[P007] Poster

12:10 PM - 1:00 PM JST(3:10 AM - 4:00 AM UTC)

[P04-469] Probiotic potential of Saccharomyces cerevisiae NIYL14840 with antioxidant and antimicrobial activities

○HyeJin Hong¹, JungAh Yoon², MyoungDong Kim^1,2 (1. Department of Food Science and Biotechnology, Kangwon National University (Korea), 2. Institute of Fermentation and Brewing, Kangwon National University (Korea))

Keywords:

Yeast,Saccharomyces cerevisiae,Probiotics,Antioxidant,Antimicrobial

Probiotic yeasts are known to survive at body temperature and withstand gastrointestinal conditions such as low pH and bile salts. They are also reported to demonstrate antioxidant and antimicrobial activities. In this study, the probiotic properties of ten Saccharomyces cerevisiae strains isolated from natural environments and fermented foods were evaluated and compared with those of the commercial probiotic strains S. boulardii CNCM I-745, ATCC MYA-796, and ATCC MYA-797. Growth at 37 °C was initially tested to see if the strains could survive at body temperature. Most strains demonstrated better growth than the commercial strains. Resistance to gastrointestinal conditions was then assessed by measuring survival rates after 4 hours of incubation at pH 2.5 and 1% oxgall, which mimic the acidic and bile environments of the gastrointestinal tract. Seven strains exhibited higher survival rates than the commercial strains. Among them, NIYL14840 showed survival rates of 90.33 ± 7.29% at pH 2.5 and 95.16 ± 1.86% in 1% oxgall, indicating strong resistance to gastrointestinal stress. Antioxidant activity was assessed using DPPH, ABTS, and FRAP assays. Both cell-free culture supernatants (CFS) and intracellular extracts were tested. When comparing the results from the three assays, the NIYL14840 strain exhibited relatively high antioxidant activity in both CFS and intracellular extracts. This suggests that the strain has antioxidant capacity both outside and inside the cells. Specifically, the reducing power, measured by the FRAP assay, was generally higher in this strain than in the commercial control strains. Antimicrobial activity was also evaluated, with six enteric pathogens tested. Both the entire culture and washed yeast cells inhibited the growth of Escherichia coli, Salmonella Typhimurium, and Salmonella Enteritidis. These results suggest that the NIYL14840 strain has strong tolerance to gastrointestinal conditions, along with antioxidant and antimicrobial activities. Therefore, it may have potential as a functional probiotic yeast compared to commercial S. boulardii strains