Pneumocin production promotes competition and DNA exchange in pneumococcal biofilms.

<p>(A) Biomass of biofilms when inoculated with single competitor strains: pneumocin producers PSD300 (Wt, BIR₁₆₄, blue circle) or PSD303 (BIR₁₆₄<i>blpAp</i>_G-90A, orange triangle), and non-producer control PSD299 (BIR_D39, blue square). (B-C) PSD300, PSD303 or PSD299 were co-inoculated with sensitive strain, D39x at ratio of 1:10 to form biofilm. Three day old biofilms were disrupted and plated on single selective media to determine (B) competition, and dual selective media to examine (C) transformation efficiency. Two-tailed Mann-Whitney tests were performed to determine statistical significance. * denotes <i>p</i><0.05, *** denotes <i>p</i><0.001.