Fig. 1

Maximizing Und-P levels in a Und-P pathway-minimized strain of E. coli. (A and E) Micrographs of cells with the indicated genotypes. Cells were grown in TB (panel A) and TB containing 500 µM IPTG (panel E) at 37 °C until the culture reached an OD₆₀₀ of 0.4 to 0.6. The cells were then photographed by phase contrast microscopy. Bar, 3 μm. (B and F) Flow cytometry data from live cells in panels A and E. Histograms of the forward scatter area from 100,000 cells are shown. The mean cell size is shown in arbitrary units (AU). (C and G) Growth curves for cells with the indicated genotypes cultured at 37 °C in TB (panel C) or TB containing 500 µM IPTG (panel G). Error bars show +/- standard deviation of the means. (D and H) Und-P levels from cells grown in panel A (after 3.5 h) and panel E (after 24 h). Und-P levels were normalized by dividing Und-P measurements by the mean CFU/ml. Absolute Und-P values are detailed in Table S1. Additional Und-P pathway mutants are shown in Fig. S1. Error bars show +/- standard error of the means. Significance was determined by using an unpaired t-test followed by Welch’s correction. *p < 0.05. Morphological data are representative of two independent experiments. Growth and Und-P measurements are representative of two independent experiments performed in triplicate. The E. coli strains shown are MAJ330 (WT), MAJ557 (ΔPGT/GT), MAJ1385 (ΔPGT/GT/vector), and MAJ1386 (ΔPGT/GT/puppS).