ENGINEERED YEAST STRAINS FOR SUSTAINABLE PRODUCTION OF ANTIMALARIAL DRUG PRECURSORS

Abstract

The growing global demand for artemisinin-based antimalarial therapies necessitates the development of sustainable and scalable methods for precursor production. This study presents the systematic metabolic engineering of Saccharomyces cerevisiae for the biosynthesis of amorphadiene, a key precursor to artemisinin. Four yeast strains (Y-AM1 to Y-AM4) were progressively engineered through heterologous gene integration, promoter modulation, pathway optimization, and transcriptional fine-tuning. Among these, strain Y-AM4 exhibited the highest amorphadiene titer at 310 mg/L in batch fermentation, representing a substantial improvement over initial constructs. Transcriptomic analysis revealed significant upregulation of pivotal genes such as HMGR and ERG20, directly correlating with enhanced precursor flux. Further enhancement was achieved through adaptive laboratory evolution, which improved growth rate, biomass yield, and stress tolerance. Fed-batch fermentation of the evolved strain increased amorphadiene production to 455 mg/L, a 47% improvement over batch cultivation. The analysis showed that the engineered pathway produced a product that was at least 96% pure. By combining gene expression studies and pathway analyses, the team developed a series of engineering steps and found different regulation in the strains of different productivity. When genetic changes are combined with improving bioprocesses, producing the needed chemicals is more affordable and practical than using plants. This study proves that yeasts engineered for biosynthesis can turn out valuable antimalarial drugs with greater strength and significantly lower costs.