FIG. 3.

Cytometric online monitoring of bacterial ghost production of E. coli NM522(pML1). Bacteria were grown at 28°C to mid-log phase and then shifted to 42°C for lysis induction [0 min (Shift)]. During the time course of 3 h, various samples were collected and analyzed cytometrically after DiBAC₄(3) staining. The bacterial particles within 0.1 μl of the original culture were characterized by means of light scatter and green fluorescence. The sampling time points indicated refer to time points postinduction of lysis [0 min (Shift)]. During ghost production, three populations of bacterial particles were detected: nonlysed, polarized cells (A); nonlysed, depolarized cells (B); and bacterial ghosts (C). The flow cytometric analysis data are presented as three-dimensional plots (SSC versus fluorescence, both on a logarithmic scale) excluding debris and the background signal.