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The accumulation of salts in building stones can lead to weathering features such as scaling, sanding or even slab detachment. To detect salts in walls at the early stages and to predict their evolution, the non-destructive technique (NDT) Infrared Thermography (IRT) was tested in a stimulated way. The main objective was to trial this technique in order to obtain more information such as the type of salt, its precise location and its concentration in building stones. Three building materials were studied, including two natural limestones and a reconstituted stone. Samples were submitted to immersion/drying tests in water and in salt solutions of Na2SO4, NaCl and MgSO4 at 7%, 14% and 26% in weight during 20 cycles of 24 h. The weight of the samples and the surface colour were recorded after each cycle. After 1, 5, 10 and 15 cycles, 3 samples were taken out for active IRT measurements. The results showed that when the porosity and the capillarity are low, the intake of salts into the porous network is low and the thermal response of the stone to heating (ΔTmax) corresponds to the salt thermal signature and has no relation with concentration. On the other hand, when the initial porosity is high, salts crystallize inside the porous network and porosity decreases. Hence, the thermal response of the porous stone is related to salt concentration and the ΔTmax increases until the stone starts to disaggregate. Active IRT is a promising NDT adapted to identify and quantify salts within building stones during the first states of accumulation.

Four dendritic ionic liquids (DILs) have been easily synthesized from 3rd generation PAMAM and PPI: PAMAM G3 NH3+ Tf2N− (1), PPI G3 NH3+ Tf2N− (2), PPI G3 NH2 Me+ BF4− (3) and PAMAM G3 NH2 Me+ BF4− (4). These DILs are fully characterized by spectroscopic methods (1H, 13C and 19F NMR) and elemental analysis. Compound 1 is hydrophobic while compounds 2–4 are hydrophilic. In order to apply these DILs for the extraction of aqueous metallic cations (Cu2+, Ni2+, Pb2+, Cd2+, and Ag+), liquid–liquid extraction and dialysis were performed. ICP technology has been used to reveal the amount of metallic cation that has been extracted. Compound 1 shows the best results especially for the extraction of Cu2+, Pb2+ and Ag+ cations (up to 98%). Two processes have been employed: liquid–liquid extraction and dialysis.

International audience; Perchlorate is an environmental contaminant of growing concern due to its potential human health effectsand widespread occurrence in surface water and groundwater. It is considered potentially toxic even at lowconcentrations (> 4 ppb) as an endocrine disruptor, especially for fetuses and infants. Analyzes have highlightedpresence of perchlorate in drinking water of Champagne-Ardenne (NE France) with two suspectedsources: a military source related to the WWI (World War I) and an agricultural one related to past use ofChilean nitrates.In order to define the origin and fate of perchlorate in groundwater, a study area of 500 km2 has been selectedeast of Reims, where drinking water catchments of the chalk aquifer are concerned with perchlorate contamination.Chalk groundwater flow and geochemistry are monitored for 2 years from June 2017 to June 2019 at 35sampling points including boreholes, springs and rivers (mainly form chalk aquifer drainage). Water samplesare collected monthly to determine the major and trace elements contents, stable water isotopes, perchlorateand organic pyrotechnic molecules. Perchlorate were detected at almost all sampling points (32 of 35) with amaximum value of 63 ppb and an average value of 11 ppb. High levels of perchlorate (> 4 ppb) were detectedmainly downstream of the Monronvilliers military camp, where quantities of ammunitions were used, storedand destroyed during and after the WWI. Statistical analysis shows no significant correlation between perchlorateand other major ions. The isotopic signature of perchlorate was analyzed and showed a synthetic origin,proving for the first time the military source of contamination in this area. In addition, groundwater datingusing CFCs and SF6 indicated an average residence time of < 30 years, implying that perchlorate contaminationis related to sources that may still subsist in the subsoil after the WWI (e.g. unexploded ammunitions)rather than military activities during the conflict. Perchlorate concentrations are relatively stable with timefor most points except for decreases observed in September 2017 and 2018. Stable isotopic analysis of waterand monitored groundwater table showed that the chalk aquifer is recharged by precipitation mainly duringthe winter season. Therefore, the decrease of perchlorate levels could possibly be explained by the very fewrecharge and low groundwater table in September, as less perchlorate is dissolved and transferred into theaquifer. This research provides insights on a combined use of hydraulic, geochemical and isotopic approachesto study the origin and transfer of contamination in chalk groundwater. The chalk aquifer properties and thelong-term influence of the WWI on groundwater quality in NE France are better clarified, with the aim toprovide appropriate recommendations in terms of water management.

International audience; To assess the influence of the composition of dissolved organic matter (DOM) on metal speciation, two models have been used: Model VI and NICA-Donnan. The speciation of Cu, Ni, Pb and Zn in the soil solution of 36 samples characterized by alkaline pH and different contamination levels has been determined. Four assumptions about DOM composition have been tested: (i) 100% of humic substances (HS) are fulvic acids (FA), (ii) 100% are humic acids (HA), (iii) 35% are HA and 65% FA and (iv) 84% are HA and 16% FA. The results obtained with the two distinct models are of the same order of magnitude; however, few differences have been highlighted regarding the description of the non-specific interactions, the Zn–FA interactions and the lowest free ion concentrations. The main result of this study is that the free ion concentrations calculated with the two models may differ by one order of magnitude depending on whether HA and/or FA are used to represent DOM. This work demonstrates the impact of the assumptions made about the DOM nature for metal speciation modelling.

Field portable X-ray fluorescence (FPXRF) technology can offer a rapid and cost-effective determination of the total elemental concentrations in soils. The aims of this study were (i) to test the capability of FPXRF to predict the element concentrations of a very large soil sample set and (ii) to assess the influence of soil moisture, known to strongly affect the quality of FPXRF analyses. A large set of 215 soil samples were analysed for Ba, Ca, Cr, Cu, Fe, Mn, Pb, Rb, Sn, Sr and Zn by inductively coupled plasma atomic emission spectroscopy (ICPAES) after aqua regia digestion and with a FPXRF analyser using a short acquisition time. Soil samples were then saturated with ultrapure water to test the influence of soil water content on FPXRF signal. For all of the elements, the total concentrations obtained with ICPAES and FPXRF showed a very high degree of linearity, indicating that FPXRF can effectively predict element concentrations in soils. A Lambert-Beer law was successfully used to describe the decrease in the FPXRF concentrations with increasing soil moisture. The attenuation coefficient obtained for each element allowed us to satisfactorily predict the FPXRF concentrations of samples for water contents as high as 136.8 %. These results show that the effect of water on signal attenuation can be corrected and that FPXRF may gradually replace chemical methods for the analysis of environmental samples.

Anthropogenic inputs of trace elements (TE) into soils constitute a major public and environmental health problem. Bioavailability of TE is strongly related to the soil physicochemical parameters and thus to the ecosystem type. In order to test whether soil parameters influence the response of the bacterial community to TE pollution, we collected soil samples across contrasting ecosystems (hardwood, coniferous and hydromorphic soils), which have been contaminated in TE and especially lead (Pb) over several decades due to nearby industrial smelting activities. Bacterial community composition was analysed using high throughput amplicon sequencing and compared to the soil physicochemical parameters. Multivariate analyses of the pedological and biological data revealed that the bacterial community composition was affected by ecosystem type in the first place. An influence of the contamination level was also evidenced within each ecosystem. Despite the important variability in bacterial community structure, we found that specific bacterial groups such as γ-Proteobacteria, Verrucomicrobia and Chlamydiae showed a consistent response to Pb content across contrasting ecosystems. Verrucomicrobia were less abundant at high contamination level whereas Chlamydiae and γ-Proteobacteria were more abundant. We conclude that such groups and ratio's thereof can be considered as relevant bioindicators of Pb contamination.

Trace element (TE) speciation modelling in soil solution is controlled by the assumptions made about the soil solution composition. To evaluate this influence, different assumptions using Visual MINTEQ were tested and compared to measurements of free TE concentrations. The soil column Donnan membrane technique (SC-DMT) was used to estimate the free TE (Cd, Cu, Ni, Pb and Zn) concentrations in six acidic soil solutions. A batch technique using DAX-8 resin was used to fractionate the dissolved organic matter (DOM) into four fractions: humic acids (HA), fulvic acids (FA), hydrophilic acids (Hy) and hydrophobic neutral organic matter (HON). To model TE speciation, particular attention was focused on the hydrous manganese oxides (HMO) and the Hy fraction, ligands not considered in most of the TE speciation modelling studies in soil solution. In this work, the model predictions of free ion activities agree with the experimental results. The knowledge of the FA fraction seems to be very useful, especially in the case of high DOM content, for more accurately representing experimental data. Finally, the role of the manganese oxides and of the Hy fraction on TE speciation was identified and, depending on the physicochemical conditions of the soil solution, should be considered in future studies.

The reconstituted stone used in the Orval Abbey is highly susceptible to salt weathering. It was produced from debris of natural stones (which were at that time in short supply) by craftsmen working in the Abbey and its composition is highly variable. The major salt involved in weathering is sodium sulfate (Na2SO4). This study focused on the thermal behavior of a reconstituted stone with various degrees of weathering observed on-site and it was studied by passive and active infrared thermography (IRT), and on the evolution of reconstituted-stone samples in a salt uptake experiment in the laboratory. On-site, the thermal responses of salt-weathered and unweathered zones were different. IRT allowed to detect unweathered though highly salt-laden zones, although correlations between thermal response and salt concentration are difficult to establish due to the influence of surface properties (color and roughness). In the laboratory, samples of the reconstituted stone were submitted to successive immersion-drying cycles in solutions of Na2SO4 with 7, 14 and 26 % concentration and characterized by weighing, surface colorimetry and active IRT. Results showed that the thermal response (increase in surface temperature due to flash excitation: T max) increased with salt concentration and with the number of cycles, as long as sample disintegration had not started. Then, it decreased and stabilized, whatever the salt concentration. Those results indicated that an increase in the thermal response of building materials (in active IRT) can be interpreted as an indicator of salt accumulation, possibly leading to damage. IRT proved to be an interesting non-destructive technique in this respect.

In champagne tasting, gaseous CO(2) and volatile organic compounds progressively invade the headspace above glasses, thus progressively modifying the chemical space perceived by the consumer. In this study, a novel, rapid, and nonintrusive method aimed to simultaneously determine the content in gaseous CO(2) and ethanol above a glass poured with champagne, using a micro-gas chromatography technique coupled with a thermal conductivity detector, was presented. The simultaneous quantification of CO(2) and ethanol in the headspace of a champagne glass was monitored, in real tasting conditions, all along the first 15 min following pouring, depending on whether or not the glass shows effervescence. Both CO(2) and ethanol were found to be enhanced by the presence of ascending bubbles, thus confirming the close link between rising bubbles and the release of gaseous CO(2) and volatile organic compounds.

A cell suspension culture was developed from calli of grape rootstock 41B in order to study the bioproduction of resveratrol. While 41B grape cultures produced no resveratrol, methyljasmonate (MeJA) elicitor treatment activated its production in a dose dependent manner. The concentration of 0.2 mM MeJA was optimal for efficient production and high accumulation of resveratrol (150 mg/L) in flask experiments. Microscopic analysis of cells monitored for viability showed that MeJA elicitor triggered expression of resveratrol fluorescence within the cells. These results led to scale-up of the culture in a 2 L stirred bioreactor where a resveratrol production of 209 mg/L being secreted into the liquid medium, corresponding to 90% of the total production. Liquid/liquid extraction of the culture medium and a solid/liquid extraction of the cells showed that other stilbenes were also produced. For the first time, trans-ɛ-viniferin, trans-δ-viniferin, and a trans-3-methylviniferin as well as trans-piceatannol were identified in a 2 L bioreactor cell cultures of grapevine. Furthermore, a one step FPLC method was developed for the purification of resveratrol and ɛ-viniferin.

Proteins have a great influence on wine quality as they exhibit a various range of properties. In fact, they are involved among others in white wine turbidity, organoleptic characteristics and foam formation in sparkling wines. These compounds could also be of major interest for varietal differentiation, regarding wine authentication and traceability issues. To provide a better understanding of the role played by these biomolecules in wine processing and explore their potential applications, there is a manifest need for the quantification and characterization of each individual one in terms of sequence, structure and intrinsic and functional properties. We thus present an overview of preparative and analytical methods for the study of proteins in grape juices and wines, from routine techniques to dedicated methodologies. They include sample preparation with chromatographic methods for the purification and identification of proteins, quantification protocols and characterization procedures such as electrophoretic techniques, immunological methods, sequencing, mass spectrometry, physico-chemical and structural analyses, and so on. We expose advantages and limits of each technique and focus on the different but complementary information they can provide. Despite the past years advances in the field proteins identification, the elucidation of the full protein profile for grape juices and wines remains strenuous. Their interactions with other wine compounds make the challenge even harder. We therefore emphasize the requirement of the techniques to be refined and suggest the developments to be expected.

In grapevine, stimulation of defence responses was evidenced in response to various types of abiotic stresses in both leaves and berries, as revealed by the increasing expression of genes encoding defence-related proteins or the stimulation of their corresponding activities. However, the capability of inflorescences to respond to abiotic stresses has never been investigated. Therefore, plant defence reactions in response to UV-C irradiation were followed in inflorescences and young clusters focusing on both bunchstems (peduncle and pedicels) and developing flowers/berries from separated floral buds stage [Biologische Bundesanstalt, Bundessortenamt and CHemical industry (BBCH) stage 57] to groat-sized berries stage (BBCH 73). For this purpose, the expression of various genes coding for pathogenesis-related (PR) proteins (class I and III chitinases, Chi1b and CH3; beta-1,3-glucanase, GLUC), an enzyme of the phenylpropanoid pathway (phenylalanine ammonia-lyase, PAL), and stilbene synthase (STS) was analysed in parallel with variations of chitinase activity and the accumulation of the phytoalexin resveratrol. Multiple defence responses were induced in bunchstems of both inflorescences and clusters following UV-C treatment. First, expression of genes encoding PR proteins was stimulated and chitinase activity was enhanced. Secondly, PAL and STS expression increased in association with resveratrol accumulation. Amazingly, none of the tested defence processes was induced in grapevine flowers following UV-C exposure, whatever the stage analysed. Similarly, in berries at fruit set, induction of gene expression was weak and neither an increase in chitinase activity nor resveratrol synthesis was noticed. However, in groat-sized berries, responsiveness to UV-C increased, as revealed by the induction of CH3, PAL, and STS expression, together with resveratrol accumulation. The differential responsiveness between bunchstems, flowers, and berries is discussed.

Background The extracellular space or apoplast forms a path through the whole plant and acts as an interface with the environment. The apoplast is composed of plant cell wall and space within which apoplastic fluid provides a means of delivering molecules and facilitates intercellular communications. However, the apoplastic fluid extraction from in planta systems remains challenging and this is particularly true for grapevine (Vitis vinifera L.), a worldwide-cultivated fruit plant. Large-scale proteomic analysis reveals the protein content of the grapevine leaf apoplastic fluid and the free interactive proteome map considerably facilitates the study of the grapevine proteome. Results To obtain a snapshot of the grapevine apoplastic fluid proteome, a vacuum-infiltration-centrifugation method was optimized to collect the apoplastic fluid from non-challenged grapevine leaves. Soluble apoplastic protein patterns were then compared to whole leaf soluble protein profiles by 2D-PAGE analyses. Subsequent MALDI-TOF/TOF mass spectrometry of tryptically digested protein spots was used to identify proteins. This large-scale proteomic analysis established a well-defined proteomic map of whole leaf and leaf apoplastic soluble proteins, with 223 and 177 analyzed spots, respectively. All data arising from proteomic, MS and MS/MS analyses were deposited in the public database world-2DPAGE. Prediction tools revealed a high proportion of (i) classical secreted proteins but also of non-classical secreted proteins namely Leaderless Secreted Proteins (LSPs) in the apoplastic protein content and (ii) proteins potentially involved in stress reactions and/or in cell wall metabolism. Conclusions This approach provides free online interactive reference maps annotating a large number of soluble proteins of the whole leaf and the apoplastic fluid of grapevine leaf. To our knowledge, this is the first detailed proteome study of grapevine apoplastic fluid providing a comprehensive overview of the most abundant proteins present in the apoplast of grapevine leaf that could be further characterized in order to elucidate their physiological function.

International audience; Chitinases and thaumatin-like proteins are important grape proteins as they have a great influence on wine quality. The quantification of these proteins in grape juices and wines, along with their purification, is therefore crucial to study their intrinsic characteristics and the exact role they play in wines. The main isoforms of these two proteins from Chardonnay grape juice were thus purified by liquid chromatography. Two fast protein liquid chromatography (FLPC) steps allowed the fractionation and purification of the juice proteins, using cation exchange and hydrophobic interaction media. A further high-performance liquid chromatography (HPLC) step was used to achieve higher purity levels. Fraction assessment was achieved by mass spectrometry. Fraction purity was determined by HPLC to detect the presence of protein contaminants, and by nuclear magnetic resonance (NMR) spectroscopy to detect the presence of organic contaminants. Once pure fractions of lyophilized chitinase and thaumatin-like protein were obtained, ultra-HPLC (UHPLC) and enzyme-linked immunosorbent assay (ELISA) calibration curves were constructed. The quantification of these proteins in different grape juice and wine samples was thus achieved for the first time with both techniques through comparison with the purified protein calibration curve. UHPLC and ELISA showed very consistent results (less than 16% deviation for both proteins) and either could be considered to provide an accurate and reliable quantification of proteins in the oenology field.

Stilbenic compounds recently have become the focus of a number of studies in medicine and plant physiology as well as have emerged as promising molecules that potentially affect human health. Stilbenes are relatively simple compounds synthesized by plants and deriving from the phenyalanine/polymalonate route, the last and key enzyme of this pathway being stilbene synthase. Here, we review the biological significance of stilbenes in plants together with their biosynthesis pathway and their metabolism both by fungi and in planta. Special attention will be paid to the role of stilbenic molecules as phytoalexins.

The grapevine phytoalexin resveratrol, the synthesis of which is achieved by stilbene synthase (STS), displays a wide range of biological effects. Most interest has centred, in recent years, on STS gene transfer experiments from grapevine to the genome of numerous plants. This work presents a comprehensive review on plant molecular engineering with the STS gene. Gene and promoter options are discussed, namely the different promoters used to drive the transgene, as well as the enhancer elements and/or heterologous promoters used to improve transcriptional activity in the transformed lines. Factors modifying transgene expression and epigenetic modifications, for instance transgene copy number, are also presented. Resveratrol synthesis in plants, together with that of its glucoside as a result of STS expression, is described, as is the incidence of these compounds on plant metabolism and development. The ectopic production of resveratrol can lead to broad-spectrum resistance against fungi in transgenic lines, and to the enhancement of the antioxidant activities of several fruits, highlighting the potential role of this compound in health promotion and plant disease control.

Invertase is a major protein of grape juice and wine. Accordingly, in order to study the biochemical and structural characteristics of this protein and for a better understanding of its physico-chemical properties, large amounts of the pure protein are needed. A simple method for the purification of the grape vacuolar invertase in a preparative-scale is described in this work. The grape protein was isolated and purified from must by ultrafiltration and anion exchange chromatography. The identification and purity determination of the grape invertase fraction were assessed by SDS-PAGE, and were then confirmed using nanoLC-chip-MS/MS analysis. The laboratory fractionation procedure presented in this work generated large quantities of pure grape vacuolar invertase from must.

The online version of the original article can be found at http://dx.doi.org/10.1007/s00216-011-4912-8 .

Levels of trans-resveratrol in Champagne wines were determined by the use of reversed-phase HPLC with UV and fluorometric detection after liquid-liquid extraction with ethyl acetate. Resveratrol concentrations in Champagne wines range from 20 to 77 μg/L except for the Champagne rosé in which resveratrol reaches several hundred micrograms per litre. The resveratrol content of Champagne wines was also shown to decrease with aging on lees.

International audience

International audience