Transcription profile of brewery yeast under fermentation conditions.
OBJECTIVE
Yeast strains, used in the brewing industry, experience distinctive physiological conditions. During a brewing fermentation, yeast are exposed to anaerobic conditions, high pressure, high specific gravity and low temperatures. The purpose of this study was to examine the global gene expression profile of yeast subjected to brewing stress.


RESULTS
We have carried out a microarray analysis of a typical brewer's yeast during the course of an 8-day fermentation in 15 degrees P wort. We used the probes derived from Saccharomyces cerevisiae genomic DNA on the chip and RNA isolated from three stages of brewing. This analysis shows a high level of expression of genes involved in fatty acid and ergosterol biosynthesis early in fermentation. Furthermore, genes involved in respiration and mitochondrial protein synthesis also show higher levels of expression.


CONCLUSIONS
Surprisingly, we observed a complete repression of many stress response genes and genes involved in protein synthesis throughout the 8-day period compared with that at the start of fermentation.


CONCLUSIONS
This microarray data set provides an analysis of gene expression under brewing fermentation conditions. The data provide an insight into the various metabolic processes altered or activated by brewing conditions of growth. This study leads to future experiments whereby selective alterations in brewing conditions could be introduced to take advantage of the changing transcript profile to improve the quality of the brew.
James
T C
TC
Moyne Institute for Preventive Medicine, Microbiology Department, Trinity College, University of Dublin, Dublin 2, Ireland.
Campbell
S
S
Donnelly
D
D
Bond
U
U
D000693:Anaerobiosis / Q000235:genetics; D003470:Culture Media; D000431:Ethanol / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005285:Fermentation; D015870:Gene Expression / Q000235:genetics*; D005800:Genes, Fungal / Q000235:genetics; D006003:Glycogen / Q000378:metabolism; D006019:Glycolysis / Q000235:genetics; D008320:Maltose / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics; D024101:Mitochondrial Proteins / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D011773:Pyruvates / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D013261:Sterols / Q000378:metabolism; D014158:Transcription, Genetic; D014233:Tricarboxylic Acids / Q000378:metabolism
D003470:Culture Media; D005230:Fatty Acids, Nonesterified; D024101:Mitochondrial Proteins; D011773:Pyruvates; D013261:Sterols; D014233:Tricarboxylic Acids; D000431:Ethanol; D008320:Maltose; D006003:Glycogen