Bacteriocinogenic <i>Pediococcus acidilactici</i> ST41VF Isolated From Bulgaria Feta Cheese: Probiotic Potential, Biopreservative Properties, and Safety Evaluation

Dairy products are traditional sources of potentially bactriocinogenic and probiotic microorganisms, especially lactic acid bacteria (LAB). This study aimed to isolate bacteriocin-producing LAB from Bulgarian feta cheese and assess their biopreservative, probiotic potential, and safety. Pediococcus acidilactici ST41VF was isolated and shown to inhibit multiple Listeria monocytogenes strains through the production of bacteriocin. This bacteriocin remained stable across a range of pH levels, temperatures, and chemical exposures relevant to pharmaceutical contexts. The highest bacteriocin concentration (6400 AU/mL) occurred during the stationary growth phase. Safety assessments revealed that ST41VF does not produce biogenic amines or gelatinase, lacks proteolytic and mucin-degrading activity, and exhibits γ-hemolytic behavior. It tolerated gastrointestinal simulations, thriving in various pH levels, salt concentrations, and ox-bile. The strain produced 4.998 g/L of d-lactic acid and 7.110 g/L of l-lactic acid, a relevant information regarding potential negative effects of d-lacid acid. Considering its robust antimicrobial activity, resilience, and safety profile, P. acidilactici ST41VF demonstrates strong potential as a biopreservative in food systems and a probiotic candidate for therapeutic applications.