Title of article :
In vivo kinetics of primary metabolism in Saccharomyces cerevisiae studied through prolonged chemostat cultivation
Author/Authors :
Wu، نويسنده , , Liang and Mashego، نويسنده , , Mlawule R. and Proell، نويسنده , , Angela M. and Vinke، نويسنده , , Jacobus L. and Ras، نويسنده , , Cor and van Dam، نويسنده , , Jan and van Winden، نويسنده , , Wouter A. and van Gulik، نويسنده , , Walter M. and Heijnen، نويسنده , , Joseph J.، نويسنده ,
Issue Information :
دوماهنامه با شماره پیاپی سال 2006
Abstract :
In this study, prolonged chemostat cultivation is applied to investigate in vivo enzyme kinetics of Saccharomyces cerevisiae. S. cerevisiae was grown in carbon-limited aerobic chemostats for 70–95 generations, during which multiple steady states were observed, characterized by constant intracellular fluxes but significant changes in intracellular metabolite concentrations and enzyme capacities. We provide evidence for two relevant kinetic mechanisms for sustaining constant fluxes: in vivo near-equilibrium of reversible reactions and tight regulation of irreversible reactions by coordinated changes of metabolic effectors. Using linear-logarithmic kinetics, we illustrate that these multiple steady-state measurements provide linear constraints between elasticity parameters instead of their absolute values. Upon perturbation by a glucose pulse, glucose uptake and ethanol excretion in prolonged cultures were remarkably lower, compared to a reference culture perturbed at 10 generations. Metabolome measurements during the transient indicate that the differences might be due to a reduced ATP regeneration capacity in prolonged cultures.
Keywords :
Equilibrium , Lin-log kinetics , Stimulus-response experiment , Prolonged chemostat cultivation , S. cerevisiae , Adaptation , metabolome , In vivo kinetics
Journal title :
Metabolic Engineering
Journal title :
Metabolic Engineering