Robustness and Plasticity of Metabolic Pathway Flux among Uropathogenic Isolates of Pseudomonas aeruginosa
Figure 2
Resolution of anaplerotic flux in [1-13C]-glucose-grown uropathogenic P. aeruginosa, P. aeruginosa PAO1, and P. putida.
For exclusive use of the ED pathway for glucose catabolism, the contribution of PEP carboxylase resulted in low 13C-enrichment of oxaloacetate (deduced from aspartate), whereas the 13C accumulated in pyruvate (alanine), which creates an excess of its single-labeled (M1) mass isotopomer (green region). In contrast, the action of pyruvate carboxylase reduced and increased the levels of pyruvate and oxaloacetate (orange region), respectively. This allowed for discrimination between these enzymes according to the combined labeling of the two molecules. Prior to inspection, the 13C-labelling data were corrected for the contribution of natural isotopes [32].