SYNERGIC EFFECT OF ENZYMES OR SURFACTANTS IN ASSOCIATION WITH A PHENOLIC DISINFECTANT ON A BACTERIAL BIOFILM

Disrupting bacterial biofilms is necessary for a wide application doma ins such as reusable medical devices, or systems of pipes for water or fluids in cosmetics, food and chemicals industry. Bacterial cells emb edded in a biofilm are less susceptible to disinfectants than suspende d cells. This property is referable to the structure of the biofilm it self. The gangue of exopolymers and the thickness of a 5-day-old biofi lm of Escherichia coli (more than 200 layers of bacteria), contribute to this decrease of susceptibility. The present work deals with the re lease of an Escherichia coli biofilm by the sequential action of enzym es and a phenolic disinfectant on the one hand, and by the sequential or simultaneous action of surfactants and the previous disinfectant on the other hand. The decrease of bacteria count per mm2 and the Scanni ng Electron Microscope observations exhibited a synergic action in eve ry case. Nevertheless, Escherichia coli biofilms quickly reconstructed even after exposition to the previous treatment.