Fig. 2

Correlation between the rrnB P1-GFP reporter and ATP. a, b Dynamics of the GFP reporter and cellular ATP levels in E. coli in minimal (a) and EZ-rich medium (b). Cellular GFP fluorescence for each sample (arbitrary fluorescence unit, a.u.) was measured by flow cytometry. Cellular ATP levels were determined by a standard luciferase assay and converted to cellular concentration in mM. Growth of bacteria is shown in minimal medium (c) and in rich medium (d). Bacterial cell counts were estimated by flow cytometry corrected with counting beads. e, f Linear correlations between cellular ATP concentration and cellular GFP levels in minimal (e) and rich medium (f). All experiments used the same BW25113 strain for consistency. All data points are mean values of at least three independent biological replicates with one standard deviation (SD). The SD for growth and the GFP signal were relatively small (< 15%) and are not shown