Investigation of antimicrobial and antioxidant properties of postbiotics produced by lactobacillus rhamnosus and limosilactobacillus reuteri and their potential application in surface decontamination of red meat
Safura Jalali, Naheed Mojgani, Setareh Haghighat, Mohammad Reza Sanjabi, Solmaz Saremnezhad
Abstract
This study investigated the antimicrobial properties of postbiotics produced by lactobacillus rhamnosus and limosilactobacillus reuteri in surface decontamination of red meat against pathogenic bacteria ( Escherichia coli and Staphylococcus aureus ). The study evaluated postbiotic activity using agar well diffusion, minimum inhibitory concentration (MIC mg/mL), minimum bactericidal concentration (MBC mg/mL), antioxidant properties, total phenolic content (TPC), and organic acid content. Among 18 meat samples, the mixed postbiotic (L. rhamnosus and L. reuteri , 100 mL/mg) displayed the strongest effect against E. coli , achieving a 5.54 log CFU/g reduction after 48 h with a well diffusion diameter of 23 mm, MIC of 20, and MBC of 25. A similar trend was observed for S. aureus , with the mixed postbiotic showing a reduction of 6.9 log CFU/g after 48 h, MIC of 25, and MBC of 50. Interestingly, the mixed postbiotic also exhibited the highest TPC (250.8 mL/mg). L. reuteri postbiotic displayed the strongest antioxidant activity (52.3 mL/mg) and highest organic acid content (18.9 mL/mg). These results suggest the potential of Lactobacilli -derived postbiotics as natural antimicrobials for controlling surface pathogens on meat products. Additionally, the observed link between TPC and antimicrobial activity warrants further investigation into the potential role of antioxidants in enhancing biopreservation efficacy. • Lactobacillus rhamnosus & reuteri postbiotics (100 mL/mg) reduced surface pathogens of meat. • Mixed postbiotics (100 mL/mg) reduced E. coli by 5.54 log CFU/g (48h). • Mixed postbiotic reduced S. aureus by 6.9 log 5 CFU/g, showed highest antioxidant activity (52.3 mL/mg). • L. reuteri postbiotic had the highest organic acid content, potentially contributing to its antimicrobial effects.