两阶段pH控制和碳氮源协同补加促进谷氨酸棒杆菌高产L-谷氨酰胺  

Two-stage pH control and synergistic addition of carbon and nitrogen sources for efficient L-glutamine production by Corynebacterium glutamicum

作　　者：刘畅 陆丹丹 浦军平 张春枝[1] 陈明[1] LIU Chang;LU Dandan;PU Junping;ZHANG Chunzhi;CHEN Ming(School of Biological Engineering,Dalian Polytechnic University,Dalian 116034,China;Zhangjiagang Huachang Pharmaceutical Co.Ltd.,Suzhou 215635,China)

机构地区：[1]大连工业大学生物工程学院,辽宁大连116034 [2]张家港市华昌药业有限公司,江苏苏州215635

出　　处：《食品与发酵工业》2024年第1期7-13,共7页Food and Fermentation Industries

基　　金：辽宁省高等学校创新人才支持计划项目(LR201907)。

摘　　要：为提高谷氨酸棒杆菌发酵产L-谷氨酰胺产量、糖酸转化率、生产强度等技术指标,该文通过响应面法优化了摇瓶发酵培养基中葡萄糖、(NH_(4))_(2)SO_(4)和玉米浆含量,并利用50 L发酵罐进行分批发酵,构建了菌体生长、底物消耗和产物生成动力学模型,进而在50 L发酵罐中采用两阶段控制pH策略,并通过补加葡萄糖和(NH_(4))_(2)SO_(4),协同控制发酵液中碳氮源浓度,促进菌体高效合成L-谷氨酰胺。结果表明,优化后发酵培养基中葡萄糖、(NH_(4))_(2)SO_(4)和玉米浆含量分别为167、61、31 g/L,摇瓶发酵L-谷氨酰胺产量达到38.13 g/L,较优化前提高了34.12%;50 L发酵罐分批发酵80 h后L-谷氨酰胺产量达42.06 g/L,糖酸转化率达到25.85%,生产强度为0.53 g/(L·h);在50 L发酵罐中基于两阶段pH控制的碳氮源协同补加策略,显著促进了谷氨酸棒杆菌高产L-谷氨酰胺,发酵周期缩短至52 h,L-谷氨酰胺产量达68.01 g/L,糖酸转化率达33.93%,生产强度为1.31 g/(L·h)。该研究对促进L-谷氨酰胺的工业化生产具有重要参考价值。To improve the fermentation level,sugar-acid conversion rate,and productivity of L-glutamine production by Corynebacterium glutamicum,the contents of glucose,ammonium sulfate,and corn syrup in fermentation medium were optimized using response surface methodology.Then the kinetic models for cell growth,substrate consumption and L-glutamine production of batch fermentation in 50 L fermenter were constructed.Furthermore,the strategy of two-stage pH control combined with coordinating the concentrations of carbon and nitrogen sources by adding glucose and ammonium sulfate in 50 L fermenter was adopted to promote L-glutamine production.The results showed that the optimized fermentation medium contained 167 g/L glucose,61 g/L(NH 4)2SO 4,and 31 g/L corn syrup,respectively.L-Glutamine yield in shaking flask fermentation reached 38.13 g/L,an increase of 34.12% compared with that before optimization.After 80 h of batch fermentation in 50 L fermenter,L-glutamine yield reached 42.06 g/L,the sugar-acid conversion rate reached 25.85%,and the productivity was 0.53 g/(L·h).The strategy of two-stage pH control combined with synergistic addition of carbon and nitrogen sources in 50 L fermenter significantly promoted L-glutamine production,shortening the fermentation period to 52 h,achieving 68.01 g/L of L-glutamine,33.93% of sugar-acid conversion and 1.31 g/(L·h)of productivity.This study provides valuable guidance for promoting industrial production of L-glutamine by C.glutamicum.

关 键 词：谷氨酸棒杆菌 L-谷氨酰胺 培养基优化 50 L发酵罐 两阶段pH控制 碳氮源协同补加 

分 类 号：TQ922[轻工技术与工程—发酵工程]