The Impact of Matrix Polysaccharide Composition on Pseudomonas aeruginosa Biofilm Dispersion

Authors: Justin Marciano, Wencheng Li, Karin Sauer

Field of Study: Biological Sciences

Faculty Mentors: Karin Sauer

Easel: 64

Timeslot: Midday

Abstract: Biofilm dispersion depends on matrix degrading enzymes (PelA & PslG). The current understanding of dispersion mechanism is primarily based on PAO1, a psl dominant strain; however, clinical p.aeruginosa isolates are characterized by distinct pel/psl composition and abundance, failing into 4 matrix classes. It is hypothesized that variation in matrix composition in P. aeruginosa influences biofilm dispersion with matrix-rich biofilm exhibiting impaired dispersion due to reduced polysaccharide degradation. Biofilm dispersion was investigated in Pseudomonas aeruginosa with PelA and PslG overproducing strains. Although these strains formed biofilms with similar overall biomass, they exhibited reduced dispersion and cell release, which correlated with increased matrix polysaccharide abundance. Assays confirmed class-specific matrix differences. Genetic complementation of key matrix-degrading enzymes (endA, pelA, and pslG) restored dispersion in matrix-rich strains, showing impaired dispersal results from insufficient matrix degradation rather than differences in biofilm growth. These findings link matrix composition to dispersion and suggest therapeutic targets.