SigB modulates biofilm formation in SCV CF07-S but is not solely responsible for the repression of proteolysis.

<p>(A) Expression ratio of the <i>asp23</i> gene as a function of growth for strains CF07-L, CF07-S, CF07-S in the presence of menadione and CF07-SΔ<i>sigB</i>. Results are expressed according to CF07-L in the early exponential phase of growth. Statistically significant differences relative to CF07-S are indicated for each growth phase (*, <i>P</i><0.05; ***, <i>P</i><0.001; ANOVA with Dunnett's posttest, <i>n</i> = 3–4). (B) Relative biofilm formation of CF07-L, CF07-S and CF07-SΔ<i>sigB</i> carrying the empty vector (pFM1) or the <i>sigB</i> expression vector (pFM2) following 48 h of incubation in the presence of 0.25 µM CdCl₂. Statistically significant differences are indicated (**, <i>P</i><0.01; ***, <i>P</i><0.001; ANOVA with Tuckey's posttest, <i>n</i> = 3). Results are expressed as means with standard deviations. (C) Proteolytic activity of CF07-L, CF07-S and CF07-SΔ<i>sigB</i> on BHIg milk-agar following 48 h of incubation.