Probiotic potential, antioxidant, and antimicrobial properties of Lactobacillus spp. isolated from indigenous food plants in Ilocos Norte, Philippines
Abstract
Purpose: To evaluate the in vitro probiotic, antioxidant, and antimicrobial properties of Lactobacillus spp. isolated from Philippine indigenous food plants (IFPs) as potential sources of non-dairy probiotic strains.Methods: Four isolates were assessed for gastrointestinal tolerance across a pH range of 2.0 – 8.0 and at bile concentrations of 0.5 and 1 %. Cell-surface characteristics, such as auto-aggregation and cell surface hydrophobicity, were measured. Bile salt hydrolase (BSH) activity was qualitatively evaluated. Ethyl acetate fractions of cell-free supernatants (EAFPs) were tested for antioxidant capacity using the DPPH assay and for antimicrobial effects against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.Results: Lentilactobacillus hilgardii DSB22 showed the highest survival at pH 2 (50.22 ± 3.32 %) and 1 % bile (80.50 ± 4.37 %) after 6 h. It also demonstrated superior auto-aggregation (79.35 ± 0.56 %) and cell surface hydrophobicity (63.36 ± 0.40 %). All isolates were BSH positive. The EAFP of L. hilgardii DSB22 exhibited strong radical scavenging capacity (73.51 ± 0.58 %) and the greatest antimicrobial effect, especially against S. aureus (18.33 ± 2.89 mm).Conclusion: Lentilactobacillus hilgardii DSB22 exhibits robust probiotic potential, and IFPs represent valuable sources of non-dairy probiotic strains.