Bioprospecting Traditional Indian Fermented Foods for Novel Probiotic Strains through Functional and Molecular Characterization

Fermented foods have long formed an essential component of traditional diets, valued for preservation, sensory appeal, and perceived health benefits. Modern microbiological research recognizes that many such foods harbor probiotics—live microorganisms that confer measurable health advantages when consumed in adequate amounts (Food and Agriculture Organization of the United Nations FAO Hill et al., 2014). In India, widely consumed fermented products such as dosa batter, pazhaya soru (fermented rice), beetroot kanji, and shrikhand are affordable and culturally embedded, yet their probiotic properties remain insufficiently characterized at the strain level. This study employed a quantitative experimental design to isolate and functionally evaluate lactic acid bacteria (LAB) from these four traditional matrices. Selective cultivation on MRS agar yielded Gram-positive, catalase-negative, non-motile rod-shaped isolates consistent with LAB morphology. Safety assessment confirmed that all isolates were γ-hemolytic, indicating absence of hemolytic virulence. Functional screening demonstrated survival under simulated gastric stress (pH 2–4), tolerance to 0.5% bile salts, and growth in NaCl concentrations up to 8%, reflecting substantial environmental resilience. Antimicrobial susceptibility profiling revealed strain-dependent responses. The pazhaya soru isolate exhibited pronounced susceptibility to tetracycline (57 mm zone of inhibition) and kanamycin (25 mm), while the dosa batter isolate showed strong inhibition against clarithromycin (40 mm) and cefoperazone (26 mm), moderate sensitivity to selected fluoroquinolones and aminoglycosides, and resistance to specific β-lactams and kanamycin. These findings suggest predominantly favorable safety profiles with limited intrinsic resistance patterns. Molecular identification via 16S rRNA gene sequencing classified the most robust isolates within Lactobacillus sensu lato taxa. Collectively, the results establish traditional Indian fermented foods as credible reservoirs of stress-tolerant and potentially safe probiotic candidates. The study provides a translational basis for developing regionally sourced probiotic formulations, while underscoring the need for comprehensive genomic validation and in vivo assessment to confirm therapeutic efficacy.