A parallel glycolysis provides a selective advantage through rapid growth acceleration

Area of Science:

• Biochemistry
• Microbiology
• Metabolic Engineering

Background:

• Glycolysis is a fundamental metabolic pathway for energy production.
• The Entner-Doudoroff (ED) pathway is an alternative glycolytic route yielding less ATP than standard glycolysis.
• The functional significance of possessing both pathways in organisms like Escherichia coli is not well understood.

Purpose of the Study:

• To investigate the role of the ED pathway in bacterial growth and adaptation.
• To determine the selective advantage of the ED pathway during dynamic environmental conditions.

Main Methods:

• Comparative growth analysis of Escherichia coli with and without the ED pathway.
• Isotope tracing to quantify metabolic flux through glycolytic pathways.
• Thermodynamic analysis of enzymatic reactions.

Main Results:

• Escherichia coli exhibits accelerated growth when the ED pathway is active following carbon and nitrogen upshifts.
• Flux through the ED pathway increases more rapidly than through standard glycolysis during growth acceleration.
• The ED pathway's rapid response is linked to its thermodynamic properties and efficient glucose import.

Conclusions:

• The ED pathway provides a selective advantage for rapid adaptation to fluctuating nutrient availability.
• This parallel glycolytic pathway enhances bacterial fitness in dynamic environments.
• The ED pathway exemplifies a metabolic design principle for promoting rapid adaptation through a seemingly redundant system.