FIG. 4.

Effects of inhibitors on the induction of acid tolerance in S. macedonicus. Prior to acidic lethal challenge at pH 3.5 for 15 min, mid-log-phase cells were either left unadapted (control) or acid adapted at pH 5.5 for 30 min in the presence of chloramphenicol (Chl), actinomycin D (Act D), cerulenin (Cer), vancomycin (Van), or penicillin (Pen) or in the absence of any inhibitor (adapted). Percentages (means ± standard deviations) of fluorescent subpopulations, as determined by flow cytometry after cFDA-PI labeling, are presented.