葡萄糖亚适量流加对谷氨酸棒杆菌产L-异亮氨酸的影响  

Effect of Suboptimal Glucose on L-Isoleucine Production by Corynebacterium glutamicum

作　　者：熊海波 刘景阳 徐庆阳[1,2] XIONG Haibo;LIU Jingyang;XU Qingyang(College of Biotechnology,Tianjin University of Science and Technology,Tianjin 300457,China;Tianjin Engineering Lab of Efficient and Green Amino Acid Manufacture,National and Local United Engineering Lab of Metabolic Control Fermentation Technology,Tianjin 300457,China)

机构地区：[1]天津科技大学生物工程学院,天津300457 [2]天津市氨基酸高效绿色制造工程实验室,代谢控制发酵技术国家地方联合工程实验室,天津300457

出　　处：《食品科学》2021年第20期30-37,共8页Food Science

基　　金：“十三五”国家重点研发计划重点专项(2018YFA0900304)。

摘　　要：通过动态调节葡萄糖对谷氨酸棒杆菌的供应速率,解决菌种在发酵产L-异亮氨酸不同时期对葡萄糖消耗能力差异的问题。实验结果表明,以谷氨酸棒杆菌YILM1504为供试菌株,在发酵初始葡萄糖添加量80 g/L、90%最大补糖速率的亚适量补糖工艺下,得到动态补糖速率为0(0~8h)、5.40~7.47(8~14 h)、7.47~7.00(16~24 h)、7.00~5.20 g/(L·h)(24~40 h),L-异亮氨酸达到44.32 g/L,糖酸转化率为19.63%。经代谢流对比分析发现,葡萄糖经戊糖磷酸途径和糖酵解途径代谢流之比为0.56,进入Ile的代谢流增强了18.92%,进入缬氨酸、亮氨酸、丙氨酸的代谢流减弱了67.12%、72.21%、30.23%,该方法针对谷氨酸棒杆菌在细胞生长阶段与产酸阶段不同的耗糖能力,提供了精细的补糖速率策略,产酸高峰期明显延长,副产物积累比例得到降低,原料利用率大幅提升。To solve the problem that the glucose consumption capacity of Corynebacterium glutamate differed at different stages of L-isoleucine production, the feeding rate of glucose was dynamically adjusted. Corynebacterium glutamate YILM1504 was cultured at an initial glucose concentration of 80 g/L and with suboptimal glucose feeding at a feeding rate equal to 90% of the maximum feeding rate. The dynamic glucose feeding rate was as follows: 0 g/(L·h) for 0–8 h, 5.40–7.47 g/(L·h) for 8–14 h, 7.47–7.00 g/(L·h) for 16–24 h, and 7.00–5.20 g/(L·h) for 24–40 h. The yield of L-isoleucine was 44.32 g/L and the conversion rate of glucose to L-isoleucine was 19.63%. The comparative analysis of metabolic flows revealed that the ratio of carbon distribution between and the hexose monophosphate pathway(HMP) and the EmbdenMeyerhof-Parnas pathway(EMP) was 0.56. Moreover, the metabolic flow toward Ile was increased by 18.92%, while the metabolic flows toward Val, Leu, and Ala were reduced by 67.12%, 72.21%, and 30.23%. In conclusion, this fine glucose feeding strategy can meet the dynamic glucose demand of C. glutamicum during the fermentation process, resulting in enhanced isoleucine titer, reduced by-product accumulation and significantly prolonged acid production peak period.

关 键 词：L-异亮氨酸 葡萄糖亚适量 谷氨酸棒杆菌 代谢流 

分 类 号：TQ922[轻工技术与工程—发酵工程]