味精粗料作为聚谷氨酸合成前体的培养条件优化

Optimizing Fermentation of Polyglutamic Acid by Unrefined Glutamic Acid as Raw Material

为降低聚谷氨酸生产成本,采用本实验室筛选得到的枯草芽孢杆菌,编号为CGMCC No.1250。考察了不同的谷氨酸钠替代品,味精粗料最佳,并考察了味精粗料的含量、碳源和氮源及其浓度、NaCl浓度、装液量以及温度等对-γPGA产量的影响。实验结果表明,对于该菌株,最适碳源和氮源分别是蔗糖和蛋白胨;在含有70 g/L蔗糖5、0 g/L蛋白胨、30 g/L NaCl,pH7.0,含味精粗料体积分数为26.6%(含谷氨酸120 g/L)的发酵液中,37℃,220 r/min培养24 h,-γPGA的产量达到41.7g/L。

In order to reduce the cost of fermentation of polyglutamic acid, Bacillus subtilis CGMCC No. 1250 screened in our lab was applied to produce polyglutamie acid with the best substitutes of sodium glutamate, unrefined （glutamie acid） raw material. The effects of the substitutes of sodium glutamate, carbon source, nitrogen source and their concentrations, volume, temperature on 7-PGA synthesis were evaluated. The best carbon and nitrogen sources were sucrose and tryptone. When 70 g/L of sucrose, 50 g/L of tryprone, 30 g/L of NaCl and 26.6 % （v/v） of unrefined raw material（ 120 g/L of sodium glutamate） were added to the media （pH7,0）, CGMCC No, 1250 was cultivated at 37℃ ,220 r/min, for 24 hours, the productivity of γ-PGA reached 41.7g/L.