FIG 8.

Multicopy expression of rscS induces biofilm formation dependent on SypF’s HPT domain. Colony biofilm formation was assessed following growth on tTBS (T), TC, TP, and TPC of the following strains: ΔsypF (KV5267) with either pKV69 (vector control) (A) or pLMS33 (wild-type rscS; pRscS) (B), ΔsypF + sypF-hpt (KV7226) with either pKV69 (vector control) (C) or pLMS33 (pRscS) (D). Pictures were taken using the Zeiss Stemi 2000-c microscope (×6.5 magnification) at 72 h before and after disruption using a toothpick. Pictures are representative of three separate experiments. Arrows indicate where “pulling,” indicating cohesion, was observed. Dotted arrows represent where “pulling” was observed but to a lesser extent, with portions of the colony breaking off during disruption. (E) Biofilm cohesion was quantified from images as described in Materials and Methods with scores of 1 assigned to a null phenotype and 4 to the most/strongest. Statistics were performed via a two-way ANOVA using Tukey’s multiple-comparison test, where biofilm strength was the dependent variable. **, P = 0.0073; ****, P < 0.0001.