文献类型：期刊文献

中文题名：溶氧对谷氨酸棒杆菌发酵产谷氨酸代谢的影响

英文题名：Influence of Dissolved Oxygen on Metabolism of Glutamic Acid Biosynthesis by Corynebacterium Glutamicum

作者：刘剑[1];赵策[1];储炬[1];杭海峰[1];郭美锦[1]

机构：[1]华东理工大学生物反应器工程国家重点实验室国家生化工程技术研究中心,上海200237

年份：2012

卷号：38

期号：4

起止页码：459

中文期刊名：华东理工大学学报（自然科学版）

外文期刊名：Journal of East China University of Science and Technology

收录：CSTPCD;;Scopus;北大核心:【北大核心2011】；CSCD:【CSCD2011_2012】；

基金：“十二五”“863”计划(2012AA021201);“十二五”“973”计划(2012CB721006);国家科技支撑项目(2011BAF02B02);中央高校基本科研业务费资助(WF1114019)

语种：中文

中文关键词：谷氨酸发酵;溶氧;酶活;氧化还原平衡;NADH/NAD-

外文关键词：glutamate fermentation; dissolved oxygen; enzyme activity; redox balance; NADH/NAD＋

摘要：分别控制0、5%、30%3种溶氧水平进行谷氨酸分批发酵,考察了3种溶氧水平下谷氨酸棒杆菌发酵的代谢响应。结果表明,随着溶氧降低,发酵液中柠檬酸和α-酮戊二酸的含量降低,三羧酸(TCA)循环还原臂途径中的有机酸含量增加,丙氨酸、缬氨酸、苯丙氨酸含量也有所增加,在溶氧为0时,乳酸和乙酸大量积累。通过分析不同溶氧水平下的相关酶活和胞内氧化还原状态,发现随着溶氧降低,谷氨酸脱氢酶酶活降低,乳酸脱氢酶酶活升高,胞内氧化还原电势升高,它们的共同作用使氧限制条件下发酵的代谢流流向TCA循环的还原臂途径和乳酸合成途径,导致谷氨酸产量下降。
Corynebacterium Glutamicurn was cultivated in three parallel 5 L fermenters under 0,5% and 30%0 dissolved oxygen concentrations, respectively. The metabolism response of Corynebacteriurn Glutarnicurn to different dissolved oxygen concentrations were investigated systematically. The results showed that as the dissolved oxygen concentration decreased, the concentrations of citrate and a- oxoglutarate decreased, the concentrations of organic acids in the reductive arm of the TCA cycle as well as the amount of alanine, valine and phenylalanine increased. When the dissolved oxygen concentration was kept at 0, lactate and acetate accumulated largely. By measuring two key enzyme activities and intracellular NADH/NAD＋ ratio under these three conditions, we found that as the dissolved oxygen concentration decreased, glutamate dehydrogenase （GDH） activity decreased, lactate dehydrogenase （LDH） activity increased, intraeellular redox potential increased. All these changes caused metabolic shift towards the reductive arm of the TCA cycle under oxygen limited condition, and which finally led to the decline of the yield of glutamate.