Québec produces more than 700 varieties of cheese with very different textures and tastes. This distinctiveness is due as much to the microbial flora they contain as to their manufacturing environment, reveal the analyses of Steve Labrie, director of the STELA centre, the largest dairy research center in Canada. It is therefore important to properly understand and manage the microbiota present.

For example, to make cheddar cheese, master cheesemakers add specific bacteria to acidify the milk. After six months, almost no traces of these microorganisms remain: they have been replaced by natural bacteria from the milk and the cheese factory environment.

Québec produces more than 700 varieties of cheese with very different textures and tastes.

The researcher from the Department of Food Sciences at Université Laval and his team used various genomic techniques to better understand the role of these microbes – bacteria, yeasts, moulds –, but above all to learn how to control them in order to improve product stability and quality. These techniques include DNA barcoding, which is used to read the genetic information of a community of microbes. In collaboration with 21 cheese factories, the scientists extracted microbial DNA from each cheese, identified the species, and quantified their concentration over time, in different batches, etc. To their great surprise, they created a bank of more than 1,100 microbial strains from Québec milk and cheese, which will make it easier to reveal the “fingerprint” of each product!

This project, which was carried out in partnership with funding from the FRQNT, Novalait, the Quebec consortium for industrial bioprocess research and innovation (CRIBIQ) and the Natural Sciences and Engineering Research Council of Canada, led to the completion of a major study on the genomics of washed-rind cheeses with Agropur, Génome Québec and Genome Canada. The goal of this study was to understand the role of microflora during the ripening process (maturing period) in order to identify the best microbes to increase the shelf life of cheeses, while ensuring the unique characteristics of Agropur’s products.