Diversity and dynamics of the microbial community during the manufacture of Calenzana, an artisanal Corsican cheese

We studied the diversity and dynamics of the microbiota of Calenzana, a Corsican raw milk cheese by microbial counting and culture-independent methods (TTGE and DGGE). Cheese from two farms, one producing goat cheese and the other one sheep cheese, was studied. The usual process for cheese making, without starter adjunct, was used. Lactococci and mesophilic lactobacilli were the dominant components of the flora during the early stages of the process. Microbial counting showed that the populations of salt-tolerant bacteria, yeasts and moulds were lower than in other artisanal Corsican cheeses. This difference was probably due to the surface microflora being removed during ripening. TTGE indicated that Lactococcus lactis ssp. lactis was the dominant subspecies throughout the process of Calenzana cheese making. DGGE showed the presence of numerous surface bacteria, (coryneforms) and various Gram-negative bacteria. Relationships between physico-chemical characteristics of the cheese and microflora change were also established. For example, the high NaCl content may explain the decrease of the lactic acid bacterial population during ripening. This study shows the consequences of various technological parameters on the diversity and dynamics of dairy microbial community.