FIG. 2.
β-Galactosidase activities of E. coli and Azoarcus sp. strain CIB harboring PN::lacZ translational fusions. (A) Azoarcus sp. strain CIB lacZ (PN::lacZ) cells were grown for 48 h in MC medium containing 3 mM benzoate either aerobically (empty bar) or anaerobically in the presence of 10 mM nitrate (filled bar). (B) E. coli M182 cells (fnr+) carrying plasmid pSJ3PN (PN) (PN::lacZ) or plasmid pSJ3RPN (RPN) (bzdR-PN::lacZ) and E. coli JRG1728 cells (fnr) carrying plasmid pSJ3PN (PN), pHW1, or pQE60-His6Fnr* (pFnr*) were grown anaerobically (filled bars) or aerobically (empty bars) in glucose-containing LB medium until they reached stationary phase. β-Galactosidase activity was measured as described in Materials and Methods. The results of one experiment are shown, and the values were reproducible in three separate experiments with standard deviations of <10%.