Purdue University School of Chemical Engineering Graduate Seminar Series Dr. John A. Morgan Associate Professor, School of Chemical Engineering Purdue University "Determination of Metabolic Fluxes in Green Organisms" November 23, 2010 3:30 - 4:30 p.m. FRNY G140 Abstract: Photosynthetic microorganisms are of prime importance in the global carbon cycle, the current source of nutrients and a promising source of biofuels. A major thrust of our research is a systems level understanding of metabolism that will enable the rational manipulation of metabolic networks in photosynthetic organisms. Evaluation of the rates and yields of metabolic pathways under different environmental and genetic conditions provides the basis for effective metabolic engineering strategies. To accomplish this goal, a key tool is the measurement of metabolic rates also as known as metabolic fluxes. We have been a leading group developing the mathematical models and measurement techniques resulting in the first metabolic flux maps for cyanobacteria (blue-green algae) and microalgae. Significant progress will be reported on the formulation of stoichiometric models of photosynthetic microbes including details of light harvesting. Constraint based models were constructed and tested for the cyanobacteria Synechocystis PCC6803, and a genome scale model for the photosynthetic algae, Chlamydomonas reinhardtii. Predictions of metabolic fluxes were calculated by specifying an objective function, such as maximizing biomass synthesis, and performing linear programming to determine optimal fluxes satisfying stoichiometric constraints. We will present our findings for predicted metabolic flux distributions under hetero-, mixo-, and autotrophic growth conditions. Experimental validation by 13C metabolic flux analysis will be detailed for the two model organisms and the results compared with the predictions. Each of these studies demonstrates the powerful insight that mathematical analysis provides on systems of complex reaction networks. Bio: John Morgan received a B.S. and M.S. in Chemical Engineering from University of Kansas and a Ph.D. from Rice University in Chemical Engineering. He then completed postdoctoral studies with Professor Douglas Clark at the University of California, Berkeley. John began his academic career as an assistant professor in the School of Chemical Engineering at Purdue University in 2000, and was promoted to Associate Professor in 2006. His research focuses on metabolic engineering of plants and microbes, with a particular focus on photosynthetic organisms. Advances in the techniques of metabolic flux analysis are integral to Prof. Morgan's research efforts. Debbie Luedtke Deborah P. Luedtke, Secretary School of Chemical Engineering Purdue University Forney Hall, Room 1144 480 Stadium Mall Drive West Lafayette, IN 47907-2100 Tel: 765-494-4365 / Fax: 765-494-0805 Email: dpmcdani@purdue.edu