FIG. 4.

Bactericidal kinetics of NC12-P₁₄ in apple juice and effects of preincubations. (A) Bacteria were incubated in the absence of NC12-P₁₄ (open circles) and in presence of 8, 16, 32, and 64 μM NC12-P₁₄ (closed circles, rectangles, asterisks, and triangles, respectively) in commercial apple juice (pH 3.6). CFU counts were performed after the specified incubation periods at 37°C. (B) Bacteria were incubated overnight in LB medium either at pH 3.6 (triangles) or pH 7 (circles), diluted to 10⁶ cells/ml in LB medium at pH 7, and incubated for 2 hours in the absence (open symbols) or presence (closed symbols) of 8 μM NC12-P₁₄. CFU counts were performed after the specified incubation periods at 37°C. (C) The peptide was incubated for 2 hours in commercial apple juice, diluted to 8 μM in LB medium, and incubated for 2 hours with bacteria. The graph describes bacterial viability in the absence of peptide (open circles) and in the presence of preincubated (asterisks) and nonpreincubated (closed circles) peptide.