title: Escherichia coli responds with a rapid and large change in growth rate upon a shift from glucose-limited to glucose-excess conditions.
abstract: Glucose pulse experiments at seconds time scale resolution were performed in aerobic glucose-limited Escherichia coli chemostat cultures. The dynamic responses of oxygen-uptake and growth rate at seconds time scale were determined using a new method based on the dynamic liquid-phase mass balance for oxygen and the pseudo-steady-state ATP balance. Significant fold changes in metabolites (10-1/10) and fluxes (4-1/4) were observed during the short (200 s) period of glucose excess. During glucose excess there was no secretion of by-products and the increased glucose uptake rate led within 40s to a 3.7 fold increase in growth rate. Also within 40-60s a new pseudo-steady-state was reached for both metabolite levels and fluxes. Flux changes of reactions were strongly correlated to the concentrations of involved compounds. Surprisingly the 3.7 fold increase in growth rate and hence protein synthesis rate was not matched by a significant increase in amino acid concentrations. This poses interesting questions for the kinetic factors, which drive protein synthesis by ribosomes.
authors: Department of Biotechnology, Delft University of Technology, Kluyver Centre for Genomics of Industrial Fermentation, Delft, The Netherlands. hilal.taymaz@gmail.com
authors: Hilal
authors: H
authors: Taymaz-Nikerel
authors: Walter M
authors: WM
authors: van Gulik
authors: Joseph J
authors: JJ
authors: Heijnen
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D048168:Escherichia coli K12 / Q000254:growth & development*; D029968:Escherichia coli Proteins / Q000096:biosynthesis*; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology*; D014176:Protein Biosynthesis / Q000187:drug effects / Q000502:physiology*; D013549:Sweetening Agents / Q000378:metabolism / Q000494:pharmacology
chemical_list: D029968:Escherichia coli Proteins; D013549:Sweetening Agents; D000255:Adenosine Triphosphate; D005947:Glucose