利用30 L发酵罐,研究了黄色短杆菌TK0303生产L-亮氨酸的发酵工艺。考察了初始葡萄糖浓度和发酵过程中3种补料策略(分批间歇流加补料、恒葡萄糖浓度流加补料和DO-在线识别流加补料)对菌体生物量、L-亮氨酸产量、副产物含量及糖酸转化率的影响。最终确定:分批补料发酵的初始葡萄糖浓度为60 g/L,葡萄糖补加采用DO-在线识别流加方式。根据溶氧响应信号的特征反馈控制葡萄糖的流加速率,可实现葡萄糖的限制培养,有效减少了发酵副产物的含量,菌体生物量和L-亮氨酸产量得到显著提高,分别为21.8 g/L和41.3 g/L,且糖酸转化率高达22.4%。

The fermentation of L-leucine by Brevibacterium flavum in 30 L bioreactor was investigated.The effects of initial glucose concentration and three glucose feeding strategies(intermittent glucose feeding,glucose-stat feeding and DO-stat glucose feeding) in fermentation process on biomass,yield of L-leucine,concentration of byprod-uct,and conversion rate were studied.The optimal concentration of initial glucose was 60 g/L and DO-stat glucose feeding was applied.According to the dissolved oxygen response signal,using feedback control,the feed rate in fer-mentation process was effectively manipulated and the accumulation of byproduct was reduced effectively.Biomass of 21.8 g/L dry cell weight could be obtained and the yield of L-leucine was 41.3 g/L,which were increased obviously.The glucose-limited fed-batch cultivation was achieved,and the conversion rate was 22.4%.