Systems-based metabolic engineering enables cells to enhance product formation by predicting gene knockout and overexpression targets using modeling tools. FOCuS, a novel metaheuristic tool, was used to predict flux improvement targets in terpenoid pathway using the genome-scale model of Saccharomyces cerevisiae, iMM904. Some of the key knockout target predicted includes LYS1, GAP1, AAT1, AAT2, TH17, KGD-m, MET14, PDC1 and ACO1. It was also observed that the knockout reactions belonged either to fatty acid biosynthesis, amino acid synthesis pathways or nucleotide biosynthesis pathways. Similarly, overexpression targets such as PFK1, FBA1, ZWF1, TDH1, PYC1, ALD6, TPI1, PDX1 and ENO1 were established using three different existing gene amplification algorithms. Most of the overexpression targets belonged to glycolytic and pentose phosphate pathways. Each of these targets had plausible role for improving flux toward sterol pathway and were seemingly not artifacts. Moreover, an in vitro study as validation was carried with overexpression of ALD6 and TPI1. It was found that there was an increase in squalene synthesis by 2.23- and 4.24- folds, respectively, when compared with control. In general, the rationale for predicting these in silico targets was attributed to either increasing the acetyl-CoA precursor pool or regeneration of NADPH, which increase the sterol pathway flux.

中文翻译：

---

基于计算机目标的酿酒酵母菌株工程用于萜烯前体的改进。

基于系统的代谢工程使细胞能够通过使用建模工具预测基因敲除和过表达目标来增强产物形成。FOCuS 是一种新的元启发式工具，用于使用酿酒酵母的基因组规模模型 iMM904 预测萜类化合物途径中的通量改善目标。预测的一些关键敲除目标包括 LYS1、GAP1、AAT1、AAT2、TH17、KGD-m、MET14、PDC1 和 ACO1。还观察到敲除反应属于脂肪酸生物合成、氨基酸合成途径或核苷酸生物合成途径。类似地，PFK1、FBA1、ZWF1、TDH1、PYC1、ALD6、TPI1、PDX1 和 ENO1 等过表达目标是使用三种不同的现有基因扩增算法建立的。大多数过表达目标属于糖酵解和戊糖磷酸途径。这些目标中的每一个都具有改善流向甾醇途径的合理作用，并且似乎不是人工制品。此外，通过 ALD6 和 TPI1 的过表达进行了一项体外研究作为验证。发现与对照相比，角鲨烯的合成分别增加了 2.23 倍和 4.24 倍。一般而言，预测这些计算机靶标的基本原理归因于增加乙酰辅酶A前体库或NADPH的再生，这增加了甾醇途径的通量。与对照相比。一般而言，预测这些计算机靶标的基本原理归因于增加乙酰辅酶A前体库或NADPH的再生，这增加了甾醇途径的通量。与对照相比。一般而言，预测这些计算机靶标的基本原理归因于增加乙酰辅酶A前体库或NADPH的再生，这增加了甾醇途径的通量。