Probiotic yeasts are specialized strains that can survive high acidic intestinal condition while retaining their sugar fermentation properties, promote gut health and enhance immune support. However, the production of indigenous probiotic food and beverages is hindered by the scarcity of these yeast strains. Hence, this study was designed to screen yeast strains for probiotic properties and evaluate their safety status. Yeast strains were isolated from palm wine and burukutu and identified using the ITS 26rDNA. Yeast isolates were further screened through in-vitro probiotic tests for tolerance to low pH, lysozyme, and bile salt; cell surface hydrophobicity, antagonistic potential and antibiotics susceptibility properties. DNase production, gelatinase and hemolytic activities were carried out as safety tests of the yeast strains. Data were analyzed using descriptive statistics and ANOVA at α0.05. Eleven yeast strains isolated from palm wine and burukutu were identified as Saccharomyces (54.54%), Pichia (18.18%), Trichopsoron (18.18%), and Meyerozyma (9.09%). Saccharomyces cerevisiae AZ71 and Meyerozyma caribbica DTO423-B5 were observed to have a survivability of 75.885% and 71.654% respectively above 70% at pH 3.0. There was a significant difference in the growth of yeast strains at 0.3% bile salt concentration with over 70% tolerance to lysozyme, cell surface hydrophobicity and auto-aggregation properties. There was a complete resistance to all the antibiotics and all the yeast strains were negative for DNase production, gelatinase and hemolytic activities. The results obtained in this study shows that indigenous alcoholic beverages can be a potential source of probiotic yeasts for food and beverage production.
Oduokpaha et al. (Wed,) studied this question.