Comparison of probiotic potential, antimicrobial activity, antioxidant capacity, and technological traits of Lactiplantibacillus plantarum strains isolated from various foods

This study investigated the technological characteristics of ten Lactiplantibacillus plantarum strains isolated from fermented foods, including growth at different temperatures (5, 10, 37, and 45 °C), tolerance to NaCl concentrations (2–10%), and proteolytic activity. Their probiotic potential, antimicrobial activity, and antioxidant capacity were compared with the commercial probiotic reference strain Lacticaseibacillus rhamnosus GG. Principal component analysis (PCA) was performed to classify the strains according to their functional properties. All L. plantarum strains exhibited similar tolerance to temperature and salt stress, whereas significant differences were observed in proteolytic activity. Their tolerance to acidic conditions (pH 2 and 3) and 0.3% (w/v) bile salts also varied among strains. Cell aggregation and surface hydrophobicity assays indicated generally similar cell-surface characteristics. In antimicrobial assays, Escherichia coli and Aspergillus flavus were the most susceptible microorganisms to the cell-free supernatant (CFS) of L. plantarum . The DPPH radical scavenging activities of L. plantarum cells and their CFS ranged from 36.6% to 56.6% and 41.03% to 79.6%, respectively. Among the tested strains, L. plantarum KMC45, isolated from Jug cheese, exhibited high survival under simulated gastrointestinal conditions, together with notable antioxidant activity (71.81%) and antibacterial activity (inhibition zones of 12.67–13.33 mm). PCA further showed that this isolate clustered most closely with L. rhamnosus GG. Considering its overall characteristics, L. plantarum KMC45 may be regarded as a promising candidate probiotic starter culture for the development of functional foods.