The LPS-functionalization of polystyrene microparticles can be made visible via the specific interactions of LPS with a fluorescence marker.
Source: BAM
For many industrial applications, microbial colonization of metallic surfaces is a fundamental problem that has safety implications. In technical systems, biofilm formation in later stages leads to microbially influenced corrosion (MIC), resulting in leaks in pipelines and the failure of valves, pumps, and filters. Biofilm formation is a dynamic process in which the planktonic cells first attach to the liquid/solid interface and then form the complex biofilm matrix through the production of extracellular polymeric substances (EPS) and cell proliferation. The transition of microorganisms from the planktonic state (individual cells) to a functioning biofilm has economic and ecological consequences and, in many cases, must also be actively combated and avoided.
The aim of this project was to develop a synthetic model system that can mimic the attachment behaviour of microorganisms. The initial attachment of microorganisms to solid surfaces is controlled by chemical and electrochemical cell-substrate interactions involving lipopolysaccharides (LPS) and cell appendages (such as pili and/or fimbriae). In this project, we focused on the LPS-driven reversible processes, as the molecular chemistry of LPS can be better characterized and controlled than the cell adhesins and appendages.
For this purpose, commercially available LPS from Pseudomonas aeruginosa was bound to the surface of polystyrene (PS) microparticles using a swell-capture process. The chemistry, morphology and surface charge of the particles were characterized. The chemical analyses revealed that from an LPS concentration of ∼ 0.7 mg/ml, there is a sudden increase in the detected LPS-specific species on the PS particle surface, indicating a better organization of the molecules. In summary, our results show that the coverage and structure of the LPS film are concentration dependent.
The presented method can be easily adapted to LPS of other bacterial strains to develop a synthetic model kit for attachment studies. In follow-up projects, the stability and attachment behaviour of LPS-functionalized microparticles on different surfaces will be evaluated with the goal of further developing them as reference materials and in reference processes.
Synthesis and characterization of lipopolysaccharide (LPS) anchored polystyrene microparticles as a synthetic model system for attachment studies
Jan David Schutter, Karl Eberhardt, Anna Maria Elert, Jörg Radnik, Daniel Geißler, Özlem Özcan Sandikcioglu
published in: Colloids and Surfaces B: Biointerfaces, 2023, volume 226, essay number 113301, pages 1 - 7.