In Vitro Assessment of Bio-Functional Properties from Lactiplantibacillus plantarum Strains
Francesco Letizia, Gianluca Albanese, Bruno Testa, Franca Vergalito, Diletta Bagnoli, Catello Di Martino, Petronia Carillo, Lucia Verrillo, Mariantonietta Succi, Elena Sorrentino, Raffaele Coppola, Patrizio Tremonte, Silvia Jane Lombardi, Roberto Di Marco, Massimo Iorizzo
Abstract
In recent years, alongside the conventional screening procedures for the evaluation of probiotics for human usage, the pharmaceutical and food industries have encouraged scientific research towards the selection of new probiotic bacterial strains with particular functional features. Therefore, this study intended to explore novel functional properties of five Lactiplantibacillus plantarum strains isolated from bee bread. Specifically, antioxidant, antimicrobial and β-glucosidase activities, exopolysaccharides (EPS) production and the ability to synthesize γ-aminobutyric acid (GABA) were evaluated. The results demonstrated that the investigated L. plantarum strains were effective in inhibiting the growth of some human opportunistic pathogens in vitro (Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis, Enterococcus faecalis and Staphylococcus aureus). Moreover, the evaluation of antioxidant and β-glucosidase activity and of EPS and GABA production, revealed a different behavior among the strains, testifying how these properties are strongly strain-dependent. This suggests that a careful selection within a given species is important in order to identify appropriate strains for specific biotechnological applications. The results highlighted that the five strains of L. plantarum are promising candidates for application as dietary supplements in the human diet and as microbial cultures in specific food productions.