Evaluation of functional properties of lactic acid bacteria isolated from traditional cheese

Abstract

The objective of this research was to study a total of 10 strains of lactic acid bacteria previously isolated from traditional cheese, explore the effects of various in vitro tests, and evaluate their functional and potential probiotic properties. We tested the strains for cholesterol assimilation, antimicrobial activity, enzyme and exopolysaccharides (EPS) production, cell surface traits, antibiofilm, and tolerance to lysozyme and phenol. E. faecalis S135 and E. durans S1121 were characterized by strong antibacterial activities against C. albicans and S. aureus. The strains E. durans S092 and E. faecalis S135 were differentiated by phytase-producing and coagulation activity, respectively. Moreover, E. faecalis S135 had a greater cholesterol reduction percentage (66.6 ± 0.00 %) than the others. Separately, E. durans S104 and L. coryniformis subsp. torquens S232 were found to possess stronger cell surface properties, e.g., auto-aggregation (94.3 ± 0.30 %) and cell surface hydrophobicity (65.1 ± 0.11 %). All LAB 10 strains were able to handle 0.4 % phenol and 2 mg/mL lysozyme well. They also had some antibiofilm activity, but not much EPS production. Industrially important strains with antimicrobial activity, such as E. durans (S1121, S092, and S104) and E. faecalis S135, could serve as bio-protective agents. These four strains can therefore find application in various fields, including the production of fermented and/or functional foods and enzymes.