The invention relates to a method for identifying a useful protein of
brewery yeast. More specifically, the invention relates to (a)
cultivating yeast under a predetermined cultivation condition; (b)
extracting a protein sample from the cultivation product of the yeast;
(c) separating the protein sample by a protein separation means,
selecting a target peak or spot, and recovering the target protein or a
fragment thereof contained in the peak or spot; (d) determining the amino
acid sequence of the target protein; (e) comparing the amino acid
sequence determined in step (d) with the amino acid sequence determined
in advance based on all or a part of genome sequence information of
bottom fermenting yeast; (f) identifying the target protein and the gene
encoding the target protein based on the results of comparison; and (g)
analyzing functions of the identified gene to identify characters given
to the yeast by the gene.