Fig. 5.

Shrinkage initiates only once growth rate drops to zero, while gradual growth resumption and resolution of periplasmic space occur simultaneously. (A) Time-lapse images of KC1193 cells grown in fresh LB in a microfluidic flow cell for 10 min, then switched to spent LB for 100 min, then switched back to fresh LB. The osmolalities of the fresh and spent LB were equalized. The periplasmic area had expanded after 20 min in spent LB and gradually shrank after the resumption of growth in fresh LB. (B) Quantification of single-cell growth rate and periplasmic area revealed that growth rate dropped to zero over ∼10 min after switching to spent LB. The periplasmic area only started to increase after the growth rate reached zero and increased steadily over the 100 min in spent LB. After the switch back to fresh LB, growth rate immediately started to increase, gradually reaching preswitch levels after >60 min. The resolution of the periplasmic area was coincident with the growth rate increase. The data points are mean ± SEM with n > 150 cells.