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Poster Presentation 2-18
Metabolic Flux Distributions in Saccharomyces cerevisiae Utilizing Starch
Mehmet Mete Altintas, Kazim Yalcin Arga, Tunahan Cakir, Kutlu Ozergin-Ulgen
Department of Chemical Engineering, University of Colorado Boulder, CO 80309-0424
Telephone: (303) 492-6530; Fax: (303) 492-4341; E-mail: altintas@colorado.edu
By the development of recombinant DNA technology, recombinant yeast strains are developed to consume several biological compounds that cannot be transported through cell walls. The recombinant yeast used in the present study is genetically modified so that it is able to digest starch by secreting alpha-amylase and gluco-amylase enzymes. Several batch and fed-batch systems with different substrate concentrations are investigated both experimentally and theoretically using a stoichiometric metabolic model. In the application of Metabolic Flux Analysis, a determined system is used by taking into consideration the compartmentation approach. The effects of initial substrate concentration and the growth rate of recombinant Saccharomyces cerevisiae culture on ethanol production on starch were investigated during growth. The function of main pathways in yeast metabolism (PPP, EMP, TCA) and the production of byproduct (glycerol) are discussed together with the role of precursors on anaerobic yeast metabolism producing ethanol. With the application of rational design methodology of metabolic engineering, new production systems can be developed for ethanol production.
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