Regulatory mechanisms coordinating amino acid and glucose catabolism in E. coli
Microbes need to coordinate utilization of nutrients but the triggering signals remain unclear. A recent "Nat Comm" paper by the Zampieri & Sauer groups (IMSB) developed a computational approach to identify the intracellular signals that prioritize amino acid over glucose degradation from dynamic exo-metabolome data.
How microbes dynamically coordinate uptake and simultaneous utilization of nutrients in complex nutritional ecosystems is still an open question. A constraint-based modeling approach is developed that exploits exo-metabolomics data to unravel adaptive decision-making processes in dynamic environments. It investigates metabolic adaptation of E. coli to continuously changing conditions during growth in complex medium. Unexpectedly, model-based analysis of time-resolved exo-metabolome data revealed that fastest growth coincides with catabolism of preferred amino acids, that reduces glucose uptake and increases acetate overflow. It is shown that high intracellular levels of the amino acid degradation metabolites pyruvate and oxaloacetate can directly inhibit the glucose uptake system, and reveal their functional role in mediating regulatory decisions for uptake and catabolism of alternative carbon sources.
Link to the publication in external page "Nature Communications".