Fig. 4.

Biofilm Extracellular Polymeric Substances (EPS) analysis of colony biofilms of S. algae CECT 5071 WT and selected transposon insertion mutants. Total carbohydrate content per unit of biofilm biomass (wet weigh) (A, C) and total protein content per unit of biofilm biomass (B, D) in CER EPS extracts and formaldehyde‐NaOH EPS extracts of the WT strain and mutants M1 (barA), M3 (thyA) and M8 (E1N14_01730). The statistical significance of the differences between the WT strain and transposon insertion mutants was calculated by One‐way ANOVA followed by Dunnett’s post hoc analysis, with P = 0.05 as the threshold for significance (*P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001). SDS‐PAGE electrophoretic profiles of extracted EPS after Stains‐All staining (E), Alcian blue staining at pH = 2.5 (F), Alcian blue staining at pH = 1.0 (G), PAS staining (H), colloidal Coomassie staining (I), and silver staining (J).