Production of industrial chemicals is a $400 billion-plus enterprise in the U.S. that impacts all aspects of society, from personal care products to building materials.  The overall goal of the Center for Biorenewable Chemicals (CBiRC) is to transform the chemical industry by integrating biological and chemical catalysis to create a generalized framework for producing biorenewable chemicals.  The current goal is to produce alpha-olephins, currently one of the 25 largest volume organic chemicals, from short-chain fatty acids instead of the current precursor ethylene.  While the workhorse organisms Escherichia coli and Saccharomyces cerevisiae produce short-chain fatty acids as intermediates for cell membrane components, modification of these organisms to produce short-chain fatty acids at a high yield and titer requires microbial metabolic engineering.  In addition to engineering the metabolic pathways to increase production of short-chain fatty acids, the fatty acid tolerance of these organisms must be addressed.  This poster will discuss the overall CBiRC goal as well as efforts to understand and increase fatty acid tolerance in E. coli and S. cerevisiae.