ALT TolC contributes to biofilm production. Bacterial cells attached to the wall of borosilicate glass test tubes following growth for 72 h at room temperature were stained with crystal violet and photographed (A and B) before the biofilm-associated crystal violet was dissolved in DMSO and quantified by measuring the absorbance at 550 nm (C and D) as described in the Materials and Methods. (A) Photograph of crystal violet-stained biofilms produced by KPPR1 and the isogenic ΔtolC mutant and (B) quantification of biofilms following destaining with DMSO. The arrow in panel A indicates the location of the air-liquid interface. Complementation of ΔtolC (B and D). The indicated strains bearing pBAD33 or pBAD33-tolC were cultured at room temperature for 72 h in LB media containing chloramphenicol and the indicated concentrations of arabinose before being (B) stained with crystal violet and photographed and (D) quantified after dissolving the dye with DMSO. Statistical significance was determined

ALT Boxplots showing the presence of T6SS genes across 21 STs of E. coli, grouped by phylogroup.

ALT (A) Table summarizing studies in which EcN has been engineered for heterologous bacteriocin production and the promoters used. (B) Schematic representation of the McC operon where the organization of the structural genes (mccA-E) and the immunity determinant (mccF) is shown with respect to the transcriptional regulatory elements.

ALT P. mirabilis wild type and mutant strains were assayed for growth in (A) LB (n = 3–6 independent experiments) or (B) chemically defined medium Minimal A (n = 4–5). Area under the curve was measured after culturing for 20 h in the indicated medium. Most mutants grew well in LB, which was the medium used for obtaining transposon mutants. However, most mutants had a deficiency in Minimal A. Error bars depict SD. Statistical significance was calculated vs wild type using one-way ANOVA with Dunnett’s multiple comparisons test.