Enhancing Fatty Acid Ethyl Ester Production in Saccharomyces Cerevisiae through Metabolic Engineering and Culture Optimization

Biodiesels in the form of fatty acyl ethyl esters (FAEEs) are a promising next generation biofuel due to their chemical properties and compatibility with existing infrastructure. It has recently been shown that expression of a bacterial acyl-transferase in the established industrial workhorse Saccharomyces cerevisiae can lead to production of FAEEs by condensation of fatty acyl-CoAs and ethanol. We report a series of novel metabolic engineering strategies for FAEE production in S. cerevisiae which were rationally designed to pull the acyl-CoA substrate from competing pathways towards product formation. In addition, we combined our engineered strain with a modification of culture conditions designed to increase lipid accumulation in yeast. These strategies acted together to increase FAEE production over 17 fold.