Abstract: pH value was used as an indicator to feedback control the feeding of glucose, ammonia and ammonium sulfate in lysine fed-batch fermentation. Fed-batch fermentation was operated under different concentrations of carbon and nitrogen sources, such that mass consumption ratio of glucose, ammonia and ammonia sulfate reached 15.7:1:1.64. The mixed solution according to aforementioned ratio was mixed into fermentation broth so as to regulate the pH value, simultaneously achieving automatic refuel of carbon and nitrogen sources. The results showed that the fluctuation of glucose concentration was maintained between 8 and 16 g/L, and ammonium between 1.5 and 3.4 g/L by using pH feedback controlling method. Compared with intermittent feeding and constant substrate concentration feeding, this method resulted in an increase in the concentration of lysine by 3.6% and 17.2% respectively, in lysine productivity by 9.5% and 28.8% and in the conversion rate from glucose to lysine by 4.9% and 18.6%.

Key words: pH feedback, lysine, fed-batch fermentation, Corynebacterium glutamicum TK-26

摘要： 建立了一种基于发酵液pH信号反馈控制赖氨酸发酵中葡萄糖、氨和硫酸铵补加的方法，通过在不同碳源和氮源浓度下进行分批补料发酵，得到葡萄糖、氨和硫酸铵的质量消耗比为15.7:1:1.64. 按此比例配制三者的混合溶液，在补料开始后代替氨水调节pH，可在发酵过程中补加碳源和氮源. 结果表明，利用该补料方式可将葡萄糖浓度维持在8~16 g/L，铵离子浓度维持在1.52~3.38 g/L，可使赖氨酸最大浓度分别比恒基质浓度补料方式和间歇补料方式提高3.6%和17.2%，产酸率提高9.5%和28.8%，糖酸转化率提高4.9%和18.6%.

关键词: pH反馈, 赖氨酸, 分批补料发酵, 谷氨酸棒杆菌TK-26