Adhesion of Nonmotile Pseudomonas aeruginosa on “Soft” Polyelectrolyte Layer in a Radial Stagnation Point Flow System:  Measurements and Model Predictions

Abstract

Prediction of bacterial deposition rates onto substrates in natural aquatic systems is quite challenging because of the inherent complexity of such systems. In this study, we compare experimental deposition kinetics of nonmotile bacteria (Pseudomonas aeruginosa) on an alginate-coated substrate in a radial stagnation point flow (RSPF) system to predictions based on DLVO theory. The "softness" of the surface layer of the bacteria and alginate-coated substrate was considered in the calculations of their electrokinetic surface properties, and the relevance of both the classical zeta potential and the outer surface potential as surrogates for surface potential was investigated. Independent of the used electrical potentials, we showed that significant discrepancies exist between theory and experiments. Analysis of microscopic images in the RSPF system has demonstrated, for the first time, that irreversible deposition of particles or cells entrapped in the secondary energy minimum can occur on the alginate layer, despite the hydrodynamic forces resulting from the radial flow in the RSPF system. It is suggested that polymeric structures associated with the surface of the particle/cell and the alginate-coated substrate are responsible for the transition between the secondary minimum and primary energy well. This mode of deposition is likely to be important in the deposition of microorganisms in complex aquatic systems.

Mobile and immobile adhesion of staphylococcal strains to hydrophilic and hydrophobic surfaces

“…The total number of adsorption and 4. Example of the distance-dependent free energy of interaction between S. epidermidis ATCC 35983 and hydrophilic glass and hydrophobic DDS-coated glass, using the extended DLVO-theory and surface characteristics as reported previously [21].…”

“…adhesion in the absence of specific ligand-receptor bonding, than it is on the number of actually adhering bacteria. Interestingly, using a similar experimental set-up and analysis, De Kerchove et al [21] showed that sliding of carboxylated latex particles was virtually absent on hydrophilic quartz but present when an alginate conditioning film was used. It was stated that the properties of the alginate (i.e.…”

Influence of natural organic matter on the deposition kinetics of extracellular polymeric substances (EPS) on silica

“…We followed the method that employed in previous works to adsorb a layer of PLL onto the silica surface [39,40], which was also provided in the Supplementary Information. Corresponding deposition experiments on PLL-coated silica surfaces were performed over the same ionic strength range in both NaCl and CaCl 2 solutions with the same EPS influent concentration as that conducted on bare silica surfaces.…”

Deposition kinetics of bacteriophage MS2 to natural organic matter: Role of divalent cations

“…These studies suggest that the retention and transport of pathogens are strongly affected by physical and chemical characteristics of water, such as ionic strength, pH, composition, and physical properties of porous media. Adhesion of pathogenic bacteria and protozoa onto different solid surfaces, such as haematite, silica, and alginate, has also been extensively studied [17][18][19][20][21][22][23]. As demonstrated in the studies focusing on bacteria and protozoa, the composition of electrolyte solution, surface properties, and background macromolecules in the solution are the main factors that govern the adhesion kinetics of bacteria and protozoa.…”