Fig. 1

Biofilms formed under treatment with NO donors. a Growth curve of free cells in the presence of different concentrations of SNP during immobilized fermentation. b After 24 h of fermentation, the culture broths from the different groups were observed. c Biofilms formed on cotton fibers after fermentation imaged by SEM. d Biofilms formed in 96-well plates for 24 h in the presence of NO donors, SNP and NOC-18, and the scavengers PTIO, NaNO₂, and NaNO₃. The wells were washed twice with PBS (200 μL) to remove free cells and stained with 1% crystal violet. Biofilm formation was measured at 570 nm after solubilizing crystal violet in acetic acid. The values are the means and standard deviations of three independent experiments. ***p < 0.001, **p < 0.01, *p < 0.05 by Student’s t-test