The discovery of biofilms dates back to the Dutch microscopist Antonie van Leeuwenhoek, who first observed them on tooth surfaces and described these tiny organisms as “animalcules in the scurf” 1.

Gram staining has guided microbiology for over a century by coloring cells purple or pink, a read-out thought to distinguish monoderms (single membrane, thick peptidoglycan) from diderms (inner and ...