Towards probiotic lactic acid bacteria strains to remove raffinose-type sugars present in soy-derived products

CONNES, C.; SILVESTRONI, A.; LEBLANC, J.G.; JUILLARD, V.; SAVOY DE GIORI, G.; SESMA, F.; PIARD, J.-C.

LE LAIT

Elsevier Science

Lugar: Amsterdam, Holanda; Año: 2004 vol. 84 p. 207 - 214

0023-7302

Lactic acid bacteria (LAB), that are widely used in food fermentations and that may survive in the gastrointestinal tract of consumers, are potent candidates as vehicles for delivery of biologically active proteins. To evaluate this potential of LAB, we focus on the degradation of alpha-galactosides of soy. These sugars, which are not degraded by the pancreatic enzymes of humans, are metabolized by gas-producing bacteria of the large intestine, thus creating intestinal disorders such as flatulence in sensitive individuals. In this study, we aim to demonstrate that alpha-galactosidase (alpha-Gal) expressing LAB can efficiently degrade alpha-galactosides: (i) in soy milk fermentation when they are used as starters; and (ii) in the small intestine when they are administered orally to animals as probiotic preparations. To reach these goals, we characterized the alpha-Gal structural gene of Lactobacillus plantarum ATCC8014. This gene, as well as the structural gene for the alpha-Gal from guar were expressed in Lactococcus lactis so that the enzymes are located in various bacterial compartments. This allows us to take into account the environmental constraints which are specific to each application. Active alpha-Gals could be produced in L. lactis and resulting strains will be evaluated both in soy milk fermentations and in oral administrations in animals. The expected outcomes of this study are discussed.