The use of genome scale metabolic flux variability analysis for process feed formulation based on an investigation of the effects of the zwf mutation on antibiotic production in Streptomyces coelicolor
The use of genome scale metabolic flux variability analysis for process feed formulation based on an investigation of the effects of the zwf mutation on antibiotic production in Streptomyces coelicolor
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DOI：
10.1016/j.enzmictec.2006.06.011
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发表时间：
2006-10-03
影响因子：
3.4
通讯作者：
Avignone-Rossa, Claudio A.
中科院分区：
文献类型：
--
作者：
Bushell, Michael E.;Sequeira, Susana I. P.;Avignone-Rossa, Claudio A.
在链霉菌中编码葡萄糖-6-磷酸脱氢酶异构体的基因（zwf）的缺失导致存活异构体中体外测定的葡萄糖-6-磷酸脱氢酶活性增加。携带其中任何一种缺失的突变体表现出显著增加的放线鸟素生物合成，这一效应无法通过简单的通量平衡模拟来预测。以实验测量变量为约束条件得到的通量变异性分布进行了检验。由于放线菌素产量的增加和营养吸收速率的变化，其通量变异性受到最显著影响的反应包括来自若干不同途径的反应。这些可以连接在一起形成一个放线菌素生成网络。它们包括谷氨酸合成和分解代谢反应。在随后的实验中，谷氨酸被喂食到稳定状态的培养中，导致放线菌素的产生增加，并且硅模型预测了在zwf模型中被放大的相同反应的重要性。在整合质粒pIJ8714上引入一个组成性表达的actII-orf4拷贝（放线素途径基因的途径特异性激活因子），导致从生长解离（典型的次级代谢物）到生长相关抗生素生产的转变。(c) 2006爱思唯尔公司版权所有。
Deletion of either of the genes (zwf), coding for glucose-6-phosphate dehydrogenase isoforms in Streptomyces coelicolor, resulted in an increase in in vitro determined glucose-6-phosphate dehydrogenase activity in the surviving isoform. Mutants carrying either one of these deletions exhibited significantly increased actinorhodin biosynthesis, an effect that was not predicted by simple flux balance simulation. The flux variability distribution, obtained using experimental measured variables as constraints, was examined. The reactions whose flux variabilities were most significantly affected, as a result of the increased actinorhodin production and changes in nutrient uptake rates, included reactions from a number of different pathways. These could be connected together to form an actinorhodin-generating network. They included glutamate synthesising and catabolising reactions. Subsequent experiments, in which glutamate was fed to steady state cultures, resulted in increased actinorhodin production and the in silico model predicted the importance of the same reactions that were amplified in the zwf model. Introduction of a constitutively expressed copy of actII-orf4, the pathway-specific activator of the actinorhodin pathway genes, on the integrating plasmid pIJ8714 resulted in a switch from growth dissociated (typical secondary metabolite) to growth associated antibiotic production. (c) 2006 Elsevier Inc. All rights reserved.