Exploring the antimicrobial attribute: characterization of lactobacillus isolate and in vitro assessment of antimicrobial activity of postbiotic cell-free supernatants against pathogenic microorganisms

This study examines the antimicrobial potential of the cell-free supernatant of a Lactobacillus isolate. The isolate was identified accurately by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial potential against four common pathogenic bacteria, namely Escherichia coli, Enterococcus faecalis, Salmonella enterica, and Streptococcus bovis, was determined by agar well diffusion assay. The results demonstrated concentration-dependent increases in inhibition zones for all tested pathogens; the postbiotic showed significant antimicrobial potential similar to reference antibiotics. This study demonstrates the potential of probiotic cell-free supernatant as a bioactive postbiotic agent that can inhibit pathogenic bacteria, thus providing alternative infection control. The results also suggest the potential of the postbiotic in being developed as a bioactive antimicrobial agent for infection management.