Fig. 4

Supernatants of P. aeruginosa PA14 disperse diverse biofilms, and D. vulgaris biofilm formation during production of putative dispersal proteins identified through RNA-seq. The biofilms of D. desulfuricans (a) and E. coli MG1655 (b) were grown for 24 h in modified Baar’s medium and LB, respectively, and the biofilms of S. aureus (c) were grown for 24 h in TSB.⁵⁹ P. aeruginosa wild-type and rhlR mutant supernatants were concentrated to 4× and contacted with the biofilms for 2 h except for the S. aureus biofilm where 1x supernatant was used instead of 4× and the contact time was 10 min (since S. aureus biofilms were dispersed quickly). At least two independent cultures were used with three replicates for each culture, and the error bars indicate one standard deviation. (d) Biofilms of D. vulgaris were formed for 48 h in modified Baar’s medium at 30 °C (anaerobically) with expression of dvu3313, dvua0018, dvua0034, dvua0066, and dvua0084 identified from the dispersal RNA-seq experiment. Vector pVLT33 was used with the biofilm-specific promoter P_dvu0304 fused to each gene. Normalized biofilm formation percentage (based on OD_540nm/OD_620nm) is shown relative to the empty plasmid control. Two independent cultures were used with three replicates for each culture, and the error bars indicate one standard deviation. ** P < 0.01 indicates significant differences versus the empty plasmid control group via one-way ANOVA