Isolation and identification of lactic acid bacteria in beetroot juice

Introduction- The consumption of fruits and vegetables and their beverages has always been of interest to consumers due to the presence of nutrients such as minerals, vitamins, and antioxidants. Since carbohydrates are present in fruit and vegetable juices, it has made them a suitable environment for the growth of lactic acid bacteria, so this study was performed to isolate and biochemically identify lactic acid bacteria from beetroot juice.Material and Methods (Or Methodology)- Beetroot juice was prepared from two kilograms of beets washed with a cold press. Sterile samples of beetroot juice were first enriched in MRS broth and then cultured on MRS agar. Gram and catalase tests were used for the initial detection of lactic acid bacteria. In the following to identify the species of lactic acid bacteria, biochemical confirmation tests such as the melting of gelatin, the ability of bacteria to grow at 15 and 45 œ C, sugars fermentation, gas production from glucose, and growth in salt with different concentrations were performed. The final verification of species was done using polymerase chain reaction (PCR).Findings- All isolates formed creamy white round colonies on MRS agar medium, were gram-positive, and were able to grow in anaerobic conditions, they were also rod-shaped and catalase-negative, which based on biochemical and molecular tests, four types of lactic acid bacteria (L .plantarum, L. helveticus, L. salivarius, L. acidophilus) have beenidentified.Conclusion- The findings of this study indicate the presence and diversity of lactic acid bacteria in beetroot juice which can be a potential substrate for the production of probiotic products.

Isolation and identification of lactic acid bacteria in beetroot juice Keywords:

Lactic acid bacteria , beetroot juice , isolation , biochemical identification , polymerase chain reaction (PCR)