Fig 1.

Modulation of the expression levels of the gtfF gene, which is responsible for the production of the β-glucan surface polysaccharide in P. freudenreichii strains CB1, LSP110, and LSP103 and their corresponding mutants. Bars: ■, WT strains, producing surface β-glucan; □, KO mutants where gtfF has been inactivated; ▩, KO-C mutants (KO strains reverted to WT). gtfF gene expression is expressed as the induction rate compared to the expression measured in the WT strain. The data were normalized with the software geNorm using groL1 as normalization gene. These results are the average of three independent experiments. Error bars indicate the standard deviation.