title: Acquired resistance to bile increases fructose-6-phosphate phosphoketolase activity in Bifidobacterium.
abstract: Two Bifidobacterium strains with acquired resistance to bile were used in this study. Significant differences on membrane-associated protein profiles were found between the bile resistant derivatives and their corresponding original strains. One of the major species detected in one of the resistant derivatives had an apparent denatured molecular mass of approximately 90 kDa, and was identified as xylulose-5-phosphate/fructose-6-phosphate phosphoketolase, the key enzyme of Bifidobacterium carbohydrate catabolism. Phosphoketolase activity was considerably higher in membrane preparations and cell-free extracts of the two bile resistant derivatives. This correlated to a greater consumption rate of glucose in resistant strains. Fructose-6-phosphate phosphoketolase activity in the strain Bifidobacterium bifidum CECT4549 and its resistant derivative was found to be partially associated with the cytoplasmic membrane through weak interactions.
authors.affiliation: Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas (CSIC), Ctra. Infiesto s/n, 33300 Villaviciosa, Asturias, Spain.
authors.forename: Borja
authors.initials: B
authors.lastname: Sánchez
authors.forename: Luis
authors.initials: L
authors.lastname: Noriega
authors.forename: Patricia
authors.initials: P
authors.lastname: Ruas-Madiedo
authors.forename: Clara G
authors.initials: CG
authors.lastname: de los Reyes-Gavilán
authors.forename: Abelardo
authors.initials: A
authors.lastname: Margolles
mesh_terms: D000222:Adaptation, Physiological; D000446:Aldehyde-Lyases / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D001644:Bifidobacterium / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D001647:Bile Acids and Salts / Q000494:pharmacology*; D002455:Cell Division; D002462:Cell Membrane / Q000201:enzymology; D004789:Enzyme Activation; D005947:Glucose / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D001647:Bile Acids and Salts; D000446:Aldehyde-Lyases; C065556:fructose-6-phosphate phosphoketolase; D005947:Glucose