Terroir 2020 banner
IVES 9 IVES Conference Series 9 How a microscopic yeast makes a big difference – how geographic limitations of yeast populations can determine the regional aroma of wine

How a microscopic yeast makes a big difference – how geographic limitations of yeast populations can determine the regional aroma of wine

Abstract

Aim: Microbial biogeography contributes to regional distinctiveness of agricultural products and is important to determine for quality and marketing of wine products. We evaluated the microbial influence on wine characteristics by considering the microbial diversity of soil, plant, grapes, must and wine in grapegrowing regions across Victoria, Australia. 

Methods and Results: We sampled soils, plant parts, grapes, must and wine across vineyards in Victoria. We extracted DNA for microbial diversity profiling of fungi and bacteria and used gas chromatography- mass spectrometry to separate and identify small molecules in the headspace of wine. At a large scale (~400km), we found that vineyard ecosystems are structured and distinguished by fungal communities, and that fungal communities were the strongest contributor to the aroma of wine. Further studies considered a smaller scale of microbial diversity and investigated the changes in fungal community composition and diversity during the annual growth cycle of the grapevine. We found that fungal ecology is dependent on the grapevine habitat (roots, leaves, flowers/fruit) and developmental stage during the annual growth cycle. The influence of microbial biogeographic patterns decreased during wine fermentation as the fungal populations were dominated by Saccharomyces spp. yeasts. Further investigation of the strain diversity of Saccharomyces cerevisiae showed that this yeast can determine geographic patterns at a small scale and determines regional distinctiveness to influence wine characteristics within a single region. 

Conclusions:

Our results show that microbial distribution patterns seen in vineyards in Europe, North America and New Zealand are also observed in Australia, but the composition of yeasts may be distinct. The ability to define a region based on microbial diversity and fermentative yeasts may assist the industry in more closely defining sub-regions in Australia.

Download the PDF

DOI:

Publication date: March 17, 2021

Issue: Terroir 2020

Type: Video

Authors

Di (Echo) Liu1, Pangzhen Zhang1, Qinglin Chen1, Jean-Luc Legras2, Deli Chen1, Kate Howell1*

1School of Agriculture and Food, University of Melbourne, Parkville 3010 Australia
2UMR SPO, INRAE, Montpellier France

Contact the author

Keywords

Fungal ecology, yeast, wine aroma 

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Assessment of the optimal number of observations in the study of vineyard soil (Rigosol)

A study of soil pH on the experimental field resulted in a high variability of pH on a very small scale. This kind of heterogenity in soil pH have effects on growth of two grapevine varieties on rootstock Kober 5BB

Read More

Descriptive analysis of Sangiovese and Cabernet-Sauvignon wines from different terroirs in D.O.C. Bolgheri (Tuscany)

Different terroirs have been identified in Bolgheri area (a viticultural appellation in the Tirrenian coast of Tuscany) by the aid of pedological, landscape and agronomic observations in 1993. Numerous preliminary observations suggested that wines obtained from these different terroirs were unique.

Read More

Biosurfactant from corn-milling industry improves the release of phenolic compounds during red winemaking

AIM: Biosurfactants can be used as emulsifier agents to improve the taste, flavour, and quality of food-products with minimal health hazards [1]. They are surface-active compounds with antioxidant and solubilizing properties [2].

Read More

Residual copper quantification on grapevine’s organs

Copper is listed among the active substances candidates for substitution (Regulation EU 2015/408). Yet still, because of the lack of valid alternatives, the European Commission recently confirmed its usage authorization by limiting the maximum amount to 28 Kg per hectare in 7 years, i.e. an average of 4 kg/year (Reg. EU 2018/1981).This restriction is due to copper accumulation in soils and surface waters both caused by a steady application, especially on perennial crops (Riepert et al., 2013). The aim of this work is to determine if treatments with reduced copper dosages are able to reach different grapevine’s organs, with particular focus on the core of bunches, and if these small amounts can ensure the respect of the legislative prescription, without compromising the phytosanitary conditions of the vineyards, thus grape yields.

Read More

Depletion Of Vine-Shoots Phenolic Composicion After Being Used As An Enological Tool For Wine Differentiation

Pruning vine-shoots are a viticulture waste that have been traditionally poorly exploited in relation to its chemical minority composition related to phenolic and volatile compounds. In this line, toasted vine-shoots supposes a proposal of enological tool to use to modulate the chemical and sensorial profile of wines. From a phenolic point of view, when vine-shoots are used during winemaking mainly influence to increase the flavanols and stilbenes content, mostly trans-resveratrol, as also an increasing in the sweet tannins and decreasing the green character and total anthocyanins, changing the violet for garnet colour.

Read More