Determination of the Intracellular Concentrations of Metabolites in Escherichia coli Collected during the Exponential and Stationary Growth Phases using Liquid Chromatography-Mass Spectrometry

Abstract

In the present study, we demonstrate that SRM LC-MS/MS method developed by Luo et al. (ref. 10) can be successfully applied to the quantitative analysis of intracellular metabolites in E. coli that are collected at the exponential and statio- nary growth phases. A focus is given on measuring the changes in the concentrations of intracellular metabolites in batch cultures, which were induced during both the dynamically changing exponential and stationary growth phases. The following intracellular metabolites are quantified in the exponential and stationary phases of E. coli growth, using the SRM mode of a triple quadrupole mass spectrometer: glucose-1-phosphate, fructose-1,6-bisphosphate, phos- phoenolpyruvate, pyruvate, acetyl-coenzyme A, 6-phosphogluconate, ribulose-5-phosphate, xylulose-5-phosphate, erythrose-4-phosphate. The determined intracellular metabolite concentration profiles are shown to be in a good agree- ment with the growth profiles of E. coli, which clearly indicates that SRM LC-MS/MS can be successfully used for following the metabolite changes induced at different growth stages.