Related Experiment Video
Updated: Jul 5, 2026

Workflow Based on the Combination of Isotopic Tracer Experiments to Investigate Microbial Metabolism of Multiple Nutrient Sources
Published on: January 22, 2018
Nitrogen catabolic repression controls the release of volatile thiols by Saccharomyces cerevisiae during wine
Cécile Thibon1, Philippe Marullo, Olivier Claisse
1Faculté d'oenologie, UMR1219, INRA, Université Bordeaux2, Talence, France.
Abstract:
Volatile thiols such as 4-methyl-4-sulfanylpentan-2-one (4MSP) and 3-sulfanylhexan-1-ol (3SH) are aromatic molecules having an important organoleptic impact on white wines. These components are produced from inodorous nonvolatile cysteinylated precursors by Saccharomyces cerevisiae metabolic activity during alcoholic fermentation. Here we provide a new insight into the genetic determinism of the production of volatile thiols by yeast. Using a gene deletion approach, we investigated the role of three yeast beta-lyases and demonstrate that Irc7p, a putative cystathionine beta-lyase, is one of the main proteins catalyzing the 4MSP and 3SH release under enological conditions. Moreover, we demonstrate that Ure2p/Gln3p proteins mainly control the bioconversion of volatile thiols by the transcriptional regulation of the IRC7 gene through the general mechanism of nitrogen catabolic repression. Finally, our findings suggest that the enantiomer balance of 3SH may be modulated by activating specifically stereoselective enzymes such as Irc7p.
More Related Videos
09:21Saccharomyces cerevisiae Metabolic Labeling with 4-thiouracil and the Quantification of Newly Synthesized mRNA As a Proxy for RNA Polymerase II Activity
Published on: October 22, 2018
08:03A Tandem Liquid Chromatography–Mass Spectrometry-based Approach for Metabolite Analysis of Staphylococcus aureus
Published on: March 28, 2017
Related Concept Videos
Bioreactor Controls-III
Microbes in Beverage Production
Riboswitches
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
Gene Regulation During Sporulation
Microbial Fermentation
Stringent Response in E. coli