Minimal inhibitory concentrations (MIC).

MIC50 was defined as the lowest concentration of the stressor that reduced bacterial growth by >50% in mid exponential growth. Results show average of independent triplicate experiments, no variation was observed. Only the stressors towards which the MIC50 of one or more of the mutants deviated from that of the wild type are indicated. AU = arbitrary units.*1 AU was defined as the bacteriocin concentration necessary for 50% inhibition of growth of E. faecalis TX5179 in mid exponential growth (OD600 ∼ 0.4 for untreated cells).