Fig 4. SUMOFLUX resolves a novel flux ratio in central carbon metabolism of E. coli.

(a) A schematic representation of the glyoxylate shunt, TCA cycle and anaplerosis from PEP flux fractions. (b) Density plot representing SUMOFLUX estimates for the flux fraction from glyoxylate shunt versus the true flux ratios for in silico data. (c) Density plot representing SUMOFLUX estimates for the flux fraction from the TCA cycle versus the true flux ratios for in silico data. Both ratios were resolved for experiment with 20% [U-¹³C] and 80% naturally labeled glucose. (d) Predictions for the three flux fractions for the experimental data. αKG– α-ketoglutarate; AcCoA—acetyl-CoA; Fum—fumarate; Gox—glyoxylate; ICT—isocitrate; MAE—mean absolute error; Mal—malate; PEP—phosphoenolpyruvate; TCA—tricarboxylic acid cycle.