Metabolic Engineering of Saccharomyces Cerevisiae for Enhanced Carotenoid Production

Metabolic engineering was utilized in an aim to optimize and study the production of carotenoids, specifically β-carotene, in engineered Saccharomyces cerevisiae strains. Our group has previously developed a novel evolutionary engineering approach to obtain hyper producer strains of isoprenoid compounds. Carotenoid production in yeast uses the cystolic mevalonate (MVA) pathway. In the MVA pathway, the catalytic domain of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) converts HMG-CoA to mevalonate.  This HMG-CoA reductase is a rate-limiting step in isoprenoid biosynthesis and overexpression of the truncated HMG-CoA reductase gene (tHMG1) has been shown to increase metabolic flux towards β-carotene production. Overexpression of tHMG1 was used to test the increase in overall production of carotenoids in our engineered strains of S. cerevisiae. All engineered strains were tested in a batch-mode bioreactor under pH, agitation, and temperature control.