(571a) Engineering Yeast for Advanced Biofuels

The development of renewable liquid transportation fuels is a key component of the national strategy to reduce CO₂ emissions, slow the progression of global climate change, and achieve energy self-sufficiency. Although bioethanol is the most commercially successful biofuel to date, its physicochemical properties and current methods of production make it an inadequate long-term solution to these problems. We are developing yeast strains that produce advanced biofuels that overcome ethanol’s limitations. In order to accelerate strain development, we have developed a set of molecular tools and strategies that facilitate the cloning, assembly, integration, and optimization of engineered pathways. We demonstrate the use of this molecular toolkit to overcome roadblocks in the molecular and cellular biology of yeast that present bottlenecks in metabolic engineering, such as the screening of isoenzymes, vectors, promoters and strains. These molecular tools also facilitate new strategies for the assembly of multigenic pathways, which we used in the combinatorial assembly of multiple “isopathways” for the production of advanced biofuels. Using these tools we have engineered yeast strains that produce three different advanced biofuels with better fuel properties than ethanol, and better compatibility with prevalent infrastructures.