Fig. 6.

Shrinkage and recovery are dependent on a functional Tol-Pal system. (A) After 4 h of starvation in M9 salts, ∆tolA cells exhibited diverse phenotypes including shrinkage, lysis, blebbing, and chaining. (B) The Tol-Pal pathway maintains viability during recovery from sudden starvation. All deletion mutants in the Tol-Pal pathway had 50 to 70% lower CFU yields compared to log phase, by contrast to the wild type for which CFU levels were maintained (Fig. 3A). The data points are mean ± SD with n = 3 replicates. (C) Quantification of the fraction of cells that outgrew from stationary phase. While virtually all wild-type cells resumed growth, 20 to 40% of Tol-Pal mutant cells exhibited lysis within 3 h, suggesting that the Tol-Pal pathway is also critical during recovery from normal stationary phase. (D) Treatment of log-phase cells with the lipoprotein signal peptidase II inhibitor globomycin causes shrinkage. MG1655 cells were treated with 20 µg/mL globomycin for 90 min.