Enhancing sesquiterpene production in Saccharomyces cerevisiae through in silico driven metabolic engineering
Enhancing sesquiterpene production in Saccharomyces cerevisiae through in silico driven metabolic engineering
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DOI：
10.1016/j.ymben.2009.07.001
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发表时间：
2009-11-01
影响因子：
8.4
通讯作者：
Nielsen, Jens
中科院分区：
文献类型：
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作者：
Asadollahi, Mohammad A.;Maury, Jerome;Nielsen, Jens
利用基因组尺度的代谢模型，鉴定了促进酿酒酵母倍半萜生物合成的新靶基因。以Opt gene为模型框架，以代谢调节最小化（minimization of metabolic adjustment， MOMA）为目标函数，评估基因缺失对酿酒酵母代谢模型中通量分布的影响。GDH1编码nadph依赖性谷氨酸脱氢酶的缺失被认为是改善酵母倍半萜生物合成的最佳靶基因。该基因的缺失增强了细胞质中其他NADPH需要酶的可用NADPH，包括HMG-CoA还原酶。然而，由于GDH1的破坏会损害氨的利用，本研究还考虑了GDH2编码的nadh依赖性谷氨酸脱氢酶同时过表达。GDH1的缺失导致最终立方滴度增加约85%。然而，该基因的缺失也导致了最大特定生长率的显著降低。过表达GDH2对最终滴度没有进一步的影响，但与GDH1缺失的菌株相比，这种改变显著提高了生长速度。(C) 2009爱思唯尔公司版权所有。
A genome-scale metabolic model was used to identify new target genes for enhanced biosynthesis of sesquiterpenes in the yeast Saccharomyces cerevisiae. The effect of gene deletions on the flux distributions in the metabolic model of S. cerevisiae was assessed using Opt Gene as the modeling framework and minimization of metabolic adjustments (MOMA) as objective function.Deletion of NADPH-dependent glutamate dehydrogenase encoded by GDH1 was identified as the best target gene for the improvement of sesquiterpene biosynthesis in yeast. Deletion of this gene enhances the available NADPH in the cytosol for other NADPH requiring enzymes, including HMG-CoA reductase. However, since disruption of GDH1 impairs the ammonia utilization, simultaneous over-expression of the NADH-dependent glutamate dehydrogenase en coded by GDH2 was also considered in this study.Deletion of GDH1 led to an approximately 85% increase in the final cubebol titer. However, deletion of this gene also caused a significant decrease in the maximum specific growth rate. Over-expression of GDH2 did not show a further effect on the final cubebol titer but this alteration significantly improved the growth rate compared to the GDH1 deleted strain. (C) 2009 Elsevier Inc. All rights reserved.