title: Characterization of gtf, a glucosyltransferase gene in the genomes of Pediococcus parvulus and Oenococcus oeni, two bacterial species commonly found in wine.
abstract: "Ropiness" is a bacterial alteration in wines, beers, and ciders, caused by beta-glucan-synthesizing pediococci. A single glucosyltransferase, Gtf, controls ropy polysaccharide synthesis. In this study, we show that the corresponding gtf gene is also present on the chromosomes of several strains of Oenococcus oeni isolated from nonropy wines. gtf is surrounded by mobile elements that may be implicated in its integration into the chromosome of O. oeni. gtf is expressed in all the gtf(+) strains, and beta-glucan is detected in the majority of these strains. Part of this beta-glucan accumulates around the cells forming a capsule, while the other part is liberated into the medium together with heteropolysaccharides. Most of the time, this polymer excretion does not lead to ropiness in a model medium. In addition, we show that wild or recombinant bacterial strains harboring a functional gtf gene (gtf(+)) are more resistant to several stresses occurring in wine (alcohol, pH, and SO(2)) and exhibit increased adhesion capacities compared to their gtf mutant variants.
authors.affiliation: UMR 1219 Oenologie, LBMA, Université Victor Segalen Bordeaux 2, INRA, ISVV, 351 cours de la Libération, 33405 Talence, France. m.dols@istab.u-bordeaux1.fr
authors.forename: Marguerite
authors.initials: M
authors.lastname: Dols-Lafargue
authors.forename: Hyo Young
authors.initials: HY
authors.lastname: Lee
authors.forename: Claire
authors.initials: C
authors.lastname: Le Marrec
authors.forename: Alain
authors.initials: A
authors.lastname: Heyraud
authors.forename: Gérard
authors.initials: G
authors.lastname: Chambat
authors.forename: Aline
authors.initials: A
authors.lastname: Lonvaud-Funel
mesh_terms: D001422:Bacterial Adhesion; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism; D006095:Gram-Positive Cocci / Q000201:enzymology* / Q000235:genetics; D018869:Heat-Shock Response; D007218:Industrial Microbiology; D008969:Molecular Sequence Data; D009154:Mutation; D010376:Pediococcus / Q000201:enzymology* / Q000235:genetics; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014920:Wine / Q000382:microbiology; D047071:beta-Glucans / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D047071:beta-Glucans; D005964:Glucosyltransferases