Antimicrobial activity of spp. isolated from fermented foods and their inhibitory effect against foodborne pathogens.

Lactic acid bacteria (LAB), known for their health benefits, exhibit antimicrobial and antibiofilm properties. This study investigated the cell-free supernatant (CFS) of spp., particularly KR3, against the common foodborne pathogens , and spp. strains were isolated from cheese, pickles and yoghurt. They were then identified by morphological, physiological and biochemical characteristics and confirmed by 16S rRNA gene sequencing. Culture supernatants from seven lactobacilli isolates showed varying inhibitory activities. Notably, KR3 and had the highest bacteriocin gene counts. KR3 CFS demonstrated significant antibacterial activity, with inhibition zones of 20 ± 0.34 mm for , 23 ± 1.64 mm for , and 17.1 ± 1.70 mm for spp. The CFS also exhibited substantial antibiofilm activity, with 59.12 ± 0.03% against , 83.50 ± 0.01% against , and 60. ± 0.04% against spp., which were enhanced at the minimum inhibitory concentration (MIC). These results highlighted the potential of KR3 in antimicrobial applications, however, further research is needed to evaluate its viability and functional properties for probiotic use. Additionally, the CFS demonstrated exceptional thermal stability, reinforcing its promise as an antimicrobial agent.