Abstract
The genus Weissella, commonly found in fermented foods, is a significant group of lactic acid bacteria (LAB) with potential probiotic properties. Several Weissella strains have been proposed as probiotics due to their biotechnological capabilities. However, a few strains may exhibit opportunistic pathogenic behavior, which restricts the widespread use of all Weissella strains in food applications. This study sought to expand our understanding of the biotechnological capabilities of Weissella spp. by examining the safety and functional characteristics of strains isolated from spontaneous fermentation. In this investigation, nine Weissella strains were evaluated for their safety and probiotic potential. The safety assessment revealed that the antibiotic resistance profiles of strains 16-2, 38-3, 69-3, 91-3, 91-5, 104-4, and 106-5 were comparable or superior to the reference strain LGG. Hemolytic activity and ammonia production were also evaluated, but no positive results were observed. Further probiotic experiments demonstrated that strain 91-5 exhibited superior performance in several areas, including survival rates in simulated gastrointestinal fluids, cell surface properties (hydrophobicity and adhesion to Caco-2 cells), ABTS+ scavenging ability, antimicrobial activity, and cholesterol assimilation in vitro. Additionally, strain 104-4 produced an exopolysaccharide (EPS) yield of 35.11 g/L after 48 h of culture in MRS-sucrose (60 g/L) medium, surpassing most previously reported values. These findings suggest that strains 91-5 and 104-4 show promise as potential probiotic candidates for the development of new functional food supplements. Furthermore, this research expands the theoretical basis for considering Weissella strains as novel probiotics.