Fig. 1

Production of the antimicrobial during growth (a) and after a treatment with chloramphenicol (b). In (a), aliquots of the cell culture were collected at all-time points, the cell-free supernatant size-fractionated and the >10 kDa fraction tested against L. monocytogenes [8]. For all time points, cell extracts were analyzed for G6PD activity and pigment production as markers of of exponential and stationary phase of growth, respectively. The antimicrobial activities are reported as % of growth inhibition (mm of inhibition halo on plates) considering 100% the maximal activity observed. In (b) the red arrow indicates the time of chloramphenicol supplementation. Grey bars indicate the % of antimicrobial activity (mm of inhibition halo on L. monocytogenes plates) considering 100% the maximal activity observed before the antibiotic treatment