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Appl Microbiol Biotechnol

Title:		Combined effects of nutrients and temperature on the production of fermentative aromas by Saccharomyces cerevisiae during wine fermentation
Author(s):		Rollero S; Bloem A; Camarasa C; Sanchez I; Ortiz-Julien A; Sablayrolles JM; Dequin S; Mouret JR;
Address:		"INRA, UMR1083, 34060, Montpellier, France"
Journal Title:		Appl Microbiol Biotechnol
Year:		2015
Volume:		20141121
Issue:		5
Page Number:		2291 - 2304
DOI:		10.1007/s00253-014-6210-9
ISSN/ISBN:		1432-0614 (Electronic) 0175-7598 (Linking)
Abstract:		"Volatile compounds produced by yeast during fermentation greatly influence the organoleptic qualities of wine. We developed a model to predict the combined effects of initial nitrogen and phytosterol content and fermentation temperature on the production of volatile compounds. We used a Box-Behnken design and response surface modeling to study the response of Lalvin EC1118(R) to these environmental conditions. Initial nitrogen content had the greatest influence on most compounds; however, there were differences in the value of fermentation parameters required for the maximal production of the various compounds. Fermentation parameters affected differently the production of isobutanol and isoamyl alcohol, although their synthesis involve the same enzymes and intermediate. We found differences in regulation of the synthesis of acetates of higher alcohols and ethyl esters, suggesting that fatty acid availability is the main factor influencing the synthesis of ethyl esters whereas the production of acetates depends on the activity of alcohol acetyltransferases. We also evaluated the effect of temperature on the total production of three esters by determining gas-liquid balances. Evaporation largely accounted for the effect of temperature on the accumulation of esters in liquid. Nonetheless, the metabolism of isoamyl acetate and ethyl octanoate was significantly affected by this parameter. We extended this study to other strains. Environmental parameters had a similar effect on aroma production in most strains. Nevertheless, the regulation of the synthesis of fermentative aromas was atypical in two strains: Lalvin K1M(R) and Affinity ECA5, which produces a high amount of aromatic compounds and was obtained by experimental evolution"
Keywords:		Fermentation Nitrogen/*metabolism Phytosterols/*metabolism Saccharomyces cerevisiae/*growth & development/*metabolism/radiation effects Temperature Volatile Organic Compounds/*metabolism Wine/*microbiology;
Notes:		"MedlineRollero, Stephanie Bloem, Audrey Camarasa, Carole Sanchez, Isabelle Ortiz-Julien, Anne Sablayrolles, Jean-Marie Dequin, Sylvie Mouret, Jean-Roch eng Research Support, Non-U.S. Gov't Germany 2014/11/22 Appl Microbiol Biotechnol. 2015 Mar; 99(5):2291-304. doi: 10.1007/s00253-014-6210-9. Epub 2014 Nov 21"