Preliminary Identification, Characterization And Selection Of Probiotic Bacteria From Natural Sources

Probiotics are advantageous microorganisms that provide health advantages to the host when consumed in sufficient quantities. In this investigation, bacteria were extracted from natural sources, including curd, milk, butter, and vegetables. The isolates were identified through a combination of morphological, biochemical, and sugar fermentation patterns were used. These included phenotypic traits, sugar fermentation, MR-VP reaction, catalase test, urease test, oxidase test, H2S production, NH3 synthesis from arginine, the use of citrate, and indole test. Twelve isolates with probiotic characteristics were identified, with seven being Gram-positive (C1, C3, C4, M1, M4, V5 and B2) and five being Gram-negative (M3, V2, V4, B1and B5). These isolates included cocci, long rod-shaped, short rod-shaped bacteria and the remaining five were cocci and long rod-shaped, respectively. The strains showed strong survival under acidic pH conditions, high bile salt and NaCl concentrations, and were found to be susceptible to the tested antibiotics without any hemolytic activity. Samples C3, C4, M1, M3, M4, and B5 showed strong antibacterial activity against gram-positive and gram-negative microorganisms, while samples C1, V2, V4, V5, B1, and B2 showed reduced efficacy. The study revealed that bacteria from various natural sources exhibit probiotic nature and possess probiotic qualities. However, further research is needed to confirm the efficacy and safety of these methods in improving human health.