Transcription factor YALI1_A16891g contributes to enhanced glycolytic flux and mevalonate production at elevated temperature in engineered Yarrowia lipolytica.

Abstract

Yarrowia lipolytica (Y. lipolytica) is an attractive host for terpenoid biosynthesis due to its high acetyl-CoA availability and robust genetic tractability. However, how fermentation temperature influences intracellular metabolic states remains insufficiently characterized. Here, the engineered mevalonate-producing strain YL17 was employed as a platform to characterize temperature-dependent metabolic responses in Y. lipolytica. Fermentation experiments across a range of temperatures revealed a clear growth-production trade-off, whereby increasing temperature enhanced mevalonate synthesis at the expense of cellular growth. 13C metabolic flux analysis revealed that higher temperature promoted a significant redistribution of carbon flux toward glycolysis, increasing acetyl-CoA generation and precursor supply. Notably, transcriptomic analysis indicated a global downregulation of genes involved in glycolysis, indicating a decoupling between transcriptional levels and flux regulation. To explore the regulatory basis underlying this phenotype, differentially expressed transcription factors were systematically analyzed, leading to the identification of YALI1_A16891g as a key regulatory candidate associated with glycolytic flux redistribution. Further analysis suggested that YALI1_A16891g may regulate downstream glycolysis-related genes under elevated temperature conditions, thereby influencing glycolytic carbon allocation and mevalonate production specifically at high temperature in Y. lipolytica. These results demonstrate that temperature can effectively reshape metabolic flux distribution and highlight transcription factor-mediated regulation as a practical target for improving precursor supply in engineered Y. lipolytica.