Probiotic properties of Weissella cibaria and Leuconostoc citreum isolated from tejuino - A typical Mexican beverage

The survival of bacterial strains isolated from tejuino was evaluated in the human gastrointestinal model (ARIS) using saline solution and simulated food as matrices. Antagonistic activity towards pathogenic bacteria, short-chain fatty acids production and adhesion to HT-29 cells were also studied. Leuconostoc citreum CIATEJ BI-49.1, Weissella cibaria CIATEJ Chryseobacterium bovis CIATEJ BI-55.1 and Bacillus safensis CIATEJ BI-75.1 were selected and inoculated in ARIS model. B. safensis and C bovis were unable to survive the simulated human gastrointestinal tract conditions. Leu. citreum seemed to be more resistant to gastrointestinal conditions than W. cibaria, recovering 7-8 log CFU/mL. In the antagonistic assay, Leu. citreum showed the highest (p < 0.05) inhibition towards S. aureus and S. Typhimurium strains, while W. cibaria had the highest (p < 0.05) activity towards L monocytogenes. In regards of short chain fatty acids production, Leu. citreum showed highest (p < 0.05) production of formic, propionic and butyric acids (0.10, 37.52 and 2.65 g/L, respectively) and higher percentage of adhesion to HT-29 cells (approximately 25%) than W cibaria (approximately 0.5%). Leu. citreum could be a potential probiotic strain due to its tolerance to gastrointestinal conditions, antagonistic activity towards foodborne pathogens, short-chain fatty acids production and adhesion to HT-29 cells. (C) 2017 Elsevier Ltd. All rights reserved.