Figure 3

Analysis of the sugar composition of the extracellular matrix and effect of hcp1 and hcp2 mutations on biofilm biovolume. A: Relative quantity of major sugars (Rha = Rhamnose, Man = Mannose, Gal = Galactose and Glc = Glucose) determined by gas chromatography in extracellular matrix (ECM) of MFE01 and MFE01Δhcp1. Values are mean results of four independent experiments, and the error bars represent standard error of the mean. Strains were compared pairwise by non-parametric Mann–Whitney two-tailed tests. ns: no significant difference. B: Gas chromatographic determinations of the absolute quantity of exopolysaccharides (EPS) in the extracellular matrix (ECM) of MFE01 and MFE01Δhcp1. Values are mean results of four independent experiments and the error bars represent standard error of the mean. Strains were compared pairwise by non-parametric Mann–Whitney two-tailed tests. *p-value <0.05. C: Biovolume of biofilms. The biofilms were grown on glass surface at 28°C for 48 h under a flow of LB medium. Biovolumes were obtained by COMSTAT analyses. Values are mean results of at least five independent experiments and the error bars represent standard error of the mean. Statistical analyses were performed using Non-parametric Mann–Whitney Tests (two tailed). ns means no significant difference in biovolume (p-value >0.05) relative to the MFE01 biofilm biovolume assay.