It has been previously shown that biological attachment mechanisms are supplemented by surface tension mediated attachment for pellicles formed by Pseudomonas aeruginosa. To further examine the role of surface tension on pellicle formation, non-ionic polyoxyethylene alcohol surfactants were added to growth media. Pellicle attachment and growth is delayed, and moduli are weakened when surfactant is added to growth media at concentrations close to and above the CMC. However, these effects are not primarily due to changes in surface tension. This can be observed by continuing modification of pellicle behavior above the CMC and distinct surfactants at identical surface tensions modifying pellicle moduli differently. Based on changes to bacteria wettability, it is determined that these surfactants modify pellicle formation by adsorbing to bacteria surfaces. Such adsorption is known to increase repulsive forces between gram negative bacteria like Pseudomonas Aeruginosa, which weakens aggregation between bacteria, affecting pellicle formation.
- Interfacial rheology
- Pseudomonas aeruginosa