Liu Leqian, Markham Kelly, Blazeck John, Zhou Nijia, Leon Dacia, Otoupal Peter, Alper Hal S
McKetta Department of Chemical Engineering, The University of Texas at Austin, 200 E Dean Keeton St., Stop C0400, Austin, TX 78712, USA.
McKetta Department of Chemical Engineering, The University of Texas at Austin, 200 E Dean Keeton St., Stop C0400, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2500 Speedway Avenue, Austin, TX 78712, USA.
Metab Eng. 2015 Sep;31:102-11. doi: 10.1016/j.ymben.2015.07.004. Epub 2015 Jul 26.
Lipogenic organisms represent great starting points for metabolic engineering of oleochemical production. While previous engineering efforts were able to significantly improve lipid production in Yarrowia lipolytica, the lipogenesis landscape, especially with respect to regulatory elements, has not been fully explored. Through a comparative genomics and transcriptomics approach, we identified and validated a mutant mga2 protein that serves as a regulator of desaturase gene expression and potent lipogenesis factor. The resulting strain is enriched in unsaturated fatty acids. Comparing the underlying mechanism of this mutant to other previously engineered strains suggests that creating an imbalance between glycolysis and the TCA cycle can serve as a driving force for lipogenesis when combined with fatty acid catabolism overexpressions. Further comparative transcriptomics analysis revealed both distinct and convergent rewiring associated with these different genotypes. Finally, by combining metabolic engineering targets, it is possible to further engineer a strain containing the mutant mga2 gene to a lipid production titer of 25g/L.
产脂生物是油脂化学产品代谢工程的理想起始材料。尽管之前的工程改造工作能够显著提高解脂耶氏酵母的脂质产量，但脂质生成的全貌，尤其是调控元件方面，尚未得到充分探索。通过比较基因组学和转录组学方法，我们鉴定并验证了一种突变型mga2蛋白，它作为去饱和酶基因表达的调节因子和强大的脂质生成因子。所得菌株富含不饱和脂肪酸。将该突变体与其他先前改造的菌株的潜在机制进行比较表明，当与脂肪酸分解代谢过表达相结合时，在糖酵解和三羧酸循环之间造成失衡可作为脂质生成的驱动力。进一步的比较转录组学分析揭示了与这些不同基因型相关的独特和趋同的重布线。最后，通过组合代谢工程靶点，有可能将含有突变型mga2基因的菌株进一步改造，使其脂质产量达到25g/L。
