References of "Vandenbol, Micheline"
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See detailFunctional screening of a metagenomic library from algal biofilms
Martin, Marjolaine ULg; Barbeyron, Tristan; Michel, Gurvan et al

in Smagghe, Guy; Boeckx, Pascal; Bossier, Peter (Eds.) et al Communications in Agricultural and Applied Biological Sciences (2013, February 08)

Macroalgae, and particularly their lignin-free polysaccharides, are increasingly used for their gelling and therapeutic properties and for the production of biofuels and renewable chemical compounds. To ... [more ▼]

Macroalgae, and particularly their lignin-free polysaccharides, are increasingly used for their gelling and therapeutic properties and for the production of biofuels and renewable chemical compounds. To extract, hydrolyze and purify this biomass, algae hydrolyzing enzymes are needed. Our work aims to identify and characterize algal biomass hydrolyzing enzymes expressed by microorganisms living on the surface of algae, by functional metagenomics. Therefore, a microbial DNA extraction method was developed to isolate the gDNA from the microorganisms of the brown algae Ascophyllum nodosum and a metagenomic library was constructed in Escherichia coli. The library was screened for diverse enzymatic activities (esterases, xylanases, cellulases, α-amylases, arabinanases, caseinases and β-glucosidases) on agar plates with specific enzymes substrates. Several new microbial enzymes (esterases, β-glucosidases, α-amylases and cellulases) were identified revealing the wealth of our library. Furthermore, those enzymes had less than 50% sequence identity with known protein sequences; meaning that our approach allows to identify new microbial enzymes expressed by uncultured microorganisms. Plate tests for medium-throughput screening of specific enzymes hydrolyzing algal polysaccharides (agarases, carrageenases and alginate lyases) are currently being developed. Our approach will probably allow us to identify new families of those ill-known enzymes, with particular enzymatic activities. [less ▲]

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See detailImpact of the depth on bacterial diversity in an agricultural soil
Stroobants, Aurore ULg; Degrune, Florine ULg; Lambert, Christophe et al

Poster (2013, February 08)

Bacteria are the most abundant and diverse microorganisms in soils. They play an important role in soil formation, contribute to plant nutrition and are involved in various processes in agroecosystems ... [more ▼]

Bacteria are the most abundant and diverse microorganisms in soils. They play an important role in soil formation, contribute to plant nutrition and are involved in various processes in agroecosystems such as nutrient cycling. The aim of this study was to evaluate the impact of the depth on bacterial diversity and quantity in an agricultural soil. Samples was collected on May 2011 and May 2012 at three different depths : 10, 25 and 45 centimeters. The quantity of total bacteria was measured by real time PCR and the analysis of the diversity was performed by the high throughput sequencing technology. Results obtained by these methods show that the biomass and the bacterial quantity and diversity (Shannon index) decrease with the depth, particularly at 45 centimeters. The biomass is, in average, 6.5 fold less important at 45 cm than at 10 cm and the quantity is 17 fold lower at 45 cm than at 10 cm. Our results also indicate that many taxa, such as Betaprotebacteria, Deltaproterobacteria, Gammaproteobacteria, Acidobacteria and Burkholderiales are influenced by the depth. The results will be presented in more details on the poster. [less ▲]

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See detailCharacterization of three new carboxylic ester hydrolases isolated by functional screening of a forest-soil metagenomic library
Biver, Sophie ULg; Vandenbol, Micheline ULg

in Journal of Industrial Microbiology & Biotechnology (2013), 40(2), 191-200

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See detailAn eYFP Reporter Gene for the Yeast Two-hybrid System
Damon, Coralie; Boxus, Mathieu; Twizere, Jean-Claude ULg et al

in Protein Journal (2013), 32(2), 126-130

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See detailSymbiont Diversity in Reticulitermes santonensis (Isoptera: Rhinotermitidae): Investigation Strategy Through Proteomics.
Bauwens, Julien ULg; Millet, Catherine ULg; Tarayre, Cédric ULg et al

in Environmental entomology (2013), 42(5), 882-7

The complex microbial community living in the hindgut of lower termites includes prokaryotes, flagellates, yeasts, and filamentous fungi. Many microorganisms are found in the termite gut, but only a few ... [more ▼]

The complex microbial community living in the hindgut of lower termites includes prokaryotes, flagellates, yeasts, and filamentous fungi. Many microorganisms are found in the termite gut, but only a few are thought to be involved in symbiotic association to participate in cellulose digestion. Proteomics provides analyses from both taxonomical and functional perspectives. We aimed to identify symbiont diversity in the gut of Reticulitermes santonensis (Feytaud), via complementary electrospray ionization associated to ion trap tandem mass spectrometry (LC-MS/MS) and two-dimensional gel electrophoresis associated to matrix-assisted laser desorption-ionization-time-of-flight mass spectrometry analysis. One specific challenge to the study of lower termites is the relatively few data available on abundant symbiotic flagellates. Analysis based on LC-MS/MS revealed few protein families showing assignments to eukaryotes and the taxonomic origin of highly represented actins could not be established. Tubulins proved to be the most suitable protein family with which to identify flagellate populations from hindgut samples using LC-MS/MS, compared with other protein families, although this method targeted few prokaryotes in our assay. Similarly, two-dimensional gel electrophoresis associated to matrix-assisted laser desorption-ionization-time-of-flight mass spectrometry did not succeed in identifying flagellate populations, but did permit the identification of most of the prokaryotic components of the symbiotic system. Finally, fungi and yeasts were identified by both methods. Owing to the lack of sequenced genes in flagellates, targeting tubulins for LC-MS/MS could allow fingerprints of flagellate populations to be established. Experimental and technical improvements might increase the efficiency of identification of prokaryotic populations in the near future, based on metaproteomic development. [less ▲]

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See detailInfluence of lignin in Reticulitermes santonensis: symbiotic interations investigated through proteomics
Bauwens, Julien ULg; Tarayre, Cédric ULg; Brasseur, Catherine ULg et al

in Symbiosis (2013)

The gut of lower termites is populated by numerous microbial species belonging to prokaryotes, fungi, yeasts and protists. These micro-organisms are organized in a complex symbiotic system, interacting ... [more ▼]

The gut of lower termites is populated by numerous microbial species belonging to prokaryotes, fungi, yeasts and protists. These micro-organisms are organized in a complex symbiotic system, interacting together and with the insect host. Their likely ability to degrade ligno-cellulosic compounds could lead to improvements in second generation biofuels production. Lignin elimination represents a critical point as this polymer significantly interferes with industrial process of cellulose. Although host produces its own lignin-degrading enzymes, some symbionts may participate in digestion of lignin and its degradation products in termite gut. Here, we compared gut proteomes from R. santonensis after rearing on artificial diets composed of cellulose with and without lignin. The effect of lignin in artificial diets on different parts of the digestive tract was compared through liquid chromatography associated with tandem mass spectrometry (LC-MS/MS) experiments. Enzymatic assays were performed to characterize activities present in R. santonensis digestive tract after feeding on artificial diets. Microscopic observations of microbial communities provided some information on population balances after feeding experiment. [less ▲]

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See detailUtilisation des termites comme source de microorganismes dans la filière de production du bioéthanol de seconde génération
Tarayre, Cédric ULg; Bauwens, Julien ULg; Brasseur, Catherine ULg et al

Poster (2012, November 14)

Les termites abritent une microflore symbiotique qui intervient dans la dégradation des fibres constitutives du bois, synthétisant des enzymes capables d’hydrolyser ses composants. Les sucres ... [more ▼]

Les termites abritent une microflore symbiotique qui intervient dans la dégradation des fibres constitutives du bois, synthétisant des enzymes capables d’hydrolyser ses composants. Les sucres fermentescibles libérés suite à cette hydrolyse sont utilisables dans le cadre de la production du bioéthanol de seconde génération. [less ▲]

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See detailCharacterizing of protein dataset with GO ontology
Dmitrieva, Joelia Borisnova; Florea, B; Li, N et al

Poster (2012, September 09)

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See detailIdentification of new microbial enzymes from forest and marine ecosystems by functional metagenomics
Martin, Marjolaine ULg; Biver, Sophie ULg; Barbeyron, Tristan et al

Poster (2012, August 21)

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See detailSTUDY OF BACTERIAL DIVERSITY IN AN AGRICULTURAL SOIL
Stroobants, Aurore ULg; Bodson, Bernard ULg; Portetelle, Daniel ULg et al

Poster (2012, August 19)

Bacterial growth in soil is dependent on soil characteristics. In this experiment, we have studied the evolution of bacterial diversity during a winter wheat crop and the impacts caused by the tillage and ... [more ▼]

Bacterial growth in soil is dependent on soil characteristics. In this experiment, we have studied the evolution of bacterial diversity during a winter wheat crop and the impacts caused by the tillage and residue incorporation. Three growth stages of wheat was chosen for this work : germination, tillering and booting. The analyse of bacterial diversity in these conditions was performed by the Next Generation Sequencing technology. Results obtained by this method indicate that the soil is composed, in average, by 38,02 (±4,81)% Proteobacteria; 19,71(±3,88)% Actinobacteria; 7,77(±1,44)% Firmicutes; 6,94(±1,58)% Fibrobacteres/Acidobacteria group; 5(±3,21)% Bacteroidetes/Chlorobi group; 3,89(±1,36)% Chloroflexi; 2,96(±0,67)% Planctomycetes; 2,87(±1,58)% Verrucomicrobia; 1,42(±0,41)% Cyanobacteria and 15,38(±2,64)% others. The tillage influences mostly the Deltaproteobacteria, Gammaproteobacteria, Actinobacteridae, Bacteroidetes/Chlorobi group and Verrucomicrobia. Residue incorporation has an impact on Betaproteobacteria, Gammaproteobacteria, Actinobacteridae, Acidimicrobidae, Firmicutes and Bacteroidetes/Chlorobi group. The wheat growth stages affect especially Betaproteobacteria, Deltaproteobacteria, Actinomycetales, Acidibacteria, Fibrobacteres and Bacillales. The results will be presented and discussed on the poster. [less ▲]

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See detailIMPACT OF DEPTH AND SOIL COMPACTION ON BACTERIAL DIVERSITY IN SOIL
Stroobants, Aurore ULg; Degrune, Florine; Olivier, Claire et al

Poster (2012, August 19)

Bacteria are the most abundant and diverse microorganisms in soils. The amount of bacteria in soils can reach 10^10 cells per gram of soil. These organisms are involved in various processes in ... [more ▼]

Bacteria are the most abundant and diverse microorganisms in soils. The amount of bacteria in soils can reach 10^10 cells per gram of soil. These organisms are involved in various processes in agroecosystems such as nutrient cycling, contributing to plant nutrition, plant health and soil structure. The knowledge about this diversity is limited because only one percent of these organisms can be cultured by laboratory methods. During the last decades, many molecular-based techniques have been developed to assess the diversity of bacterial communities. The aim of this study was to determine the quantity and diversity of bacteria in two agricultural soils with differents soil management practices (tillage and no tillage) at different depths (10, 30 and 45 centimeters) and different compaction levels (high and low). Quantity was evaluated by real time PCR and diversity was analysed by the DGGE (Denaturing Gradient Gel Electrophoresis) technique. The results show that soil management has an impact on bacterial quantity at 45 centimeters and quantity is higher in till soil. Compaction level affects the bacterial quantity in till soil, quantity is higher in low compaction. And finally, depth influences the bacterial quantity in till and no till soil. In both soils, quantity decreases with the depth. The results will be presented and discussed on the poster. [less ▲]

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See detailTermites artificially-fed on unusual diet and resulting enzymatic switches
Bauwens, Julien ULg; Tarayre, Cédric ULg; Matteotti, Christel et al

Poster (2012, August)

Wood-feeding termites as Reticulitermes santonensis generally feed on cellulose, hemicelluloses and lignin. However, these opportunistic insects are also able to degrade other carbohydrates, such as ... [more ▼]

Wood-feeding termites as Reticulitermes santonensis generally feed on cellulose, hemicelluloses and lignin. However, these opportunistic insects are also able to degrade other carbohydrates, such as starch. The production of putative endogenous α - amylase has been previously shown in R. flavipes, as the disappearance of the major symbiotic flagellates from the hindgut. Here, we compared enzymatic activities (CMCase, MCCase, xylanase, amylase, α- and β-glucosidase) between different fractions of the digestive tract of starch-, cellulose-, and wood-fed termites. Main compounds of the artificial diets, namely starch or MCC, resulted in differential enzymatic activity. Even the substitution of wood by artificial diets itself seemed to induce changes in enzymatic activities, regardless of the main substrate in the diet, as we observed strong midgut α-glucosidase activity only for artificially-fed termites. Preliminary assays to isolate and characterize enzymes were performed using proteomic methods. [less ▲]

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See detailIdentification of bacteria community associated with earthworm gut
Lemtiri, Aboulkacem ULg; Alabi, Taofic; Bodson, Bernard ULg et al

Poster (2012, July 26)

The role of earthworms in soil fertility and transformation of organic waste was regulary cited to be of first importance. Associated to these macro-invertebrates, a large diversity of micro-orgnisms are ... [more ▼]

The role of earthworms in soil fertility and transformation of organic waste was regulary cited to be of first importance. Associated to these macro-invertebrates, a large diversity of micro-orgnisms are found indirectly in their closed environment or directly in their gut. Functional aspects of these interactions and symbiosis in relation with soil characteristics and fertility rates are poorly developed. Here, the micro-organisms diversity and potential related functions of earthworm gut were investigated using a proteiomic approach for both protein and micro-organism identifications. Microbial community investigation was detected by proteomic approach based on bidimensional electrophoresis coupled with mass spectrometry using Matrix Assisted Laser Desorption Ionisation – time of flight (Maldi-Tof). Diversity of gut associated bacterial communities was discussed. Indeed, application of particular crop production practices such as crop residue management at the field level could regulate the gut bacterial communities in earthworm but also microbials in soils. Agricultural systems had to consider the microbial and associated organisms in the soil to enhance fertlility and crop production in sustainable ways. [less ▲]

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See detailImpact of soil management on earthworm diversity according to differential plowing and plant residue incorporation
Lemtiri, Aboulkacem ULg; Alabi, Taofic; Zirbes, Lara ULg et al

Poster (2012, July 02)

Earthworms are largely distributed in terrestrial ecosystems and their abundance and diversity in soils are significantly affected by biotic (macro- and micro-organisms) and abiotic factors: soil ... [more ▼]

Earthworms are largely distributed in terrestrial ecosystems and their abundance and diversity in soils are significantly affected by biotic (macro- and micro-organisms) and abiotic factors: soil properties (pH, texture, structure…); agricultural management system and climate change. Here, tillage effect of earthworm population combined with crops residual management was investigated and correlated with soils properties. From wheat experimental field plots, the diversity of earthworm according to the field crop management was assessed. Application of particular crop production practices such as the integration of different levels of crop residues, diverse parts of wheat straws, at the field level regulate earthworm diversity and population abundance. Indeed, tillage reduced earthworm population with a 35% rate also corresponding to changes in soil properties. Agricultural practices had to be adapted to include consideration on macro-invertebrate abundance and diversity to maintain efficient soil fertility and allow sustainable crop production [less ▲]

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See detailSelection and cultivation of hydrolytic microorganisms extracted from the digestive tract of the termite Reticulitermes santonensis (3DV.1.55)
Tarayre, Cédric ULg; Bauwens, Julien ULg; Matteotti, Christel ULg et al

Poster (2012, June 21)

Biofuel production can be based on the use of fermentable substrates issued from the hydrolysis of lignocellulosic biomass stemming from agricultural residues and by-products. However, such substrates are ... [more ▼]

Biofuel production can be based on the use of fermentable substrates issued from the hydrolysis of lignocellulosic biomass stemming from agricultural residues and by-products. However, such substrates are not easy to degrade. Enzymes (cellulases, xylanases, etc.) can be used for this purpose and pre-treatments can increase their action by providing more available extremities. The digestive tract of the termite Reticulitermes santonensis contains various microorganisms (bacteria, molds, protists) able to degrade the wood components. These microorganisms act as consortia, leading to a better hydrolysis than in the cow rumen. Our purpose is the isolation of microorganisms from termite guts in order to evaluate their potential for hydrolysis of lignocellulosic materials. This approach led us to isolate and to study a bacteria (Bacillus sp.) displaying a xylanase activity, a mold (Aspergillus sp.) displaying a cellulase activity and a chrysophyte (protist) displaying an amylase activity. [less ▲]

Detailed reference viewed: 47 (16 ULg)