The Experts below are selected from a list of 357 Experts worldwide ranked by ideXlab platform
Arianna Lovato - One of the best experts on this subject based on the ideXlab platform.
-
Plant and fungus transcriptomic data from grapevine berries undergoing artificially-induced Noble Rot caused by Botrytis cinerea.
Data in brief, 2019Co-Authors: Arianna Lovato, Sara Zenoni, Giovanni Battista Tornielli, Teresa Colombo, Elodie Vandelle, Annalisa PolverariAbstract:Abstract Noble Rot is a latent infection of grape berries caused by the necRotrophic fungus Botrytis cinerea, which develops under specific climatic conditions. The infected berries undergo biochemical and metabolic changes, associated with a rapid withering, which altogether offer interesting organoleptic features to sweet white wines. In this paper, we provide RNAseq datasets (raw and normalized counts as well as differentially expressed genes lists) of the transcriptome profiles of both grapevine berries (Vitis vinifera cv. Garganega) and B. cinerea during the establishment of Noble Rot, artificially induced in controlled conditions. The sequencing data are available in the NCBI GEO database under accession number GSE116741. These data were exploited in a comprehensive meta-analysis of gene expression during Noble Rot infection, gray mold and post-harvest withering. This highlighted an important common transcriptional reprogramming in different botrytized grape berry varieties and led to the identification of key genes specifically modulated during Noble Rot infection, which are described in the article entitled “Specific molecular interactions between Vitis vinifera and Botrytis cinerea are required for Noble Rot development in grape berries” Lovato et al., 2019.
-
Specific molecular interactions between Vitis vinifera and Botrytis cinerea are required for Noble Rot development in grape berries
Postharvest Biology and Technology, 2019Co-Authors: Arianna Lovato, Sara Zenoni, Giovanni Battista Tornielli, Teresa Colombo, Elodie Vandelle, Annalisa PolverariAbstract:Abstract Under peculiar climatic conditions, the beneficial form of the necRotrophic fungus Botrytis cinerea can develop on grape berries as a latent infection, known as Noble Rot, which induces positive biochemical and metabolic changes in the berries, including an increase in the sugar content and the production of aromatic compounds that improve wine quality. The infected berries undergo rapid withering, which is required to produce famous sweet white wines such as Sauternes and Tokaj. To gain insight into the molecular interactions between grapevine berries (Vitis vinifera) and B. cinerea during the establishment of Noble Rot, we prepared a large-scale transcriptomics dataset representing Noble Rot development and carried out a comparative meta-analysis with gray mold infection and natural post-harvest withering. In particular, we artificially induced berry botrytization of two grape varieties (Garganega and Moller-Thurgau) and sampled them at different stages of Noble Rot for comparative whole-transcriptome analysis, highlighting important common transcriptional reprogramming in both varieties reflecting an accelerated withering process. Simultaneously, we analyzed the modulation of B. cinerea genes and compared the expression profile during Noble Rot development with the previously reported gray mold infection profile, revealing the onset of an infection process by the fungus in its beneficial form associated with reduced virulence. This, together with the restrained plant defense response observed in botrytized berries, may favour the development of Noble Rot instead of gray mold. Finally, the comprehensive meta-analysis of gene expression during Noble Rot infection, gray mold and post-harvest withering led to the identification of key genes specifically modulated during Noble Rot infection.
-
The Induction of Noble Rot (Botrytis cinerea) Infection during Postharvest Withering Changes the Metabolome of Grapevine Berries (Vitis vinifera L., cv. Garganega).
Frontiers in plant science, 2017Co-Authors: Stefano Negri, Arianna Lovato, Annalisa Polverari, Filippo Boscaini, Elisa Salvetti, Sandra Torriani, Mauro Commisso, Roberta Danzi, Maurizio Ugliano, Giovanni Battista TornielliAbstract:The natural or induced development of Noble Rot caused by the fungus Botrytis cinerea during the late stages of grapevine (Vitis vinifera L.) berry ripening is used in some traditional viticulture areas to produce high-quality wines such as Sauternes and Tokaji. In this research, we wanted to verify if by changing the environmental conditions during post-harvest withering we could induce the Noble Rot development on harvested berries in order to positively change the wine produced from withered Garganega berries. Therefore, we exposed the berries to postharvest withering under normal or artificially humid conditions, the latter to induce Noble Rot. The presence of Noble Rot symptoms was associated with the development of B. cinerea in the berries maintained under humid conditions. The composition of infected and non-infected berries was investigated by untargeted metabolomics using liquid chromatography/mass spectrometry. We also explored the effects of the two withering methods on the abundance of volatile organic compounds in wine by yeast-inoculated micro-fermentation followed by targeted gas chromatography/mass spectrometry. These experiments revealed significant metabolic differences between berries withered under normal and humid conditions, indicating that Noble Rot affects berry metabolism and composition. As well as well-known botrytization markers, we detected two novel lipids that have not been observed before in berries infected with Noble Rot. Unraveling the specific metabolic profile of berries infected with Noble Rot may help to determine the compounds responsible for the organoleptic quality traits of botrytized Garganega wines.
-
Approcci di ‘Biologia dei Sistemi’ per la caratterizzazione del processo di appassimento delle uve utilizzate nella produzione di vini di qualità nel Veronese. Approcci di ‘Biologia dei Sistemi’ per la caratterizzazione d
country:ITA, 2014Co-Authors: Arianna LovatoAbstract:In questo lavoro si sono valutate le condizioni ambientali che favoriscono lo sviluppo di Botrytis cinerea e si sono ottenute per la prima volta indicazioni sperimentali riguardo ai meccanismi molecolari di colonizzazione del substrato da parte del microrganismo, in forma larvata e non.In this work, the environmental condition for the development of the Noble Rot were evaluated. Moreover, sperimental indication about the molecular mechanisms of fungal colonization were obtained
-
Approcci di \u2018Biologia dei Sistemi\u2019 per la caratterizzazione del processo di appassimento delle uve utilizzate nella produzione di vini di qualit\ue0 nel Veronese. Approcci di \u2018Biologia dei Sistemi\u2019 per la caratterizzazione dei microrganismi coinvolti nel processo di appassimento delle uve utilizzate nella produzione di vini di qualit\ue0 nel Veronese
country:ITA, 2014Co-Authors: Arianna LovatoAbstract:In questo lavoro si sono valutate le condizioni ambientali che favoriscono lo sviluppo di Botrytis cinerea e si sono ottenute per la prima volta indicazioni sperimentali riguardo ai meccanismi molecolari di colonizzazione del substrato da parte del microrganismo, in forma larvata e non.In this work, the environmental condition for the development of the Noble Rot were evaluated. Moreover, sperimental indication about the molecular mechanisms of fungal colonization were obtained
Giacomo Zapparoli - One of the best experts on this subject based on the ideXlab platform.
-
Correlating Noble Rot Infection of Garganega Withered Grapes with Key Molecules and Odorants of Botrytized Passito Wine.
Foods (Basel Switzerland), 2019Co-Authors: Barbara Simonato, Marilinda Lorenzini, Fabio Finato, Michela Cipriani, Giacomo ZapparoliAbstract:Experimental passito wines with different percentages of naturally Noble-Rotten grapes of the Garganega variety were analyzed to evaluate key molecules and odorants related to the typical aroma and sensory profile of botrytized passito wine. Remarkable changes in the concentration of 1-octen-3-ol, 4-terpineol, benzaldehyde, N-(3-methylbutyl)acetamide, and sherry lactone 1 and 2 were observed between sound and Noble-Rotten wines. Wines were perceived to be different for floral, honey, figs, apricot, and caramel scents. By partial least square regression these descriptors were well correlated to samples. An important positive contribution of sherry lactones, N-(3-methylbutyl)acetamide, vanillin, benzaldehyde, and γ-butyrolactone to honey, apricot, and caramel was observed. It is conceivable that oxidative effects of Botrytis cinerea infection play an important role in the genesis of these chemical and sensory aroma markers. This study provides a predictive tool for winemakers that use natural grape withering to produce wines whose aroma profile is not standardized due to the seasonal variation of Noble Rot incidence.
-
Filamentous fungi associated with natural infection of Noble Rot on withered grapes.
International journal of food microbiology, 2018Co-Authors: Marilinda Lorenzini, Barbara Simonato, Fabio Favati, P. Bernardi, A. Sbarbati, Giacomo ZapparoliAbstract:The effects of Noble Rot infection of grapes on the characteristics of different types of wine, including Italian passito wine, are well known. Nevertheless, there is still little information on filamentous fungi associated with Noble-Rotten grapes. In this study, withered Garganega grapes for passito wine production, naturally infected by Noble Rot, were analyzed and compared to sound grapes. Skin morphology and fungal population on berry surfaces were analyzed. Scanning electron microscopy analysis revealed microcracks, germination conidia and branched hyphae on Noble-Rotten berries. Penicillium, Aureobasidium and Cladosporium were the most frequent genera present. Analysis of single berries displayed higher heterogeneity of epiphytic fungi in those infected by Noble-Rot than in sound berries. Penicillium adametzoides, Cladosporium cladospoirioides and Coniochaeta polymorpha were recovered. These, to the best of our knowledge, had never been previously isolated from withered grapes and, for C. polymorpha, from grapevine. This study provided novel data on Noble Rot mycobiota and suggests that fungi that co-habit with B. cinerea could have an important role on grape and wine quality.
-
Identification of potential pRotein markers of Noble Rot infected grapes
Food chemistry, 2015Co-Authors: Marilinda Lorenzini, Giacomo Zapparoli, Renato Millioni, Cinzia Franchin, Giorgio Arrigoni, Barbara SimonatoAbstract:The evaluation of Botrytis cinerea as Noble Rot on withered grapes is of great importance to predict the wine sensory/organoleptic properties and to manage the winemaking process of Amarone, a passito dry red wine. This report describes the first pRoteomic analysis of grapes infected by Noble Rot under withering conditions to identify possible markers of fungal infection. 2-D gel electrophoresis revealed that pRotein profiles of infected and not infected grape samples are significantly different in terms of number of spots and relative abundance. PRotein identification by MS analysis allowed to identify only in infected berries pRoteins of B. cinerea that represent potential markers of the presence of the fungus in the withered grapes.
-
Selection of Botrytis cinerea and Saccharomyces cerevisiae strains for the improvement and valorization of Italian passito style wines
FEMS yeast research, 2013Co-Authors: Michela Azzolini, Marilinda Lorenzini, Sandra Torriani, Emanuele Tosi, Stefano Faccio, Giacomo ZapparoliAbstract:In order to improve the quality of Italian passito wine, produced from withered grapes that can be naturally infected by Noble Rot, in this study, a novel pRotocol was developed to select suitable cultures of both Botrytis cinerea to infect grapes (as Noble Rot) and of Saccharomyces cerevisiae to ferment grapes. A total of 16 B. cinerea isolated from withered grapes were typified by RAPD-PCR, and three representative strains were selected for physiological characterization. The strains showed different mycelial growth and enzymatic activities (i.e. polygalacturonase, pRotease, and laccase). A total of 15 yeasts were isolated from spontaneous fermented wines, these were identified as S. cerevisiae , and typified at strain level. Seven strains were selected according to RAPD-PCR profiles and tested for their fermentation performances. The effects of B. cinerea and S. cerevisiae cultures on the aroma profile of sweet style wine were preliminary evaluated fermenting artificially botrytized grapes induced with B. cinerea infection. The combination of selected fungi affected the aroma profile of wine according to the variation of the content of important molecules (i.e. alcohols, esters, and lactones). This study has provided valuable information to develop new natural cultures destined to induce grape botrytization and manage fermentation in passito winemaking.
-
Post-harvest grape infection of Botrytis cinerea and its interactions with other moulds under withering conditions to produce Noble-Rotten grapes
'Wiley', 2013Co-Authors: Marilinda Lorenzini, Emanuele Tosi, Michela Azzolini, Giacomo ZapparoliAbstract:ABSTRACT Aims: to investigate the interactions between Botrytis cinerea and other moulds during grape withering and post-harvest infection to obtain Noble-Rotten grapes. Methods and Results: Strains of Botrytis cinerea, Penicillium expansum, Penicillium crustosum, Aspergillus niger, Fusarium verticilloides and Alternaria alternata, isolated from naturally withered grapes and identified by molecular tools, were used to infect Garganega and Corvina grapes. Individually sterilized berries were infected by a single inoculation of each strain or a simultaneous inoculation of B. cinerea together with one of each of the other moulds. Withering kinetics, glycerol, gluconic acid, total polyphenols, total anthocyanins and laccase activity greatly varied among each strain and also in respect to untreated berries. Successful Noble Rot settlement was ascertained by an additional infection assay carried out on non-sterilized berries. Conclusions: The suitability of inducing Noble Rot infection during grape withering and the improvement of the health of Noble-Rotten grapes has been demonstrated. Significance and impact of the study: This study provides insights on the effects of mould interactions on withered grape quality. Implementing Noble Rot induction by post-harvest infection in winery drying fruit rooms to standardize the level of grape botrytization is encouraged
Barbara Simonato - One of the best experts on this subject based on the ideXlab platform.
-
Correlating Noble Rot Infection of Garganega Withered Grapes with Key Molecules and Odorants of Botrytized Passito Wine.
Foods (Basel Switzerland), 2019Co-Authors: Barbara Simonato, Marilinda Lorenzini, Fabio Finato, Michela Cipriani, Giacomo ZapparoliAbstract:Experimental passito wines with different percentages of naturally Noble-Rotten grapes of the Garganega variety were analyzed to evaluate key molecules and odorants related to the typical aroma and sensory profile of botrytized passito wine. Remarkable changes in the concentration of 1-octen-3-ol, 4-terpineol, benzaldehyde, N-(3-methylbutyl)acetamide, and sherry lactone 1 and 2 were observed between sound and Noble-Rotten wines. Wines were perceived to be different for floral, honey, figs, apricot, and caramel scents. By partial least square regression these descriptors were well correlated to samples. An important positive contribution of sherry lactones, N-(3-methylbutyl)acetamide, vanillin, benzaldehyde, and γ-butyrolactone to honey, apricot, and caramel was observed. It is conceivable that oxidative effects of Botrytis cinerea infection play an important role in the genesis of these chemical and sensory aroma markers. This study provides a predictive tool for winemakers that use natural grape withering to produce wines whose aroma profile is not standardized due to the seasonal variation of Noble Rot incidence.
-
Filamentous fungi associated with natural infection of Noble Rot on withered grapes.
International journal of food microbiology, 2018Co-Authors: Marilinda Lorenzini, Barbara Simonato, Fabio Favati, P. Bernardi, A. Sbarbati, Giacomo ZapparoliAbstract:The effects of Noble Rot infection of grapes on the characteristics of different types of wine, including Italian passito wine, are well known. Nevertheless, there is still little information on filamentous fungi associated with Noble-Rotten grapes. In this study, withered Garganega grapes for passito wine production, naturally infected by Noble Rot, were analyzed and compared to sound grapes. Skin morphology and fungal population on berry surfaces were analyzed. Scanning electron microscopy analysis revealed microcracks, germination conidia and branched hyphae on Noble-Rotten berries. Penicillium, Aureobasidium and Cladosporium were the most frequent genera present. Analysis of single berries displayed higher heterogeneity of epiphytic fungi in those infected by Noble-Rot than in sound berries. Penicillium adametzoides, Cladosporium cladospoirioides and Coniochaeta polymorpha were recovered. These, to the best of our knowledge, had never been previously isolated from withered grapes and, for C. polymorpha, from grapevine. This study provided novel data on Noble Rot mycobiota and suggests that fungi that co-habit with B. cinerea could have an important role on grape and wine quality.
-
Identification of potential pRotein markers of Noble Rot infected grapes
Food chemistry, 2015Co-Authors: Marilinda Lorenzini, Giacomo Zapparoli, Renato Millioni, Cinzia Franchin, Giorgio Arrigoni, Barbara SimonatoAbstract:The evaluation of Botrytis cinerea as Noble Rot on withered grapes is of great importance to predict the wine sensory/organoleptic properties and to manage the winemaking process of Amarone, a passito dry red wine. This report describes the first pRoteomic analysis of grapes infected by Noble Rot under withering conditions to identify possible markers of fungal infection. 2-D gel electrophoresis revealed that pRotein profiles of infected and not infected grape samples are significantly different in terms of number of spots and relative abundance. PRotein identification by MS analysis allowed to identify only in infected berries pRoteins of B. cinerea that represent potential markers of the presence of the fungus in the withered grapes.
-
Effects of Noble Rot on must composition and aroma profile of Amarone wine produced by the traditional grape withering pRotocol
Food Chemistry, 2012Co-Authors: Emanuele Tosi, Barbara Simonato, Bruno Fedrizzi, Michela Azzolini, Fabio Finato, Giacomo ZapparoliAbstract:The effects of Noble Rot on the overall quality of Amarone wine, a “Passito” dry red wine, produced by a traditional withering grape process are poorly understood. Wines obtained from healthy and selected grapes infected by Noble Rot were compared. Validation of the experimental plan was carried out by determining glycerol and gluconic acid content, laccase activity and microbial analysis of the musts. Botrytis cinerea infection produced significant variation in esterase and β-glucosidase activity of grape must. Aroma analysis in healthy and botrytised wines was carried out by SPE extraction followed by GC–MS quantification. A decrease of several fermentative esters was observed in botrytised wine, while wine produced from healthy grapes showed a higher fatty acid content. Molecules such as 1-octen-3-ol, phenylacetaldehyde and furaneol were positively linked to the Noble-Rotten grapes. Interestingly, γ-nonalactone and 4-carbethoxy-γ-butyrolactone increased, while sherry lactones decreased in botrytised wine. The strong increase of N-(3-methylbutyl)acetamide was related to B. cinerea grape infection.
-
Effects of Noble Rot on must composition and aroma profile of Amarone wine produced by the traditional grape withering pRotocol
'Elsevier BV', 2012Co-Authors: Emanuele Tosi, Barbara Simonato, Bruno Fedrizzi, Michela Azzolini, Fabio Finato, Giacomo ZapparoliAbstract:The effects of Noble Rot on the overall quality of Amarone wine, a \u201cPassito\u201d dry red wine, produced with traditional withering grape process is still poorly investigated. Wines obtained from healthy and selected grapes infected by Noble-Rot were compared. Validation of the experimental plan was carried out by determining glycerol and gluconic acid content, laccase activity and microbial analysis of the musts. The B. cinerea infection produced significant variation on esterase and \u3b2-glucosidase activity of grape must. Aroma analysis in healthy and botrytized wines, was carried out by SPE extraction followed by GC\u2013MS quantification. A decrease of several fermentative esters was observed in botrytized wine, while the one produced from healthy grapes showed a higher fatty acid content. Molecules such as 1-octen-3-ol, phenylacetaldehyde and furaneol were correlated positively linked to the Noble-Rotten grapes. Interestingly, \u3b3-nonalactone and 4-carbethoxy-\u3b3-butyrolactone increased, while Sherry lactones decreased in botrytized wine. The strong increase of N-(3-methylbutyl)-acetamide was related to B. cinerea grape infection
Lorenzini Marilinda - One of the best experts on this subject based on the ideXlab platform.
-
Induction of grape botrytization during withering affects volatile composition of Recioto di Soave, a "passito"-style wine
'Springer Science and Business Media LLC', 2013Co-Authors: Tosi E., Fedrizzi B., Finato F., Azzolini Michela, Lorenzini Marilinda, Torriani Sandra, Cipriani M, Zapparoli GiacomoAbstract:The influence of Noble Rot on the quality of Recioto di Soave, a "passito" sweet white wine, is greatly variable depending on the occurrence of favourable seasonal conditions for the mould infection. Botrytized wines were produced from grapes inoculated with conidia suspensions to evaluate the effects of Noble Rot on volatile compounds profile of Recioto di Soave wine. Different development stages of Botrytis cinerea and degree of grape withering were ascertained by must analysis. Several volatile components were involved in marked changes depending on the infection and grape withering level. Fruity esters, carbonyl compounds, phenols, lactones and acetamides greatly changed among botrytized wines. The results demonstrated that the level of B. cinerea infection and the degree of grape withering exert considerable influence on the volatile composition of this sweet wine. Strain-dependent effects were also preliminary ascertained. The process of induction of grape botrytization presented in this study could be recommendable for the industrial production of botrytized Recioto di Soave win
-
Induction of grape botrytization during withering affects volatile composition of Recioto di Soave, a "passito"-style wine
'Springer Science and Business Media LLC', 2013Co-Authors: Tosi E., Fedrizzi B., Finato F., Azzolini Michela, Lorenzini Marilinda, Torriani Sandra, Cipriani M, Zapparoli GiacomoAbstract:The influence of Noble Rot on the quality of Recioto di Soave, a "passito" sweet white wine, is greatly variable depending on the occurrence of favourable seasonal conditions for the mould infection. Botrytized wines were produced from grapes inoculated with conidia suspensions to evaluate the effects of Noble Rot on volatile compounds profile of Recioto di Soave wine. Different development stages of Botrytis cinerea and degree of grape withering were ascertained by must analysis. Several volatile components were involved in marked changes depending on the infection and grape withering level. Fruity esters, carbonyl compounds, phenols, lactones and acetamides greatly changed among botrytized wines. The results demonstrated that the level of B. cinerea infection and the degree of grape withering exert considerable influence on the volatile composition of this sweet wine. Strain-dependent effects were also preliminary ascertained. The process of induction of grape botrytization presented in this study could be recommendable for the industrial production of botrytized Recioto di Soave win
-
A study on the yeast and mould biota associated with the production of Italian wines from post-harvest dried grapes
2012Co-Authors: Lorenzini MarilindaAbstract:I vini Passiti ottenuti da uve che hanno subito un processo di appassimento sono vini rinomati e apprezzati dai consumatori principalmente per le complesse note sensoriali dovute al particolare processo di vinificazione. La fase di sovra-maturazione \ue8 fortemente influenzata dai microrganismi presenti sull\u2019acino e in particolare da Botrytis cinerea in forma nobile. La presenza di questa muffa favorisce la disidratazione dell\u2019acino e modifica la composizione del mosto che, infatti, presenta un elevato tenore zuccherino e contiene metaboliti secondari prodotti dalla muffa che possono inibire il processo fermentativo. Date queste condizioni stressanti per i lieviti, la fermentazione spontanea \ue8 spesso accompagnata da elevata produzione di acidit\ue0 volatile oltre che a blocchi o arresti fermentativi. Di conseguenza, per controllare meglio questa fase critica una strategia biotecnologica innovativa potrebbe essere l'utilizzo di colture starter di lieviti autoctoni ben adattati a queste condizioni. L\u2019obiettivo di questo progetto di ricerca \ue8 stato - quindi - quello di acquisire conoscenze sulla diversit\ue0 microbica associata alla produzione di alcuni vini italiani (quali Amarone, Vin Santo di Gambellara e Vino Santo Trentino) e di ottimizzare il processo di vinificazione attraverso l'uso di ceppi selezionati di B. cinerea e di lieviti autoctoni durante il processo di appassimento e la fermentazione. In questo contesto, \ue8 stata allestita un\u2019ampia collezione di muffe, tra cui B. cinerea, isolate da uve appassite, e una collezione di lieviti costituita da lieviti Saccharomyces e non-Saccharomyces isolati durante il processo di affinamento in caratelli e durante la fase di fermentazione di mosto Garganega utilizzato per la produzione del Vin Santo di Gambellara. Per quento riguarda l\u2019appassimento, a processo concluso, il vino ottenuto da queste uve \ue8 stato analizzato gas-cromatograficamente. I vini ottenuti hanno indicato differenze importanti tra le tesi inoculate e l'uva di controllo (non inoculata) per diversi composti volatili liberi. Come previsto, il livello pi\uf9 alto di 1-otten-3-olo (sapore di muffa) \ue8 stato trovato per i vini ottenuti da uve inoculato. Questi dati suggeriscono che l'inoculo di ceppi selezionati di B. cinerea su uva pu\uf2 influenzare le caratteristiche organolettiche del mosto/vino, consentendo cos\uec una diversificazione del prodotto finale. Per quanto riguarda le prove di fermentazione guidata, l'analisi dei vini ha rivelato che la fermentazione spontanea produce un elevato livello di acetato di etile rispetto alle tesi inoculate con i ceppi selezionati di S. cerevisiae. Pertanto, l'uso di ceppi autoctoni pu\uf2 limitare la produzione di acidit\ue0 volatile. Inoltre, l'analisi dei composti volatile ha evidenziato come tutti i vini ottenuti dai mosti fermentati con i ceppi selezionati presentano aromi associati a frutta bianca, alla rosa mandorla, fragola e caramello enfatizzando le propriet\ue0 aromatiche e il sapore del Vin Santo di Gambellara. L'analisi sensoriale ha ulteriormente confermato le differenze tra i diversi vini suggerendo quindi che l'uso di ceppi selezionati pu\uf2 migliorare il processo di fermentazione di vini passiti. In conclusione, questo progetto di ricerca ha evidenziato che l'uso di ceppi indigeni opportunamente selezionati (muffe e lieviti) \ue8 in grado di migliorare l\u2019intero processo di produzione dei vini passiti minimizzando i rischi di blocchi, arresti fermentativi e produzione di acidit\ue0 volatile, nonch\ue8 di influenzare positivamente la qualit\ue0 sensoriale del prodotto finito. Unitamente all\u2019uso di culture starter, l'uso di metodi alternativi validi in sostituzione all\u2019anidride solforosa (SO2) potrebbe migliorare l'impatto commerciale dei vini privi di conservanti chimici. In questo modo pu\uf2 essere soddisfatta la sempre pi\uf9 elevata domanda da parte dei consumatori di vini sicuri, salubri e organoletticamente distintivi.The wines obtained from post-harvest dried grapes are renowned wines, appreciated by consumers because of their complex sensorial notes due to the special vinification process, which involves the withering of grapes. The over-ripening phase is strongly influenced by the heterogeneous fungal biota present on the grape berry skin, and particularly by Botrytis cinerea. The development of the Noble Rot in berries affects the composition of the grape juice that presents high sugar content and inhibitory substances, as well. Therefore, grape juice fermentation proceeds hardly and is often accompanied by high production of volatile acidity. To better control the critical steps of Passito winemaking process, i.e. withering and fermentation, the use of suitable selected starter cultures could be applied as an innovative biotechnological strategy. Aims of this project were to increase knowledge about the diversity and evolution of indigenous eukaryotic microbiota associated with the production of some selected Italian wines (i.e. Amarone, Vin Santo di Gambellara, and Vino Santo Trentino) and to optimize the whole winemaking process through the use of selected indigenous strains of B. cinerea and yeasts. To these purposes, a large collection of moulds including B. cinerea was assembled; while a collection of yeasts (Saccharomyces and non-Saccharomyces) from wine aging in barrels and from the fermentation process of Garganega grape juice used for the production of Vin Santo di Gambellara was constituted. The isolates were identified using phenotypic and molecular methods, and then the collections were dereplicated by RAPD-PCR, PCR-RFLP, TEs, and microsatellite analysis. These techniques allowed the detection of a high genetic biodiversity among the B. cinerea and yeast isolates. The presence of distinctive strains could differentiate the withering of the studied grapes and the fermentation process, consequently selected strains of B. cinerea and yeasts were further characterized for several oenological properties (i.e. laccase activity and fungicide resistance for B. cinerea; resistance to stressful conditions and production of secondary metabolites for yeasts). In this way, strains of B. cinerea, S. cerevisiae and Zygosaccharomyces spp. were selected and tested in pilot-scale induction and fermentation trials, respectively. Considering the withering phase, at the end of the process the grapes were crushed and the grape juices were fermented. The gas-chromatographic analysis of the obtained wines indicated important differences between the inoculated and control grapes for several free volatile compounds. As expected, higher level of 1-octen-3-ol (mould flavor) was found for the wines obtained from the inoculated grape. These data suggest that the inoculum of selected B. cinerea strains on grapes influence the organoleptic characteristics of the must/wine, thus allowing a diversification of the final product. As regard the fermentation phase, the use of indigenous S. cerevisiae and non-Saccharomyces strains improved the fermentation process of Vin Santo di Gambellara. Indeed, failure to initiate fermentation and stuck fermentation were avoided, and a lower level of ethyl acetate was produced respect to the spontaneous fermentation. All selected S. cerevisiae yeasts produced flavors associated with white fruit, rose note, almond note and strawberry and caramel fragrance that emphasized the aromatic and flavor properties of this Passito wine. In conclusion, this research project suggests that the use of selected indigenous strains (moulds and yeasts) could improve the fermentation process of Passito wines minimizing risky conditions and improving the sensory quality of the final product. In other side, the use of valid alternative methods to SO2 addiction could improve the commercial impact of the wines free of chemical preservatives. In this way the modern consumer demand for wines that are safe and characterized by particular organoleptic flavour can be satisfied
Tatiana Giraud - One of the best experts on this subject based on the ideXlab platform.
-
The 'Dr Jekyll and Mr Hyde fungus': Noble Rot versus gray mold symptoms of Botrytis cinerea on grapes.
Evolutionary applications, 2013Co-Authors: Elisabeth Fournier, Pierre Gladieux, Tatiana GiraudAbstract:Many cryptic species have recently been discovered in fungi, especially in fungal plant pathogens. Cryptic fungal species co-occurring in sympatry may occupy slightly different ecological niches, for example infecting the same crop plant but specialized on different organs or having different phenologies. Identifying cryptic species in fungal pathogens of crops and determining their ecological specialization are therefore crucial for disease management. Here, we addressed this question in the ascomycete Botrytis cinerea, the agent of gray mold on a wide range of plants. On grape, B. cinerea causes severe damage but is also responsible for Noble Rot used for processing sweet wines. We used microsatellite genotyping and clustering methods to elucidate whether isolates sampled on gray mold versus Noble Rot symptoms in three French regions belong to genetically differentiated populations. The inferred population structure matched geography rather than the type of symptom. Noble Rot symptoms therefore do not seem to be caused by a specific B. cinerea population but instead seem to depend essentially on microclimatic conditions, which has applied consequences for the production of sweet wines.