Lactic bacteria form a important group for human health due to their production of some antimicrobial substances, which are capable to inhibit the proliferation of wide rang pathogenic bacteria. Recently, the used isolated, selected lactic acid bacterial strains from diverse ecosystems in food bio-preservation was considerably augmented the duration of bio-preservation. The main aim of the present work was the isolation and the screening of large range of lactic acid bacteria from Algerian human milk and the characterization of the molecules responsible for antimicrobial activity. The primary screening indicated the isolation 13 lactic acid bacterial strains from Algerian human breast milk, where the identification has been achieved by the study of phenotypical, physiological and biochemical characteristics. On others hand, the evaluation of the antagonistic activity of the isolated, selected lactic acid bacteria against some pathogenic bacteria strains such as Staphylococcus aureus UT 602, S. aureus CECT 86T, S. aureus ATCC 25923, S. aureus ATCC 43300, E. coli ATCC 25922 has been achieved by the using agar well diffusion method and the study of the E. coli ATCC 25922 bacterial growth in the absence and in the presence of the supernatant of the cultivated selected lactic acid bacteria (LbC3). Furthermore, the identification of the bacteriocin producing selected lactic acid bacteria (LbC3) by the using of 16S rRNA gene sequence analysis indicated their belonging to the genus Lactobacillus brevis. The obtained results indicated that the highest amount of bacteriocin was yielded at 30°C and pH-value of 6. Hence, the study of bacterial growth of E. coli ATCC 25922 in the absence and in the presence of the supernatant L. brevis (LbC3) indicated a considerable biomass reduction accompanied with unbalanced growth after adding of the supernatant. The isolated, selected antagonistic L. brevis has manifested high level of resistance toward to vancomycin, tobramycine, nalidixique acid, nitroxolin and oxacilin and sensible against penicillin, pristinamycin, chloramphenicol.
