Figure 6. Biofilm formation by luxS mutant in conditioned media.

luxS⁻ cells growing in MT medium during 24 h were reinoculated in wild type MT CM or MT+P CM and in ppk⁻ppx⁻ MT CM from different growth times, as indicated. Biofilm formation was determined 24 h after the shift to CM. 48 h MT cultures were used as control (–). Different letters indicate significant differences according to Tukey's test with a p-value of 0.05.