Isolation, molecular characterization and screening of indigenous lactobacilli for their abilities to produce bioactive conjugated linoleic acid (CLA)

Ingestion of conjugated linoleic acid poised many health benefits; however, amount of CLA one can get through generalized diet in is inadequate in exerting the desired benefits. Therefore, presence of CLA producing lactobacilli in dairy fermented foods has a tremendous potential to increase the CLA content. Therefore, present study was focused to isolate and characterize CLA producing lactobacilli from different dairy products and human faeces. Arguably, 283 lactobacilli were isolated from various sources and tested for CLA production. Fifty-seven CLA producing (≥20 µg/ml) lactobacilli were selected from screening in de Man, Rogosa and Sharpe (MRS) broth and reconstituted with skim milk (SM), supplemented with 0.5 mg/ml of linoleic acid. Positive strains were classified into-L. plantarum (44%), L. gasseri (30%), L. fermentum (21%) and L. salivarius (5%) species. Nineteen most efficient strains (CLA ≥25 µg/ml) were further assessed in SM for CLA production. Total 08 strains produced significantly higher CLA in SM than MRS and also produced cis 9, trans 11, trans 10, cis 12 and trans 9, trans 11 isomers. Overall, L. plantarum HIF15 was reported as the best producer of CLA and other 08 lactobacilli may be utilized for the formulation of CLA-enriched functional foods to support these bacteria to synthesize CLA in the human gut.