Yeasts in fermented food and kefir: In vitro characterization of probiotic traits

The probiotics are live microorganisms that, when administered in adequate amounts, confer a beneficial effect on host’s health. Although most probiotics are bacteria, however, one yeast species ( Saccharomyces boulardii) has also been characterized as probiotic. In this study, yeasts have been very important in the food industry and have several beneficial properties that bacteria do not have. In this study, yeast strains were isolated from fermented food and beverage. Various physiological features of the candidate probiotic isolates were preliminarily investigated, including bile salt and acid tolerance, cell surface hydrophobicity, autoaggregation, antioxidant activity, and β-galactosidase activity. We demonstrated several yeast strains have potential as probiotics. For example, Saccharomyces cerevisiae JYC2508 adapted well in a bile salt and acid tolerance test and also had good autoaggregation ability. Moreover, Kluyveromyces marxianus JYC2528 grew well in the bile salt and acid tolerance test and also had good performance with antioxidant activity, cell surface hydrophobicity, and β-galactosidase activity. The overall findings of this study showed that these yeast strains may offer promising probiotic traits relevant for further study.