Changes in microbiota during the cheese making process – from the raw milk to the final cheeses

The objectives were to evaluate effects of feeding different types of silages on the microbiota of the raw milk and the resulting cheeses. Different silages were produced without additives, acid treated and inoculated with a LAB starter culture, and each silage was fed to dairy cows during a three-week period. A brine-salted long ripened type of hard cheeses was produced and samples of milk, cheese curd and cheese during ripening were collected, and their microbiota characterised using 16S rRNA sequencing. Raw milk microbiota consisted of many different genera, the top 20 genera explaining 75% of the relative abundance. In cheese Lactococcus , followed by Leuconostoc and Lactobacillus, were the dominant genus throughout the ripening, indicating a strong influence from the starter culture. Feeding the different silages did not result in differences in the microbiota in the raw milk or ripened cheeses. Results at amplicon sequence variant level showed that the relative abundance of LAB present both in the raw milk and in cheeses, decreased along the value chain.