Isolation and characterization of beneficial bacteria from probiotic drinks and assessment of their antibacterial activity against natural and artificial sugars

Probiotic drinks are well-known fermented beverages that include live strains of yeast and helpful bacteria. These beverages are well-known for their possible health advantages, which include strengthening the immune system and enhancing digestion. The probiotic potential of the bacterial strains found in probiotic drinks makes them particularly interesting. Isolating bacteria from probiotic beverages, characterizing them biochemically, and assessing their antibacterial effectiveness against both natural and artificial sugars are the objectives of this study. Probiotic yogurt and Yakult samples will be collected from the local market. Nutrient agar plates were plated with serial dilutions of each beverage, which were then incubated for 24 hours at 37°C. Gram staining, catalase test, and oxidase test were performed to observe the isolated colonies for their morphology and characterize the isolated bacterial strains. Antibacterial Activity testing on the isolated bacteria was performed by the double disc diffusion method to determine their resistance patterns. Gram staining, catalase, and oxidase assays were among the biochemical tests used to describe the isolated bacterial strains. The disc diffusion method was utilized to ascertain the bactericidal activity of the isolated bacteria against both natural sugars (stevia and xylitol) and artificial sugars (saccharine and aspartame). Bacterial strains were isolated from the probiotic drinks, including Lactobacillus spp., Bifidobacterium spp. The biochemical tests confirmed the identity of the bacterial strains. The antibacterial activity of the isolated strains varied against different sugars. Lactobacillus spp. showed the highest antibacterial activity against stevia and xylitol, while Bifid bacterium spp. showed maximum antibacterial activity against saccharine and aspartame.