Terroir 2020 banner
IVES 9 IVES Conference Series 9 Microbial metagenomics of vineyard soils and wine terroir

Microbial metagenomics of vineyard soils and wine terroir

Abstract

Aims: The aims of this study were to (i) characterize bacterial and fungal communities in selected Australian vineyard soils and (ii) determine if the soil microbiome composition and diversity varied between different zones within a vineyard. 

Rationale: The soil on which vines are grown has been suggested to impart a unique quality to the grapes and wine due to the physiological responses of the vines to soil type, topography and climatic conditions, in addition to their viticultural management. The influence of bacteria and fungi in wine fermentation is well known but little is known about the effect of soil microbes, other than microbial pathogens, on grape composition or their role in vintage or site (terroir) impacts on grape composition. 

Methods and Results: We investigated the potential relationships between soil microbiome composition measured using a metagenomic approach (16S rRNA and ITS region amplicon and metagenomic sequencing) and inherent spatial variation in grape metabolite composition, specifically the concentration of the ‘impact aroma compound’ rotundone in Shiraz grapes (Vitis vinifera L.) grown in vineyards in the Grampians region of Victoria and in the Adelaide Hills in South Australia. Results from the metagenomics analysis of surface soil samples collected from the previously identified ‘rotundone zones’ in a vineyard indicated marked differences in the genetic diversity and composition of the soil bacterial and fungal microbiomes of these zones. Soils from the high rotundone zone exhibited higher diversity of bacteria, but lower diversity of fungi, compared to the soils in the Low rotundone zone. In addition, the network analysis of the microbial community in the High rotundone zone soils appeared well structured, especially with respect to the bacterial community, compared to that in the Low rotundone zone soils. A few specific taxa/groups of microorganisms e.g. Acidobacteria-GP4 and GP7, Rhizobiales, Burkholdiales, Gaiellales, Alphaproteobacteria and the Nectriaceae and Tremellaceae families of fungi, were associated with the rotundone-based variation. Short-term mulching effects did not seem to mask the rotundone zone-based variation. Predictive functional profiling using 16S rRNA marker gene sequences, FAPROTAX-based analysis indicated differences in functional categories such as manganese oxidation, methylotrophy, methanotrophy, oxidation of sulfur compounds. These findings suggest that the observed taxonomic variation needs to be translated into functional aspects of soil microbiome before mechanistic links to rotundone concentrations can be established.

Conclusions:  

Distinct differences in soil bacterial and fungal community composition and structure in different zones within the same vineyard are associated with different propensities for grape berry rotundone concentration. Also, high rotundone zone soil exhibited a well-connected microbial community network by comparison with the Low rotundone zone soil.

Significance and impact of the Study: These findings of a systematic rotundone zone-based variation in soil microbiomes paves the way to bring together understanding of microbial ecology and viticultural management for improved grape composition and wine flavour (terroir).

Download the PDF

DOI:

Publication date: March 17, 2021

Issue: Terroir 2020

Type: Video

Authors

Vadakattu Gupta1, Rob Bramley1, Paul Greenfield2, Julian Yu3, Markus Herderich4

1CSIRO Ag & Food, Urrbrae, SA, Australia 
2CSIRO Energy, North Ryde, NSW, Australia 
3Arizona State University, Arizona, USA 
4AWRI, Urrbrae, SA, Australia

Contact the author

Keywords

Rotundone, microbiome diversity, bacteria, fungi, grapes

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Uncovering the interplay between Copper and SO2 tolerance in Saccharomyces cerevisiae

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.20.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...
Read More

Promoting sustainability in Mediterranean agriculture: insights from the Portuguese vine & wine sector

Agroecology is an integrated approach that simultaneously applies ecological and social concepts and principles to redesign and manage food and agricultural systems, promoting agroecosystems with the necessary biological, socio-economic, and institutional diversity and alignment to support greater efficiency. Thus, several studies have been carried out at promoting the adoption of more agroecological practices among farmers and a wider audience concerning soil conservation and health maintenance.

Read More

Changes in grape-associated microbiome as a consequence of post-harvest withering

AIM: Grape withering is an oenological post-harvest process used for production of reinforced and sweet wines. Drying can be carried out by keeping the ripe grape in traditional large, well-aired rooms (non-controlled environment) or, more and more often, in a warehouse under controlled conditions of airflow and relative humidity (controlled environment)[1].

Read More

Bioanalytical workflow for exploring the chemical diversity and antioxidant capacity of grape juice peptides

The oxidative stability of white wines is related to a flow of chemical reactions involving a number of native wine containing compounds composing their antioxidant metabolome.

Read More

VINIoT – Precision viticulture service

The project VINIoT pursues the creation of a new technological vineyard monitoring service, which will allow companies in the wine sector in the SUDOE space to monitor plantations in real time and remotely at various levels of precision. The system is based on spectral images and an IoT architecture that allows assessing parameters of interest viticulture and the collection of data at a precise scale (level of grape, plant, plot or vineyard) will be designed. In France, three subjects were specifically developed: evaluation of maturity, of water stress, and detection of flavescence dorée. For the evaluation of maturity, it has been decided first to work at the berry scale in the laboratory, then at the bunch scale and finally in the vineyard. The acquisition of the spectral hyperstal image as well as the reference analyzes to measure the maturity, were carried out in the laboratory after harvesting the berries in a maturity monitoring context. This work focuses on a case study to predict sugar content of three different grape varieties: Syrah, Fer Servadou and Mauzac. A robust method called Roboost-PLSR, developed in the framework of this work (Courand et al., 2022), to improve prediction model performance was applied on spectra after the acquirement of hyperspectral images. Regarding the evaluation of water stress, to work with a significant variability in terms of water status, it has been worked first with potted plants under 2 different water regimes. The facilities have allowed the supervision of irrigation and micro-climatic conditions. The regression models on agronomic variables (stomatal conductance, water potential, …) are studied. To detect flavescence dorée, the experimental plan has consisted of work at leaf scale in the laboratory first, and then in the field. To detect the disease from hyper-spectral imaging, a combination of multivariate curve resolution-alternating least squares (MCR-ALS) and factorial discriminant analysis (FDA) was proposed. This strategy proved the potential towards the discrimination of healthy and infected leaves by flavescence dorée based on the use of hyperspectral images (Mas Garcia et al., 2021).

Read More