Immunomodulatory properties of the β-glucan surface polysaccharide of Propionibacterium freudenreichii, a dairy bacterium with probiotic potential
Résumé
P. freudenreichii (PF) is a Gram + species, with the GRAS (Generally Recognized As Safe) status in the USA and a Qualified Presumption of Safety (QPS) status in Europe. It is widely consumed by humans because it is an essential ripening culture in Swiss type cheeses (Emmental, Leerdammer®…), which contain more than 109 live cells / g of cheese. It is also used as a probiotic in food supplement (Propio-Fidus®). Recently, 30% of the strains of PF were shown shown to produce a (1→3, 1→2)-β-D-glucan surface polysaccharide. A single gene (named gtfF) is responsible for the biosynthesis. Here we investigated the role(s) of this β-glucan.