Zhu Jiang, Gu Yang, Yan Yijing, Ma Jingbo, Sun Xiaoman, Xu Peng
School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China.
Department of Chemical, Biochemical and Environmental Engineering, University of MD, Baltimore County, Baltimore, MD, United States.
Front Bioeng Biotechnol. 2023 Jan 13;11:1098116. doi: 10.3389/fbioe.2023.1098116. eCollection 2023.
Systematic gene knockout studies may offer us novel insights on cell metabolism and physiology. Specifically, the lipid accumulation mechanism at the molecular or cellular level is yet to be determined in the oleaginous yeast . Herein, we established ten engineered strains with the knockout of important genes involving in central carbon metabolism, NADPH generation, and fatty acid biosynthetic pathways. Our result showed that NADPH sources for lipogenesis include the OxPP pathway, POM cycle, and a trans-mitochondrial isocitrate-α-oxoglutarate NADPH shuttle in . Moreover, we found that knockout of mitochondrial NAD isocitrate dehydrogenase IDH2 and overexpression of cytosolic NADP isocitrate dehydrogenase IDP2 could facilitate lipid synthesis. Besides, we also demonstrated that acetate is a more favorable carbon source for lipid synthesis when glycolysis step is impaired, indicating the evolutionary robustness of . This systematic investigation of gene deletions and overexpression across various lipogenic pathways would help us better understand lipogenesis and engineer yeast factories to upgrade the lipid biomanufacturing platform.
系统的基因敲除研究可能会为我们提供有关细胞代谢和生理学的新见解。具体而言，产油酵母中分子或细胞水平的脂质积累机制尚待确定。在此，我们构建了十个工程菌株，敲除了参与中心碳代谢、NADPH生成和脂肪酸生物合成途径的重要基因。我们的结果表明，用于脂肪生成的NADPH来源包括氧化磷酸戊糖途径、磷酸戊糖途径循环以及线粒体间异柠檬酸-α-酮戊二酸NADPH穿梭。此外，我们发现敲除线粒体NAD异柠檬酸脱氢酶IDH2和过表达胞质NADP异柠檬酸脱氢酶IDP2可以促进脂质合成。此外，我们还证明，当糖酵解步骤受损时，乙酸盐是更有利于脂质合成的碳源，这表明了……的进化稳健性。这种对各种脂肪生成途径中基因缺失和过表达的系统研究将有助于我们更好地理解脂肪生成，并改造酵母工厂以升级脂质生物制造平台。
