Fig. 2

Comparison of the bacteriostatic activities of media produced in the presence of different acids. The evolution of the contamination was measured over 7 days and was expressed as the logarithmic variation of the initial inoculum (Δlog CFU: colony-forming unit). a Hydrochloric acid pH = 5.39 green lines, pH = 5.45 blue dotted lines, pH = 5.63 red dotted lines, and pH = 5.91 orange dotted lines. b Citric acid pH = 4.79 green lines, pH = 4.81 blue dotted lines, and pH = 4.94 red dotted lines. c Sorbic acid 0.05% green lines and 0.1%. d Boric acid 0.84% (pH = 5.41) and 0.26% (pH = 6.00 blue dotted lines). All experiments were performed in triplicate and completed with tests at higher and lower concentrations (not shown)