In the case of the PPV zone, the similarity of the microbiota could derive from the specific raw materials or be due to an establishment of a resident microbiota in that specific environment. The fact that a zone-specific microbiota could not be observed suggests that the microbial biogeography in such environments is determined not only by the specific food matrix that is manipulated in a specific area but again to other factors (surface composition, ecological factors, nutrient availability, cleaning frequency) that play a fundamental role in defining the microbiota. Therefore, it can be speculated that the microbial composition of each single microenvironment is only partially affected by the food handled.