title: 13C-Labeled metabolic flux analysis of a fed-batch culture of elutriated Saccharomyces cerevisiae.
abstract: This study addresses the question of whether observable changes in fluxes in the primary carbon metabolism of Saccharomyces cerevisiae occur between the different phases of the cell division cycle. To detect such changes by metabolic flux analysis, a 13C-labeling experiment was performed with a fed-batch culture inoculated with a partially synchronized cell population obtained through centrifugal elutriation. Such a culture exhibits dynamic changes in the fractions of cells in different cell cycle phases over time. The mass isotopomer distributions of free intracellular metabolites in central carbon metabolism were measured by liquid chromatography-mass spectrometry. For four time points during the culture, these distributions were used to obtain the best estimates for the metabolic fluxes. The obtained flux fits suggested that the optimally fitted split ratio for the pentose phosphate pathway changed by almost a factor of 2 up and down around a value of 0.27 during the experiment. Statistical analysis revealed that some of the fitted flux distributions for different time points were significantly different from each other, indicating that cell cycle-dependent variations in cytosolic metabolic fluxes indeed occurred.
authors.affiliation: Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
authors.forename: Roeland
authors.initials: R
authors.lastname: Costenoble
authors.forename: Dirk
authors.initials: D
authors.lastname: Müller
authors.forename: Timo
authors.initials: T
authors.lastname: Barl
authors.forename: Walter M
authors.initials: WM
authors.lastname: van Gulik
authors.forename: Wouter A
authors.initials: WA
authors.lastname: van Winden
authors.forename: Matthias
authors.initials: M
authors.lastname: Reuss
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Heijnen
mesh_terms: D002247:Carbon Isotopes / Q000378:metabolism*; D002853:Chromatography, Liquid; D046508:Culture Techniques; D053858:Metabolic Networks and Pathways; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
chemical_list: D002247:Carbon Isotopes