Peroxisomal Compartmentalization of the Methylerythritol-4-phosphate Pathway Alleviates Cellular Stress and Enhances Geraniol Production in Saccharomyces cerevisiae.

Abstract

Terpenoids are a diverse class of compounds with significant application potential. While prokaryotic bacteria synthesize terpenoids via the methylerythritol-4-phosphate (MEP) pathway, fungi utilize the mevalonate (MVA) pathway. The MVA pathway has been widely employed for efficient terpenoid production in bacteria such as Escherichia coli, but the MEP pathway performs poorly for biosynthesis in yeast. In this study, we constructed a compartmentalized MEP pathway to enhance monoterpenoid production in Saccharomyces cerevisiae. By introducing a geraniol synthase, we initially achieved the production of geraniol from glucose. Further effective incorporation of a cytosolic MEP pathway with nine enzymes increased geraniol production by 174.5%. However, this also significantly inhibited cell growth. Overexpression analysis revealed that flavodoxin and flavodoxin reductase were major contributors to growth inhibition, which could also be a factor limiting the application of the MEP pathway. To address these issues, we employed peroxisomal compartmentalization to isolate the MEP pathway from cytosolic metabolism. This strategy alleviated growth inhibition and improved geraniol production by 93.18% compared to that of cytosolic expression. Through additional metabolic engineering, we optimized peroxisomal geraniol production, achieving a yield of 30.64 mg/L. Our findings demonstrate the potential of compartmentalized MEP pathway expression as a viable approach for enhancing terpenoid biosynthesis in yeast, offering valuable insights for future metabolic engineering efforts.