Dynamics of Pseudomonas aeruginosa association with anionic hydrogel surfaces in the presence of aqueous divalent-cation salts

► PAK strain of Pseudomonas aeruginosa exhibits burst association on anionic hydrogel membranes. ► Bursting arises from reversible aqueous divalent-cation bridging. ► Divalent cations collapse the anionic gel and destroy surface binding sites for the bacteria. ► The few strongly bound bacteria on the gel are likely due to increased hydrophilicity of the anionic gel surface. ► This study emphasizes a delicate balance of physical and chemical forces between bacteria and substrate surfaces.