References of "Fauconnier, Marie-Laure"
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See detailEffect of sun-drying on flavonoïd composition and antioxidant activity of three dark fig varieties
Bachir Bey, M.; Richard, Gaetan ULg; Fauconnier, Marie-Laure ULg et al

Poster (2014, February 07)

The aim of the study was to investigate the effect of sun-drying on individual flavonoïd and antioxidant activities of three dark fig varieties (Azenjar, Bouankik, and Aberkane). Flavonoïd compounds were ... [more ▼]

The aim of the study was to investigate the effect of sun-drying on individual flavonoïd and antioxidant activities of three dark fig varieties (Azenjar, Bouankik, and Aberkane). Flavonoïd compounds were identified and quantified using high-performance liquid chromatography. The results showed that all samples significantly differed in their flavonoïd compositions. [less ▲]

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See detailInteractions of a potential plant elicitor mannolipid with plant model membranes
Polo Lozano, Damien ULg; Lins, Laurence ULg; Ongena, Marc ULg et al

Poster (2014, February 07)

The use of chemical pesticides causes problems for human health and environment. In this context, there is an increasing interest for alternative products such as biopesticides. Among them, elicitors act ... [more ▼]

The use of chemical pesticides causes problems for human health and environment. In this context, there is an increasing interest for alternative products such as biopesticides. Among them, elicitors act on the plants by inducing systemic resistance against diseases caused by fungal, viral, bacterial agents and insects. The target of the elicitors is supposed to be the plant plasma membranes (PPM). The main mechanisms of interaction of many elicitors involve proteic receptors but lipid-based elicitors (LBE) may preferably interact with the lipidic fractions of PPM. However there is no detailed information at the molecular level on the PPM-LBE interactions. Our work is focused on a original synthetic LBE composed of a mannoside linked to a myristic acid. It has potential elicitor activities as shown by the assays on tobacco root cells. These activities could be related to its interaction with the lipidic phase of PPM. Since PPM are complex entities, the analyses of the PPM- molecule interactions are quite difficult. In this context, these interactions were carried out using biomimetic membranes of PPM such as Langmuir monolayers and multilayers. The effects of our molecule on these membranar systems were investigated by biophysical and in silico approaches. [less ▲]

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See detailUse of GC-MS in SIM-Scan mode for a selective quantification of polluting volatile organic compounds (VOC) in food industries
Eloundou Mballa, Pierre ULg; DETHIER, Bérénice ULg; Fauconnier, Marie-Laure ULg

Poster (2014, February 07)

The control of atmospheric emission discharges by food industries is classically achieved in two phases. The first one consists of sampling the target atmosphere followed by concentrating the volatile ... [more ▼]

The control of atmospheric emission discharges by food industries is classically achieved in two phases. The first one consists of sampling the target atmosphere followed by concentrating the volatile organic compounds (VOC) contained in a defined volume of this atmosphere on an adsorbing agent. These compounds are then thermally desorbed (TD) or desorbed with a solvent. In the second phase, the gas phase chromatogram (GC) will be coupled with mass spectrometry (MS) or flame ionization detector (FID) for compounds analysis. Quantitative analysis are usually achieved with solvent desorption followed by GC-FID. However, this mode imposes the dilution of the sample by a solvent and consequently may cause high detection thresholds as well as important matrix effect and possible interferences due to chemical reactions between analytes and the solvent. Besides, a preliminary qualitative analysis (GC-MS identification) is necessary. Combining TD-GC-MS allows very low detection thresholds to be reached, and the matrix effect and the interferences caused by products of the reactions between analytes and the solvent to be eliminated. The use of this combination in selected ion monitoring (SIM) mode allows targeting analytes via their characteristic ions, increasing their sensitivity and repeatability insuring more accuracy for simultaneous qualitative and quantitative analysis. This technique was experimented for seeking VOC in the atmosphere around food industries. [less ▲]

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See detailContribution to the study of alliinase, the active principle of garlic
DETHIER, Bérénice ULg; Ponchaux, Julien; Laloux, Morgan et al

Poster (2014, February 07)

Alliinase is a crucial enzyme in the Allium genus. The conversion of its substrates, cysteine sulfoxides, into volatile thiosulfinates is an important mechanism in the defence of the plant. It also ... [more ▼]

Alliinase is a crucial enzyme in the Allium genus. The conversion of its substrates, cysteine sulfoxides, into volatile thiosulfinates is an important mechanism in the defence of the plant. It also provides the typical pungent flavour of garlic. As a matter of fact, the thiosulfinates decompose in a range of organosulfur compounds (OSC) known for their biological activities (antioxidant, anticancer, anti-diabetes properties, etc.). The environment of the decomposition of the thiosulfinates determines the type and amount of products released. A deeper knowledge of the conditions that form each OSC could help us in the preparation of garlic-based nutraceutics in the perspective of healthier food consumption. This study aims to improve the extraction and purification the enzyme alliinase in order to perform the reaction between the enzyme and its substrates and assess the potentialities of garlic preparations. Three methods have been applied to evaluate the efficiency of the extractions and purifications of the enzyme. A first idea of the purity of the enzyme is given by an electrophoresis separation of each sample on a polyacrylamide gel (SDS-PAGE). The protein content is then measured by UV-vis spectrometry with Lowry-Folin reagent for the coloration and BSA as an external standard. Finally, the specific activity is assessed by an indirect measure of the pyruvate (released as a co-product): the addition of NADH and lactate dehydrogenase turns the pyruvate in lactate, and the disappearance of NADH is measured by UV-vis spectrometry at 340 nm. The extraction of the enzyme from garlic was performed either by PEG 8000 precipitation or by ammonium sulphate precipitation. Two purifications were tested: affinity chromatography (on ConA) and size-exclusion chromatography. The combination of the ammonium sulphate process with the ConA chromatography provided the purest enzyme, with the best activity but a lower yield than the size-exclusion process. Finally the stability of the enzyme has been assessed at 4, -20 and -80 °C, showing that the enzyme could be kept at -80 °C for over 4 months without deterioration, while activity loss was observed at higher temperature. [less ▲]

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See detailQuantitative gas chromatography - mass spectrometry profiling of volatile organic compounds produced by barley (Hordeum distichon L.) roots according to plant age
Delory, Benjamin ULg; Delaplace, Pierre ULg; du Jardin, Patrick ULg et al

Poster (2014, February 07)

In chemical ecology, the roles played by root-emitted volatile organic compounds (VOCs) in biotic interactions and the quantitative analysis of such chemicals in root tissues remain poorly documented. In ... [more ▼]

In chemical ecology, the roles played by root-emitted volatile organic compounds (VOCs) in biotic interactions and the quantitative analysis of such chemicals in root tissues remain poorly documented. In this context, this study aims at developing a fully automated analytical methodology allowing both identification and accurate quantification of VOCs produced by roots of a monocotyledon plant species. Briefly, VOC emitted by crushed barley roots are successively trapped by dynamic headspace sampling on Tenax TA adsorbents, thermally desorbed and cryofocused, separated by gas chromatography (GC) and finally analysed by mass spectrometry (MS) in both SCAN and selected ion monitoring modes. Results show that barley roots mainly produce four volatile aldehydes, namely hexanal, (E)-hex-2-enal, (E)-non-2-enal and (E,Z)-nona-2,6-dienal. These molecules are well-known linoleic (C18:2) and linolenic (C18:3) acid derivatives produced via the lipoxygenase and the hydroperoxide lyase pathways of higher plants. Our findings contrast with analyses documented on aboveground barley tissues that mainly emit C6 aldehydes, alcohols and their derivative esters. Moreover, preliminary results indicate quantitative changes in the volatile profile contained in barley roots according to plant age. Multivariate statistical analyses are currently underway to quantitatively assess these changes using plants at five selected developmental stages ranging from germination to the end of tillering. [less ▲]

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See detailAllelopathic potential of sunflower against the great brome
Bouhaouel, Imen ULg; Gfeller, Aurélie; Fauconnier, Marie-Laure ULg et al

Poster (2014, February 06)

Control methods commonly used to suppress the great brome (Bromus diandrus Roth., syn. Bromus rigidus Roth. subsp. gussonii Parl.) in Tunisian cereal crop are essentially chemical, raising both efficacy ... [more ▼]

Control methods commonly used to suppress the great brome (Bromus diandrus Roth., syn. Bromus rigidus Roth. subsp. gussonii Parl.) in Tunisian cereal crop are essentially chemical, raising both efficacy and safety issues. The introduction of allelopathic species into the crop rotation or utilizing allelopathic plants as living/green mulches has been suggested as a cost-effective way to reduce the weed presence. Among these species, the sunflower (Helianthus annuus L.) has shown an allelopathic potential against some troublesome weed species. In this study, we analyzed the biological activities of water extract of different tissues (root, shoot, leaf and flower) of sunflower on the seedling establishment of the great brome. In a second experiment, the allelopathic influence of sunflower residues (leaf or flower) against this weed was also studied under glasshouse conditions at more advanced stages of growth using different concentrations (0, 6, 12 and 18g tissue dry weight / kg of soil). The first experiment showed an effect depending on the parts of the sunflower. Indeed, the roots seem to be the less allelopathic part (22% of root inhibition growth) as compared to the leaves and flowers (82% and 100%, respectively). This potential seems to simultaneously affect the radicle and the coleoptile growth of the great brome. In the second experiment, weed growth was inhibited in a dose-dependent manner, using increasing amounts of sunflower residues. The allelopathic potential of the leaves or flowers reduced both the root or shoot length and biomass accumulation of the weed. These results suggest that the sunflower can be a good previous crop for cereal cultivation by controlling the presence of some weeds, including the great brome. In this perspective, the inhibitory effects of sunflower residues on cultivated cereals in the field need to be assessed. [less ▲]

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See detailNew alternatives to chemical pesticides: deciphering the action mechanisms of lipid based plant elicitors via complementary biophysical and biological approaches.
Nasir, Mehmet Nail ULg; Polo Lozano, Damien ULg; Luzuriaga Loaiza, Walter ULg et al

Poster (2014, February)

Nowadays, many health and environmental problems are caused by the use of chemical pesticides. In this context, an increasing demand for alternative products such as biopesticides has been observed. Among ... [more ▼]

Nowadays, many health and environmental problems are caused by the use of chemical pesticides. In this context, an increasing demand for alternative products such as biopesticides has been observed. Among biopesticides, elicitor molecules which are able to trigger immune defense responses in plants are one of the most promising options. Although numerous elicitors have been discovered, the mechanisms involved in the perception, by plants, of only a few molecules have been identified. These elicitors usually interact with proteic receptors but we have recently shown that they may also act on the lipid phase of the plasma membrane. This project first aims to improve our understanding of the molecular mechanisms involved in the recognition of specific lipid based elicitors (LBE). On that basis, the FIELD project will contribute to the design and the development of innovative compounds derived natural LBE. A multi-disciplinary approach, based on chemistry, bio-physics, bio-chemistry, and phytopathology will be followed by a consortium of different research groups from Gembloux Agro-Bio Tech in close collaboration with teams from foreign institutions. [less ▲]

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See detailTechnologie de production de masse d’insectes - INSECTECH
Richard, Gaetan ULg; Hance, Thierry; Fauconnier, Marie-Laure ULg et al

Report (2014)

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See detailAssessing the foraging behavior of Agriotes sordidus wireworms in dual-choice olfactometers
Barsics, Fanny ULg; Fiers, Marie; Fauconnier, Marie-Laure ULg et al

in Communications in Agricultural and Applied Biological Sciences (2014), 79(2), 151-156

The different steps of the foraging process of wireworms (Coleoptera: Elateridae) would be better understood if accurate and holistic information regarding the role of plant-produced chemicals ... [more ▼]

The different steps of the foraging process of wireworms (Coleoptera: Elateridae) would be better understood if accurate and holistic information regarding the role of plant-produced chemicals constituting their environment were available. Volatile organic compounds (VOC) play important roles in the interactions between plants and insects in many ecosystems, whether they take place aboveground or belowground. The roles of VOC are still relatively unknown for wireworms, and deserve attention. Here, we performed three experimentations with barley roots as baits. In the two first, we assessed the effect of chopped roots and fungus infected roots on the orientation of wireworms. In the third experiment, the larvae were confronted to both healthy and fungus infected roots. We discuss the results in terms of suitability of the olfactometers we designed for the investigation of olfaction in wireworms, and we provide suggestions to improve their use. [less ▲]

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See detailIdentification of 1-methyloctyl butanoate as the major sex pheromone component from females of the saddle gall midge, Haplodiplosis marginata (Diptera: Cecidomyiidae)
Censier, Florence ULg; Fischer, Christophe ULg; Laurent, Pascal et al

in Chemoecology (2014)

The saddle gall midge, Haplodiplosis marginata (von Roser) (Diptera: Cecidomyiidae), has undergone a resurgence recently as a pest of cereals in Belgium and other European countries. An effective ... [more ▼]

The saddle gall midge, Haplodiplosis marginata (von Roser) (Diptera: Cecidomyiidae), has undergone a resurgence recently as a pest of cereals in Belgium and other European countries. An effective monitoring tool of saddle gall midge flights is needed in order to understand the enigmatic population dynamics of this pest, and to design an integrated management strategy. Therefore, volatile compounds emitted by females (alkan-2-ols and alk-2-yl butanoates) were identified, and the chirality of the emitted esters was determined to be the R absolute configuration. In field-trapping experiments, racemic non-2-yl butanoate attracted substantial numbers of H. marginata males. Thus, this compound will be useful in baited traps for monitoring seasonal flight patterns, and improving integrated management of the saddle gall midge in agricultural systems. [less ▲]

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See detailReprogramming of fatty acid and oxylipin synthesis in rhizobacteria-induced systemic resistance in tomato
Mariutto, Martin; Fauconnier, Marie-Laure ULg; Ongena, Marc ULg et al

in Plant Molecular Biology (2014), 84(4-5), 455-476

The rhizobacterium Pseudomonas putida BTP1 stimulates induced systemic resistance (ISR) in tomato. A previous work showed that the resistance is associated in leaves with the induction of the first enzyme ... [more ▼]

The rhizobacterium Pseudomonas putida BTP1 stimulates induced systemic resistance (ISR) in tomato. A previous work showed that the resistance is associated in leaves with the induction of the first enzyme of the oxylipin pathway, the lipoxygenase (LOX), leading to a faster accumulation of its product, the free 13-hydroperoxy octadecatrienoic acid (13-HPOT), 2 days after Botrytis cinerea inoculation. In the present study, we further investigated the stimulation of the oxylipin pathway: metabolites and enzymes of the pathway were analyzed to understand the fate of the 13-HPOT in ISR. Actually the stimulation began upstream the LOX: free linolenic acid accumulated faster in P. putida BTP1-treated plants than in control. Downstream, the LOX products 13-fatty acid hydroperoxides esterified to galactolipids and phospholipids were more abundant in bacterized plants than in control before infection. These metabolites could constitute a pool that will be used after pathogen attack to produce free fungitoxic metabolites through the action of phospholipase A2, which is enhanced in bacterized plants upon infection. Enzymatic branches which can use as substrate the fatty acid hydroperoxides were differentially regulated in bacterized plants in comparison to control plants, so as to lead to the accumulation of the most fungitoxic compounds against B. cinerea. Our study, which is the first to demonstrate the accumulation of an esterified defense metabolite during rhizobacteria-mediated induced systemic resistance, showed that the oxylipin pathway is differentially regulated. It suggests that this allows the plant to prepare to a future infection, and to respond faster and in a more effective way to B. cinerea invasion. [less ▲]

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See detailPlants as a source of green corrosion inhibitors on mild steel in hydrochloric acid: The case of oil extract of leaves of Pistacia lentiscus from Saidia Morocco
Aouinti, Fatima; Elmsellem, Hicham; Bachiri, Ali et al

in Journal of Chemical and Pharmaceutical Research (2014), 6(7), 10-23

The aim of this work was to characterize the essential oils of Pistacia lentiscus (P.L) from Saidia Morocco and analysis by gas chromatograph interfaced with a mass spectrometer (GC-MS). The Corrosion ... [more ▼]

The aim of this work was to characterize the essential oils of Pistacia lentiscus (P.L) from Saidia Morocco and analysis by gas chromatograph interfaced with a mass spectrometer (GC-MS). The Corrosion inhibition effect of organic oil and extract of leaves of Pistacia lentiscus (P.L) of mild steel in 1M HCl solution was carried out using, gravimetric, electrochemical polarization and EIS methods. Experiments are performed by varying concentration of the inhibitor. The inhibition efficiency increases with increased organic oil and extract concentration to attain a maximum value of 96.34 % and 86.59% at 1g/L for oil and extract respectively. The study reveals that oil, was dominated by monoterpene hydrocarbons (44.99%) followed by xygenated monoterpenes (13.66%) and Sesquiterpene hydrocarbons (16.59%). Among them, limonene (18.92%), α-pinene (13.94%), β- caryo phyllene (6.93%) and terpinen-4-ol (5.57%) were identified as major components. The Pistacia lentiscus oil and extract acts a mixed inhibitor and showed a result of the growth in the compactness of the protecting film dressing. The organic oil and extract adsorbs on the mild steel surface according to a Langmuir isotherm adsorption model. [less ▲]

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See detailWhole-genome sequence of Serratia symbiotica strain CWBI-2.3T, a free-living symbiont of the Black Bean Aphid Aphis fabae
Foray, Vincent; Grigorescu, Alina ULg; Sabri, Ahmed et al

in Genome Announcements (2014), 2(4),

The gammaproteobacterium Serratia symbiotica is one of the major secondary symbionts found in aphids. Here, we report the draft genome sequence of S. symbiotica strain CWBI-2.3T, previously isolated from ... [more ▼]

The gammaproteobacterium Serratia symbiotica is one of the major secondary symbionts found in aphids. Here, we report the draft genome sequence of S. symbiotica strain CWBI-2.3T, previously isolated from the black bean aphid Aphis fabae. The 3.58-Mb genome sequence might provide new insights to understand the evolution of insect-microbe symbiosis. [less ▲]

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See detailCharacterization and Adsorption Study of Thymol on Pillared Bentonite
El Miz, Mohamed; Salhi, S.; Chraibi, I. et al

in Open Journal of Physical Chemistry (2014), 4(3), 98-116

Pillared clay (PILC) was prepared from Moroccan clay and characterized, and its aqueous thymol adsorption capacities were studied using a batch equilibrium technique. So, we tested the encapsulation of ... [more ▼]

Pillared clay (PILC) was prepared from Moroccan clay and characterized, and its aqueous thymol adsorption capacities were studied using a batch equilibrium technique. So, we tested the encapsulation of thymol by aluminum pillared clay (PILC). The PILCs displayed a total surface area of 270 m2/g, a total pore volume of 0.246 cm3/g and an average pore diameter of 8.9 Å, which corresponds to the size of Al13 forming the pillars between the clay layers. The adsorption capacity shown by the PILCs for thymol from water is close to 319 mg∙g−1 for low solid/liquid ratio (0.2%). This result suggests that the PILCs have both hydrophobic and hydrophilic characteristics, as a result of the presence of silanol and siloxane groups formed during the pillaring and calcination of the PILCs. The experimental data were analyzed by the Freundlich and the Langmuir isotherm types for low values of equilibrium concentration. The rise of the isotherm in this range of concentrations was related to the affinity of thymol for clay sites, and the equilibrium data fitted well with the Freundlich model with maximum adsorption capacity of 319.51 mg/g for a ratio RS/L = 0.2%. Pseudo-first and pseudo-second-order kinetic models were tested with the experimental data and pseudo-first order kinetics was the best for the adsorption of thymol with coefficients of correlation R² ≥0.986, and the adsorption was rapid with 90% of the thymol adsorbed within the first 20 min. [less ▲]

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See detailComposition chimique et activité antimicrobienne de l’huile essentielle de Thymus vulgaris du Nord d’Algérie
Sidali, L.; Brada, M.; Fauconnier, Marie-Laure ULg et al

in PhytoChem & BioSub Journal (2014), 8(3), 156-161

Twenty five constituents were identified by GC MS analysis of essential loils from. Thymus vulgaris. The main compounds identified were carvacrol (55,2%),γ-terpinene (12,6%), p-cymene (9,3%), linalol (3,9 ... [more ▼]

Twenty five constituents were identified by GC MS analysis of essential loils from. Thymus vulgaris. The main compounds identified were carvacrol (55,2%),γ-terpinene (12,6%), p-cymene (9,3%), linalol (3,9%) and α-terpinene (2,8%). The obtained Essential oils exhibited antibacterial and antifungal activities against S.P. Sterptococcus, staphylococcus aureus, E.coli, Klebscila and condidat albicans. [less ▲]

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See detailComparative study of volatile secondary metabolite of Cistus libanotis during different process
Zidane, H.; Fauconnier, Marie-Laure ULg; Sindic, Marianne ULg et al

in Journal of Chemical and Pharmaceutical Research (2014), 6(8), 281-287

Chemical composition of the essential oils of Cistus libanotis from eastern Morocco (Tafoughalt and Jerrada) extracted from different season was analyzed by GC-MS and GC-FID. The hydro-distilled essential ... [more ▼]

Chemical composition of the essential oils of Cistus libanotis from eastern Morocco (Tafoughalt and Jerrada) extracted from different season was analyzed by GC-MS and GC-FID. The hydro-distilled essential oil content ranged from 0, 27 % to 0, 46%, the maximum amounts were observed in summer while minimum in winter for Tafoughalt, whereas the oil obtained from Jerrada had the highest yield (0, 61 %). The essential oils consisted of terpineol-4 as the most abundant component (18, 70 % - 24, 91 %), followed by γ-terpinene (9, 82 % - 12, 25 %), camphene (5, 86 % - 13, 58 %), sabinene (7, 86 % - 9, 89 %) and α-thujene (6, 92 % - 10, 12 %). Samples collected in all seasons were found to be richer in monoterpenes hydrocarbons (52, 68 % - 57, 59 %). None sesquiterpene hydrocarbons found in the oils from summer and autumn. Drying period of leaves at normal air laboratory and distillation time also affect the oil content and composition. There was variation in terpineol-4 content from 22, 23 % (4th day of drying) to 19, 27 % (29th day of drying), and from 35, 60 % (1 hour of distillation) to 24, 17 % (4 hours of distillation). It can be concluded that the harvesting season, period of drying and the time of distillation had an effect on the yield of essential oil and chemical composition of various compounds. [less ▲]

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