Probiotic Potential of Yeasts Isolated From Traditional Indian Fermented Foods

Twenty yeast strains were isolated from traditional Indian fermented foods (idli and jalebi batter) and were screened for various probiotic properties. Seven of these isolates could survive in conditions similar to the gut with a survival rate as high as 100% at pH 2.0-2.5 and bile salt concentration of 1%. They were able to grow at 37oC and were resistant to commonly used antibiotics. Auto-aggregation ability and cell surface hydrophobicity was observed to be high for all of the isolates. Antimicrobial action was exhibited by these isolates against enteric pathogens (i.e., E. coli, Salmonella sp., Staphylococcus aureus, Vibrio cholerae and Pseudomonas sp.). Further, they were observed to produce phytase, β-galactosidase, L-asparaginase, protease and lipase, thus could be useful in degrading anti-nutrients and improving digestion. Most of them were vitamin B12 (except J15) and exopolysaccharide producers. All of them had the ability to assimilate cholesterol in the range 57-88.5%. None of the strains produced DNase and gelatinase, thus ascertaining their safe use. These isolates were identified as Saccharomyces cerevisiae, Candida tropicalis, Aureobasidium sp. and Pichia manschuria.