Macrowine 2021
IVES 9 IVES Conference Series 9 Response of different nitrogen supplementation on Saccharomyces cerevisiae metabolic response and wine aromatic profile

Response of different nitrogen supplementation on Saccharomyces cerevisiae metabolic response and wine aromatic profile

Abstract

The wine yeast Saccharomyces cerevisiae can highly affect wine aromatic profile by producing and/or mediating the release of a whole range of metabolites (such as thiols, esters, and terpenes), which in turn contribute to enhanced aroma and flavor. These metabolites depend on yeast metabolism activated during fermentation which can constitute the ‘’metabolic footprint’’ of the yeast strain that carried out the process. The aim of the present research was to study the metabolism of S. cerevisiae under two different nitrogen supplementation status and to investigate the relative expression of specific genes, that are directly related to the biosynthesis of specific potent odornats such as, terpenes and esters. 

The commercial yeast strains 1X (S.cerevisiae) and 2X (S.cerevisiae x S.bayanus) were inoculated in Moschofilero (Vitis Vinifera L. cv) grape must under two different concentrations of yeast assimilable nitrogen (YAN), a  low at 150 mg/L and a high at 300 mg/L. The produced wines were analyzed for their standard enological parameters, their volatile composition by SPE/GC–MS analysis as well as for their sensory profile. Totally 8 fermentations trials, were realised in triplicate. The fermentation was monitored by measuring the optical density and sugar consumption. Metabolic response was tested through real-time RT-PCR of genes implicated in aroma production of esters and terpenes such as ATF1, ATF2, EEB1, EHT1, IAH1, BGL2, EXG1. Sampling for metabolites and gene expression analysis were taken at the time of inoculation, after 48 hours, when two thirds of the sugars were depleted and at the end of the alcoholic fermentation (< 2g/L rs).

In terms of the volatile characterization of the wines, esters, linalool and nerol appeared to be clearly distinct between the different levels of YAN, which confirms the specialization in volatile compounds production among different nitrogen concentration levels. For instance, linalool was found to be at 0.05 mg/L for low nitrogen concentration, while high nitrogen levels resulted to a concentration of 0.12 mg/L. Real-time-PCR results revealed that, in both cases of nitrogen implementation, the analyzed genes were found to be expressed mainly before the fermentation of the 70% of the sugars. In addition, an overexpression of the BGL2 gene, corresponded well to the linalool concentration found, was observed in case of high nitrogen condition. Also, the EHT1 was expressed five times higher in case of high nitrogen concentration. Finally, correlations between ethyl esters and EEB1, acetate esters and ATF2 (p<0.05) were also found in both cases. 

Our study revealed the impact of different nitrogen implementations on the volatile compounds and the relative expression of specific genes. Metabolic analysis of selected volatile components of the wine aroma in conjunction with transcriptional analyses provide a great approach to orient the fermentation process towards a desirable wine aromatic profile.

DOI:

Publication date: September 3, 2021

Issue: Macrowine 2021

Type: Article

Authors

Despina Lola, Chrysanthi KALLONIATI, Maria DIMOPOULOU, Maria Ioanna XENIA, Emmanouil FLEMETAKIS, Yorgos KOTSERIDIS

Laboratory of Oenology and Alcoholic Drinks (LEAD), Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece, Laboratory of Molecular Biology, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece, Department of Wine, Vine and Beverage Sciences, School of Food Science, University of West Attica, Greece, Laboratory of Oenology and Alcoholic Drinks  (LEAD), Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece Laboratory of Molecular Biology, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece, Laboratory of Enology and Alcoholic Drinks (LEAD), Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece

Contact the author

Keywords

yeast metabolism, yan, nitrogen supplementation, volatile profile, gene expression

Citation

Related articles…

First step in the preparation of a soil map of the Protected Designation of Origin Valdepeñas (Central, Spain)

This work is a first step to make a map of vineyard soils. The characterization of the soils of the Protected Designation of Origin (D.P.O.) Valdepeñas will allow to group the studied profiles according to their physico-chemical characteristics and the concentrations of most relevant chemical elements. 90 soil profiles were analysed throughout the territory and the soils were sampled and described according to FAO (2006) and classified according to and Soil Taxonomy (2014). All samples were air dried, sieved and some physico-chemical parameters were determined following standard protocols. Also, major and trace elements were analysed by X-ray fluorescence. The statistically study was made using the SPSS program. Trend maps were made using the ArcGIS program. The studied soils have the following average properties: pH, 8.3; electrical conductivity, 0,20 dS/m (low); clay, 18.8% (medium) and CaCO3, 17.1% (high). In the study for the major elements. The major elements of these soils are Si, followed by Ca and Al, with an average content of 203.7 g/kg, 105.5 g/kg and 74.0 g/kg respectively. On the other hand, 27 trace elements have been studied. Of all of them, it can be highlighted the average values of Ba (361.8 mg/kg), Sr (129.3 mg/kg), Rb (83.4 mg/kg), V (74.2 mg/kg) and Ce (70.6 mg/kg). Ba, V and Ce values are higher and the values of Sr and Rb are lower to those found in the literature. The discriminant analysis shows a percentage of grouping of 91%. The content of chemical elements together with the physico-chemical characteristics allows grouping the soils in 4 group according to their order in the classification to Soil Taxonomy; due to the importance of the Calcisols in Castilla-La Mancha, it has been decided to establish them as their own group even if they do not appear in Soil Taxonomy classification.

VineyardFACE: Investigation of a moderate (+20%) increase of ambient CO2 level on berry ripening dynamics and fruit composition

Climate change and rising atmospheric carbon dioxide concentration is a concern for agriculture, including viticulture. Studies on elevated carbon dioxide have already been on grapevines, mainly taking place in greenhouses using potted plants or using field grown vines under higher CO2 enrichment, i.e. >650 ppm. The VineyardFACE, located at Hochschule Geisenheim University, is an open field Free Air CO2 Enrichment (FACE) experimental set-up designed to study the effects of elevated carbon dioxide using field grown vines (Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon). As the carbon dioxide fumigation started in 2014, the long term effects of elevated carbon dioxide treatment can be investigated on berry ripening parameters and fruit metabolic composition.
The present study aims to investigate the effect on fruit composition under a moderate increase (+20%; eCO2) of carbon dioxide concentration, as predicted for 2050 on both Riesling and Cabernet Sauvignon. Berry composition was determined for primary (sugars, organic acids, amino acids) and secondary metabolites (anthocyanins). Special focus was given on monitoring of berry diameter and ripening rates throughout three growing seasons. Compared to previous results of the early adaptative phase of the vines [1], our results show little effect of eCO2 treatment on primary metabolites composition in berries. However, total anthocyanins concentration in berry skin was lower for eCO2 treatment in 2020, although the ratio between anthocyanins derivatives did not differ.
[1] Wohlfahrt Y., Tittmann S., Schmidt D., Rauhut D., Honermeier B., Stoll M. (2020) The effect of elevated CO2 on berry development and bunch structure of Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon. Applied Science Basel 10: 2486

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

Is wine terroir a valid concept under a changing climate?

The OIV[i] defines terroir as a concept referring to an area in which collective knowledge of the interactions between the physical and biological environment (soil, topography, climate, landscape characteristics and biodiversity features) and vitivinicultural practices develops, providing distinctive wine characteristics. Those are perceptible in the taste of wine, which drives consumer preference and, therefore, wine’s value in the marketplace. Geographical indications (GI) are recognized regulatory constructs formalizing and protecting the nexus between wine taste and the terroir generating it. Despite considering updates, GIs do not consider the nexus as a dynamic one and do not anticipate change, namely of climate. Being climate a fundamental feature of terroir, it strongly impacts wine characteristics, such as taste. According to IPCC[ii], many widespread, rapid and unprecedented changes of climate occurred, some being irreversible over hundreds to thousands of years. Climatic shifts and atmospheric-driven extreme events have been widely reported worldwide. Recent climatic trends are projected to strengthen in upcoming decades, whereas extremes are expected to increase in frequency and intensity, forcing wines away from GI definitions. Geographical shifts of viticultural suitability are projected, often moving into regions and countries different from current ones. Some authors propose adaptation in viticulture, winemaking and product innovation. We show evidence of climate changing wine characteristics in the Douro valley, home of 270-year-old Port GI. We discuss herein resist or adapt stances for when climate changes the nexus between terroir and wine characteristics. Using the MED-GOLD[iii] dashboard, a tool allowing for easy visual navigation of past and future climates, we demonstrate how policymakers can identify future moments, throughout the 21st century under different emission scenarios, when GI specifications will likely need updates (e.g., boundaries, varieties) to reduce climate-change impacts.