In vitro assessment of probiotic potentials of yeast strains isolated from a cereal-based (Ogi)) traditional fermented food

Abstract

This present research focused on the isolation of yeast strains from fermented African cereal-based food with promising probiotic attributes. Yeast isolates were obtained from a locally produced cereal-based food “Ogi” also known as Akamu. The yeast was evaluated for their stress tolerance (pH, bile, temperature, NaCl, gastric juice), adhesion properties (auto-aggregation, hydrophobicity) and susceptibility to antibiotics. The strains performed well at 37 °C and exhibited strong ability to tolerate acid (pH 3) and bile salt (1.5%) environment with a percentage survival range of 60-82.61% and 62.96-83.67% respectively. Candida tropicalis (A4) gave the highest salt tolerance at 1% (89.29) and 4% (92.86), while Saccharomyces cerevisiae (A2) showed greater ability to survive the stimulated gastrointestinal conditions at 42.86%. The strains exhibited high auto-aggregation (68.8-94.9%) and a good hydrophobicity to chloroform and toluene. Susceptibility profile of the yeast strains to antibacterial antibiotics showed that all the yeasts presented a resistance pattern. These results indicate that C. tropicalis and S. cerevisiae both have the capability to serve as probiotic agents and can be proposed for various applications. Also, fermented cereal-based Ogi with its wide array of health benefits can serve as a carrier for the delivery of probiotics to both animals and humans as food supplements.