STTR Phase I: A novel combinatorial technology for engineering product tolerance traits in yeast

This Small Business Technology Transfer (STTR) Phase I project proposes to engineer butanol tolerance in the yeast Saccharomyces cerevisiae using a novel combinatorial genetic technology designed to enable yield enhancements in microbial production organisms. Microbial production of renewable fuels and chemicals is rapidly expanding. However, toxic products or by-products and engrained metabolic fluxes often limit yields. Companies engaged in this space are actively searching for solutions. Novel genetic technologies are required that can help overcome these limitations. The proposed technology is designed as a new way to reprogram a cell and confer useful phenotypes. Synthetic genes are constructed using proprietary combinatorial strategies, limiting the ability of organisms to generate compensatory genetic or epigenetic changes. High-complexity expression libraries of these genes are transferred into the organism followed by selection or screening for desirable characteristics. The proposed experiments will demonstrate the feasibility of the technology in a screen for tolerance of butanol - a second-generation biofuel and important chemical precursor - using Saccharomyces cerevisiae, a yeast commonly used for alcohol production. The genes discovered during this work will be of direct interest to companies employing yeast for fuel and chemical production. The broader impact/commercial potential of this project, if successful, will be the enablement of improvements in microbes used for production of chemicals, fuels, pharmaceuticals, foods, and food ingredients. There is increasingly widespread use of microbial organisms (bacteria, fungi, yeasts, cyanobacteria, and algae) to produce these materials. Fuels and chemicals produced from such renewable sources generate roughly $75B in annual product sales, and this industry is experiencing rapid expansion. However, improving the yield and efficiency of production organisms is limited by the highly complex regulatory systems that govern yield, resistance, metabolism and growth. Current genetic methods are capable only of incremental improvements. Dramatic increases in yield and efficiency will require harnessing the massive combinatorial potential of genomes - the material on which natural evolution works. The proposed technology has multiple advantages over current approaches, especially regarding the probability of achieving a phenotype of interest, novelty of the active genes, transferability of the phenotype, speed and cost. This technology promises dramatically more effective creation of microbes with improved characteristics in multiple industries. It also will enable breakthroughs in our understanding of how important traits relating to growth, yield and productivity are encoded in biological systems.