High-resolution 13C nuclear magnetic resonance studies of glucose metabolism in Escherichia coli.

Abstract
High-resolution 13C NMR spectra of suspensions of E. coli cells were obtained at 90.5 MHz by using the Fourier transform mode. Anaerobic cells incubated with [1-13C]glucose show a time course of glycolysis in which the .alpha. and .beta. glucose anomers disappear at different rates, lactate, succinate, acetate, alanine and valine accumulate as end products of glycolysis, and fructose bisphosphate appears as an intermediate. Fructose bisphosphate is labeled at C-1 and C-6 during [1-13C]-glucose catabolism. Upon oxygenation, glutamate appears with the 13C enrichment at the C-4, C-3 and C-2 positions, with the C-4 most intense. The position of the 13C label showed that valine is formed by condensation of pyruvate and that Ca enters the tricarboxylic acid cyclic mainly through acetyl CoA.