Etude dynamique des populations bactériennes lactiques du lait cru réfrigéré dans la région de Mila.

Abstract

The microbial flora of milk was cultured using dependent culture methods. The identification of bacterial isolates was carried out using phenotypic methods based on cultural, morphological, and biochemical criteria. The variations in the number of lactic bacteria and the kinetic parameters of microbial growth were analyzed during refrigeration using Origin 06 software. The initial microbial count in the raw milk sample collected from the farm basin was 3.21 log CFU/mL. The maximum growth reached 7.17 log CFU/mL. The maximum growth rate was 0.56 log CFU/mL, and the generation time varied between 1.78 days in the farm basin. The lactic bacteria populations identified were Acinetobacter, Pseudomonas, Streptococcus, Lactococcus, Enterococcus, and Lactobacillus. These results confirm that although refrigeration limits overall microbial growth, it promotes the selection of cold-adapted flora, notably lactic acid bacteria, which can influence the technological quality of raw milk.