a single factor experiment.Finally,the optimized fermentation process was compared with that using peptone and glucose as nitrogen and carbon sources.Results Under the conditions of corn pulp 40 g/L,ammonium sulfate 5g/L,sugar beet honey 350 g/L and sodium glutamate 70 g/L,the yield of γ-polyglutamic acid reached 45.34 g/L,which was higher than 40.46 g/L of the fermentation level of peptone and glucose.Conclusion By using cheap nitrogen source corn pulp,ammonium sulfate and carbon source beet honey,γ-polyglutamic acid can be produced at low cost,the yield is increased by 12%and the production cost is reduced by more than 20%.