Safe food and reduced waste: Optimal use of sanitizers against biofilm in food production premises

Some bacteria, such as Pseudomonas and Staphylocoocus are frequently found in food production environments, and the pathogen Listeria monocytogenes can persist for years. It has for a long time been suggested that some strains contain specific resistance mechanisms enabelling persistence in the food production environment. After the results obtained in this project, this hypothesis should be reconsidered, Bacteria isolated from the food industry produced a biofilm that partly outcompeted Listeria monocytogenes. The biofilms were relatively resistant against cleaning and disinfection agents. Whole genome sequencing was used to look for survival mechanisms in bacteria with high survival abilities. The results indicate that persistence in the food environments are mostly a function of high growth rate at low temperatures and rough surface materials and not sophisticated molecular mechanisms in certain strains. Interestingly, we got an indication that components found in some foods can inhibit Listeria monocytogenes in the food production environment, but not the background microbiota. Furthermore, using our biofilm models, we found that more environmentally friendly cleaning agents can be used without losing effect.

For most foods, survival, growth and activities of microorganisms are determining for the safety, quality and shelf life. Proper sanitation and hygienic quality of food production premises is a prerequisite to provide customers and consumers with safe and high quality food. Innovations in food production including increased production and consumption of fresh, natural and ready-to-eat foods have revealed new microbial challenges and emphasized the fundamental role of sanitation for reducing the risks of c ross-contamination. Why microorganisms survive sanitation regimes and how sanitation in combination with environmental and microbial factors affects biofilm formation, persistence and elimination is largely unknown. Despite its important role, there is li mited knowledge assuring optimal use and effect of sanitizers in diverse food industries. This project will aim to close important knowledge gaps. The project will identify critical contamination points in food production processes, evaluate microbial and environmental factors of importance for microbial survival/elimination and evaluate cost-effective sanitation strategies, accordingly. Novel technology and methods will enable understanding of key factors for sanitation efficacy under realistic condition s. This will provide basis for targeted and cost-effective sanitation practices and emphasize important factors for microbial control through sanitation in food industry premises.