Biofilm
Japanese: バイオフィルム（生物膜）
A community formed by microorganisms attached to surfaces, enclosed in a self-secreted matrix of polysaccharides and other substances. Highly resistant to antimicrobials and difficult to remove.
Biofilm is a membrane-like community that microorganisms create. The slime in drains, dental plaque, deposits on contact lenses—biofilms exist throughout daily life.
When microorganisms attach to a surface, they secrete a matrix of polysaccharides and proteins to envelop themselves. Within this film, antimicrobial penetration is blocked, and resistance can be up to 1,000 times greater than for free-floating cells.
In fermentation, biofilms are a double-edged sword. The house microbes dwelling on the inner walls of wooden barrels form biofilms, yet these contribute to the unique flavor of each brewery.