High-yield production of hydroxytyrosol through metabolic engineering of Yarrowia lipolytica

Hydroxytyrosol (HT) is a natural antioxidant widely employed in the food production, pharmaceutical, and cosmetic industries. Microbial fermentation for HT production holds significant potential for industrial applications. In this study, we constructed and optimized a biosynthetic pathway for HT in Yarrowia lipolytica for the first time. Initially, HT biosynthesis was achieved by introducing hpaBC, along with ARO10 and ADH6 from Saccharomyces cerevisiae. By employing strategies such as relieving feedback inhibition in the shikimate pathway, optimizing cofactor supply, weakening competing pathways, and balancing metabolic flux, the HT titer was elevated to 2438.27 mg/L. Finally, the engineered strain HT43 produced 11.9 g/L of HT in a 1.3 L bioreactor, which was 917.5 times higher than the initial level. This work sets a new record for the de novo production of HT in a microbial host, achieving the highest titer reported to date, and it offers a novel fermentation strategy with potential for industrial HT production.