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Oral Presentation 2-05 Metabolic Engineering of Anaplerotic Reactions for Succinic Acid and Pyruvic Acid Production
Mark A. Eiteman, Elliot Altman Center for Molecular BioEngineering Department of Biological and Agricultural Engineering University of Georgia,
Athens, GA 30602 Telephone: (706) 542-0833; Fax: (706) 542-8806; E-mail:
eiteman@engr.uga.edu Anaplerotic reactions are those biochemical steps which replenish the intermediates consumed for the generation of biomass. These biochemical reactions are necessary for cell growth, but are not necessary for cell maintenance. Our research involves the metabolic engineering of central metabolism using important characteristics of anaplerotic reactions. We recently have applied different metabolic engineering strategies to the production of succinic acid and pyruvic acid from glucose by Esterichia coli. In the case of succinic acid, the expression of heterologous pyruvate carboxylase increases product yield and productivity in a recombinant strain of E. coli producing succinic acid in a dual-phase (aerobic/anaerobic) fermentation. Selection of the ideal time for a transition between these two process phases based on physiological milestones leads to a final succinic acid concentration of about 100 g/L in 75 h. In the case of pyruvic acid, a different metabolic engineering approach leads to pyruvic acid production to 50 g/L in 30 h.
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