Figure 4

Effects of cadBA mutations on biofilm formation. A Biofilm-forming capacity of E. tarda in normal and acid conditions. TX01, TX01ΔcadA, TX01ΔcadB, TX01ΔcadBA, TX01ΔcadAC, and TX01ΔcadBC were inoculated into LB broth at pH = 7.0 and 5.5, then incubated in polystyrene plates for 24 h. Biofilm formations were determined by measuring the A₅₇₀ of the final eluates of crystal violet staining. Data are presented as the means ± SEM (N = 3). N, the number of times the experiment was performed. **, P < 0.01; *, P < 0.05. B The viability of biofilm growth of E.tarda was determined by confocal laser scanning microscopy (CLSM). Cells in the biofilms were stained with a BacLight LIVE/DEAD kit to reveal viable (green fluorescence) and non-viable (red fluorescence) bacteria.