Potential of Lactiplantibacillus plantarum, Levilactobacillus brevis and Lactococcus lactis strains as functional cultures for dairy industry

The functional properties of foodborne lactic acid bacteria (LAB) are related to their metabolites. In this study, the most important functional properties of LAB isolates isolated from different fermented foods were investigated. These include, primarily EPS production capabilities and the properties of the EPS structures they produce, antimicrobial activities, and resistance to the simulative gastrointestinal system, which is one of the important tests for the concept of potential probiotic isolates, were investigated. Among the isolates, the BL4, CL6 and KL2 belonging to the Lactiplantibacillus plantarum species, the EL1 belonging to the Levilactobacillus brevis species, and CL3 belonging to the Lactococcus lactis species were determined to be strong EPS producers. When the EPS structures produced by the strains were examined, especially EPS-EL1 obtained from the Lv. brevis EL1 showed shear thinning behavior and moreover, it was stated that it could provide significant rheological contribution for dairy industry applications. Moreover, this strain showed high antimicrobial activity against the bacterial pathogen E. coli ATCC 25922 and high resistance against gastrointestinal simulation medium along with CL6. On the other hand, high antimicrobial activity of the Lp. plantarum BL4 and the Lc. lactis CL3 strains was determined against the yeast pathogen C. albicans ATCC 10131. This reveals that the Lv. brevis EL1 strain is especially likely to be used for different functions such as co-culture and adjuvant culture in the dairy industry. As a result, it was revealed that these 5 strains have different supportive properties that can be used in the dairy industry, for various fermentation processes.