Researchers discovered that a bacterium called Serratia plymuthica can effectively remove copper from contaminated water using special protective layers of polymers it produces. These polymer layers, especially the protein components, act like tiny magnets that capture copper ions from solution. The study found that when these bacteria form biofilms on porous surfaces, they become even more effective at removing copper from industrial wastewater, achieving up to 97% removal efficiency even under harsh acidic conditions.