Patent ID: 7504239

Claim:
A method of differentiating bottom-fermenting yeast from wild yeast comprising synthesizing a pair of primers consisting of (i) a primer consisting of the base sequence set forth in SEQ ID NO: 7 and (ii) a primer consisting of 15-30 nucleotides of a sequence that is complementary to a base sequence of chromosome IX of Saccharomyces cerevisiae located downstream from a sequence selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, and SEQ ID NO: 6; performing PCR (Polymerase Chain Reaction) to produce a PCR amplification product, wherein the primers for said PCR consist of said pair of primers, the template for said PCR is a DNA separated from a yeast specimen, and said PCR is performed by denaturing for 10 seconds to 2 minutes at a temperature of 90-98° C., annealing for 20 seconds to 2 minutes at a temperature of 40-75° C., and extending for 1-20 minutes at a temperature of 65-75° C., with 10-30 cycles; and differentiating whether said yeast is bottom-fermenting yeast or wild yeast, based on the PCR amplification product, wherein said wild yeast is yeast not used for brewing and said wild yeast belongs to a genus selected from the group consisting of the genus Hansenula , the genus Brettanomyces , the genus Candida , and the genus Saccharomyces , wherein when the wild yeast is from the genus Saccharmyces said wild yeast is a species selected from the group consisting of Saccharomyces cerevisiae, Saccharomyces bayanus and Saccharomyces diastaticus , and wherein said bottom-fermenting yeast is Saccharomyces pastorianus.