PFAS comprise a family of more than 6,000 virtually indestructible fluorinated compounds that are now subject to European regulations. Existing treatment processes are costly, energy-intensive, or waste-generating, and biological approaches face a major hurdle: effectively defluorinating PFOA and PFOS quickly and at high concentrations remains impossible to date. Among the candidate enzymes, laccases stand out: functioning in the open air, they break down PFOA in the presence of mediators. However, the literature remains dominated by fungal enzymes, which are effective in acidic environments, whereas the water to be treated is neutral to basic. The project therefore focuses on the CotA laccase from Bacillus subtilis—which is heat-stable, active in basic environments, naturally bound to the spore, and easily optimizable—as well as on Pseudomonas strains capable of forming pollutant-tolerant biofilms. During sessile growth, the biofilm matrix traps PFAS, protects the enzyme, and creates conditions favorable for co-metabolism. Since this approach has never been quantified, it opens up an unexplored scientific niche.