A study of the antimicrobial activity of lactic acid bacteria strains isolated from cow’s milk and Sharri cheese

Lactic acid bacteria due to the safety reason is used in food industry in fermentation and in medicine as a bacteriocins. The aim of this study is to isolate Lactic Acid Bacteria from raw cow's milk and traditional Sharri cheese, and investigate their antimicrobial effects against Staphylococcus aureus, Listeria monocytogenes, Listeria ivanovii, and Listeria innocua. A total of 110 strains were isolated from milk samples of five farmers and samples of two traditional cheese producers. Among them, 47 strains exhibited inhibitory activity against at least one pathogenic indicator, with 20 isolates originating from milk samples and 27 from cheese samples. Eleven strains could inhibit the growth of all tested pathogenic indicators. Specifically, 68.08% of the isolates showed inhibitory activity against Staphylococcus aureus, 51.06% against Listeria monocytogenes, 48.94% against Listeria innocua, and 36.17% against Listeria ivanovii. These findings suggest that LAB cultures isolated from milk and artisanal cheese can serve as potential starter cultures in milk processing technology, which can help promote food security.