不同溶氧条件下谷氨酸棒杆菌发酵过程代谢物及关键酶酶活分析  

Analysis of metabolites and changes in enzyme activities in the glutamate fermentation under different dissolved oxygen concentration

作　　者：卢志洪[1] 刘志成[2] 郑穗平[2] 

机构地区：[1]华南理工大学轻工与食品学院,广东广州510640 [2]华南理工大学生物科学与工程学院,广东广州510006

出　　处：《中国酿造》2010年第6期28-31,共4页China Brewing

基　　金：国家科技支撑计划资助(2007BAK36B03)

摘　　要：分别在10%和30%溶氧条件下,使用2L罐进行谷氨酸发酵,分析了这2种发酵状态下细胞外和细胞内代谢物含量和关键酶活性变化。结果表明,10%溶氧和30%溶氧情况下产酸分别达到36.02 g/L和38.22 g/L,表明高溶氧适合产酸。溶氧低时,乳酸脱氢酶在发酵中期活性很高,从酶学角度揭示溶氧低易生成乳酸,却不利于谷氨酸的积累。不同溶氧水平下,α-酮戊二酸、丙酮酸乳酸、柠檬酸、琥珀酸表现出相似的变化规律,但其在成峰时间和最大浓度有一定差别。发酵后期胞外各有机酸含量出现一定程度的下降,表明其可作为碳源被细胞重新利用。The extracellular and intracellular metabolites and key enzymes activity of glutamate fermentation in 2 L fermentor were investigated under 10% and 30% dissolved oxygen concentration, respectively. The results showed that the glutamate production reached 36.02 g/L and 38.22 g/L under 10% and 30% dissolved oxygen concentration, respectively, which indicated that high dissolved oxygen condition was suitable for glutamate production. Low dissolved oxygen concentration can prompt lactic acid production due to high LDH activity. However, Low dissolved oxygen concentration was not benefitical for glutamate production. The productions of a-ketoglutarate, pyruvate, citrate and succinate were similar under different dissolved oxygen levels. The concentrations of these four organic acids decreased in the late period, suggesting that they can be used as carbon sources.

关 键 词：谷氨酸发酵 胞外代谢物 胞内代谢物 关键酶 

分 类 号：TQ920.6[轻工技术与工程—发酵工程]