||Bacteria Escherichia coli
||Bennett BD, Kimball EH, Gao M, Osterhout R, Van Dien SJ, Rabinowitz JD. Absolute metabolite concentrations and implied enzyme active site occupancy in Escherichia coli. Nat Chem Biol. 2009 Aug5(8):593-9 Table - link PubMed ID19561621
||Researchers quantified metabolites by Liquid chromatography-mass spectrometry (LC-MS/MS) using an isotope ratio-based approach (8). As isotope-labeled standards for many metabolites are not available, they used uniformly 13C-labeled glucose medium to label the intracellular metabolome of E. coli (25). This enabled the use of commercially
available unlabeled compounds as internal standards.
||The total observed intracellular metabolite pool was approximately 300 mM. A small number of metabolites dominate the metabolome on a molar basis, with glutamate being the most abundant, followed by glutathione.