Adhesion forces of the sea-water bacterium Paracoccus seriniphilus on titanium: Influence of microstructures and environmental conditions

Abstract

The bacterial attachment to surfaces is the first step of biofilm formation. This attachment is governed by adhesion forces which act between the bacterium and the substrate. Such forces can be measured by single cell force spectroscopy, where a single bacterium is attached to a cantilever of a scanning force microscope, and force-distance curves are measured. For the productive sea-water bacterium Paracoccus seriniphilus, pH dependent measurements reveal the highest adhesion forces at pH 4. Adhesion forces measured at salinities between 0% and 4.5% NaCl are in general higher for higher salinity. However, there is an exception for 0.9% where a higher adhesion force was measured than expected. These results are in line with zeta potential measurements of the bacterium, which also show an exceptionally low zeta potential at 0.9% NaCl. In the absence of macromolecular interactions, the adhesion forces are thus governed by (unspecific) electrostatic interactions, which can be adjusted by pH and ionic strength. It is further shown that microstructures on the titanium surface increase the adhesion force. Growth medium reduces the interaction forces dramatically, most probably through macromolecular bridging.

FluidFM as a tool to study adhesion forces of bacteria - Optimization of parameters and comparison to conventional bacterial probe Scanning Force Spectroscopy

“…Further, we used the well-studied gram negative bacterium Paracoccus seriniphilus in terms of SCFS [25] to compare the immobilization by means of FluidFM with the well-established immobilization with polydopamine.…”

FluidFM as a Tool to Study Adhesion Forces of Bacteria - Optimization of Parameters and Comparison to Conventional Bacterial Probe Scanning Force Spectroscopy

“…10). Whereas an increase of the adhesion force with the contact time was already shown elsewhere when Paracoccus seriniphilus is immobilized by polydopamine [17], we used the FluidFM for immobilization. To counteract the effect of decreasing adhesion forces with an increasing number of force-distance curves, we measured with increasing and subsequently decreasing contact times, thereby using the same cell.…”

“…To assess if the immobilization with the FluidFM leads to different results compared to the conventional immobilization method using polydopamine, we investigated the adhesion force of Paracoccus seriniphilus, which is well-studied in terms of SCFS with polydopamine [17]. For this purpose, we compared the development of the adhesion forces of bacteria immobilized by the FluidFM with bacteria immobilized by means of the chemical functionalization of the cantilever with polydopamine.…”

“…Therefore, we used the FluidFM to physically immobilize the bacteria on the opening of a FluidFM cantilever and determined parameters for recording force-distance curves. Further, we used the well-studied gramnegative bacterium Paracoccus seriniphilus in terms of SCFS [17] to compare the immobilization by means of FluidFM with the well-established immobilization with polydopamine.…”

Editorial: In Focus Issue on Bacterial-Surface Interactions

“…Finally, important insights gained from fundamental quantitative studies in bacterial-surface interactions were highlighted in two very different technique-focused articles exploring the adhesion properties of bacteria on metallic surfaces 7 and the surface interactions associated with direct interspecies electron transfer that occurs in biofilms. 8 Davoudi et al…”