Probiotic Potential of Indigenous Yeast Isolated from Chao, a Traditional Indonesian Fermented Fish

Abstract

Indigenous yeasts from traditional fermented foods represent a promising yet underexplored source of probiotic candidates. Chao, a traditional fermented fish from Pangkajene Kepulauan Regency, South Sulawesi, is characterized by yeast-associated fermentation, suggesting its potential as a promising source of functional microorganisms. This study aimed to evaluate the probiotic potential of yeast isolates from Chao through integrated physiological, functional, and molecular analyses. Yeasts were isolated using yeast peptone dextrose (YPD) medium and screened for tolerance to acidic pH, bile salts, and osmotic stress, as well as for hydrophobicity and co-aggregation with pathogenic bacteria. Out of 40 isolates, 3 strains (C32B.1, C35B.1, and C37B.1) exhibited strong tolerance to gastrointestinal-like conditions and favorable adhesion-related properties. The selected isolates demonstrated high cell surface hydrophobicity (>65%) and moderate to strong co-aggregation ability with pathogenic bacteria. Functional characterization demonstrated that these isolates possessed notable bioactivities, including antidiabetic activity (up to 70.20%), antioxidant activity (>73%), and anti-inflammatory potential (>56%), with activities increasing in a concentration-dependent manner. Molecular identification based on 18S rRNA gene sequence analysis revealed that the selected isolates were affiliated to Pichia kudriavzevii (99.74% similarity). These findings highlight the potential of indigenous yeasts from Chao as promising probiotic candidates and support their application in functional food development and related biotechnological industries from traditional fermented foods.