Potential Probiotic Yeasts Isolated from Idli and Selroti, Indian Ethnic Fermented Cereal-based Foods

Introduction: In the present study, we focused on the screening of the potential probiotic yeasts isolated from two Indian fermented cereal-based foods, viz., idli and selroti. A total of 260 yeast isolates were isolated from the batters of idli (140 isolates) and selroti (120 isolates). Methods: Preliminary screening of basic probiotic traits such as tolerance to low pH, bile, and cell surface attachment was checked for the selection of potential probiotic yeasts from total isolates. Finally, 8 yeast isolates were selected for further in-depth assessment by in vitro and genetic screening, which included Clavispora lusitaniae AIY-4, Wickerhamomyces anomalus MIY-30, Pichia kudriavzevii BIY-8 (from idli), Yarrowia lipolytica SGLY-15, Y. lipolytica SGLY-21, Candida parapsilosis SPRY-17, C. parapsilosis SBRY-12, and Kodamaea ohmeri SBRY-25 (from selroti). Results: A principal component analysis (PCA) biplot was designed to evaluate the differences and similarities amongst the yeast strains, and two clusters were formed using the paired group (UPGMA) algorithm and Euclidean similarity index. Cluster one was comprised of Cl. lusitaniae AIY- 4, W. anomalus MIY-30, C. parapsilosis SBRY-12, and P. kudriavzevii BIY-8, and another cluster included C. parapsilosis SBRY-12 and Y. lipolytica SGLY-21. Conclusion: Hence, based on statistical analysis for probiotic in vitro and genetic screening, Wickerhamomyces anomalus MIY-30 (idli) and Kodamaea ohmeri SBRY-25 (selroti) were selected as the most potential probiotic strains.