Modeling diauxic glycolytic oscillations in yeast

Area of Science:

• Biochemistry
• Systems Biology
• Metabolic Dynamics

Background:

• Glycolytic oscillations in starved yeast cells serve as a model for metabolic switching.
• Open-flow systems allow sustained oscillations, characterized by quenching and bifurcation analysis.
• Closed-system experiments offer a transient dynamic similar to open systems.

Purpose of the Study:

• To demonstrate that closed-system experiments are valuable for studying yeast cell metabolism dynamics.
• To improve existing models by explaining transient behaviors in closed systems, such as NADH spikes.
• To investigate secondary metabolic pathways and the role of acetaldehyde regulation.

Main Methods:

• Utilizing experimental quenching and bifurcation analysis on yeast cell suspensions.
• Comparing dynamics between open-flow and closed-system experimental setups.
• Developing and refining computational models of yeast glycolysis, incorporating regulatory mechanisms.

Main Results:

• Closed-system dynamics were shown to be a transient form of open-system dynamics.
• The original model failed to capture transient behaviors like initial NADH spikes.
• An extended model, including regulation of pyruvate decarboxylase and alcohol dehydrogenase, improved transient descriptions.

Conclusions:

• Closed-system experiments are effective for studying yeast cell metabolic switching.
• Acetaldehyde regulation is a key factor in observed metabolic dynamics.
• The extended model provides a more accurate representation of transient metabolic behavior in yeast.