Effect of the inhibition of SecA by Rose Bengal (RB) on the ability to form biofilms and secrete biosurfactant-like molecules. −RB (red): Absence of Rose Bengal, +RB (green): presence of Rose Bengal. BS: B. subtilis, PK9: B. subtilis transformed with pKIKO9 expressing AprE-His, PK10: B. subtilis transformed with pKIKO10 expressing AmyE-His, PK15: B. subtilis transformed with pKIKO15 expressing TasA-His, PK20: B. subtilis transformed with pKIKO20 that expresses TapA-His. CR: Congo Red, CVA: crystal violet assay. LB: Lysogeny Broth. (a) LB agar supplemented with Congo Red in the presence or absence of RB. (b) Immunodetection using anti-TasA, anti-TapA, and anti-His antibodies. (c) LB supplemented with Congo Red in the presence or absence of Rose Bengal, X1: PK20 + LB + CR and X2 = PK20 + LB + CR + RB. (d) Crystal violet assay in the presence or absence of Rose Bengal, X3: PK20 in the absence of CVA and X4: PK20 in the presence of CVA. (e) Production of biosurfactant-like molecules in the presence or absence of Rose Bengal. X5: biosurfactant production in the absence of RB and X6: biosurfactant production in the presence of RB.