Engineering Metabolic Pathways and Enzymes for the Synthesis of Fatty Acids and Polyketides in Yeast

Polyketides and fatty acids are of critical importance as biorenewable chemical precursors, biofuels, and pharmaceuticals. Both are synthesized via complex polyketide or fatty acid synthases, with many using acetyl-CoA and malonyl-CoA as starter and extender units. We have engineered and combined multiple pathways in the yeast Saccharomyces cerevisiae for the production of these valuable compounds and to allow the synthesis of novel variants. We have combined enzyme engineering (of the pathway and synthase enzymes), extensive metabolic pathway engineering for increased cofactor and precursor pools, and cultivation strategies to substantially increase titers and yields of a variety of products, including fatty acids (FAs) of varying lengths, triacetic acid lactone (TAL), 6-methylsalicylic acid (6-MSA), and dihydromonocolin L (DML; precursor to lovastatin). For the high-level production of TAL, our work has focused on overexpression of native and variant Gerbera hybrida 2-pyrone synthases (2-PS), engineering of the yeast metabolic pathways, and implementation of various cultivation strategies. These interventions increased TAL titer from 0.07 g/L to 10.5 g/L and yield from