Tuesday, July 31, 2007 - 11:00 AM
S79
Advances in Engineering of Eschericia coli to Produce Ethanol and other Commodity Products
Laura R. Jarboe, K.T. Shanmugam, and L.O. Ingram. Microbiology and Cell Science, University of Florida, Bldg 981 Museum Rd, Gainesville, FL 32611
Increasing competition for finite petroluem supplies continues to spur interest in using renewable biomass as a feedstock for automotive fuels and chemicals. In a joint report by the USDA and DOE, it has been estimated that the US could produce over 1.3 billion tons of cellulosic biomass per year on a sustainable basis. Approximately 70% of the dry weight of this cellulosic biomass is represented by two carbohydrates, cellulose (a homopolymer of glucose) and hemicellulose (mixed sugar polymers, primarily xylose). After depolymerization, these represent potential substrates for microbial conversion to fuels and chemicals. Escherichia coli has the native ability to metabolize all of the sugar constituent of woody biomass but normally makes a mixture of fermentation products. A combination of metabolic engineering and metabolic evolution have been used to develop derivatives that produce ethanol at high yields in mineral salts medium. Analogous approaches have been used to produce other useful chemicals such as L-lactate and D-lactate. Each product has been produced at concentrations of over 1 M with fermentation times of less than 48 h in inexpensive mineral salts medium.