Abstract
INTRODUCTION: Traditional fermented foods are rich reservoirs of probiotic microorganisms, yet several remain scientifically underexplored. The current research focused on the screening, isolation, identification, and assessment of potential probiotic isolates exhibiting β-galactosidase activity from naturally fermented Palmyra palm (Borassus flabellifer) nectar, a culturally significant, traditional beverage consumed in India. METHODS: A total of 80 bacterial isolates were obtained under aseptic conditions and screened through cultural, microscopic, and biochemical analyses. Fifty-six Gram-positive, catalase-negative isolates were shortlisted for probiotic evaluation. Selected isolates were assessed for simulated gastrointestinal conditions, cell surface properties (auto-aggregation, hydrophobicity, co-aggregation and Biofilm production), β-galactosidase and exopolysaccharide production, antioxidant activity, antibiotic susceptibility, and safety through hemolysis and DNase activity. RESULTS: Seventeen isolates exhibited desirable adhesion-related traits, of which seven strains demonstrated superior probiotic potential. These strains tolerated acidic and bile conditions, produced high levels of exopolysaccharides (573-785 mg/L) and β-galactosidase (110.25-221.09 U/mL), and showed significant cell surface hydrophobicity (35.87-69.93%), auto-aggregation (59.29-82.76%), and co-aggregation with pathogens Salmonella Typhi (MTCC 733) 46.58 - 70.87% and S. flexneri (ATCC 12022) 53.45 - 78.85%. They also exhibited substantial hydroxyl radical scavenging activity (57.68-70.66%) and were safe and antibiotic-susceptible. DISCUSSION: The findings highlight the probiotic potential and functional attributes of Palmyra nectar - derived bacteria. Their ability to survive gut-like conditions, hydrolyze lactose, adhere to intestinal mucosa, and provide antioxidant benefits supports their application in functional foods and nutraceuticals aimed at improving gut health and lactose digestion.