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Influence of carbon and nitrogen source on production of volatile fragrance and flavour metabolites by the yeast Kluyveromyces marxianus
Author(s) -
Gethins Loughlin,
Guneser Onur,
Demirkol Aslı,
Rea Mary C.,
Stanton Catherine,
Ross R. Paul,
Yuceer Yonca,
Morrissey John P.
Publication year - 2015
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/yea.3047
Subject(s) - kluyveromyces marxianus , isoamyl acetate , isoamyl alcohol , yeast , fusel alcohol , biology , biochemistry , kluyveromyces , ethyl acetate , isobutanol , food science , fermentation , chemistry , saccharomyces cerevisiae , alcohol
The yeast Kluyveromyces marxianus produces a range of volatile molecules with applications as fragrances or flavours. The purpose of this study was to establish how nutritional conditions influence the production of these metabolites . Four strains were grown on synthetic media, using a variety of carbon and nitrogen sources and volatile metabolites analysed using gas chromatography–mass spectrometry (GC–MS). The nitrogen source had pronounced effects on metabolite production: levels of the fusel alcohols 2‐phenylethanol and isoamyl alcohol were highest when yeast extract was the nitrogen source, and ammonium had a strong repressing effect on production of 2‐phenylethyl acetate. In contrast, the nitrogen source did not affect production of isoamyl acetate or ethyl acetate, indicating that more than one alcohol acetyl transferase activity is present in K. marxianus. Production of all acetate esters was low when cells were growing on lactose (as opposed to glucose or fructose), with a lower intracellular pool of acetyl CoA being one explanation for this observation. Bioinformatic and phylogenetic analysis of the known yeast alcohol acetyl transferases ATF1 and ATF2 suggests that the ancestral protein Atf2p may not be involved in synthesis of volatile acetate esters in K. marxianus , and raises interesting questions as to what other genes encode this activity in non‐ Saccharomyces yeasts. Identification of all the genes involved in ester synthesis will be important for development of the K. marxianus platform for flavour and fragrance production. Copyright © 2014 John Wiley & Sons, Ltd.