title: Substrate preference of Bifidobacterium adolescentis MB 239: compared growth on single and mixed carbohydrates.
abstract: The utilization of mono-, di-, and oligosaccharides by Bifidobacterium adolescentis MB 239 was investigated. Raffinose, fructooligosaccharides (FOS), lactose, and the monomeric moieties glucose and fructose were used. To establish a hierarchy of sugars preference, the kinetics of growth and sugar consumption were determined on individual and mixed carbohydrates. On single carbon sources, higher specific growth rates and cell yields were attained on di- and oligosaccharides compared to monosaccharides. Analysis of the carbohydrates in steady-state chemostat cultures, growing at the same dilution rate on FOS, lactose, or raffinose, showed that monomeric units and hydrolysis products were present. In chemostat cultures on individual carbohydrates, B. adolescentis MB 239 simultaneously displayed alpha-galactosidase, beta-galactosidase, and beta-fructofuranosidase activities on all the sugars, including monosaccharides. Glycosyl hydrolytic activities were found in cytosol, cell surface, and growth medium. Batch experiments on mixtures of carbohydrates showed that they were co-metabolized by B. adolescentis MB 239, even if different disappearance kinetics were registered. When mono-, di-, and oligosaccharides were simultaneously present in the medium, no precedence for monosaccharides utilization was observed, and di- and oligosaccharides were consumed before their constitutive moieties.
authors.affiliation: Department of Pharmaceutical Sciences, University of Bologna, Bologna, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Amaretti
authors.forename: Elena
authors.initials: E
authors.lastname: Tamburini
authors.forename: Tatiana
authors.initials: T
authors.lastname: Bernardi
authors.forename: Anna
authors.initials: A
authors.lastname: Pompei
authors.forename: Simona
authors.initials: S
authors.lastname: Zanoni
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vaccari
authors.forename: Diego
authors.initials: D
authors.lastname: Matteuzzi
authors.forename: Maddalena
authors.initials: M
authors.lastname: Rossi
mesh_terms: D001644:Bifidobacterium / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism*; D018533:Biomass; D050260:Carbohydrate Metabolism; D003470:Culture Media / Q000737:chemistry; D006026:Glycoside Hydrolases / Q000378:metabolism
chemical_list: D003470:Culture Media; D006026:Glycoside Hydrolases