Sarah Hammer is National Science Foundation Graduate Research Fellow in the Department of Chemical and Biological Engineering. Advised by Professor José Avalos, her research seeks to address the need for sustainable liquid transportation fuels. While ethanol is the most widely used liquid biofuel, its incompatibility with existing infrastructure limits its ability to replace more than 10% of gasoline consumption in the United States. Branched-chain higher alcohols are promising alternatives, which can be used as complete fuel substitutes in gasoline engines or converted to jet fuel. Combining traditional metabolic engineering approaches with structural and synthetic biology, Sarah’s research focuses on engineering yeast for the production of branched-chain higher alcohols from biomass-based sugars. In addition, she is interested in the practical and political challenges that must be overcome in order for alternative liquid fuels to penetrate the market.