FIG 3 .

The gshA transposon mutant is defective for biofilm formation compared to the wild-type and complemented strains. Biofilms were grown in 96-well plates for 24 h in M9 medium (A) and TSB (B). Biofilms were rinsed three times with PBS, treated with 0.4% crystal violet for 15 min, rinsed again three times with PBS, and resuspended in 33% acetic acid. Biomass was read using a spectrophotometer at 550 nm. Values are means plus standard deviations (error bars) from four independent experiments. Values that are significantly different (P < 0.05) are indicated by an asterisk.