碳酸盐对谷氨酸产生菌在缺氧条件下产有机酸的影响  

Influence of bicarbonate on organic acid of glutamic acid-producing bacteria under oxygen deprivation

作　　者：于芳[1] 郑璞[1] 倪晔[1] 董晋军[1] 王兴林[1] 孙志浩[1] 

机构地区：[1]江南大学生物工程学院工业生物技术教育部重点实验室,无锡214122

出　　处：《生物加工过程》2011年第5期22-26,共5页Chinese Journal of Bioprocess Engineering

基　　金：国家高技术研究发展计划(863计划)资助项目(2006AA020301-09)

摘　　要：考察谷氨酸产生菌在缺氧条件下积累L-乳酸和琥珀酸的情况。结果表明:在缺氧条件下,嗜乙酰乙酸棒杆菌(Corynebacterium acetoacidophilum)ATCC 13870积累有机酸的浓度随菌体密度的增大而增加,其中琥珀酸和乳酸积累的最适pH分别为7.5和8.0,最高质量浓度分别为22.5和60 g/L。碳酸盐是影响产酸与有机酸分布的主要因素。比较ATCC 13870在NaHCO3浓度为40和400 mmol/L时的代谢通量,发现后者合成琥珀酸的代谢通量比前者提高了214.1%,合成乳酸的代谢通量降低了61.8%,说明PEP节点处的代谢通量分配明显受NaHCO3浓度的影响,而PYR节点受环境因素的影响不明显。Succinic acid and lactic acid accumulation by L-glutamic acid-producing bacteria under oxygen deprivation were investigated. Results showed that Corynebacterium acetoacidophilum ATCC 13870 could accumulate notable concentration of organic acid, in which the yield of organic acid increased with its cell density. The optimal pH values for succinic acid and lactic acid generation by C. acetoacidophilum ATCC 13870 were 7.5 and 8.0, respectively, at which the concentrations of succinic acid and lactic acid reached to 22. 5 and 60.0 g/L, correspondingly. Bicarbonate was the key factor influencing organic acid synthesis more than glucose. The metabolic flux to the sueeinic acid synthesis pathway increased by 214. 1%, while the flux to the lactic acid synthesis pathway decreased by 61.8% with increasing sodium bicarbonate concentration from 40 mmol/L to 400 mmol/L. This indicated that PEP node was evidently influenced by sodium bicarbonate concentration but the influence of PYR node was less.

关 键 词：谷氨酸产生菌 乳酸 代谢流 缺氧 琥珀酸 

分 类 号：TQ922.1[轻工技术与工程—发酵工程]