Improved Cholesterol Assimilation in Lactobacillus Fermentum MTCC 8711 by Over Expression of Bile Salt Hydrolase Gene

1681 Words4 Pages

Whole genome shot gun sequence analysis of L. fermentum MTCC 8711 (GenBank Acc. No. AP008937) showed the presence of two bsh genes designated as bsh1 and bsh2 respectively. The 927 nucleotide long bsh1 gene, though exhibited 99% similarity with L. fermentum F1 bile salt hydrolase (bsh) gene with the Nucleotide BLAST analysis, did not produce any promising activity with cloning and expression experimenting. Bsh2 was 978 bp long and showed 99% homology with the bsh gene of L. fermentum NCDO394. Primers were designed to amplify the bsh2 gene from the genome of L. fermentum MTCC 8711 with the NcoI and AscI restriction fragments introduced in them. PCR amplification with these set of primers resulted in 1kb amplicon.

Over expression of BSH in native L. fermentum MTCC 8711
Recombinant L. fermentum MTCC 8711 harbouring pBSHCM were studied for over expression of the bile salt hydrolase gene. Expression was induced with 0.5, 1, 2 and 3 percentages of xylose for 4h. Extracellular and intracellular fractions were collected and quantitated using ninhydrin assay and SDS-PAGE analysis. For extracellular expression of bile salt hydrolase 2% of xylose was found to be optimal concentration, resulting with 0.5 enzyme activity (U/ml) as shown in Figure 1. In the case of intracellular expression, 0.23 U/ml of maximal enzyme activity was obtained with 1% xylose concentration. Extra cellular bile salt hydrolase enzyme activity was found to be predominant over the intracellular expression. Furthermore enzyme activity was found to be more specific towards the glyco conjugated bile salt upon the tauro conjugates (Data not shown). Extra cellular fractions with different concentrations of xylose induction were resolved on SDS-PAGE. The coomassie stained...

... middle of paper ...

...he functionality of the bsh genes of Lactobacillus plantarum WCFS1 was explored using Bsh-deficient host Lactococcus. lactis NZ9000 by use of the NICE system (Lambert et al 2008). Few reports are also available on the heterologous expression of the probiotic lactobacillus strains in other host strains other than Lactobacillus such as E. coli (Oh et al 2008, Kumar et al 2013). However no reports are found on the overexpression of the bsh gene in the native host Lactobacillus spp. Since Lactobacilli are very much employed in the fermented food industry, preparation of fermented foods such as yoghurt using bsh active probiotic strains would serve as a finctional biotherapeutic. Therefore, use of recombinant bsh overproducing Lactobacillus fermentum MTCC 8711 could be a potential probiotic strain that could be applies as a biotherapeutic to overcome hypercholesteremia.

More about Improved Cholesterol Assimilation in Lactobacillus Fermentum MTCC 8711 by Over Expression of Bile Salt Hydrolase Gene

Open Document