title: MFA for overdetermined systems reviewed and compared with rna expression data to elucidate the difference in shikimate yield between carbon- and phosphate-limited continuous cultures of E. coli W3110.shik1.
abstract: The present contribution focuses on the mathematical techniques used to solve steady state metabolic models for the case of an overdetermined system. Even when parts of the system are underdetermined it is possible to solve the model partially and obtain statistically meaningful results. This is illustrated with data gathered from a set of E. coli W3110.shik1 phosphate- or carbon-limited continuous cultures. It is shown that the low yield in shikimate for C-limited cultures is not due to a lower flux going to the shikimate pathway but is caused by a high secretion of byproducts. Carbon-limited cultures could be better for shikimate production than carbon-abundant cultures provided the byproduct secretion is reduced. Finally, flux calculations are compared with RNA expression data.
authors.affiliation: BIOMATH, Department of Applied Mathematics, Biometrics and Process Control, Ghent University, Coupure Links 653, Belgium. gaspard.lequeux@biomath.ugent.be
authors.forename: Gaspard
authors.initials: G
authors.lastname: Lequeux
authors.forename: Louise
authors.initials: L
authors.lastname: Johansson
authors.forename: Jo
authors.initials: J
authors.lastname: Maertens
authors.forename: Peter A
authors.initials: PA
authors.lastname: Vanrolleghem
authors.forename: Gunnar
authors.initials: G
authors.lastname: Lidén
mesh_terms: D002244:Carbon / Q000737:chemistry / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000379:methods; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D008433:Mathematics; D015233:Models, Statistical; D010710:Phosphates / Q000737:chemistry / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods; D012313:RNA / Q000096:biosynthesis / Q000235:genetics*; D012765:Shikimic Acid / Q000737:chemistry / Q000378:metabolism*
chemical_list: D010710:Phosphates; D012765:Shikimic Acid; D012313:RNA; D002244:Carbon