Fig. 4

In vitro biofilm production and autoaggregation. a. The WT isolates and the selected NM variants were characterized for their ability to produce biofilm in M63 minimal medium supplemented with glucose. In six out of eight couples (CNR152A1, CNR105A6, KPA28006, KPA28008, CNR137J2 and KP1), the NM variant was more efficient in biofilm formation than the parental M strain. Only CNR149J2 showed an opposite trend: the M variant showed a better ability to form biofilm under tested conditions. p-values of < 0.001 ***, < 0.01 ** and < 0.05 * were considered significant. b. Autoaggregation assay of M and NM variant in spent M63/Glu medium. M = mucoid, NM = non-mucoid are indicated according to the figure key