Saccharomyces cervisiae

Global proteome changes in prolonged chemostat cultivations of Saccharomyces cerevisiae

We applied a two-compartment scale-down chemostat system simulating glucose gradients to characterize the long-term (100’s of hours) response of S. cerevisiae to fluctuating glucose concentrations. A wild-type strain and a recombinant strain, expressing an insulin precursor, were cultured in the scale-down system, and analyzed at the physiological and proteomic level.

Phenotypes of both strains were compared to those observed in a well-mixed chemostat. Our results show that S. cerevisiae subjected to long term chemostat conditions undergoes a global reproducible shift in its cellular state and that this transition occurs faster and is larger in magnitude for the recombinant strain including a significant decrease in the expression of the insulin product. We find that the transition can be completely avoided in the presence of glucose gradients as the strains subjected to glucose fluctuations under otherwise constant culture conditions exhibited constant levels of the measured proteome for over 250 hours.

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Nikolaus Sonnenschein
Associate Professor
DTU Bioengineering