OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 OENO IVAS 9 OENO IVAS 2019 9 Grape and wine microorganisms: diversity and adaptation 9 Nitrogen metabolism in Kluyveromyces marxianus and Saccharomyces cerevisiae: towards a better understanding of fermentation aroma production

Nitrogen metabolism in Kluyveromyces marxianus and Saccharomyces cerevisiae: towards a better understanding of fermentation aroma production

Abstract

During wine alcoholic fermentation, yeasts produce volatile aroma compounds from sugar and nitrogen metabolism. Some of the metabolic pathways leading to these compounds have been known for more than a century. Yet, the differences in compound yield and nature between species remain poorly understood. Using a two-pronged approach of isotopic filiation and transcriptome analysis, this study endeavoured to shed new light on the utilisation of nitrogen sources by two wine-related yeast species, Saccharomyces cerevisiae Lalvin EC1118® (Lallemand) and Kluyveromyces marxianus IWBT Y885. 

The data showed that, although the order and intensity of uptake of nitrogen sources was broadly similar, those of ammonium and arginine differed. Furthermore, the utilisation of assimilated amino acids also differed significantly. While S. cerevisiae redistributed the nitrogen in these amino acids evenly for the production of other amino acids, K. marxianus clearly favoured specific amino acids. As for amino acids used as substrates for the production of aroma compounds, the fate of leucine and valine did not differ significantly between the two species. However, phenylalanine metabolism differed, and a larger proportion of phenylalanine was channelled through the Ehrlich pathway in K. marxianus, resulting in increased production of phenylethanol. Transcriptome data suggest that this shift can be explained by the higher expression of aromatic amino transferases in K. marxianus. Taken together, the data show that metabolic pathways are broadly conserved, but that individual nitrogen sources are not always assimilated and metabolised in identical ways. The study also provides new insights on the modulation of fermentative aroma profiles by yeast species of commercial interest.

DOI:

Publication date: June 10, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Benoit Divol, Stephanie Rollero, Audrey Bloem, Anne Ortiz-Julien, Florian Bauer, Carole Camarasa

Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa

Contact the author

Keywords

Nitrogen metabolism, Kluyveromyces marxianus, Saccharomyces cerevisiae, Fermentative aroma compounds 

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Sparkling wines and atypical aging: investigating the risk of refermentation

Sparkling wine (SW) production entails a two-steps process where grape must undergoes a primary fermentation to produce a base wine (BW) which is then refermented to become a SW. This process allows for the development of a new physicochemical profile characterized by the presence of foam and a different organoleptic profile.

Influence of toasting oak wood on ellagitannin structures

Ellagitannins (ETs) have been reported to be the main phenolic compounds found in oak wood. These compounds, belonging to the hydrolysable tannin class of polyphenols, are esters of hexahydroxydiphenic acid (HHDP) and a polyol, usually glucose or quinic acid. They own their name to their capacity to be hydrolysed and liberate ellagic acid and they have an impact on astringency and bitterness sensation, which is strongly dependant on their structure. The toasting phase is particularly crucial in barrels fabrication and influences wood composition.

New acylated flavonols identified in the grape skin of Vitis vinifera cv. Tannat and their wines

Flavonols are a class of flavonoid compounds derived from plant secondary metabolism. There they play different roles like antioxidants, internal regulators and UV screenings. In red wines, flavonols have increasingly received consideration by part of scientific and winemakers according their properties began to arise known. Among these stand out wine colour stabilization and their value as bioactive compounds. In this work the complete series of the acetylated and p-coumaroylated derivatives of the 3-O-glycosides of methoxylated flavonols, namely isorhamnetin, laricitrin and syringetin, have been identified in grapes and their respective wines from Vitis vinifera cv. Tannat.

Caratterizzazione vitivinicola delle “Terre del Piacenziano” ricomprese nella zona D.O.C. “colli piacentini” attraverso l’analisi sensoriale dei vini prodotti

I territori della Riserva Geologica del Piacenziano sono parte del pedeappennino piacentino e sono noti per essere la culla del Pliocene, quel periodo di storia della Terra compreso tra 5.3 e 1.8 milioni di anni fa. Gli strati argillosi e sabbiosi riccamente fossiliferi qui presenti sono da sempre oggetto di studi geo-paleontologici tant’è che il Pliocene medio (3.6-2.6 milioni di anni fa) è internazionalmente noto come Piacenziano. Le analisi sensoriali strutturate dei vini qui prodotti hanno evidenziato, soprattutto per il vino Monterosso, le positive peculiarità dei loro caratteri sensoriali e descritto gli scostamenti significativi del loro profilo sensoriale rispetto agli altri vini presi a riferimento.