title: Evaluation of the ability of Bifidobacterium longum to metabolize human intestinal mucus.
abstract: The ability of Bifidobacterium longum to use intestinal mucus as a metabolizable source was characterized. Bifidobacterium longum biotype longum NCIMB8809 was grown in a chemically semi-defined medium supplemented with human intestinal mucus, and the cytoplasmic protein profiles and several glycosyl hydrolase activities were analysed and compared with those obtained from the same bacterium grown in the absence of mucus. We were able to identify 22 different proteins in the cytoplasmic fraction, of which nine displayed a different concentration in the presence of mucus. Among the proteins whose concentrations varied, we found specific enzymes that are involved in the response to different environmental conditions, and also proteins that mediate interaction with mucus in bacteria. Significant changes in some glycoside-hydrolysing activities were also detected. In addition, stable isotope labelling of amino acids in cell culture demonstrated that B. longum incorporates leucine from the glycoprotein matrix of mucin within its proteins. This study provides the first proteomic data regarding the interaction of B. longum with intestinal mucus, and contributes to the understanding of the behaviour of this intestinal species in its natural ecological niche.
authors.affiliation: Instituto de Productos Lácteos de Asturias (CSIC), Asturias, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Ruiz
authors.forename: Miguel
authors.initials: M
authors.lastname: Gueimonde
authors.forename: Yohann
authors.initials: Y
authors.lastname: Couté
authors.forename: Seppo
authors.initials: S
authors.lastname: Salminen
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Sanchez
authors.forename: Clara G
authors.initials: CG
authors.lastname: de los Reyes-Gavilán
authors.forename: Abelardo
authors.initials: A
authors.lastname: Margolles
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001426:Bacterial Proteins / Q000032:analysis; D001644:Bifidobacterium / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D006023:Glycoproteins / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D006801:Humans; D007554:Isotopes / Q000378:metabolism; D009093:Mucus / Q000378:metabolism*; D020543:Proteome / Q000032:analysis; D013194:Staining and Labeling / Q000379:methods
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D003470:Culture Media; D006023:Glycoproteins; D007554:Isotopes; D020543:Proteome; D006026:Glycoside Hydrolases