Fig. 4: Potassium release and membrane potential.
a Intracellular potassium (K+) leakage in E. coli and S. simulans after direct CAP treatment at pH = 7.4 (red circles) and pH = 4.5 (blue squares). b Representative membrane potential alteration (in neutral buffer, pH = 7.4) in S. simulans after direct CAP, argon or air treatment via a fluorescent dye DiSC2(5). Arrows indicate the time points when nisin was added to dissipate the membrane potential. c Average initial DiSC2(5) fluorescence upon different treatments. Potassium (K+) leakage experiments were performed twice in duplicates. Membrane potential measurements with DiSC2(5) were conducted twice independently on S. simulans at least in triplicates. Values are the mean ± SD (n ≥ 4). One-way ANOVA analysis was used to compare the difference between CAP-treated samples towards corresponding controls (+/*p < 0.05, ++/**p < 0.01, +++/***p < 0.001, ++++/****p < 0.0001).
