Tidsskrift: Molecules, vol. 25, p. 15, 2020
Open Access: gold
Effective cleaning and disinfection (C&D) is pivotal for the control of Listeria monocytogenes in food processing environments. Bacteria in biofilms are protected from biocidal action, and eective strategies for the prevention and removal of biofilms are needed. In this study, dierent C&D biofilm control strategies on pre-formed L. monocytogenes biofilms on a conveyor belt material were evaluated and compared to the eect of a conventional chlorinated, alkaline cleaner (agent A). Bacterial reductions up to 1.8 log were obtained in biofilms exposed to daily C&D cycles With normal user concentrations of alkaline, acidic, or enzymatic cleaning agents, followed by disinfection using peracetic acid. No significant dierences in bactericidal eects between the treatments were observed. Seven-day-old biofilms were more tolerant to C&D than four-day-old biofilms. Attempts to optimize biofilm eradication protocols for four alkaline, two acidic, and one enzymatic cleaning agent, in accordance with the manufacturers’ recommendations, were evaluated. Increased concentrations, the number of subsequent treatments, the exposure times, and the temperatures of the C&D agents provided between 4.0 and >5.5 log reductions in colony forming units (CFU) for seven-day-old L. monocytogenes biofilms. Enhanced protocols of conventional and enzymatic C&D protocols have the potential for improved biofilm control, although further optimizations and evaluations are needed.