Cloning and Characterization of the Beer Foaming Gene CFG1 from Saccharomyces pastorianus

摘要

Foam production is an essential characteristic of beer, generated mainly from the proteins present in the malt and, to a minor extent, from the mannoproteins in brewer's yeast cell walls. Here, we describe the isolation and characterization of the novel fermentation gene CFG1 (Carlsbergensis foaming gene) from Saccharomyces pastorianus. CFG1 encodes the cell wall protein Cfglp, a 105 kDa protein highly homologous to Saccharomyces cerevisiae cell wall mannoproteins, particularly those involved in foam formation, such as Awalp and Fpglp. Further characterization of Cfglp revealed that this hovel protein is responsible for beer foam stabilization. This report represents the first time that a brewing yeast foaming gene has been cloned and its action fully characterized.