title: Development of engineered yeast for biosorption of beer haze-active polyphenols.
abstract: Compared to most other alcoholic beverages, the shelf life of beer is much more limited due to its instability in the bottle. That instability is most likely to appear as turbidity (haze), even sedimentation, during storage. The haze in beer is mostly caused by colloidal particles formed by interactions between proteins and polyphenols within the beer. Therefore, beers are usually stabilized by removing at least one of these components. We developed and constructed a Saccharomyces cerevisiae strain with a proline-rich QPF peptide attached to the cell wall, using the C-terminal anchoring domain of α-agglutinin. The QPF peptide served to bind polyphenols during fermentation and, thus, to decrease their concentration. Strains displaying QPF were able to bind about twice as much catechin and epicatechin as a control strain displaying only the anchoring domain. All these experiments were done with model solutions. Depending on the concentration of yeast, uptake of polyphenols was 1.7-2.5 times higher. Similarly, the uptake of proanthocyanidins was increased by about 20 %. Since the modification of yeasts with QPF did not affect their fermentation performance under laboratory conditions, the display of QPF appears to be an approach to increase the stability of beer.
authors: Department of Biotechnology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Dejvice, Czech Republic.
authors: Rudolf
authors: R
authors: Cejnar
authors: Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Dejvice, Czech Republic.
authors: Kateřina
authors: K
authors: Hložková
authors: Department of Biotechnology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Dejvice, Czech Republic.
authors: Lukáš
authors: L
authors: Jelínek
authors: Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Dejvice, Czech Republic.
authors: Pavel
authors: P
authors: Kotrba
authors: Department of Biotechnology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Dejvice, Czech Republic. Pavel.Dostalek@vscht.cz.
authors: Pavel
authors: http://orcid.org/0000-0003-2973-1643
authors: P
authors: Dostálek
mesh_terms: D001515:Beer / Q000382:microbiology*; D044946:Biflavonoids / Q000378:metabolism; D002392:Catechin / Q000378:metabolism; D005516:Food Microbiology; D059808:Polyphenols / Q000378:metabolism*; D044945:Proanthocyanidins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism
chemical_list: D044946:Biflavonoids; D059808:Polyphenols; D044945:Proanthocyanidins; C017674:procyanidin; D002392:Catechin
keywords: Beer colloidal stability; Procyanidin removal; QPF peptide; Saccharomyces cerevisiae