Regulating the Metabolic Flux of Pyruvate Dehydrogenase Bypass to Enhance Lipid Production in Saccharomyces cerevisiae

To achieve high efficiency in microbial cell factories, it is crucial to redesign central carbon fluxes to ensure an adequate supply of precursors for producing high-value compounds. In this study, we employed a multi-omics approach to rearrange the central carbon flux of the pyruvate dehydrogenase (PDH) bypass, thereby enhancing the supply of intermediate precursors, specifically acetyl-CoA. This enhancement aimed to improve the biosynthesis of acetyl-CoA-derived compounds, such as terpenoids and fatty acid-derived molecules, in Saccharomyces cerevisiae. Through transcriptomic and lipidomic analyses, we identified ALD4 as a key regulatory gene influencing lipid metabolism. Genetic validation demonstrated that overexpression of the mitochondrial acetaldehyde dehydrogenase (ALDH) gene ALD4 resulted in a 20.1% increase in lipid production. This study provides theoretical support for optimising the performance of S. cerevisiae as a "cell factory" for the production of commercial compounds.This study aimed to identify a metabolic engineering strategy that increases lipid synthesis by S. cerevisiae during anaerobic fermentation. Multi-omics analyses are conducted to identify important regulatory genes that responsible for increasing lipid synthesis. The synthesis of acetyl-CoA and lipids was effectively promoted by regulating the flow of glycolytic carbon flux to PDH bypass pathway. Our study provides new insights and directions for further development of PDH bypass-based metabolic engineering strategies to enhance the microbial synthesis of industrial lipid compounds.