IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Unravelling the microbial community structure and aroma profile of Agiorgitiko wine under different inoculation schemes

Unravelling the microbial community structure and aroma profile of Agiorgitiko wine under different inoculation schemes

Abstract

Agiorgitiko (Vitis vinifera L. cv.) is the most widely cultivated indigenous red grape variety in Greece, known for the production of Protected Designation of Origin Nemea wines. The aim of the present study was to evaluate five different combinations of yeast starters, previously isolated from spontaneous alcoholic fermentation of the same grape variety, for their oenological potential in terms of fermentation predominance and capacity as well as aromatic contribution to Agiorgitiko wine production. Grapes from the Nemea region, crashed and pressed, were inoculated with different yeast species/strains in pure and mixed cultures.  In particular, wines were produced in duplicate with the addition of (A) Saccharomyces cerevisiae SFA1, (B) S. cerevisiae SFA2, (C) S. cerevisiae SFA3, (D) S. cerevisiae SFA3, Hanseniaspora opuntiae SFB1 and (E) S. cerevisiae SFA3, H. opuntiae SFB1, H. opuntiae SFB2 and Hanseniaspora uvarum SFC1. At specific time points during the alcoholic fermentation, amplicon-based metagenomics analysis was employed to unravel the microbial community structure at the genus level. In the end of the fermentation process oenological parameters including volatile acidity, residual sugars and ethanol were determined according to the OIV protocols while the volatile compounds produced were measured by GC/MS. Finally, all produced wines were evaluated  by quantitative descriptive analysis. As expected, Saccharomyces dominated the yeast/fungal microbiota of the A-C wine samples throughout fermentation, followed by Aspergillus, Cladosporium and Aureobasidium, mainly at the early fermentation stage. In D and E wine samples, although Hanseniaspora was the predominant genus in early fermentation, the relative abundance of Saccharomyces rapidly increased and dominated until the end of the fermentation. Compared to yeast/fungi, bacterial community was characterized by a quite higher diversity. Although similar genera were identified in all wine samples (A-E), e.g. Bacillus, Oenococcus, Lactococcus, Staphylococcus and Acinetobacter, their relative abundances varied depending on the sample and fermentation stage. As far as the volatile profile was concerned, the GC/MS analysis revealed that the use of different species/yeasts modified the flavor and aroma of the produced wines. More specifically, exceptional amounts of higher alcohols and medium-chain fatty acid esters (known for their floral and fruity contribution) were observed in the co-inoculated wines (D and E), resulting in a more distinct and intense aromas. According to sensory evaluation the co-inoculation with three different yeast species (wine sample E) significantly increased the aromatic typicity characterized by red fruits aromas. Understating the microbial community structure during the alcoholic fermentation could lead to higher quality wine product and constitute a strong tool to direct wine sensory traits

Acknowledgments

This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call “Greece – Israel Call for Proposals for Joint R&D Projects 2019” (project code: T10ΔΙΣ-00060).

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Dimopoulou Maria¹, Kazou Maria², Drosou Fotini¹, Sellas Vassilis¹, Dourtoglu Vassilis¹ and Tsakalidou Effi²

¹Department of Wine, Vine, and Beverage Sciences, School of Food Science, University of West Attica, Athens, Greece
²Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece

Contact the author

Keywords

amplicon-based metagenomics analysis, wine aromas, regional yeast, Agiorgitiko

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Climate projections over France wine-growing region and its potential impact on phenology

Climate change represents a major challenge for the French wine industry. Climatic conditions in French vineyards have already changed and will continue to evolve. One of the notable effects on grapevine is the advancing growing season. The aim of this study is to characterise the evolution of agroclimatic indicators (Huglin index, number of hot days, mean temperature, cumulative rainfall and number of rainy days during the growing season) at French wine-growing regions scale between 1980 and 2019 using gridded data (8 km resolution, SAFRAN) and for the middle of the 21th century (2046-2065) with 21 GCMs statistically debiased and downscaled at 8 km. A set of three phenological models were used to simulate the budburst (BRIN, Smoothed-Utah), flowering, veraison and theoretical maturity (GFV and GSR) stages for two grape varieties (Chardonnay and Cabernet-Sauvignon) over the whole period studied. All the French wine-growing regions show an increase in both temperatures during the growing season and Huglin index. This increase is accompanied by an advance in the simulated flowering (+3 to +9 days), veraison (+6 to +13 days) and theoretical maturity (+6 to +16 days) stages, which are more noticeable in the north-eastern part of France. The climate projections unanimously show, for all the GCMs considered, a clear increase in the Huglin index (+662 to 771 °C.days compared to the 1980-1999 period) and in the number of hot days (+5.6 to 22.6 days) in all the wine regions studied. Regarding rainfall, the expected evolution remains very uncertain due to the heterogeneity of the climates simulated by the 21 models. Only 4 regions out of 21 have a significant decrease in the number of rainy days during the growing season. The two budburst models show a strong divergence in the evolution of this stage with an average difference of 18 days between the two models on all grapevine regions. The theoretical maturity is the most impacted stage with a potential advance between 40 and 23 days according to wine-growing regions.

The combined effects of climate, soils, and deficit irrigation on yield and quality of Touriga Nacional under high atmospheric demand in the Douro Region

Global warming is one of the biggest environmental, social and economic threats in several viticultural regions. In the Douro Valley, changes are expected in the coming years, namely an increase in temperature and a decrease in precipitation. These changes are likely to have consequences for the production and quality of wine.
The aim of this study was to explore the effects of different soil characteristics combined with several deficit irrigation strategies, managed throughout ETc references and predawn leaf water potentials thresholds, on physiology, yield, and qualitative attributes on the Touriga Nacional variety under years of mild to severe water and heat stress.
The studies were conducted over seven years (2015 to 2021) in two plots of a commercial vineyard located at Quinta do Ataíde (Symington Family Estates) planted in 2011 and 2014 at 170 meters elevation, growing under three water regimes: non-irrigated (NI) and two deficit irrigation strategies (30% and 60% ETc) assessed weekly by Ψpd. The site has an annual rainfall below 500 mm, with high atmospheric demand. Climate data was collected from a weather station, located on site. Berry ripening was followed weekly for fruit analysis. At harvest, yield, vigour and pruning weight per vine were determined from 90 vines by treatment. Each season at veraison the NDVI Index was accessed by a drone. The soils physic-chemistry in the experimental blocs were analysed and grouped by SWHC. Delta C-13 analyses were also performed per treatment in two years.Irrigation had a positive effect on yield per vine, mostly due to an increase in berry and cluster weight, and fertility index through the years. A significant increase in sugar content, colour and phenols was observed with deficit irrigation in some years, but vine vigour related to soil characteristics had by far the greatest impact on quality.

Influence of agronomic practices in soil water content in mid-mountain vineyards

In the context of LIFE project MIDMACC (LIFE18 CCA/ES/001099), several pilots have been installed in vineyards in mid mountain areas of Catalonia (NE Spain) to test well stablished agronomic practices to increase the adaptation of Mediterranean mid mountain to climate change. Soil water content (SWC) at three different depths (15, 30 and 45cm) was measured in continuum from August 2020. One pilot (WC) included a well-established green cover (GC), a new GC (NC) and a conventional soil management (CM, tilling+herbicides). NC presented an intermediate state between WC and CM, responding similarly to CM in autumn but quickly reaching similar SWC to WC, then following the same evolution till next spring, with CM presenting lower values along autumn and winter. Then vegetation activation decreased SWC in all plots, (much slower in CM, lacking GC). Sensibility to spring rains is again intermediate for NC, which joins SWC evolution of CM by the end of spring till next autumn. It is expected that NC will resemble WC more and more as its GC develops. In the pilot combining vine training (VSP vs Gobelet) and hillside management (slope vs terrace), no clear pattern could be related with these conditions. However, both terraces seem to be more sensitive to spring rains. A third pilot included new vineyards (7 and 1 year old). In the new vineyard (N), higher canopy development, a spontaneous green cover and row straw resulted in a slower SWC dynamic, not so sensitive to rains but conserving more soil water in spring and most of summer, even with presumably a higher water extraction by vines. In the newest vineyard (VN) the deepest sensor is still sensitive to rain events all over the year and SWC is always highest at this depth, revealing small water capture by vines.

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.

Adapting the vineyard to climate change in warm climate regions with cultural practices

Since the 1980s global regime shift, grape growers have been steadily adapting to a changing climate. These adaptations have preserved the region-climate-cultivar rapports that have established the global trade of wine with lucrative economic benefits since the middle of 17th century. The advent of using fractions of crop and actual evapotranspiration replacement in vineyards with the use of supplemental irrigation has furthered the adaptation of wine grape cultivation. The shift in trellis systems, as well as pruning methods from positioned shoot systems to sprawling canopies, as well as adapting the bearing surface from head-trained, cane-pruned to cordon-trained, spur-pruned systems have also aided in the adaptation of grapevine to warmer temperatures. In warm climates, the use of shade cloth or over-head shade films not only have aided in arresting the damage of heat waves, but also identified opportunities to reduce the evapotranspiration from vineyards, reducing environmental footprint of vineyard. Our increase in knowledge on how best to understand the response of grapevine to climate change was aided with the identification of solar radiation exposure biomarker that is now used for phenotyping cultivars in their adaptability to harsh environments. Using fruit-based metrics such as sugar-flavonoid relationships were shown to be better indicators of losses in berry integrity associated with a warming climate, rather than solely focusing on region-climate-cultivar rapports. The resilience of wine grape was further enhanced by exploitation of rootstock × scion combinations that can resist untoward droughts and warm temperatures by making more resilient grapevine combinations. Our understanding of soil-plant-atmosphere continuum in the vineyard has increased within the last 50 years in such a manner that growers are able to use no-till systems with the aid of arbuscular mycorrhiza fungi inoculation with permanent cover cropping making the vineyard more resilient to droughts and heat waves. In premium wine grape regions viticulture has successfully adapted to a rapidly changing climate thus far, but berry based metrics are raising a concern that we may be approaching a tipping point.