Evaluation of probiotic potential of yeast isolated from traditional cheese manufactured in Ardabil

Evaluation of probiotic potential of yeast isolated from traditional cheese manufactured in Ardabil
Shohreh Nasiri poroj,¹ Sorour Alipanah,^2,* Neda Zamani,³
1. Department of Microbiology, Faculty of Life Sciences, Islamic Azad University, North Tehran Branch
2. Department of Microbiology, Faculty of Life Sciences, Islamic Azad University, North Tehran Branch
3. Department of Microbiology, Faculty of Life Sciences, Islamic Azad University, North Tehran Branch
Introduction: As the food industry continues developing new products and processes, consumers are focused on food safety, diet and health aspects of their food. Yeasts are important microorganisms in the fermentation of foods and beverages, and some yeasts have been used as biocontrol agents and novel probiotics. During the last decades, since they have shown numerous beneficial effects on human health, their usage as probiotics has been increasing. Probiotics are desirable and natural tools for providing balance to the intestinal microflora. They are consumed either as food or non-food preparations. New species of probiotics are constantly being identified. In this study, isolation, characterization, and identification of yeast strains from natural sources and retail cultures were investigated. Some probiotic properties of the isolates were determined.
Methods: Samples were collected from traditional cheeses. The samples were cultured in the YGC agar medium by pour plate method Then, differentiation between yeast isolates was performed by CHOROM agar media and molecular identification of the isolated isolates was performed by PCR and sequencing of PCR products. All isolates were also investigated for their ability to grow in SD broth at different temperatures, at different pH, and different levels of added ox bile. The yeast isolates were tested for antimicrobial drug sensitivity against antifungal agents were placed on yeast inoculated YGC medium plates. The antagonistic properties of isolated yeast species were determined by modifying the disc diffusion method.
Results: A Set of five isolates were isolated from four locales during three periods of sampling and after the preparation of three serial dilutions, they were cultured on YGC agar. Biochemical and morphological analyses were accurately performed for all five isolates .four isolates were positive urea. Three isolates weren't able to ferment arabinose sugar and grow at 45 ° C. Genetic identification was used for the one isolate, SH04, which was similar to saccharomyces boulardii species respectively. All isolates, especially SH04 isolate, were able to grow at different pH and salts. All isolates have had probiotic properties.
Conclusion: Probiotics play a critical and vital role in human nutrition. In recent years, new strain isolation, characterization and verification of potential health benefits particularly related to probiotic traits have been a very attractive area for researchers. Probiotic properties are strain-specific, therefore new strains must be well characterized. The results indicated that this yeast showed notable potential probiotic properties.
Keywords: Yeast, Isolation, probiotic