Colicin production and release depend on growth phase and medium. (A-D) Mean histograms of E2crimson expression measured using flow cytometry at various stages of growth of duplicate experiments in LB (A), M9-amino acids (B), M9-glucose (C), and M9-glucose + amino acids (D). E2crimson serves as a proxy for colicin production. Colors of histograms correspond to the color-coded time-points on the corresponding growth curves (above). The first bin of all histograms (cells not expressing E2crimson) is not included for clarity. The population fraction that expresses E2crimson (i.e. the area under the curve) increases along the growth curve in all media, the expression distribution has a distinct profile for the four media. (E-H) YFP expression histograms in LB (E), M9-amino acids (F), M9-glucose (G), and M9-glucose + amino acids (H) throughout the growth phase of a strain carrying plasmid pColE2 ∆ cel::EYFP. YFP expression is a proxy for lysis protein production.