In Vitro Probiotic Characterization of Yeasts with their Postbiotics' Antioxidant Activity and Biofilm Inhibition...

Area of Science:

• Food Microbiology
• Probiotics and Prebiotics
• Yeast Biotechnology

Background:

• Traditional fermented foods are rich sources of diverse yeast strains.
• Investigating yeast strains for probiotic potential and postbiotic properties is crucial for health applications.
• Antioxidant activity (AOA) and biofilm inhibition capacity (BIC) are key functional traits.

Purpose of the Study:

• To evaluate the in vitro probiotic potential and postbiotic properties of yeasts isolated from fermented foods.
• To assess antioxidant activity (AOA) and biofilm inhibition capacity (BIC) of selected yeast strains and their cell-free supernatants (CFS).
• To identify superior yeast strains for potential use as probiotics or in functional foods.

Main Methods:

• Molecular identification of yeast strains using start codon targeted polymorphisms.
• In vitro assessment of probiotic characteristics: viability in simulated gastric/pancreatic juices, autoaggregation, hydrophobicity, and AOA.
• Evaluation of CFS for AOA and BIC against pathogenic bacteria (Cronobacter sakazakii, Listeria monocytogenes, Pseudomonas aeruginosa, Staphylococcus aureus).

Main Results:

• Several yeast strains, including Kluyveromyces lactis, Saccharomyces cerevisiae, Pichia kudriavzevii, Wickerhamomyces anomalus, and Torulaspora delbrueckii, exhibited significant in vitro probiotic properties, outperforming the reference strain Saccharomyces boulardii MYA-796.
• Cell-free supernatants (CFS) displayed enhanced AOA compared to live cells and demonstrated strong BIC, particularly against Listeria monocytogenes and Staphylococcus aureus.
• Specific strains (K. lactis TC11, S. cerevisiae M33T1-2, P. kudriavzevii S96, W. anomalus OB7Y1, T. delbrueckii KY31) were identified with superior probiotic potential based on gastric survival, autoaggregation, and AOA.

Conclusions:

• Yeast strains isolated from traditional fermented foods possess valuable in vitro probiotic and postbiotic functionalities.
• CFS from certain yeast strains exhibit potent antioxidant and antimicrobial properties, effective against key foodborne pathogens.
• The identified superior yeast strains hold promise for development into functional ingredients for food and health sectors.