Open AccessEffects of a hexokinase II deletion on the dynamics of glycolysis in continuous cultures of Saccharomyces cerevisiae
Author(s) -
Diderich Jasper A.,
Raamsdonk Léonie M.,
Kuiper Arthur,
Kruckeberg Arthur L.,
Berden Jan A.,
Teixeira de Mattos M.Joost,
Dam Karel
Publication year - 2002
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/j.1567-1364.2002.tb00081.x
Subject(s) - chemostat , biology , biochemistry , fructose , hexose , saccharomyces cerevisiae , hexokinase , steady state (chemistry) , glycolysis , strain (injury) , wild type , metabolism , yeast , mutant , chemistry , enzyme , genetics , anatomy , bacteria , gene
Abstract In glucose‐limited aerobic chemostat cultures of a wild‐type Saccharomyces cerevisiae and a derived hxk2 null strain, metabolic fluxes were identical. However, the concentrations of intracellular metabolites, especially fructose 1,6‐bisphosphate, and hexose‐phosphorylating activities differed. Interestingly, the hxk2 null strain showed a higher maximal growth rate and higher Crabtree threshold dilution rate, revealing a higher oxidative capacity for this strain. After a pulse of glucose, aerobic glucose‐limited cultures of wild‐type S. cerevisiae displayed an overshoot in the intracellular concentrations of glucose 6‐phosphate, fructose 6‐phosphate, and fructose 1,6‐bisphosphate before a new steady state was established, in contrast to the hxk2 null strain which reached a new steady state without overshoot of these metabolites. At low dilution rates the overshoot of intracellular metabolites in the wild‐type strain coincided with the immediate production of ethanol after the glucose pulse. In contrast, in the hxk2 null strain the production of ethanol started gradually. However, in spite of the initial differences in ethanol production and dynamic behaviour of the intracellular metabolites, the steady‐state fluxes after transition from glucose limitation to glucose excess were not significantly different in the wild‐type strain and the hxk2 null strain at any dilution rate.