Production of Fatty Acid-Derived Fuels and Chemicals in Saccharomyces Cerevisiae

Rapidly increasing energy demands, limited fossil fuel reserves, and the environmental risk associated with extracting these have led to a growing interest in microbial biofuel production. Fatty acids, used in nature for cellular energy storage, are among the most energy-dense molecules produced naturally, and can be converted into high-value molecules such as fuels, lubricants, and other chemicals. We previously reported on engineered the budding yeast Saccharomyces cerevisiae to produce free fatty acids at titers up to 400 mg/L. Here, we systematically optimized our original production strain by optimizing flux through the fatty acid biosynthesis pathway, balancing cofactor recycling, limiting production of side products, and optimizing the metabolic state of the cell. We combined beneficial engineering strategies to produce a fatty acid overproducer with production titers over 800 mg/L. Our results demonstrate the power of rational, systematic engineering to overcome pathway inefficiencies and improve product titer.