Production of biofuels from renewable resources is necessary for satisfying growing global demand for transportation fuels and an essential component of the future energy mix. Interest in biofuels production stems from the fact that biofuels can substitute for petroleum-based fuels in all modes of transportation, ranging from automobiles to buses, trucks, ships and aircraft, most of which will not be powered by other renewable energies, such as wind or solar, in the foreseeable future. However, significant scientific and technological breakthroughs are still needed to achieve a truly commercially viable and environmentally safe biofuel industry, including utilization of sustainable feedstocks, improvements in methods of production and quality of end-product fuels.
The Stephanopoulos lab is engaged in several biofuel projects. We are developing yeast strains that utilize both cellulosic and hemicellulosic components of biomass for alcohol production. Our goal is the development of processes that attain high yield, titer and volumetric productivity. To this end we are pursuing strain engineering and process optimization. We are also improving the tolerance of yeast strains to the inhibitory compounds contained as side products in the hydrolysates of cellulosic biomass, as well as to the toxicity of the biofuels produced. The use of such strains would increase the ultimate cost-effectiveness of existing and future methods of production. The laboratory is also actively developing microorganisms that produce advanced biofuels with properties superior to ethanol regarding energy density, volatility, corrosiveness and ease of separation. Advanced biofuels can be blended with or substitute gasoline or diesel, or act as chemical precursors to produce jet fuel. To achieve these goals, we employ a variety of disciplines and technologies, including metabolic engineering, transcriptomic analysis, global transctiption machinery engineering (gTME), directed evolution, enzymology and enzyme engineering, microfluidic systems for high throughput screening, metabolic flux analysis and bioreactor design and optimization. Finally, we pursue the biosynthesis of oil and lipids from carbohydrate feedstocks, which can be directly used as fuels or generate fuel substitutes after additional catalytic reforming.