FIG. 4.

Characterization of the biofilm defect of CMPG5413. (A) Biofilm formation under different conditions. Biofilm formation of wild-type L. rhamnosus GG (LGG WT) in mTSB medium was included as a positive control and set to 100%. Complementation of biofilm formation by CMPG5413 was attempted by genetic complementation with a functional luxS gene on plasmid pCMPG5339 and by the addition of 10 μg/ml EPS to mTSB medium. (B) Comparison of EPS-b production in different media. Data are the means of triplicate experiments, and error bars indicate standard deviations. (C) TEM analysis of wild-type L. rhamnosus GG and mutant strain CMPG5413. The cell wall and EPS layer (absent in mutant) are indicated.