Figure 3.

Evaluation of the effect of single and mixed CFSs produced in MRS and TIL on S. aureus growth and biofilm formation. S. aureus planktonic cells and biofilm OD₆₀₀ after 24, 48, and 72 h of treatment with CFSs from LR06, LJO02 and their combination (MIX condition) produced in (a) MRS and (b) TIL (considering T₀ = 100% strain viability in each experimental condition). OD = optical density. CFSs = cell-free supernatants. (c) Planktonic cell and (d) biofilm S. aureus viability assessment after 24, 48, and 72 h of treatment with CFSs from LR06, LJO02, and MIX conditions. Data are expressed as mean ± SD of 3 independent experiments (n = 4). All tested conditions significantly reduced both S. aureus planktonic cells and biofilm formation compared to the growth control in LB (p < 0.0001). Two-way ANOVA was applied with Tukey’s comparison test. *p < 0.05, **p < 0.01, ****p < 0.0001. RFU = relative fluorescence units. (e) CV-reading at 570 nm of S. aureus biofilm at the 3 tested time points. (f) Representative 2D and 3D images of CV-stained S. aureus biofilm after 72 h of treatment with the CFSs produced in MRS (top) and TIL (bottom). 2D pictures magnification: 460 X. Scale bar: 100 μm.