FIG. 3.
Effects of penicillin G on the growth of conditional gcp mutants. (A) spacp-regulated gcp mutant RN4220/Pspac-gcp; (B) gcp antisense mutant WCUH29/gcp-as. The indicated strains and the control, WCUH29/pYH4, were grown in TSB in the presence of different concentrations of inducer (either IPTG or ATc). Penicillin (20× MIC) was added to the exponential-phase cultures at a final concentration of 8 μg/ml. The bacterial cultures were continuously incubated, and the OD600 values for the cultures were measured every hour for 8 h.