Characterization of technological properties of Enterococcus and Lactobacillus strains isolated from raw camel milk for potential use in dairy fermentations

Abstract

This study evaluated the technological properties of 10 lactic acid bacteria strains belonging to the speices of Enterococcus faecalis, E. faecium, Lactobacillus brevis, and Lb. plantarum previsiouly  isolated from raw camel milk and relevant for dairy fermentations. Enterococcal strains were found to be slow acid producers, although E. faecalis exhibited better acidifying activity after 24h of incubation. E. faecalis showed significantly higher proteolytic activity than E. faecium, increasing between 6 and 24h. Growth kinetics revealed an initial lag phase followed by robust growth for most strains, with potential limitation for E. faecium due to its low proteolysis. Autolytic activity demonstrated inter-strain variability, with some E. faecium strains being as autolytic as Lb. plantarum. Diacetyl production was confirmed in Enterococcus and Lb. plantarum, but absent in Lb. brevis. Finally, peptidase activities, essential for protein degradation and bitterness reduction, were highlighted, with lactobacilli being recognized for their diverse enzymatic repertoire. These findings contribute to a better understanding of the technological potential of these strains for specific applications in the dairy industry, by identifying their strengths and limitations.