Abstract

Eighty three strains of Leuconostoc mesenteroides were isolated from 12 samples of raw camel milk collected from different Algerian zones. Based on morphological, biochemical and physiological characters tests, 36.52% strains were identified as L. mesenteroidesspp. mesenteroides, 30.71% as L. mesenteroides spp. dextranicum and 3.32% as L. mesenteroides spp. cremoris. The interactions study revealed that seven strains were able to inhibit the growth of Listeria monocytogenes, Listeria innocua, Listeria ivanovii, Staphylococcus aureus, Escherichia coli and Lactobacillus plantarum. Setting aside the pH effect, H₂O₂ effect and using proteolytic enzymes, the inhibitory agent was determined as proteinous nature substance. Treatment of the cell-free supernatant of the bacteriocin-producing strains by Tween 80 increased the inhibition activity, contrary to the urea which decreased it.

Key words: Raw camel milk, Leuconostoc mesenteroides, Listeria spp., bacteriocin, biopreservation.