Characterization of Probiotic Properties of Antifungal Lactobacillus Strains Isolated from Traditional Fermenting Green Olives

The aim of this work is to characterize the potential probiotic properties of 14 antifungalLactobacillusstrains isolated from traditional fermenting Moroccan green olives. The molecular identification of strains indicated that they are composed of fiveLactobacillus brevis, twoLactobacillus pentosus, and sevenLactobacillus plantarum. In combination with bile (0.3%), all the strains showed survival rates (SRs) of 83.19-56.51% at pH 3, while 10 strains showed SRs of 31.67-64.44% at pH 2.5. All the strains demonstrated high tolerance to phenol (0.6%) and produced exopolysaccharides. The autoaggregation, hydrophobicity, antioxidant activities, and surface tension value ranges of the strains were 10.29-41.34%, 15.07-34.67%, 43.11-52.99%, and 36.23-40.27 mN/m, respectively. Bacterial cultures exhibited high antifungal activity againstPenicilliumsp.The cell-free supernatant (CFS) of the cultures showed important inhibition zones againstCandida pelliculosa(18.2-24.85 mm), as well as an antibacterial effect against some gram-positive and gram-negative bacteria (10.1-14.1 mm). The neutralized cell-free supernatant of the cultures displayed considerable inhibitory activity againstC. pelliculosa(11.2-16.4 mm). None of the strains showed acquired or horizontally transferable antibiotic resistance or mucin degradation or DNase, hemolytic, or gelatinase activities.Lactobacillus brevisS82, Lactobacillus pentosusS75, andLactobacillus plantarumS62 showed aminopeptidase, beta-galactosidase, and beta-glucosidase activities, while the other enzymes of API-ZYM were not detected. The results obtained revealed that the selected antifungalLactobacillusstrains are considered suitable candidates for use both as probiotic cultures for human consumption and for starters and as biopreservative cultures in agriculture, food, and pharmaceutical industries.