Biological Profiling of Postbiotics of Lactobacillus plantarum: Antibacterial, Antioxidant, and Cytotoxic Properties Under In Vitro and Food Circumstances.

The objective of this study was to analyze the chemical profile (gas chromatography-mass spectrometry), cell-based safety (cell viability, SOD and GSH-Px activity, NO production, and ROS activity), antioxidant properties (hydroxyl-, DPPH-radical scavenging activity, and linoleic acid peroxidation inhibitory activity), biofilm and auto-aggregation inhibitory activity, and antibacterial effects (minimum inhibitory concentration, minimum bactericidal concentration and minimum effective concentration) of Lactobacillus plantarum postbiotics (LPPs) in relation to Escherichia coli and Staphylococcus aureus. LPPs demonstrated notable Radical scavenging activity, with values of 72.30 ± 3.41% for hydroxyl RSA, 95.76 ± 3.72% for DPPH, and 20.98 ± 1.67% for linoleic acid peroxidation inhibition. Additionally, they demonstrated antibacterial effects against S. aureus (29.45 mm inhibition zone, minimum inhibitory concentration (MIC) of 32 µg/mL, minimum bactericidal concentration (MBC) of 50 µg/mL, minimal effective concentration (MEC) of 30 mg/mL for whole milk and 55 mg/mL for meat) and E. coli (21.17 mm inhibition zone, MIC 80 µg/mL, MBC 120 µg/mL, MEC 65 mg/mL milk, 85 mg/mL meat) with statistical significance noted (P < 0.05). LPPs demonstrated a positive effect on KDR cell viability, resulting in a significant enhancement of SOD and GSH-Px functions in these cells. Additionally, LPPs resulted in a decrease in NO production and a reduction in ROS levels (P < 0.05). Consequently, LPPs present a promising strategy for addressing the proliferation of S. aureus and E. coli, and they hold potential for application in the food industry to mitigate safety concerns associated with pathogenic microbes.