FIG. 5.

(A) Growth of E. coli JB23 in complex medium exposed to different concentrations of 2-chlorophenol. Cultures were grown to an OD₅₄₆ of 0.4, at which time (0 min) the chemical shock was applied. ●, control; , 0.25 mM 2-chlorophenol; □, 0.5 mM 2-chlorophenol; , 1 mM 2-chlorophenol; ✳, 1.5 mM 2-chlorophenol. (B) Expression of the htpG gene was determined as specific β-galactosidase activity of the htpG-lacZ fusion protein. ■, 0 mM 2-chlorophenol; ▧, 0.25 mM 2-chlorophenol; , 0.5 mM 2-chlorophenol; ▤, 1.0 mM 2-chlorophenol; , 1.5 mM 2-chlorophenol.