Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/20/2004
Publication Date: 6/25/2004
Citation: Liu, Z., Slininger, P.J. 2004. Development of genetically engineered stress tolerant ethanologenic yeasts using integrated functional genomics for effective biomass conversion to ethanol [abstract]. Proceedings of the Conference of Agriculture as a Producer and Consumer of Energy. Selected Paper Abstracts, Session D, Paper No. 7. Interpretive Summary: As interest in alternative energy sources increases, the significance of agriculture as an energy producer has been recognized. However, biomass pretreatment generates fermentation inhibitors which interfere with biomass conversion to ethanol. The economics of fermentation-based bioprocesses rely extensively on the performance of microbial biocatalysts available for industrial application. We initiated an integrated functional genomic study to investigate stress tolerance mechanisms of yeasts and develop genetically engineered, more robust strains for more cost-efficient bioethanol production. This study reports genomic analysis of yeasts in response to representative inhibitors. The newly developed, more tolerant strains show distinct gene expression profiles compared with those of a wild type. These results demonstrate yeast tolerance improvement potential and will assist interpretation of molecular mechanisms of the stress tolerance involved in bioethanol fermentation. Also presented is our current knowledge and our accomplishments in the areas of metabolic conversion pathways of inhibitors, adaptive response of yeasts to the inhibitors, potential for yeast tolerance improvement, byproduct utilization issues, stress tolerance mechanisms, and novel strain design and genetic engineering. This study impacts industrial experts, economists, and government leaders because it provides baseline reference for decision makers to develop a road map to guide private and public policies influencing future energy consumption and production in agriculture, particularly in the area of biotechnology impact on more efficient biomass conversion to ethanol.
Technical Abstract: Inhibitory compounds generated during acid hydrolysis of renewable agricultural biomass interfere with subsequent ethanol fermentation. We elucidate the chemical stress tolerance mechanisms of Saccharomyces cerevisiae using genomic expression analysis; and develop genetically engineered novel ethanologenic strains to detoxify fermentation inhibitors in situ for effective bioethanol production.