Exoproteome of bacterial competition in food safety of dairy products: one health and EXPO 2015 related topics

One of the key topics of one health initiative organization is to promote the collaboration between different research fields for the counteraction of food pathogens and spoiling agents. Listeria monocytogenes growth inhibition represents one of the worst challenges in the production of processed dairy products. Lactic acid bacteria (LAB) are part of the typical microbiome of dairy products, including cheese, and their role in listeria growth inhibition could be the keystone. Exoproteome of Listeria monocytogenes and two different strains of Lactic Acid Bacteria in co-culture have been studied in order to highlight mechanisms of bacterial competition useful to improve food safety. Filtered culture and spent medium were lyophilized and proteins separated by 1D – Tricine gel and 2D electrophoresis coupled to a LC-MS/MS shotgun approach. Metabolites from the same media were analysed by GC-MS . Among proteins and metabolites analysed there were highlighted, because of their importance, enolase protein of listeria and GABA amminoacid. Both this results, confirmed by experimental evidences, and, in particular, listeria-specific enolase (Moonlighting protein) could be used to evaluate specific strategies for its growth inhibition using different strains of LAB.