Open AccessBy‐product formation during exposure of respiring Saccharomyces cerevisiae cultures to excess glucose is not caused by a limited capacity of pyruvate carboxylase
Author(s) -
Bauer Jürgen,
Luttik Marijke A.H.,
Flores CarmenLisset,
Dijken Johannes P.,
Pronk Jack T.,
Niederberger Peter
Publication year - 1999
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1999.tb08715.x
Subject(s) - pyruvate carboxylase , phosphoenolpyruvate carboxylase , biochemistry , chemostat , phosphoenolpyruvate carboxykinase , chemistry , biology , enzyme , bacteria , genetics
Upon exposure to excess glucose, respiring cultures of Saccharomyces cerevisiae produce substantial amounts of ethanol and acetate. A possible role of a limited anaplerotic capacity in this process was investigated by overexpressing pyruvate carboxylase and by replacing it with a heterologous enzyme ( Escherichia coli phosphoenolpyruvate carboxylase). Compared to the wild‐type, neither the pyruvate carboxylase (Pyc)‐overexpressing nor the transgenic strain exhibited reduced by‐product formation after glucose pulses to aerobic glucose‐limited chemostat cultures. An increased intracellular malate concentration was observed in the two engineered strains. It is concluded that by‐product formation in S. cerevisiae is not caused by a limited anaplerotic capacity.