Fig. 6: Enzymatic digestion of eRNA leads to loss of eDNA fibres and loss of biofilm viscoelasticity.

Three-dimensional (3-D) confocal micrographs of five-day eDNA specific TOTO-1-stained P. aeruginosa PAO1 wildtype biofilm (green) a with 0.1 mg ml⁻¹ DNase I pre-treatment and b 0.3 mg ml⁻¹ RNase H treatment, c 0.1 mg ml⁻¹ DNase I pre-treatment followed by subsequent 0.3 mg ml⁻¹ RNase H digestion. The thickness of biofilm is 8 μm. Scale bars represent 10μm. d smiFISH confocal micrograph fluorescence intensity quantification (n = 3) of extracellular DNA fibre reduction (green bars) across different enzymatic treatments such as DNase I (D I), RNase A (R A) and RNase H (R H). e Rheogram of five-day Pseudomonas aeruginosa PAO1 wildtype biofilm (n = 3) pre-treated with 0.1 mg ml⁻¹ DNaseI followed by either RNase A or RNase H treatment in frequency sweep at 25 °C, 0.026 mm gap, 0.3 amplitude showing that DNase I pretreatment followed by 0.3 mg ml⁻¹ of both RNase A or RNase H digestion respectively reduces (i.e., increases tan δ) or removes (tan δ > 1) biofilm elasticity. The standard deviation bars indicated in 6d are generated based on the mean values calculated from biological triplicates. For e, the biological triplicates are averaged for each condition and plotted against frequency. Relevant source data for Fig. 6d, e are provided as a source data file.