Macrowine 2021
IVES 9 IVES Conference Series 9 Screening of soil yeasts with fermentative capacity from the antarctic continent for their application in the wine industry

Screening of soil yeasts with fermentative capacity from the antarctic continent for their application in the wine industry

Abstract

AIM: In the last years, many wineries are increasing experimentation to produce more distinguishable beverages. In this sense, the reduction of the fermentation temperature could be a useful tool because it preserves volatile compounds and prevents wines from browning, particularly in the case of white wines. However, low fermentation temperatures usually produce an early stop in the fermentation. Hence, the employment of new yeast strains able to operate at low temperatures could solve this problem, giving rise to different characteristics in wines. The Antarctic Continent is a crucial source for the isolation of new microorganisms and bioactive metabolites, given the competitive conditions of this environment with low temperatures, scarce carbon sources and high UV radiation. Considering this, the objective of this study was the isolation and characterization of fermentative yeast from the Antarctic Continent with potential for use in the wine industry.

METHODOLOGY: Six soil samples collected in Fildes Bay, west of King George Island and three soil samples from King George Island were processed for yeast isolation. Samples were suspended in sterile water and dilutions of each suspension were inoculated onto yeast medium (YM) agar plates with antibiotics, which were then incubated at 4, 10, and 18 °C until visible colony growth. Colonies with a non-filamentous appearance were selected, which were reseeded on YM agar without antibiotics. Alcohol tolerance was performed using concentrations of 3, 6, or 9% alcohol. Later on, sugar tolerance was analyzed using fructose and glucose in a 1:1 proportion; with 5, 10, 15, 20, or 25% of sugar in the medium. Those isolates with microscopic characteristics of interest were selected to determine fermentative activity in vitro using a simple colorimetric assay with phenol red, as a pH indicator. To differentiate the isolates, and discard replicates, a fingerprinting assay with arbitrary primers was performed. Identification of the isolates was carried out using PCR and ITS region primers with BLAST bioinformatics tools.

RESULTS: Nine soil samples collected from the Antarctica were processed for yeast isolation. We obtained 125 yeasts from the soil samples, with a growth temperature of 10ºC. Overall, 25 yeasts have fermentative activity and are able to tolerate a culture medium with at least 20% glucose and up to 6% of ethanol. The isolates were also characterized by optical microscopy and fingerprinting using PCR with arbitrary primers to discard identical strains and allowed us to discriminate 10 unique strains with fermentative capacity from the 25 isolates. To determine the identity of the isolated yeasts, the amplification and sequence of the 18S RNA was performed.

CONCLUSION:

The Antarctic continent has proven to be a source of fermentative yeasts with high potential for their use in the wine industry.

DOI:

Publication date: September 3, 2021

Issue: Macrowine 2021

Type: Article

Authors

Laura Navarro, Cristina Úbeda, Mariona Gil i Cortiella, Ana Gutierrez, Gino Corsini, Nancy Calisto

Biomedical Sciences Institute, Health Sciences Faculty, Autonomous University of Chile, Santiago, Chile., Nutrition and Food Sciences Department, Faculty of Pharmacy, University of Seville, Seville, Spain. Applied Chemical Sciences Institute, Autonomous University of Chile, Santiago, Chile. Biomedical Sciences Institute, Health Sciences Faculty, Autonomous University of Chile, Santiago, Chile. Biomedical Sciences Institute, Health Sciences Faculty, Autonomous University of Chile, Santiago, Chile. Chemical engineering department, Faculty of Engineering, Magallanes University, Punta Arenas, Chile. Biomedical Sciences Institute, Health Sciences Faculty, Autonomous University of Chile, Santiago, Chile.

Contact the author

Keywords

antarctic yeast, low temperature fermentation, yeast isolation, yeast characterization

Citation

Related articles…

austrianvineyards.com: online viewer of all designations of Austrian wine

To digitally record and present all the origins of Austrian wines in the same perfect and clear way was the motivation for the Austrian Wine Marketing Board (Austrian Wine) to start with the project in 2018. In June 2021 the results were presented to the public in an online viewer showing all the designations of Austrian wine, available at https://austrianvineyards.com in a largely barrier-free manner. The online viewer provides tailored individual maps fitted to the respective zoom level. The smallest unit of wine-origins in Austria is called Ried and is displayed in a plot-specific manner highlighting areas under vine. Information on the Ried include administrative district, winegrowing municipality, cadastral municipality, large collective vineyard site, specific winegrowing region, generic winegrowing region, winegrowing area and, in many cases, an illustrative picture. Complementary data on the size, elevation (minimum-maximum), orientation (in 8 sectors plus flat) and gradient (minimum, maximum, average) are based on the area under vine according to the EU’s Integrated Administration and Control System. Additional information covers climate data. The diagrams are taken from the monthly breakdown of data in the annals of the Central Institute for Meteorology and Geodynamics, Austria provide a display of values for air temperature, precipitation, and sunshine hours for the reference year and the long-term average. Seasonal aggregated data on temperature, precipitation, and sunshine hours complete the display. Short descriptions with emphasis on geology and soil, field name in historical maps, etymology of the denomination, and main planted variety complements the available information for the main designations in the online viewer. These descriptions are compiled by winegrowers, geologists, historians, and journalists. All the information and data can be extracted to a pdf-file. Printed vineyard maps are also available. Missing content regarding wine origins in Styria will be completed in winter 2021/22.

Climate change impacts: a multi-stress issue

With the aim of producing premium wines, it is admitted that moderate environmental stresses may contribute to the accumulation of compounds of interest in grapes. However the ongoing climate change, with the appearance of more limiting conditions of production is a major concern for the wine industry economic. Will it be possible to maintain the vineyards in place, to preserve the current grape varieties and how should we anticipate the adaptation measures to ensure the sustainability of vineyards? In this context, the question of the responses and adaptation of grapevine to abiotic stresses becomes a major scientific issue to tackle. An abiotic stress can be defined as the effect of a specific factor of the physico-chemical environment of the plants (temperature, availability of water and minerals, light, etc.) which reduces growth, and for a crop such as the vine, the yield, the composition of the fruits and the sustainability of the plants. Water stress is in many minds, but a systemic vision is essential for at least two reasons. The first reason is that in natural environments, a single factor is rarely limiting, and plants have to deal with a combination of constraints, as for example heat and drought, both in time and at a given time. The second reason is that plants, including grapevine, have central mechanisms of stress responses, as redox regulatory pathways, that play an important role in adaptation and survival. Here we will review the most recent studies dealing with this issue to provide a better understanding of the grapevine responses to a combination of environmental constraints and of the underlying regulatory pathways, which may be very helpful to design more adapted solutions to cope with climate change.

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

Protected Designation of Origin (D.P.O.) Valdepeñas: classification and map of soils

The objective of the work described here is the elaboration of a map of the different types of vineyard soils that to guide the famers in the choice of the most productive vine rootstocks and varieties. 90 vineyard soils profiles were analysed in the entire territory of the Origen Denominations of Valdepeñas. The sampling was carried out in 2018 (June to October) by making a sampling grid, followed by photointerpretation and control in the field. The studied soils can be grouped into 9 different soil types (according to FAO 2006 classification): Leptosols, Regosols, Fluvisols, Gleysols, Cambisols, Calcisols, Luvisols and Anthrosols. A map showing the soil distribution with different type of soils has been made with the ArcGIS program. Regarding to the choice of rootstock, Calcisoles are soils with a high active limestone content, so the rootstocks used in these soils must be resistant to this parameter; Luvisols are deep soils with high clay content, so they will support vigorous rootstocks. Because the cartographic units are composed of two or more subgroups, with are associated in variable proportions, 9 different soil associations have been established; Unit 1: Leptosols, Cambisols and Luvisols (80%, 15% and 5% respectively); Unit 2: Cambisols with Regosols and Luvisols (40%, 30% and 30% respectively); Unit 3: Cambisols and Gleysols with Regosols (40%, 40% and 20% respectively); Unit 4: Regosols with Cambisols, Leptosols and Calcisols (40%, 30%, 15% and 15% respectively); Unit 5: Cambisols, Leptosols, Calcisols and Regosols (25% each of them); Unit 6: Luvisols with Cambisol and Calcisols (80%, 10% and 10% respectively); Unit 7: Luvisols and Calcisols with Cambisols (40%, 40% and 20% respectively); Unit 8: Calcisols with, Cambisols and Luvisols (80%, 10% and 10% respectively); Unit 9: Anthrosols. These study allow to elaborate the first map of vineyard soils of this Protected Designation of Origin in Castilla-La Mancha.

Mapping and tracking canopy size with VitiCanopy

Understanding vineyard variability to target management strategies, apply inputs efficiently and deliver consistent grape quality to the winery is essential. However, despite inherent vineyard variability, the majority are managed as if they are uniform. VitiCanopy is a simple, grower-friendly tool for precision/digital viticulture that allows users to collect and interpret objective spatial information about vineyard performance. After four years of field and market research, an upgraded VitiCanopy has been created to achieve a more streamlined, technology-assisted vine monitoring tool that provides users with a set of superior new features, which could significantly improve the way users monitor their grapevines. These new features include:
• New user interface
• User authentication
• Batch analysis of multiple images
• Ease the learning curve through enhanced help features
• Reporting via the creation of colour maps that will allow users to assess the spatial differences in canopies within a vineyard.
Use-case examples are presented to demonstrate the quantification and mapping of vineyard variability through objective canopy measurements, ground-truthing of remotely sensed measurements, monitoring of crop conditions, implementation of disease and water management decisions as well as creating a history of each site to forecast quality. This intelligent tool allows users to manage grapevines and make informed management choices to achieve the desired production targets and remain profitable.