Growth yields for selected E. coli mutants in media with G2P, G3P, and phosphate (Pi) as sole phosphorus sources. The growth yield was determined by measuring the final optical density at 600 nm (OD) after growth in 0.4% glucose-MOPS liquid media with various concentrations of the phosphorus sources. All strains are derivatives of BW14893 [Δlac(X74) ΔphoA532 Δphn33-30]. The strains tested were BW14893 (parental strain), WM5085 (del ugp), WM7184 (del glpT), and WM7186 (del glpD). The concentrations used were 30, 60, 125, and 250 μM.

Proton-coupled ³¹P NMR spectra for G2P and G3P. Solutions (500 mM) of the highest grades commercially available were analyzed by ³¹P NMR as described in the text. The spectrum of G2P has the predicted doublet at 2.38 and 2.32 ppm, with splitting caused by the single proton on the C-2 position. The spectrum of G3P has the predicted triplet centered at 2.80 ppm, with splitting caused by two protons at the C-3 position. Integration of the observed peaks shows that G2P is contaminated by minor amounts of phosphate (Pi) and G3P, whereas G3P has slightly higher concentrations of both phosphate and G2P. The percentage of the total phosphorus for each compound is indicated in parentheses. The spectra were aligned using the phosphate peak at 1 ppm.

Utilization of G2P, G3P, and phosphate (Pi) as sole phosphorus sources by individual ugp mutants. Strains were streaked on 0.4% glucose-MOPS media with the phosphorus sources indicated at a concentration of 0.5 mM. All strains are derivatives of BW14893 [Δlac(X74) ΔphoA532 Δphn33-30]. The following strains were tested (from left to right): top row, BW14893, WM5085 (ΔugpBAECQ), WM5089 (ΔugpB), and WM5087 (ΔugpE); bottom row, WM5088 (ΔugpA), WM5063 (ΔugpC), and WM5086 (ΔugpQ).