Fig. 6
Biofilm formation assays with both glass tubes and 24-well culture plates. A The biofilm formation of the WT, ΔarcA and pBAD33-arcA+ strains cultured in the glass tubes. B The biofilm mass determined by staining surface-attached cells with crystal violet. C The biofilm formation was measured at OD570. D The biofilm formation of the WT, ΔarcA and pBAD33-arcA+ strains cultured in 24-well plates. E The biofilm formation was measured at OD595. Significant differences were indicated by asterisks (***P < 0.001)