Biofilm Formation and Structure in Pseudomonas aeruginosa

Pseudomonas aeruginosa establishes biofilms through a coordinated series of events beginning with reversible attachment to a surface, irreversible adhesion mediated by adhesins and exopolysaccharides, microcolony formation, maturation into three-dimensional structures, and eventual dispersion of motile cells. The biofilm matrix comprises extracellular polymeric substances (EPS), principally the polysaccharides Psl, Pel and alginate, along with extracellular DNA, proteins and lectins. Psl often forms a helical scaffold that promotes cell–cell cohesion, while Pel contributes to intercellular adhesion and modulates biofilm biomechanics. In mucoid strains, alginate further enhances matrix viscosity and protects against host defences. Localised production of cyclic-di-GMP shifts bacterial physiology from planktonic to biofilm growth, regulating matrix synthesis and adhesin expression. Mature biofilms exhibit heterogeneous microenvironments with nutrient and oxygen gradients, conferring increased tolerance to antibiotics and immune clearance. This lifestyle underpins chronic infections in cystic fibrosis lungs, medical device colonisation and industrial biofouling, driving efforts to develop matrix-targeting therapies and anti-biofilm coatings.

Research from Nature Portfolio

Recent studies have shown that a genome-reduced respiratory bacterium can be engineered to secrete multiple biofilm-degrading enzymes and bactericidal effectors, effectively dissolving P. aeruginosa biofilms in endotracheal tubes and enhancing antibiotic efficacy in a murine lung infection model. This synthetic approach demonstrates the feasibility of live-biotherapeutic strategies to dismantle mature biofilms and treat ventilator-associated pneumonia.

Other work has elucidated the role of the bacterial lectin LecB in matrix organisation by binding specifically to Psl exopolysaccharide. LecB–Psl interactions concentrate matrix components at the biofilm periphery, increasing retention of both cells and polysaccharides, and thereby reinforcing structural integrity. This finding identifies lectins as key matrix proteins that cross-link polysaccharide networks.

Biofilm Formation and Structure in Pseudomonas aeruginosa publication trend

The graph below shows the total number of articles in biofilm formation and structure in pseudomonas aeruginosa across all publications each year (not limited to Nature Index journals).

Technical terms

Biofilm: A structured community of microbial cells enclosed in a self-produced matrix and adherent to a surface.

Exopolysaccharide (EPS): Extracellular polysaccharides secreted by bacteria that form the scaffold of biofilm matrices.

Lectin: A carbohydrate-binding protein that mediates interactions within the matrix.

Endo-β-glucosidase: An enzyme that cleaves internal β-1,4-glycosidic bonds in glucose-containing polysaccharides.

Cyclic-di-GMP: A secondary messenger molecule that regulates transitions between planktonic and biofilm lifestyles.

References

1. Engineered live bacteria suppress Pseudomonas aeruginosa infection in mouse lung and dissolve endotracheal-tube biofilms. Nature Biotechnology (2023).
2. The Pseudomonas aeruginosa lectin LecB binds to the exopolysaccharide Psl and stabilizes the biofilm matrix. Nature Communications (2019).
3. Bespoke Activity-Based Probes Reveal that the Pseudomonas aeruginosa Endoglycosidase, PslG, Is an Endo-β-glucanase. Journal of the American Chemical Society (2025).
4. Glycoside hydrolase processing of the Pel polysaccharide alters biofilm biomechanics and Pseudomonas aeruginosa virulence. npj Biofilms and Microbiomes (2023).
5. Divergent molecular strategies drive evolutionary adaptation to competitive fitness in biofilm formation. The ISME Journal: Multidisciplinary Journal of Microbial Ecology (2024).
6. Assembly and Development of the Pseudomonas aeruginosa Biofilm Matrix. PLOS Pathogens (2009).
7. Biosynthesis of the Pseudomonas aeruginosa Extracellular Polysaccharides, Alginate, Pel, and Psl. Frontiers in Microbiology (2011).
8. Pseudomonas aeruginosa uses a cyclic‐di‐GMP‐regulated adhesin to reinforce the biofilm extracellular matrix. Molecular Microbiology (2010).