Montpellier, France
Montpellier, France

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Almeida P.,New University of Lisbon | Barbosa R.,New University of Lisbon | Zalar P.,University of Ljubljana | Imanishi Y.,Kanto Gakuin University | And 10 more authors.
Molecular Ecology | Year: 2015

The domestication of the wine yeast Saccharomyces cerevisiae is thought to be contemporary with the development and expansion of viticulture along the Mediterranean basin. Until now, the unavailability of wild lineages prevented the identification of the closest wild relatives of wine yeasts. Here, we enlarge the collection of natural lineages and employ whole-genome data of oak-associated wild isolates to study a balanced number of anthropic and natural S. cerevisiae strains. We identified industrial variants and new geographically delimited populations, including a novel Mediterranean oak population. This population is the closest relative of the wine lineage as shown by a weak population structure and further supported by genomewide population analyses. A coalescent model considering partial isolation with asymmetrical migration, mostly from the wild group into the Wine group, and population growth, was found to be best supported by the data. Importantly, divergence time estimates between the two populations agree with historical evidence for winemaking. We show that three horizontally transmitted regions, previously described to contain genes relevant to wine fermentation, are present in the Wine group but not in the Mediterranean oak group. This represents a major discontinuity between the two populations and is likely to denote a domestication fingerprint in wine yeasts. Taken together, these results indicate that Mediterranean oaks harbour the wild genetic stock of domesticated wine yeasts. © 2015 John Wiley & Sons Ltd.


PubMed | CNRS Sciences for Enology and French National Institute for Agricultural Research
Type: Journal Article | Journal: Plant, cell & environment | Year: 2016

Ectomycorrhizal (ECM) association can improve plant phosphorus (P) nutrition. Polyphosphates (polyP) synthesized in distant fungal cells after P uptake may contribute to P supply from the fungus to the host plant if they are hydrolyzed to phosphate in ECM roots then transferred to the host plant when required. In this study, we addressed this hypothesis for the ECM fungus Hebeloma cylindrosporum grown in vitro and incubated without plant or with host (Pinus pinaster) and non-host (Zea mays) plants, using an experimental system simulating the symbiotic interface. We used


PubMed | French Atomic Energy Commission, University of Perugia, University of Manchester, Kanto Gakuin University and 4 more.
Type: Journal Article | Journal: Molecular ecology | Year: 2015

The domestication of the wine yeast Saccharomycescerevisiae is thought to be contemporary with the development and expansion of viticulture along the Mediterranean basin. Until now, the unavailability of wild lineages prevented the identification of the closest wild relatives of wine yeasts. Here, we enlarge the collection of natural lineages and employ whole-genome data of oak-associated wild isolates to study a balanced number of anthropic and natural S.cerevisiae strains. We identified industrial variants and new geographically delimited populations, including a novel Mediterranean oak population. This population is the closest relative of the wine lineage as shown by a weak population structure and further supported by genomewide population analyses. A coalescent model considering partial isolation with asymmetrical migration, mostly from the wild group into the Wine group, and population growth, was found to be best supported by the data. Importantly, divergence time estimates between the two populations agree with historical evidence for winemaking. We show that three horizontally transmitted regions, previously described to contain genes relevant to wine fermentation, are present in the Wine group but not in the Mediterranean oak group. This represents a major discontinuity between the two populations and is likely to denote a domestication fingerprint in wine yeasts. Taken together, these results indicate that Mediterranean oaks harbour the wild genetic stock of domesticated wine yeasts.


Dufrechou M.,CNRS Sciences for Enology | Sauvage F.-X.,CNRS Sciences for Enology | Bach B.,CNRS Sciences for Enology | Bach B.,France Inter | Vernhet A.,Montpellier SupAgro
Journal of Agricultural and Food Chemistry | Year: 2010

High temperatures (typically 80 °C) are widely used to assess wine stability with regard to protein haze or to study mechanisms involved in their formation. Dynamic light scattering experiments were performed to follow aggregation kinetics and aggregate characteristics in white wines at different temperatures (30-70 °C). Aggregation was followed during heating and cooling to 25 °C. Results were coupled with the study of the time-temperature dependence of heat-induced protein aggregation. At low temperature (40 °C), aggregation developed during heating. Colloidal equilibria were such that attractive interactions between species led to the rapid formation of micrometer-sized aggregates. At higher temperatures (60 and 70 °C), enhanced protein precipitation was expected and observed. However, high temperatures prevented aggregation, which mainly developed during cooling. Depending on the wine, cooling induced the formation of sub-micronic metastable aggregates stabilized by electrostatic repulsions, or the rapid formation of micrometer-sized aggregates, prone to sedimentation. © 2010 American Chemical Society.


Peyches-Bach A.,CNRS Sciences for Enology | Dombre C.,Montpellier University | Moutounet M.,CNRS Sciences for Enology | Peyron S.,Montpellier University | Chalier P.,Montpellier University
Journal of Agricultural and Food Chemistry | Year: 2012

The objectives of this study were to demonstrate that the presence of ethanol in a solution containing two esters and two aromatic alcohols has several consequences on the sorption of these compounds into polyethylene (PE) film. First, sorption of ethanol into the PE film occurred at the same time as water and reached 8 kg m-3 using 12% v/v of ethanol. This sorption was associated with an increase in PE crystallinity, which may have prevented the sorption of volatile compounds despite their strong affinity with PE film, as evaluated by Hansen solubility parameters. Moreover, increasing the ethanol concentration increased the solubility of the four volatile compounds. In the case of aromatic alcohols, the sorption was decreased in the presence of ethanol as expected. In the case of esters, as their hydrolysis was substantial in the presence of water, the consequence was a higher sorption into the PE film in the presence of ethanol than in its absence. Nevertheless, the sorption also depended on the concentration of ethanol and the heterogeneity of the ethanol-water mixture as well as the presence of other volatile compounds, as in the case of 4-ethylphenol. In conditions simulating wine packaging, losses of volatile compound by sorption and by permeation estimated after only 5 days of contact varied between 0.08 and 25% for 2-phenylethanol and ethyl hexanoate, respectively. © 2012 American Chemical Society.


Rienth M.,Montpellier SupAgro | Torregrosa L.,Montpellier SupAgro | Sarah G.,Montpellier SupAgro | Ardisson M.,Montpellier SupAgro | And 2 more authors.
BMC Plant Biology | Year: 2016

Background: Fruit composition at harvest is strongly dependent on the temperature during the grapevine developmental cycle. This raises serious concerns regarding the sustainability of viticulture and the socio-economic repercussions of global warming for many regions where the most heat-tolerant varieties are already cultivated. Despite recent progress, the direct and indirect effects of temperature on fruit development are far from being understood. Experimental limitations such as fluctuating environmental conditions, intra-cluster heterogeneity and the annual reproductive cycle introduce unquantifiable biases for gene expression and physiological studies with grapevine. In the present study, DRCF grapevine mutants (microvine) were grown under several temperature regimes in duly-controlled environmental conditions. A singly berry selection increased the accuracy of fruit phenotyping and subsequent gene expression analyses. The physiological and transcriptomic responses of five key stages sampled simultaneously at day and nighttime were studied by RNA-seq analysis. Results: A total of 674 millions reads were sequenced from all experiments. Analysis of differential expression yielded in a total of 10 788 transcripts modulated by temperature. An acceleration of green berry development under higher temperature was correlated with the induction of several candidate genes linked to cell expansion. High temperatures impaired tannin synthesis and degree of galloylation at the transcriptomic levels. The timing of malate breakdown was delayed to mid-ripening in transgressively cool conditions, revealing unsuspected plasticity of berry primary metabolism. Specific ATPases and malate transporters displayed development and temperature-dependent expression patterns, besides less marked but significant regulation of other genes in the malate pathway. Conclusion: The present study represents, to our knowledge the first abiotic stress study performed on a fleshy fruits model using RNA-seq for transcriptomic analysis. It confirms that a careful stage selection and a rigorous control of environmental conditions are needed to address the long-term plasticity of berry development with respect to temperature. Original results revealed temperature-dependent regulation of key metabolic processes in the elaboration of berry composition. Malate breakdown no longer appears as an integral part of the veraison program, but as possibly triggered by an imbalance in cytoplasmic sugar, when efficient vacuolar storage is set on with ripening, in usual temperature conditions. Furthermore, variations in heat shock responsive genes that will be very valuable for further research on temperature adaptation of plants have been evidenced. © 2016 The Author(s).


Zago E.,LUnite Mixte de Recherche Ingenierie des Agro polymeres et Technologies Emergentes | Durand E.,LUnite Mixte de Recherche Ingenierie des Agro polymeres et Technologies Emergentes | Barouh N.,LUnite Mixte de Recherche Ingenierie des Agro polymeres et Technologies Emergentes | Lecomte J.,LUnite Mixte de Recherche Ingenierie des Agro polymeres et Technologies Emergentes | And 2 more authors.
Journal of Agricultural and Food Chemistry | Year: 2015

4-Vinyl guaiacol (2) was lipophilized through the electrophilic addition of peracids to its vinylic double bond. Those peracids were formed in situ, by the Candida antarctica lipase-B-assisted perhydrolysis of carboxylic acids ranging from C2 to C18, in hydrogen peroxide solution. The addition of peracids with 4-8 carbons in their alkyl chains led to the formation of two regioisomers, with the prevalence of hydroxyesters bearing a primary free hydroxyl (4c-4e). This prevalence became more pronounced when peracids with longer alkyl chains (C10-C18) were used. In this case, only isomers 4f-4h were formed. The antioxidant activity of the resulting hydroxyesters was assessed by means of the conjugated autoxidizable triene (CAT) assay, and it was found out that the 4-vinyl guaiacol antioxidant activity was significantly increased by grafting alkyl chains with 2-8 carbons. © 2015 American Chemical Society.


Koffi E.N.,CIRAD - Agricultural Research for Development | Koffi E.N.,Nangui Abrogoua University | Le Guerneve C.,CNRS Sciences for Enology | Lozano P.R.,CIRAD - Agricultural Research for Development | And 4 more authors.
Industrial Crops and Products | Year: 2013

Water extracts of Justicia secunda leaves are used by village communities in southern countries to prepare traditional medicines at home. The beverage is usually obtained by boiling the plant in water. On a pilot plant scale, water extracts were processed using an extraction-concentration procedure achieved in a three-step process, including ultrasound-assisted water extraction followed by cross-flow microfiltration of the crude extract and its concentration by reverse osmosis. As the processing conditions were milder than for homemade preparations, the extract obtained was enriched in natural leaf flavonoids. At each step of the pilot plant process, the co-products obtained were analyzed for total polyphenol and total flavonoid contents by the UV-vis spectrophotometric method. The process allowed a better leaf water-extraction of polyphenol compounds than the homemade extraction. The crude extract was concentrated 28 times (v/v) at room temperature by membrane volume reduction, and the total content of polyphenol compounds of the concentrated extract was 17 times higher than those of the crude extract. Individual polyphenol compounds were characterized by HPLC-DAD analysis at λmax=325nm. Additional structure characterization was carried out for the two major flavonoid compounds found (65% of total HPLC-DAD peak area of the flavones-type compounds) in the water extracts by tandem mass spectrometry (LC-ESI-MS2) and by nuclear magnetic resonance (1H NMR, 13C NMR). They were identified as luteolin 7-O-[β-glucopyranosyl-(1→2)-β-rhamnosyl-(1→6)] β-glucopyranoside and luteolin 7-O-[β-apiofuranosyl-(1→2)]-β-xylopyranoside. © 2013 Elsevier B.V.


PubMed | CNRS Sciences for Enology
Type: Journal Article | Journal: Journal of agricultural and food chemistry | Year: 2010

High temperatures (typically 80 C) are widely used to assess wine stability with regard to protein haze or to study mechanisms involved in their formation. Dynamic light scattering experiments were performed to follow aggregation kinetics and aggregate characteristics in white wines at different temperatures (30-70 C). Aggregation was followed during heating and cooling to 25 C. Results were coupled with the study of the time-temperature dependence of heat-induced protein aggregation. At low temperature (40 C), aggregation developed during heating. Colloidal equilibria were such that attractive interactions between species led to the rapid formation of micrometer-sized aggregates. At higher temperatures (60 and 70 C), enhanced protein precipitation was expected and observed. However, high temperatures prevented aggregation, which mainly developed during cooling. Depending on the wine, cooling induced the formation of sub-micronic metastable aggregates stabilized by electrostatic repulsions, or the rapid formation of micrometer-sized aggregates, prone to sedimentation.


PubMed | CIRAD - Agricultural Research for Development and CNRS Sciences for Enology
Type: Journal Article | Journal: Journal of agricultural and food chemistry | Year: 2015

4-Vinyl guaiacol (2) was lipophilized through the electrophilic addition of peracids to its vinylic double bond. Those peracids were formed in situ, by the Candida antarctica lipase-B-assisted perhydrolysis of carboxylic acids ranging from C2 to C18, in hydrogen peroxide solution. The addition of peracids with 4-8 carbons in their alkyl chains led to the formation of two regioisomers, with the prevalence of hydroxyesters bearing a primary free hydroxyl (4c-4e). This prevalence became more pronounced when peracids with longer alkyl chains (C10-C18) were used. In this case, only isomers 4f-4h were formed. The antioxidant activity of the resulting hydroxyesters was assessed by means of the conjugated autoxidizable triene (CAT) assay, and it was found out that the 4-vinyl guaiacol antioxidant activity was significantly increased by grafting alkyl chains with 2-8 carbons.

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