Engineering Saccharomyces cerevisiae for α-terpineol production from corn stover hydrolysate via UV mutagenesis and PCL1-mediated tolerance enhancement

Abstract

Engineered Saccharomyces cerevisiae offers a sustainable platform for converting lignocellulosic hydrolysates into high-value chemicals, supporting circular bioeconomy goals. However, multicomponent inhibitors in lignocellulosic hydrolysates often hinder bioconversion efficiency. In this study, strain T1 with enhanced tolerance to corn stover hydrolysate (CSH) was developed by optimizing the xylose metabolic pathway and applying UV mutagenesis. Transcriptomic analysis showed that in strain T1, genes encoding cell cycle regulatory proteins, such as PCL1, were upregulated, thereby contributing to CSH resistance. Physiological analyses showed that improved robustness was associated with stable cell morphology, budding efficiency, and cytoskeletal integrity. Interestingly, strain T1 exhibited superior performance in converting CSH into acetyl-CoA derivatives. Therefore, strain T1 was utilized as a chassis for converting CSH into α-terpineol through engineering modifications, including enhancement of intracellular precursor biosynthesis, optimization of key enzyme copy numbers, and dynamic regulation of ergosterol synthesis. Finally, the engineered strain D22 achieved an α-terpineol titer of 13.6 mg/L from CSH in shake-flask cultivation, representing the first demonstration of α-terpineol biosynthesis directly from CSH. This work offers insights into robust strain design and efficient lignocellulosic biomass valorization, contributing to sustainable biomanufacturing.