Identification and Characterization of Lactobacillus brevis P68 with Antifungal, Antioxidant and Probiotic Functional Properties

In the present study, Lactobacillus pentosus, L. plantarum, L. fermentum, L. brevis, L. paraplantarum, L. buchneri, and L. acidipiscis, which are strains capable of producing antifungal metabolites against food-spoilage fungi, were isolated and identified based on 16S rRNA gene sequencing from different traditional pickles. L. brevis P68 exhibited significant antifungal activity, and it's in vitro antioxidant and probiotic properties were investigated. The antifungal compound was characterized based on C-13 nuclear magnetic resonance (NMR), H-1 NMR, infrared, and mass spectral data. The minimum inhibitory concentration (MIC) of the compounds was assessed using the broth micro-dilution technique. The MIC of the compounds against Penicillium chrysogenum and P. roqueforti was 2.5 mg mL(-1) and that against Gibberella moniliformis and Aspergillus clavatus was 5.0 mg mL(-1). In addition, the H2O2 (1.0 mM) hydroxyl radical, and DPPH scavenging activity inhibition rates were 32.76 and 48.63 %, respectively, and the activities toward the glutathione peroxidase and superoxide dismutase enzymes were high. This strain tolerated low pH and bile salt, exhibited bile salt hydrolase and extracellular enzyme activities, and was sensitive to common antibiotics with high hydrophobicity. This study revealed that the antifungal, antioxidant, and probiotic properties of L. brevis P68 confirmed its application to the food industry.