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Hydrogen sulphide production by bottom‐fermenting yeast is related to nitrogen starvation signalling
Author(s) -
Ogata Tomoo
Publication year - 2013
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/jib.96
Subject(s) - yeast , fermentation , saccharomyces cerevisiae , catabolite repression , biochemistry , gene , biology , chemistry , mutant
Bottom‐fermenting yeast subjected to nitrogen starvation during exponential growth were found to produce hydrogen sulphide. In order to investigate a possible relationship between nitrogen starvation and hydrogen sulphide production, bottom‐fermenting yeast strains, with depressed nitrogen starvation responses, were constructed by disrupting GLN3 and GAT1 , encoding transcription factors that activate the transcription of NCR (nitrogen catabolite repression)‐sensitive genes. In order to construct additional bottom‐fermenting yeast strains with depressed nitrogen starvation responses, DAL80 ‐, GZF3 ‐ and URE2 ‐overexpressing strains were also constructed as these genes are also involved in NCR, and repress transcription of NCR‐sensitive genes. Bottom‐fermenting yeast have two types of genes, those derived from Saccharomyces cerevisiae ‐type and S . bayanus ‐type genomes. Both types of genes were disrupted/overexpressed in the constructed strains. In wort fermentations, all of the constructed strains produced less hydrogen sulphide and less of the thiol off‐flavour compounds, 3‐methyl‐2‐butene‐1‐thiol and 2‐mercapto‐3‐methyl‐1‐butanol than the parent strains. Copyright © 2013 The Institute of Brewing & Distilling