Cloning of Wheat LTP1500 and TwoFusarium culmorumHydrophobins inSaccharomyces cerevisiaeand Assessment of Their Gushing Inducing Potential in Experimental Wort Fermentation

Abstract

The potential of surface active proteins to affect gushing upon their formation in situ during fermentation was investigated. This was achieved by cloning the genes of two hydrophobins of F. culmorum and of a wheat lipid transfer protein (LTP1500) in Saccharomyces cerevisiae, with expression of these genes under control of the constitutive TPI (triose phosphate isomerase) promoter. The transgenic yeast clones were used for fermentation of wort. The resulting beers were bottled and examined for the occurrence of gushing. Gushing was induced by the class II hydrophobin FcHyd5p of the fungus F. culmorum, found in naturally occurring cases of gushing worldwide.