Designing a primer pair for amplification of the priming glycosyltransferase (p-gtf) undecaprenyl-phosphate sugar phosphotransferase (rfbP) partial gene to screening exopolysaccharide (EPS)-producing Bifidobacterium spp.

Searching for exopolysaccharides (EPS)-producing bacteria could be interested in the exploration of new probiotic strains. EPS have beneficial effects on health and play crucial roles in adhesion mechanisms, control of pathogens, maintain survival/viability of microorganism during technology food process/storage, and contribute to rheological properties of fermented foods. The ability to produce EPS by some bifidobacteria strains is demonstrated. Bifidobacteria, commonly inhabitants of the gastrointestinal tract of humans and animals, are used in foods as probiotic. Although, EPS biosynthesis in bifidobacteria is not known, hypothesis could be proposed based on the functional analysis of few genes and on sequences homology studies (P. Ruas-Madiedo, Salazar, and de los Reyes-Gavilán 2009). The priming glycosyltransferase, p-gtf, is the key enzyme involved in the catalyses of the first step of EPS-units biosynthesis. The role plays by p-gtf genes was confirmed altering or interrupting EPS production through inactivation of these genes (Low et al. 1998). In spite of the low amino acid, the intraspecies homology of a single p-gtf is high for the presence of conserved domains involved in the lipophilic carriers interaction ( Ruas-Madiedo et al. 2007).