FIG. 3.

Changes in RpoS activity in E. coli commensal strain BJ4 (parent) and BJ4L1 (rpoS). Both strains contained the spvR/spvA′::luxCDABE fusion plasmid. Growth was followed by OD measurements at 600 nm (open symbols). RpoS activity was expressed as log RLU/OD₆₀₀ (solid symbols). The experiment was performed twice with similar results, and standard deviations between experiments are given. Significant differences in RpoS activity were noted between BJ4 and BJ4L1 after 9 h of growth (P < 0.001).