FIG. 2.

Deletion of rluC suppresses the cold sensitivity of the ΔbipA mutant. (A) Six fast-growing suppressor colonies were chosen for growth rate analysis. Each was grown in broth culture and analyzed at 20°C using a Bioscreen C reader. Each of the strains was analyzed in triplicate, and error bars represent the standard error of mean for each strain. AF600 grew slowly compared to the wild type MG1655, whereas all six suppressors had increased growth rates compared to that of AF600. The growth curve for only a single representative suppressor strain (KKSUP1) is shown. (B) Wild-type (TB28 rluC⁺ bipA⁺), ΔbipA (KK30), and ΔbipA ΔrluC (KK33) strains were analyzed to assess the ability of a precise rluC deletion to suppress cold sensitivity. As noted in the legend to panel A, each strain was analyzed in triplicate. All curves are shown with error bars; some bars are too small to be distinguishable.