Intracellular metabolites measured by LC-MS/MS were classified by visual inspection (A–D) Unclassified metabolites are listed in one group (E) Metabolite concentrations are indicated on the vertical axis (μM), and time on the horizontal axis. Diamonds, squares, and triangles indicate data from control, 5 mM, and 10 mM lactate-containing cultures, respectively (triplicate experiments). Abbreviations: 6-phospho-D-gluconate (6PG), 3-phospho-D-glycerate (3PG), Iso-Citrate (Iso-Cit), Phosphoenolpyruvate (PEP), Glyceraldehyde 3-phosphate (GAP), Acetyl-CoA (AcCoA), Sedoheptulose 7-phosphate (S7P), Oxaloacetate (OXA), 2-oxoglutarate (AKG), D-Fructose 1,6-bisphosphate (D-F16P), D-Fructose 6-phosphate (D-F6P), D-Ribose 5-phosphate (D-R5P), D-Glucose 6-phosphate (D-G6P), D-Xylulose 5-phosphate (D-X5P), D-Ribulose 5-phosphate (D-Ru5P), D-Erythrose 4-phosphate (D-E4P), pyruvate (PYR), dihydroxyacetone phosphate (DHAP), L-Serine (L-Ser), L-Asparagine (L-Asn), L-Leucine (L-Leu), L-Tryptophan (L-Try), L-Phenylalanine (L-Phe), L-Cysteine (L-Cys), D-Glucose 1-phosphate (D-G1P), L-Tyrosine (L-Tyr), L-Arginine (L-Arg), L-Aspartic acid (L-Asp), L-Glutamate (L-Glu), L-Proline (L-Pro), L-Glycine (L-Gly), L-Alanine (L-Ala), L-Citrulline (L-Cit), L-Lysine (L-Lys).