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…

Blend wines made of Syrah, Marselan and Tannat, had better color and more phenolic diversity than varietal wines

Background: Elaborating red-wines from grape cultivars with different polyphenolic profiles could improve wine color and its phenolic-dependent characteristics

Read More

The challenge of improving oenological quality in favorable conditions for productivity

Marselan (Cabernet-Sauvignon x Grenache), has been planted for more than 20 years now in Uruguay. Due to its good agronomic and oenological aptitudes under uruguayan conditions, it is currently the red variety with highest plantation rate. The objective of the study was to identify management practices, aimed at improving quality in highly productive vineyards, different fruit/leaf regulation methods were tested in southern Uruguay.

Read More

Beyond liking scores: the importance of the drinking experience to understand our consumers

The presentation will approach the understanding of wine consumers´ perception based on the experiential model suggested by Warell (2008). In this framework, wine consumption gives rise to a
variety of experiences related to the perception, understanding, and judgment of the product. These
multidimensional facets of the drinking experience can be explored by measuring affective, cognitive,
and sensory responses of consumers, which are shown to be stable regardless of the social context.

Read More

Efficacy of tannins of different botanical origin as partial or total substitute of SO2 to preserve a Cortese white wine during storage in cellar

While SO2 is one of the oldest and widest additive used in enology for its well-known antioxidant, anti-laccase and antimicrobial properties, it can cause health problems in some individuals.

Read More

Reaction Mechanisms of Copper and Iron with Hydrogen Sulfide and Thiols in Model Wine

Fermentation derived sulfidic off-odors due to hydrogen sulfide (H2S) and low molecular weight thiols are commonly encountered in wine production and removed by Cu(II) fining. However, the mechanism underlying Cu(II) fining remains poorly understood, and generally results in increased Cu concentration that lead to deleterious reactions in finished wine. The present study describes a mechanistic investigation of the iron and copper mediated reaction of H2S, cysteine, 3-sulfanylhexan-1-ol, and 6-sulfanylhexan-1-ol with oxygen. The concentrations of H2S, thiols, oxygen, and acetaldehyde were monitored over time. It was found that Cu(II) was rapidly reduced by both H2S and thiols to Cu(I).

Read More