How new molecular approaches have contributed to shedding light on microbial dynamics in Parmigiano Reggiano cheese

Parmigiano Reggiano (PR) is a long ripened raw milk product designation of origin (PDO) cheese manufactured according to traditional technology in a defined geographical area. This review focuses on the recent developments in the study of PR microbial ecology and dynamics. Cheesemaking process was studied, starting from the raw milk, followed by the natural whey starter (NWS), the curd and finally the cheese at different aging times. Results reported in different studies highlight how distinct bacterial populations are intertwined throughout the cheesemaking, and this connected role is related to microbial composition dynamics and proteolytic profile. The cheese microbiota is shaped by the cheesemaking process, that in spite of small variations among dairies ensures the reproducibility of the final product. The cyclic nature of the alternating microbial population in subsequent production batches and the connection with the territory and farming systems lie at the basis of PR sensory attributes.