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.

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…

Implication of secondary viral infections on grafting success rated in nurseries

Grapevine grafting is a complex process that since the establishment of phylloxera has become mandatory for grapevine. Grafting success in grapevine nurseries considerably varies among years and batches with most variety/rootstock combinations reach a high success rate (between 75% and 90%), but some combinations show lower success rates of around 40-50%. The causes of this variation are unknown, although biotic stresses like those caused by some viral infections have been demonstrated to affect the process. European certification schemes for the vegetative propagation of the vine include five major viruses (Arabis mosaic virus, Grapevine Fanleaf Virus, Grapevine Fleck Virus, and Grapevine-associated Leafroll Virus 1 and 3).

AGEING BOTTLED WINES SUBMERGED IN SEA: DOES IT IMPACT WINE COMPOSITION?

Aging wines is a common practice in oenology, which in recent years has undergone some innovations. Currently, we are witnessing the practice of aging bottled wine in depth, immersed in the sea or in reservoirs, for variable periods of time, but so far, little is known about the impact of aging in depth on the physicochemical properties, of wines.
The objective of this work was to evaluate the impact of this practice on the physicochemical characteristics, in particular to verify changes in the volatile composition of wines bottled and subsequently immersed in depth. A red wine from Cabernet Sauvignon was bottled and a set of bottles were submerged from July to February (2020), another set of bottles were submerged from February to September (2020) and another set was kept in the wine cellar. Bottles from each set were analyzed (in triplicate) in July 2021.

Exploring the regulatory role of the grapevine MIXTA homologue in cuticle formation and abiotic stress resilience

The outer waxy layer of plant aerial structures, known as the cuticle, represents an important trait that can be targeted to increase plant tolerance against abiotic stresses exacerbated by environmental transition. The MIXTA transcription factor, member of the R2R3-MYB family, is known to affect conical shape of petal epidermal cells in Anthirrinum, cuticular thickness in tomato fruit and trichome formation and morphology in several crops. The aim of this study was to investigate the role of the grapevine MIXTA homologue by phenotypic and molecular characterization of overexpressing and knock-out grapevine lines.

Nuove tecnologie per la viticoltura in zone di alto valore ambientale

Gli autori presentano gli ultimi risultati delle ricerche dei DIAF sulla meccanizzazione delle operazioni colorali in zone di difficile accesso e transitabilità quali le aree marginali, i terreni terrazzati e altre realtà agricole caratterizzate da spazi estremamente ristretti (vivaismo, orticoltura, ecc.).

La vinicultura en regiones tropicales Brasileras

La producción mundial de uvas para mesa es obtenida de viñedos localizados entre los paralelos 30 y 50º Latitud Norte y 30 y 40º Latitud Sur.