title: Heterologous expression of surface-active proteins from barley and filamentous fungi in Pichia pastoris and characterization of their contribution to beer gushing.
abstract: The spontaneous over-foaming of beer upon opening, i.e. beer gushing, is an unwanted phenomenon for the brewing industry. Currently, surface-active proteins from filamentous fungi and non-specific lipid transfer proteins (nsLTP1) from barley are discussed as gushing inducers. In our study the class I hydrophobin FcHyd3p from Fusarium culmorum, the class II hydrophobin Hfb2 from Trichoderma reesei, the alkaline foam protein A (AfpA) from F. graminearum and nsLTP1 from Hordeum vulgare cv. Marnie (barley) were heterologously expressed in Pichia pastoris and used in gushing tests. The class I hydrophobin FcHyd3p was unable to induce gushing in beer. The class II hydrophobin Hfb2 was able to induce gushing in beer, but proved to be inhibited by heat treatment as well as by the presence of enriched hop compounds. Both resulted in a reduced gushing potential. AfpA and nsLTP1 exhibited no gushing-inducing potential at the amounts added to beer. Addition of these proteins to beer or carbonated water previously treated with class II hydrophobins revealed a gushing reducing character.
authors: Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Weihenstephaner, Steig 16, 85350 Freising, Germany.
authors: Georg
authors: G
authors: Lutterschmid
authors: Monika
authors: M
authors: Muranyi
authors: Matthias
authors: M
authors: Stübner
authors: Rudi F
authors: RF
authors: Vogel
authors: Ludwig
authors: L
authors: Niessen
mesh_terms: D000595:Amino Acid Sequence; D001515:Beer / Q000382:microbiology*; D002352:Carrier Proteins / Q000737:chemistry; D003001:Cloning, Molecular; D050556:Fatty Acid-Binding Proteins; D005285:Fermentation; D005516:Food Microbiology; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics; D005658:Fungi / Q000737:chemistry* / Q000235:genetics; D005670:Fusarium / Q000737:chemistry / Q000235:genetics; D001467:Hordeum / Q000737:chemistry* / Q000382:microbiology; D006358:Hot Temperature; D008969:Molecular Sequence Data; D010843:Pichia / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D014242:Trichoderma / Q000737:chemistry / Q000235:genetics
chemical_list: D002352:Carrier Proteins; D050556:Fatty Acid-Binding Proteins; D005656:Fungal Proteins; C422456:Ltp1 protein, barley; D010940:Plant Proteins; D011994:Recombinant Proteins