BB-rel@ldeleger:BB-rel-F-25648083-001 JSONTXT

L. johnsonii FI9785 was able to produce biofilms on glass tubes (Additional file 1: Figure S1A) and on sterile microscope slides under aerobic conditions (Additional file 1: Figure S1B). We also tested microaerobic and anaerobic conditions, which would be encountered in the GI tract, and found that oxygen limitation did not affect the biofilm formation on sterile microscope slide surfaces (data not shown). Biofilm formation was also seen in polystyrene 96 well plates using crystal violet, and this method was selected to measure variations in biofilms between wild type and mutant strains to investigate the effect of EPS production on biofilm formation (Figure 2). Comparison of L. johnsonii FI9785 with the well-known probiotic strain L. rhamnosus GG indicated that biofilm formation of these two strains was quite similar.