Figure 4.

Effects of increasing or decreasing expression of TF on cell viability at 50°C. TF-overproducing, TF-underproducing, and wild-type strains were grown until mid-log phase at 37°C in LB medium supplemented with arabinose to induce TF overexpression or glucose to inhibit TF expression, as in Fig. 3A. The cultures were then shifted to a water-bath at 50°C. Aliquots were taken from each culture before and at different times after shift to 50°C. Cells were diluted and plated on Petri dishes at 37°C to determine the number of surviving bacteria.