Isolation, characterization and conjugated linoleic acid production potential of bifidobacterial isolates from ruminal fluid samples of Murrah buffaloes

Abstract In the present study, we investigated the potential of Bifidobacterium spp., isolated from ruminal fluid samples from buffaloes ( Bubalus bubalis ) for conjugated linoleic acid (CLA) production. A total of 294 isolates were obtained from 86 ruminal fluid samples using Bifidus Selective Medium (BSM) medium, and based on phospoketolase assay, 24 isolates were presumptively confirmed to be Bifidobacterium species. Further, the isolates were confirmed morphologically, biochemically and by PCR assays for genus specific (16s rDNA) and transaldolase genes. All 24 strains were positive for conversion of linoleic acid (LA) to CLA by spectrophotometric screening. Gas chromatographic analysis showed that the strains produced cis 9, trans 11 and tran 10, cis 12 CLA isomers in LA-supplemented deMan-Rogosa-Sharpe (MRS) broth. The strains were identified as B. thermophilum (n = 21) and B. pseudolongum (n = 3) based on 16 rDNA sequence analysis. The study shows that Bifidobacterium spp., present in the rumens of buffaloes produce CLA from LA and the strains may have the potential to be used as probiotics to enhance the nutraceutical value of ruminant food products.