FIGURE 4.

Biofilm formation by ISP50 and IRP41 strains. Overnight cultures of ISP50 and IRP41 were 50-fold diluted in LB and incubated in each well of a 96-well plate for 24 h at 37°C. Then the biofilm was stained with 0.1% crystal violet (A), dissolved by 0.2 ml of decolorizing solution and subjected to measurement at OD₅₉₀ (B). ****P < 0.0001 by Student’s t-test.