文献类型：期刊文献

中文题名：大肠杆菌及其耐乙酸突变菌的连续培养和代谢流比较

英文题名：Comparison of metabolic fluxes in Escherichia coli and its acetate-tolerant mutant in continuous culture

作者：张艳军[1];张晓云[1];李志敏[1];叶勤[1]

机构：[1]华东理工大学生物反应器工程国家重点实验室,上海200237

年份：2008

卷号：59

期号：1

起止页码：160

中文期刊名：化工学报

外文期刊名：CIESC Journal

收录：CSTPCD;;EI(收录号：20080811110679);Scopus;北大核心:【北大核心2004】；CSCD:【CSCD2011_2012】；

基金：国家高技术研究发展计划项目(2002AA217021)~~

语种：中文

中文关键词：大肠杆菌;乙酸;代谢流;酶活

外文关键词：Escherichia coli; acetic acid; metabolic flux; enzyme activity

摘要：在氮源限制基本培养基中连续培养大肠杆菌DH5α及其乙酸耐受突变株DA19。与DH5α相比,突变株DA19降低了葡萄糖的消耗,减少了乙酸和丙酮酸的生成,提高了菌体关于葡萄糖的得率。利用物料平衡和代谢反应的化学计量关系,分析了二者在比生长速率0.13 h-1下的稳态代谢流分布。与DH5α相比,DA19的三羧酸循环流量高,酵解途径的流量低,从而减少了乙酸等副产物的分泌,反映了能量代谢效率的明显提高。比较了二者异柠檬酸裂解酶、6-磷酸葡萄糖脱氢酶、磷酸果糖激酶、异柠檬酸脱氢酶和乙酸激酶的活性,酶活变化与代谢流结果基本一致。
Escherichia coli DH5α and its acetate-tolerant mutant DA19 were continuously cultured in nitrogen-limited defined media. Compared with DH5α, DA19 showed improved growth yield due to decreased specific glucose consumption rate and formation of less acetic acid and pyruvate at a similar dilution rate. Based on mass balance and metabolic reaction stoichiometry, the metabolic flux distribution in DH5α and DA19 at a dilution rate of 0.13 h^-1 was calculated. Compared with DH5α, DA19 had a higher flux of tricarboxylic acid cycle and a lower flux of Embden-Meyerhof-Parnas pathway so it decreased the secretion rate of by-products, such as acetate and pyruvate. This indicated that DA19 had higher efficiency in energy metabolism. The activities of isocitrate lyase, 6-phosphoglucose dehydrogenase, phosphofructokinase, isocitrate dehydrogenase and acetokinase were measured, and the difference of activities between the two strains were consistent with the difference of metabolic fluxes.