 IVES 9 IVES Conference Series 9 Expanding the biotechnological potential of M. pulcherrima/fructicola clade for wine-related applications

Expanding the biotechnological potential of M. pulcherrima/fructicola clade for wine-related applications

Abstract

AIM: Strains belonging to M. pulcherrima/fructicola clade are frequently isolated from flowers, fruits and grape musts, and exhibit a broad spectrum of enzymatic activities and antimicrobial potential (Morata et al., 2019; Sipiczki, 2020; Vicente et al. 2020). By reason of these features, selected strains of this clade have been proposed as non-Saccharomyces starter cultures for winemaking. In this study, with a view to valorise the biotechnological potential of these strains, a new Metschnikowia sp. strain, DBT012, was selected for application in vinification trials of Valpolicella’s fresh and withered typical grapes for reduction of SO₂addition and increase of aromatic complexity. Further, in the framework of the investigation on the biodiversity of a collection of strains, distinct pulcherrimin-producing isolates from spontaneous fermentation and grapes were putatively recognized as Metschnikowia spp. and selected for genotypic and phenotypic characterisation.

METHODS: Lyophilised cultures of the reference strain DBT012 were tested in pilot-scale vinifications (mixed-cultures with S. cerevisiae). The isolates were characterised based on enzymatic activities (e.g., sulphite-reductase and beta-glucosidase activities) and growth under different wine-related stress conditions (e.g., ethanol, high sugar content). Genetic fingerprinting techniques (e.g., (GTG)5 and microsatellite) were performed for de-replication of isolates and strain typing. Whole-genome sequencing of the reference strain was carried out to analyse the correlation between genotype and phenotype, and comparative analyses with available type strains were performed to deepen the taxonomic aspects and molecularly identify this strain.

RESULTS: Use of Metschnikowia sp. DBT012 reduced the acetaldehyde content in wines, and positively influenced the wine aroma. About 50 Metschnikowia strains were characterised, which displayed a significant phenotypic diversity in terms of β-glucosidase and esterase activities, H2S production and growth at high sugar concentrations. The relationship of those features with genotypic and genomic distinctiveness of the reference strain was highlighted.

CONCLUSIONS:

The well-characterised thematic collection of strains belonging to M. pulcherrima/fructicola clade presented here constitutes an important reservoir of biodiversity for applications in different wine-related scenarios.

DOI:

Publication date: September 3, 2021

Issue: Macrowine 2021

Type: Article

Authors

Eleonora Troiano,Renato, LEAL BINATI, Ilaria, CHECCHIA, Ilaria, LARINI, Veronica, GATTO, Gianluca, VENERI, Giacomo, ZAPPAROLI, Vittorio, CAPOZZI, Elisa, SALVETTI, Sandra, TORRIANI, Giovanna, E., FELIS

Department of Biotechnology, University of Verona, Italy, Department of Biotechnology, University of Verona, Italy, Department of Biotechnology, University of Verona, Italy, Department of Biotechnology, University of Verona, Italy, Department of Biotechnology, University of Verona, Italy, Department of Biotechnology, University of Verona, Italy , Department of Biotechnology, University of Verona, Italy, Institute of Sciences of Food Production, National Research Council (CNR), Italy, Department of Biotechnology, University of Verona, Italy, Department of Biotechnology, University of Verona, Italy, Department of Biotechnology, University of Verona, Italy

Contact the author

;

Keywords

metschnikowia, wine microbiology, biodiversity, biotechnological potential

Citation

‘Cabernet Sauvignon’ (Vitis vinifera L.) berry skin flavonol and anthocyanin composition is affected by trellis systems and applied water amounts

Trellis systems are selected in wine grape vineyards to mainly maximize vineyard yield and maintain berry quality. This study was conducted in 2020 and 2021 to evaluate six commonly utilized trellis systems including a vertical shoot positioning (VSP), two relaxed VSPs (VSP60 and VSP80), a single high wire (SH), a high quadrilateral (HQ), and a guyot (GY), combined with three levels of irrigation regimes based on different crop evapotranspiration (ETc) replacements, including a 25% ETc, 50% ETc, and 100% ETc. The results indicated SH yielded the most fruits and accumulated the most total soluble solids (TSS) at harvest in 2020, however, it showed the lowest TSS in the second season. In 2020, SH and HQ showed higher concentrations in most of the anthocyanin derivatives compared to the VSPs. Similar comparisons were noticed in 2021 as well. SH and HQ also accumulated more flavonols in both years compared to other trellis systems. Overall, this study provides information on the efficacy of trellis systems on grapevine yield and berry flavonoid accumulation in a currently warming climate.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

VINIoT: Precision viticulture service for SMEs based on IoT sensors network

The main innovation in the VINIoT service is the joint use of two technologies that are currently used separately: vineyard monitoring using multispectral imaging and deployed terrain sensors. One part of the system is based on the development of artificial intelligence algorithms that are feed on the images of the multispectral camera and IoT sensors, high-level information on water stress, grape ripening status and the presence of diseases. In order to obtain algorithms to determine the state of ripening of the grapes and avoid losing information due to the diversity of the grape berries, it was decided to work along the first year 2020 at berry scale in the laboratory, during the second year at the cluster scale and on the last year at plot scale. Different varieties of white and red grapes were used; in the case of Galicia we worked with the white grape variety Treixadura and the red variety Mencía. During the 2020 and 2021 campaigns, multispectral images were taken in the visible and infrared range of: 1) sets of 100 grapes classifying them by means of densimetric baths, 2) individual bunches. The images taken with the laboratory analysis of the ripening stage were correlated. Technological maturity, pH, probable degree, malic acid content, tartaric acid content and parameters for assessing phenolic maturity, IPT, anthocyanin content were determined. It has been calculated for each single image the mean value of each spectral band (only taking into account the pixels of interest) and a correlation study of these values with laboratory data has been carried out. These studies are still provisional and it will be necessary to continue with them, jointly with the training of the machine learning algorithms. Processed data will allow to determine the sensitivity of the multispectral images and select bands of interest in maturation.

How does aromatic composition of red wines, resulting from varieties adapted to climate change, modulate fruity aroma?

One of the major issues for the wine sector is the impact of climate change linked to the increasing temperatures which affects physicochemical parameters of the grape varieties planted in Bordeaux vineyard and consequently, the quality of wine. In some varietals, the attenuation of their fresh fruity character is accompanied by the accentuation of dried-fruit notes [1]. As a new adaptive strategy on climate change, some winegrowers have initiated changes in the Bordeaux blend of vine varieties [2]. This study intends to explore the fruitiness in wines produced from grape varieties adapted to the future climate of Bordeaux. 10 commercial single–varietal wines from 2018 vintage made from the main grape varieties in the Bordeaux region (Cabernet franc, Cabernet-Sauvignon and Merlot) as well as from indigenous grape varieties from the Mediterranean basin, such as Cyprus (Yiannoudin), France (Syrah), Greece (Agiorgitiko and Xinomavro), Portugal (Touriga Nacional) and Spain (Garnacha and Tempranillo), were selected among 19 samples using sensory descriptive analyses. Both sensory and instrumental analyses were coupled, to investigate their fruity aroma expression. For sensory analysis, samples were prepared from wine, using a semi preparative HPLC method which preserves wine aroma and isolates fruity characteristics in 25 specific fractions [3,4]. Fractions of interest with intense fruity aromas were sensorially selected for each wine by a trained panel and mixed with ethanol and microfiltered water to obtain fruity aromatic reconstitutions (FAR) [5]. A free sorting task was applied to categorize FAR according to their similarities or dissimilarities, and different clusters were highlighted. Instrumental analysis of the different FAR and wines demonstrated variations in their molecular composition. Results obtained from sensory and gas chromatography analysis enrich the knowledge of the fruity expression of red wines from “new” grape varieties opening up new perspectives in wine technology, including blending, thus providing new tools for producers.

Phenological characterization of a wide range of Vitis Vinifera varieties

In order to study the impact of climate change on Bordeaux grape varieties and to assess the adaptation capacities of candidates to the grape varieties of this wine region to the new climatic conditions, an experimental block design composed of 52 grape varieties was set up in 2009 at the INRAE Bordeaux Aquitaine center. Among the many parameters studied, the three main phenological stages of the vine (budburst, flowering and veraison) have been closely monitored since 2012. Observations for each year, stage and variety were carried out on four independent replicates. Precocity indices have been calculated from the data obtained over the 2012-2021 period (Barbeau et al. 1998). This work allowed to group the phenological behaviour of the grapevine varieties, not only based on the timing of the subsequent developmental stages, but also on the overall precocity of the cycle and the total length of the cycle between budburst and veraison. Results regarding the variability observed among the different grape varieties for these phenological stages are presented as heat maps.