Tuesday, April 30, 2013
Exhibit Hall
The microbial production of fatty alcohols is an attractive process for the production of chemicals from renewable sources. Fatty alcohols have numerous applications in the production of detergents, surfactants, and personal care products. Towards this goal, the expression levels of a thioesterase, an acyl-coA ligase, and an acyl-coA reductase have been individually tailored to increase the yield of fatty alcohols from carbon feedstocks in E. coli. Multiple copies of a thioesterase gene from Umbellularia californica (BTE) under the control of an inducible promoter were integrated into the chromosome, and the native acyl-coA ligase (fadD) from E. coli was also placed under the control of an inducible promoter. An acyl-coA reductase with activity towards both acyl-CoAs and fatty aldehydes proved the most effective in conversion to the final alcohol product. In addition, our previously generated model of free fatty acid production was used to select the best fermentation conditions for fatty alcohol production. Using our model and metabolic engineering strategies, we were able to engineer a strain that produces fatty alcohols with a yield of greater than 0.05 g per gram of glucose consumed. Despite the increase in fatty alcohol yield, further improvement is necessary to reach economic viability. Additionally, toxicity effects of the fatty alcohol product will likely need to be addressed during further engineering efforts.