title: Effects of yeast cell-wall characteristics on 4-ethylphenol sorption capacity in model wine.
abstract: Saccharomyces cerevisiae is an efficient biosorbant, used in winemaking to reduce the concentration of undesirable molecules such as fatty acids. Volatile phenols such as 4-ethylphenol, which causes a horsy smell in wine, are particular targets of this type of curative process. This study demonstrates that the sorption capacity of 4-ethylphenol by yeasts is greatly influenced by strain nature, methods, and medium used for biomass production and drying after harvesting. S. cerevisiae mutant strains with deletion of genes encoding specific proteins involved in cell-wall structure and composition were studied, and a major role for mannoproteins in 4-ethylphenol sorption was identified. It was confirmed that 4-ethylphenol sorption occurs at the surface of the yeast wall and that not all mannoproteins are determinants of sorption: the sorption capacity of cells with deletion of the Gas1p-encoding gene was 75% lower than that of wild type. Physicochemical properties of yeast cell surface have been also studied.
authors.affiliation: Lallemand SAS, 31702 Blagnac, France.
authors.forename: Rémi
authors.initials: R
authors.lastname: Pradelles
authors.forename: Herve
authors.initials: H
authors.lastname: Alexandre
authors.forename: Anne
authors.initials: A
authors.lastname: Ortiz-Julien
authors.forename: David
authors.initials: D
authors.lastname: Chassagne
mesh_terms: D002473:Cell Wall / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D008954:Models, Biological; D010636:Phenols / Q000737:chemistry* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014920:Wine / Q000032:analysis* / Q000382:microbiology
chemical_list: D010636:Phenols; D029701:Saccharomyces cerevisiae Proteins; C042291:4-ethylphenol