摘要
目的:建立并完善嗜乙酰乙酸棒杆菌YL012及其突变株LCHA0082合成L-谷氨酰胺的中心代谢网络。方法:分别测定了它们在特定培养时段(48h^50h)L-谷氨酰胺等代谢物的胞外浓度,由此计算这一时段这些代谢物在发酵液中积累(或消耗)的速率,分别作出这两株菌在拟稳态下的代谢流量分布图,进而研究诱变育种过程中不同诱变标记对代谢网络中L-谷氨酰胺合成流量分布的影响。结果:育种操作使流量分配朝着有利于L-谷氨酰胺合成的方向改变,流入谷氨酸节点的流量由29.198mmol/L.h上升到44.854mmol/L.h,提高到原来的1.5倍左右,合成L-谷氨酰胺的流量由18.138mmol/L.h上升至31.065mmol/L.h,效果明显。结论:从代谢流量分析角度上,证明诱变育种对代谢流量的改变起到明显的作用,代谢流量分析也为新的设计育种提供了思路。
Objective： In this paper, the center metabolic networks of Corynebacterium acetoacidophilum YL012 and its mutant LCHA0082 were established and modified.Method： The eoncentrations of extra - cellular metabolites were determined under substeady - state （48 h- 50 h） in the batch culture. The metabolic flux distribution maps of the two strains were obtained and compared after the accumulation（or consumption） rates of these metabolites were measured in the broth in the specific time. Result：These results indicate that the breeding process skew the metabolic flux towards the formation of L - glutamine obviously, The flow to node of glutamate increased from 29.198 mmol/L·h to 44. 854 mmol/L·h, about 1.5 times of the original;The flow to L- glutamine synthesis changed from 18. 138 mmol/L·h to 31.065 mmol/L·h, the effect was significant. Condusion： Tiffs study revealed the usefulness of breeding process towards existing production strains after the metabolic flux analysis as a tool. The analysis may play an important role in helping us to rationally re - design metabolism for further improvement of fermentation process.
出处
《生物技术》
CAS
CSCD
北大核心
2009年第4期63-67,共5页
Biotechnology
