Fig. 2

Survival strategy of stressed Escherichia coli cells employing σ^E-directed cell lysis. The figure denoted the dead cells as the red fraction and the viable but non-culturable (VBNC) cells as green. Upon entry into the stationary phase, the stressed cells of E. coli are transformed into VBNC state and undergo lysis with a concomitant increase in the amounts of alternative sigma factor σ^E (i.e., the σ^E-directed programmed cell death, PCD), as shown by the yellow line. Optimistically, this mechanism might be important for stressed cells of E. coli because the extracellular fractions of lysed cells might act as nutritional supplement for the survival of the remaining population