FIG. 6.

ClpB is not required for stress resistance. The L028 wild-type (WT) strain and the ΔclpB mutant strain were grown exponentially at 37°C with aeration in BHI medium until the OD₆₀₀ reached 0.3. The culture was divided into two parts, one of which was subjected to various stresses. Stresses assayed were temperature shifts to 42, 44, 48, or 55°C; addition of puromycin to a final concentration of 15 (pmc15), 30 (pmc30), or 60 (pmc60) μg/ml; 0.01% SDS; or 2% NaCl. Values represent the percentage of cell growth with respect to the control culture performed in the absence of stress (grown in BHI at 37°C) 2 h after the stress was applied. In all cases, there was no significant difference in the growth curves between the wild-type and the mutant strains.