References of "Richel, Aurore"
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See detailHemicelluloses and Lignin in Biorefineries
wertz, Jean-Luc; Deleu, Magali ULg; Coppée, Séverine et al

Book published by CRC Press (in press)

Hemicelluloses and Lignin in Biorefineries provides an understanding of lignocellulosic biomass, which is mainly composed of cellulose, hemicelluloses, and lignin. It promotes the valorization of these ... [more ▼]

Hemicelluloses and Lignin in Biorefineries provides an understanding of lignocellulosic biomass, which is mainly composed of cellulose, hemicelluloses, and lignin. It promotes the valorization of these molecules in the context of the bioeconomy and presents hemicelluloses and lignin, which are generated in lignocellulosic biorefineries, as the molecules of the future. The viability of these molecules lies in their renewability and potential. This book covers all aspects of hemicelluloses and lignin including structure, biosynthesis, extraction, biodegradation, and conversion. The book also looks ahead to the socioeconomic and environmental value of biobased industry and emphasizes an understanding of the potential of lignocellulosic biomass. [less ▲]

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See detailEffect of Organic Solvents on Microalgae Growth, Metabolism and Industrial Bioproduct Extraction: A Review
Miazek, Krystian ULg; Kratky, Lukas; Sulc, Radek et al

in International Journal of Molecular Sciences (2017)

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See detailSbCOMT (Bmr12) is involved in the biosynthesis of tricin-lignin in sorghum
Eudes, Aymerick; Dutta, Tanmoy; Deng, Kei et al

in PLoS ONE (2017), 12(6), 1-11

Lignin in plant biomass represents a target for engineering strategies towards the development of a sustainable bioeconomy. In addition to the conventional lignin monomers, namely p-coumaryl, coniferyl ... [more ▼]

Lignin in plant biomass represents a target for engineering strategies towards the development of a sustainable bioeconomy. In addition to the conventional lignin monomers, namely p-coumaryl, coniferyl and sinapyl alcohols, tricin has been shown to be part of the native lignin polymer in certain monocot species. Because tricin is considered to initiate the polymerization of lignin chains, elucidating its biosynthesis and mechanism of export to the cell wall constitute novel challenges for the engineering of bioenergy crops. Late steps of tricin biosynthesis require two methylation reactions involving the pathway intermediate selgin. It has recently been demonstrated in rice and maize that caffeate O-methyltransferase (COMT) involved in the synthesis syringyl (S) lignin units derived from sinapyl alcohol also participates in the synthesis of tricin in planta. In this work, we validate in sorghum (Sorghum bicolor L.) that the O-methyltransferase responsible for the production of S lignin units (SbCOMT / Bmr12) is also involved in the synthesis of lignin-linked tricin. In particular, we show that biomass from the sorghum bmr12 mutant contains lower level of tricin incorporated into lignin, and that SbCOMT can methylate the tricin precursors luteolin and selgin. Our genetic and biochemical data point toward a general mechanism whereby COMT is involved in the synthesis of both tricin and S lignin units. [less ▲]

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See detailLaccase detoxification of lignocellulose hydrolysate
Cornet, Iris; Soti, Valentin; Richel, Aurore ULg et al

Poster (2017, May 22)

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See detailStructure impact of two galactomannan fractions on their viscosity properties in dilute solution, unperturbed state and gel state
Gillet, Sébastien; Aguedo, Mario ULg; Petrut, Raoul et al

in International Journal of Biological Macromolecules (2017), 96

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See detailBeech wood Fagus sylvatica dilute-acid hydrolysate as a feedstock to support Chlorella sorokiniana biomass, fatty acid and pigment production
Miazek, Krystian ULg; Remacle, Claire ULg; Richel, Aurore ULg et al

in Bioresource Technology (2017), 230(April 2017), 122131

This work evaluates the possibility of using beech wood (Fagus sylvatica) dilute-acid (H2SO4) hydrolysate as a feedstock for Chlorella sorokiniana growth, fatty acid and pigment production. Neutralized ... [more ▼]

This work evaluates the possibility of using beech wood (Fagus sylvatica) dilute-acid (H2SO4) hydrolysate as a feedstock for Chlorella sorokiniana growth, fatty acid and pigment production. Neutralized wood acid hydrolysate, containing organic and mineral compounds, was tested on Chlorella growth at different concentrations and compared to growth under phototrophic conditions. Chlorella growth was improved at lower loadings and inhibited at higher loadings. Based on these results, a 12% neutralized wood acid hydrolysate (Hyd12%) loading was selected to investigate its impact on Chlorella growth, fatty acid and pigment production. Hyd12% improved microalgal biomass, fatty acid and pigment productivities both in light and in dark, when compared to photoautotrophic control. Light intensity had substantial influence on fatty acid and pigment composition in Chlorella culture during Hyd12%-based growth. Moreover, heterotrophic Chlorella cultivation with Hyd12% also showed that wood hydrolysate can constitute an attractive feedstock for microalgae cultivation in case of lack of light. [less ▲]

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See detailInfluence of corn variety, drying temperature and moisture content at harvest on the saccharides released during an in vitro pepsin-pancreatin digestion
Odjo, Sylvanus; Huart, François ULg; Bera, François ULg et al

in Starch-Stärke (2017)

High-Performance Anion-Exchange Chromatography Coupled with Pulsed Amperometric Detection (HPAEC-PAD) was used to quantify and to determine the nature of saccharides released after the digestion of two ... [more ▼]

High-Performance Anion-Exchange Chromatography Coupled with Pulsed Amperometric Detection (HPAEC-PAD) was used to quantify and to determine the nature of saccharides released after the digestion of two corn grains submitted to different drying and harvesting protocols. Five saccharides were quantified: glucose, maltose, isomaltose, maltotriose and glucosyl-maltotriose. After a subsequent hydrolysis with amyloglucosidase of the released sugar, the amount of total glucose recovered increased with the increase in drying temperature and the moisture content of grain at harvest. These results suggest that structural changes induced within corn starch granules during drying affect their hydrolysis by amylases. These changes may lead to different pathways of sugar absorption in the small intestine of monogastrics. Thus, corn grains with a similar composition may lead to different levels of metabolizable energy upon gastro-intestinal digestion. [less ▲]

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See detailPlant fibers for renewable growing media: acidification or inoculation with biocontrol fungi to reduce the N drawdown in extruded Miscanthus straw
Vandecasteele, Bart; Debode, Jane; Muylle, Hilde et al

Conference (2017)

Peat based growing media are not sustainable and not easily colonized by biocontrol organisms. Plant fibers may allow for partially replacing peat in growing media and they may have the potential to carry ... [more ▼]

Peat based growing media are not sustainable and not easily colonized by biocontrol organisms. Plant fibers may allow for partially replacing peat in growing media and they may have the potential to carry biocontrol organisms. However, they may also carry plant pathogens and they may vary in their degree of biodegradability and their interaction with N, and thus they may affect the quality of growing media. Several defiberization techniques were tested for flax shives, miscanthus and reed straw for their ability to (1) kill plant pathogens present on the plant fibers, (2) reduce the N-fixation risk of the fibers and (3) provide fibers serving as carrier of biocontrol fungi. Flax shives obtained from various sources were colonized by viable microsclerotia of the plant pathogen Verticillium dahliae. However, when sufficiently high temperatures were reached during defiberization, this technique killed the plant pathogen on the shives, allowing the use of defiberized flax shives in growing media. Untreated flax shives, miscanthus or reed straw were characterized by high N immobilization. Using these plant fibers as peat replacement in growing media may thus reduce N availability for plants. According to the incubation trials results, extruding, retruding and applying disc refining significantly reduced the N immobilization for miscanthus straw without affecting the pH of the fiber, while steam explosion significantly reduced the pH and resulted in higher N immobilisation. Extruding and retruding the flas shives increased the N fixation. Defiberized pure miscanthus or reed straw and flax shives were easily colonized by fungal biocontrol strains, e.g. Trichoderma spp. . The effect of inoculation with fungi or acidification on N fixation was tested for extruded miscanthus fibers. Inoculation with shiitake (Lentinula edodes) or Agrocybe aegerita, i.e., 2 fungi without biocontrol properties was effective in reducing the N immobilization only in a specific pH range and at high colonization degree and/or for fungi with fast colonization, but never increased the N fixation when successfully inoculated. Inoculation of extruded Miscanthus fibers with different strains of biocontrol fungi did not increase nor decrease the N immobilization. Reducing the pH of the fibers between pH 2.5 and 4.7 was effective in reducing the microbial activity and the N fixation. Finetuning the conditions is necessary when applying acidification or inoculation for reducing the N fixation in plant fibers. N immobilization in growing media is related to biological activity. We compared 3 methods to determine the microbial biomass on plant fibers in growing media incubated with mineral N fertilizers, i.e., fumigation-extraction, plfa and Q-PCR, and used water-extractable C to measure the easily available C in the plant fibers. The extrusion of miscanthus straw with or without inoculation of a biocontrol organism reduced the N immobilization when compared with the pure fiber. In case of flax shives, defiberization of plant fibers kills plant pathogens that may be present on the fibers when sufficiently high temperatures are reached during defiberization. Inoculation of plant fibers with biocontrol fungi may be beneficial for increasing the disease resistance in growing media, and we found that inoculation of extruded Miscanthus fibers with biocontrol fungi did not increase nor decrease the N immobilization. [less ▲]

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See detailAdaptation of Severity Factor Model According to the Operating Parameter Variations Which Occur During Steam Explosion Process
Jacquet, Nicolas ULg; Richel, Aurore ULg

in Thomsen, Hedegaard Mette; Trajano, Heather L.; Ruiz, Hector A. (Eds.) Hydrothermal Processing in Biorefineries Production of Bioethanol and High Added-Value Compounds of Second and Third Generation Biomass (2017)

Literature shows that steam explosion is a relevant process for the pretreatment of lignocellulosic biomass in the aims to improve the accessibility of materials by modification of their physicochemical ... [more ▼]

Literature shows that steam explosion is a relevant process for the pretreatment of lignocellulosic biomass in the aims to improve the accessibility of materials by modification of their physicochemical properties. All physicochemical modifications are functions of many parameters (pressure/temperature, retention time, pH, etc.) which are not constant and must be taken into account to estimate the pretreatment intensity. Previous paragraphs show that some models integrate the evolution of temperature/pressure and pH during the process. However, the biomass complexity indicates that many other parameters could be involved, which suggest that models developed today don’t give an accurate estimation of the treatment severity. To achieve a complete model, each parameter involved in the process should be further studied specifically to identify their effect on the process intensity. This approach would permit to know more precisely the effects of each parameter on the biomass structure and identify their impact on steam explosion intensity. [less ▲]

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See detailStructure impact of two galactomannan fractions on their viscosityproperties in dilute solution, unperturbed state and gel state
Gillet, Sébastien; Aguedo, Mario ULg; Petrut, Raul Flaviu ULg et al

in International Journal of Biological Macromolecules (2017), 96

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See detailEffect of steam explosion treatment on chemical composition and characteristic of organosolv fescue lignin
Maniet, Guillaume ULg; Schmetz, Quentin ULg; Jacquet, Nicolas ULg et al

in Industrial Crops and Products (2017), 99

Tall fescue, a grass currently grown as forage, presents a good potential as a feedstock in the developmentof biorefining. In this study, combination of steam explosion and an acetic/formic acid ... [more ▼]

Tall fescue, a grass currently grown as forage, presents a good potential as a feedstock in the developmentof biorefining. In this study, combination of steam explosion and an acetic/formic acid “organosolv”pretreatments are applied on raw fescue to optimize lignin extraction yields and obtain specific products.In a first step, fescue is pretreated by steam explosion under severity factors from 1.4 to 4.2. Thesetreatments allow hemicelluloses solubilization and open the lignocellulosic structure. Steam explodedsolid residues are then treated with an acetic acid (50%)/formic acid (30%)/water (20%) mixture. Extractedlignins are precipitated and characterized by size exclusion chromatography (SEC),31P NMR and HSQCNMR. Results show that acetic and formic acids extracted lignins present G, H and S units with ferulate andp-coumarate. Lignin typical linkages identified are of -O-4 and spirodienone substructures. Combinationof steam explosion and acetic and formic acid pretreatments increases extraction yields from 30% to100%. Moreover, an increase of the steam explosion treatment intensity induces chemical modificationsin lignin structure such -O-4 and spirodienone substructure degradations, increase of free COOH andphenolic OH bonds, decrease of aliphatic OH ferulate and p-coumarate bonds and changes in G/H/S unitsproportions. Steam explosion intensity affects also lignin molecular weights. [less ▲]

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See detailCorn stover as feedstock for the production of ethanol: chemical composition of different anatomical fractions and varieties
Berchem, Thomas ULg; Roiseux, Olivier; Vanderghem, Caroline et al

in Biofuels, Bioproducts and Biorefining (2017)

The available grain corn stover produced in Belgium is estimated at 290 000 dry tons, a suffi cient amount to supply a biorefi nery. Differences regarding size, prematurity, and drying speed have been ... [more ▼]

The available grain corn stover produced in Belgium is estimated at 290 000 dry tons, a suffi cient amount to supply a biorefi nery. Differences regarding size, prematurity, and drying speed have been observed among the cultivated grain corn varieties in Wallonia (Belgium). This study aims to evaluate the variation in composition of different anatomical fractions (stalks, leaves, cobs, and husks) of three Walloon varieties of grain corn stover (SyMultitop, Padrino, and Alduna) with significant production volumes. In addition, the Padrino variety was assessed for variation in chemical composition at three harvesting times. Walloon grain corn stover contains large amounts of polysaccharides (33.4% to 41.3% of glucans and 13.9% to 28.2% of xylans) and lignin (10.4% to 15.3%). Some différences were noted between varieties and anatomical fractions. Depending on how the feedstock is harvested, it is possible to produce between 79 and 81 M liters of ethanol per year without adversely affecting soil sustainability. [less ▲]

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See detailImpact of pollen resources drift on common bumblebees in NW Europe
Roger, N.; Moerman, R.; Carvalheiro, L. G. et al

in Global Change Biology (2017), 23(1), 68-76

Several bee species are experiencing significant population declines. As bees exclusively rely on pollen for development and survival, such declines could be partly related to changes in their host plant ... [more ▼]

Several bee species are experiencing significant population declines. As bees exclusively rely on pollen for development and survival, such declines could be partly related to changes in their host plant abundance and quality. Here, we investigate whether generalist bumblebee species, with stable population trends over the past years, adapted their diets in response to changes in the distribution and chemical quality of their pollen resources. We selected five common species of bumblebee in NW Europe for which we had a precise description of their pollen diet through two time periods (‘prior to 1950’ and ‘2004–2005’). For each species, we assessed whether the shift in their pollen diet was related with the changes in the suitable area of their pollen resources. Concurrently, we evaluated whether the chemical composition of pollen resources changed over time and experimentally tested the impact of new major pollen species on the development of B. terrestris microcolonies. Only one species (i.e. B. lapidarius) significantly included more pollen from resources whose suitable area expanded. This opportunist pattern could partly explain the expansion of B. lapidarius in Europe. Regarding the temporal variation in the chemical composition of the pollen diet, total and essential amino acid contents did not differ significantly between the two time periods while we found significant differences among plant species. This result is driven by the great diversity of resources used by bumblebee species in both periods. Our bioassay revealed that the shift to new major pollen resources allowed microcolonies to develop, bringing new evidence on the opportunist feature of bumblebee in their diets. Overall, this study shows that the response to pollen resource drift varies among closely related pollinators, and a species-rich plant community ensures generalist species to select a nutrient-rich pollen diet. © 2016 John Wiley & Sons Ltd [less ▲]

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See detailComprehension of an organosolv process for lignin extraction on Festuca arundinacea and monitoring of the cellulose degradation
Schmetz, Quentin ULg; Maniet, Guillaume ULg; Jacquet, Nicolas ULg et al

in Industrial Crops and Products (2016), 94

It is commonly accepted that the current society needs to partially substitute fossil resources by renewable ones. Among many solutions, one approach consists in the development of biorefinery involving ... [more ▼]

It is commonly accepted that the current society needs to partially substitute fossil resources by renewable ones. Among many solutions, one approach consists in the development of biorefinery involving lignocellulosic biomass to produce bio-based materials and fuels. This study focuses on the comprehension of an organosolv treatment designed to break the complex lignocellulosic structure for high purity lignin extraction from tall fescue (Festuca arundinacea Schreb.). This grass benefits from an increasing interest in Western Europe and has been suggested as feedstock for biorefinery. However, its use as material for high purity lignin production has not been determined yet. Ethanol/water, 92/8% [v/v] with H2SO4 0.32 M was investigated at pilot scale under conventional heating (5 °C min−1 during 30 min and stabilized at 148 °C for 5 min). Precipitated lignin were analyzed as well as the composition of side-stream products (recovered cellulosic pulp and the aqueous hydrolysate). Lignin has been recovered at a purity level of 90% with a yield of 60%. The main contaminants were nitrogen containing compounds and degraded hemicelluloses. 2D-HSQC NMR (Two Dimension-Heteronuclear Single Quantum Correlation Nuclear Magnetic Resonance) revealed a co-extraction of ferulates and coumarates function as well as arabinoxylan. Cellulose was recovered at 53% purity with 60% yield. The conditions appear to be too harsh for tall fescue and led to significant amount of cellulose degradation. A process using a lower alcohol concentration will be developed to provide better yields of both cellulose and lignin. [less ▲]

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See detailLe profil en fibres alimentaires de légume modifie leur fermentation intestinale et la production d’acides gras à chaine courte dans modèle in vitro humain
Kalala Bolokango, Gaetan ULg; Kambashi Mutiaka, Bienvenu ULg; Njeumen, Patrick et al

Poster (2016, December 01)

La modulation du microbiote intestinal induite par les fibres alimentaires (DF)a des conséquences positives sur la santé, notamment sur l’obésité et ses comorbidités. La nature et l’ampleur des ... [more ▼]

La modulation du microbiote intestinal induite par les fibres alimentaires (DF)a des conséquences positives sur la santé, notamment sur l’obésité et ses comorbidités. La nature et l’ampleur des changements dépendent du type de fibres.Les légumes sont des sources privilégiées de DF, certaines espèces et variétés fournissant davantage de DF solubles (SDF), d’autres étant plus riches en DF insolubles (IDF). Contrairement aux SDF, les IDF sont souvent considérées comme peu fermentescibles, ne contribuant que faiblement à une modulation de l’écophysiologie intestinale. En opposition à cette hypothèse, pour explorer si l’impact potentiel sur la santé intestinale des légumes varie suivant leur nature, des légumes présentant des teneurs et des profils en DF différents ont été comparés dans un modèle in vitro de fermentation colique. [less ▲]

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See detailNutritional Composition and Rearing Potential of the Meadow Grasshopper (Chorthippus parallelus Zetterstedt)
Paul, Aman ULg; Frederich, Michel ULg; Uyttenbroeck, Roel ULg et al

in Journal of Asia-Pacific Entomology (2016), 19(4), 1111-1116

Insects, particularly those belonging to the family Acrididae (grasshoppers), are commonly consumed as human food in many parts of the world. Grasshoppers of the species Chorthippus parallelus are ... [more ▼]

Insects, particularly those belonging to the family Acrididae (grasshoppers), are commonly consumed as human food in many parts of the world. Grasshoppers of the species Chorthippus parallelus are abundantly found throughout Europe. However, these insects were not consumed by Europeans till now, but could possibly be used as human food, which is why we investigated their chemical composition. We found that they contain high level of proteins (69%), with an excellent amino acid profile and protein digestibility (97%). Furthermore, specimens of C. parallelus have an interesting fatty acids profile and minerals composition. Preliminary toxicity assessment indicates that these insects do not exhibit toxicity towards neutrophil cells (white blood cells). These data suggest that C. parallelus could be considered for human consumption. Rearing trials done during the study show that commercial rearing could be developed to produce sufficient biomass for sustaining human consumption. [less ▲]

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See detailHydrocracking and ionic liquids pretreatments effects on aldehydes extraction and lignin modification of Arabidopsis and Sorghum
Jacquet, Nicolas ULg; Richel, Aurore ULg

Scientific conference (2016, November 16)

Study shown the effect of hydrocracking and ionic liquids pretreatments on aldehydes extraction and physico-chemical properties modification of model ligninfrom Arabidopsis and Sorghum. Result of the ... [more ▼]

Study shown the effect of hydrocracking and ionic liquids pretreatments on aldehydes extraction and physico-chemical properties modification of model ligninfrom Arabidopsis and Sorghum. Result of the study show various effect of the pretreatment on the molecular weight of lignin and make links between pretratment applied and chemical links between lignin monomers. [less ▲]

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See detailThermochemical conversion of sugar industry by-products to biofuel
Nicodème, Thibault ULg; Jacquet, Nicolas ULg; Richel, Aurore ULg

Poster (2016, October 24)

Poster concernant la conversion des co-produits de l'industrie sucrière en biocarburants via la voie thermochimique. Description des procédés tels que la gazéification, Fischer-Trospch, la pyrolyse.

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