Biofilm predation assay.

<p>Biofilms of <i>E. coli</i> CO1 were pre-formed for 48 h in 96-well microtiter plates. Predator cultures containing either <i>B. bacteriovorus</i> 109JA or a <i>pilT</i> mutant were added and the plates incubated for a further 24 h. Residual biofilm cells were stained with crystal violet and the optical density at 600 nm (OD600) determined (*p<0.005). To exclude secreted factors contributing to the decrease in remaining biofilm, a 0.45 µm filtrate of a <i>B. bacteriovorus</i> 109JA culture used as a control. The percent biofilm remaining relative to the 109JA filtrate is shown on the secondary axis. Data presented were an average of 12-wells per replicate repeated in triplicate. Statistical significance was measured using a 1-way ANOVA with a Bonferonni corrected post-hoc Students T-test, *p<0.005.