References of "Portetelle, Daniel"
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See detailScreening of a soil metatranscriptomic library by functional complementation of Saccharomyces cerevisiae mutants.
Kellner, Harald ULg; Luis, Patricia; Portetelle, Daniel ULg et al

in Microbiological Research (2011), 166(5), 360368

Metatranscriptomics applied to environmental transcripts provides unique opportunities to reveal microbial activity in the environment and to discover novel enzymes of potential use in biotechnological ... [more ▼]

Metatranscriptomics applied to environmental transcripts provides unique opportunities to reveal microbial activity in the environment and to discover novel enzymes of potential use in biotechnological applications. Here, by functional complementation of a pho5(-) mutation (affecting a repressible acid phosphatase) and a his3(-) mutation in Saccharomyces cerevisiae, we identified fungal genes encoding an acid phosphatase and an imidazoleglycerol-phosphate dehydratase in a metatranscriptomic library, which was obtained by reverse-transcribed polyA fraction of total RNA extracted from the organic layer of a sugar maple forest soil, constructed in the modified yeast secretion vector pTEF-MF-SfiI A/B. Yeast transformants exhibiting phosphatase activity were identified in a colony-staining assay and transformants with his3(-)-complementing genes were detected by plating on histidine-deficient medium. In each screen one DNA insert was found and sequenced. The sequenced his3(-)-complementing gene showed strong similarity to a basidiomycete imidazoleglycerol-phosphate dehydratase (76% identity to a Phaffia rhodozyma enzyme). The candidate showing phosphatase activity was found to produce phosphatase extracellularly, the enzyme showing highest activity at pH 4 and between 40 and 50°C when 4-nitrophenyl phosphate was used as substrate. The sequenced insert showed strong similarity to a basidiomycete acid phosphatase (60% identity to Postia placenta). [less ▲]

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See detailKeep bacteria under control: Dietary modulation of gut microflora in farm animals by use of hen egg yolk antibodies
Marcq, Christopher ULg; Thewis, André ULg; Portetelle, Daniel ULg et al

E-print/Working paper (2010)

This review article focuses on the use of IgY in therapy or prophylaxis of diseases in veterinary medicine as well as in the context of functional foods to modulate microflora in animal.

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See detailFungal gene expression in a forest soil
Kellner, Harald ULg; Portetelle, Daniel ULg; Vandenbol, Micheline ULg

Poster (2010, August)

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See detailAntibodies Dynamics in the Broiler Digestive Tract after Salmonella Typhimurium Oral Challenge
Marcq, Christopher ULg; Cox, Edwin; Thewis, André ULg et al

in Duclos, Michel; Nys, Yves (Eds.) XIIIth European Poultry Conference: Program & Book of Abstracts, World's Poultry Science Journal, Volume 66, Supplement (2010, August)

This study aimed to provide directions for Salmonella challenge experiment conception by offering a better understanding of the relationship between age and mucosal immune responsiveness of chicken ... [more ▼]

This study aimed to provide directions for Salmonella challenge experiment conception by offering a better understanding of the relationship between age and mucosal immune responsiveness of chicken. Intestinal maternal immunity of Salmonella-free chicks was monitored by ELISA analyses at 2, 9 and 16 days of age. At 21 days of age, chicks were orally inoculated with Salmonella Typhimurium. Three inoculum doses (3 x 10E3, 3 x 10E6, 3 x 10E9 cfu/bird) and an uninfected control were then compared concerning mucosal immune status of the small intestine and cecum. Results suggest that difficulties encountered to infect very young chicks can be related, at least partly, to maternal immunity. The relatively low level of intestinal immune defences observed thereafter could indicate a right time to perform an experimental infection of birds and to maximize the spreading of the pathogen during challenge experiment. After infection of 3-week-old chickens, the mucosal immune response was rapid with increased anti-Salmonella Typhimurium IgA titers. There was a linear relationship between specific IgA levels in intestinal and cecal secretions and the challenge dose initially inoculated. [less ▲]

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See detailCaractérisation de la diversité des organismes symbiotiques et des activités glycosyl hydrolases dans le tube digestif de Reticulitermes santonensis (Feytaud) par une approche multidisciplinaire
Bauwens, Julien ULg; Matteotti, Christel ULg; Brognaux, Alison ULg et al

Scientific conference (2010, July 08)

Le bioéthanol cellulosique pourrait être une solution pour satisfaire le besoin croissant en énergie renouvelable. Actuellement, l’efficience de la transformation de la cellulose en sucres fermentescibles ... [more ▼]

Le bioéthanol cellulosique pourrait être une solution pour satisfaire le besoin croissant en énergie renouvelable. Actuellement, l’efficience de la transformation de la cellulose en sucres fermentescibles reste le principal facteur limitant. La recherche de nouvelles glycosyl hydrolases constitue une voie potentielle d’amélioration de la valorisation des composés ligno-cellulosiques. Trois types de glycosyl hydrolases sont généralement produites par les organismes capables d’utiliser efficacement ces composés : les endoglucanases, les exoglucanases/cellobiohydrolases, et les β-glucosidases. Dans les processus de digestion de la cellulose par les animaux, des organismes symbiotiques tels que des bactéries, des protistes et/ou des champignons sont fréquemment observés. Ces organismes contribuent en grande partie voir totalement à la production des complexes enzymatiques nécessaires. Chez les termites inférieures, comme notre modèle Reticulitermes santonensis (Feytaud), des protistes et des bactéries sont impliqués dans un système symbiotique complexe. Une étude multidisciplinaire est menée afin d’approfondir les rôles respectifs des différents groupes de symbiontes, via des approches « omiques », à savoir la protéomique (ESI-LC-MS-MS, 2D-SDS-PAGE couplée avec une analyse en spectrométrie de masse du type MALDI-TOF pour l’identification des protéines), la génomique (avec une approche métagénomique basée sur la construction d’une large banque de cDNA), la métabolomique (caractérisation des produits de dégradation de carbohydrates via une strategie LC-MS). De plus, l’isolation de microorganismes a également été employée dans la caractérisation de la diversité et de l’activité des glycosyl hydrolases chez R. santonensis. [less ▲]

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See detailComplementation of Saccharomyces cerevisiae mutants using a soil metatranscriptomic library
Kellner, Harald ULg; Luis, Patricia; Portetelle, Daniel ULg et al

Poster (2010, May 21)

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See detailIntegrated “omics” approaches to investigate the chemical aspects of symbiosis in termites and potential application in ligno-cellulosic use.
Bauwens, Julien ULg; Matteotti, Christel ULg; Brognaux, Alison ULg et al

Scientific conference (2010, May 05)

Cellulosic bioethanol could be one of the solutions to satisfy the increasing demand in renewable energy. The most limitative problem is the efficiency of cellulose transformation into fermentable sugars ... [more ▼]

Cellulosic bioethanol could be one of the solutions to satisfy the increasing demand in renewable energy. The most limitative problem is the efficiency of cellulose transformation into fermentable sugars. Investigations to select new glycosyl hydrolases are an interesting approach that constitutes a potential opportunity to improve the valorization of lignocellulosic materials. Three major types of glycosyl hydolases are generally produced by organism’s that are able to efficiently use cellulosic compounds: the endoglucanases, the exoglucanases/cellobiohydrolases and the β-glucosidases. In the ability to transform lignocellulosic materials by animals, symbioses are generally observed with a range of micro-organisms including bacteria, protists and/or fungi that largely (or completely) contribute to the production of the needed enzymatic complexes. In termites, such active enzymes are produced in the insect digestive tract, by the termite insect itself or by symbiotic organisms. Within lower termites gut, such as in our model Reticulitermes santonensis (Feytaud), protists and bacteria are associated and involved in a complex symbiotic system. To investigate the respective role of the insect and different groups of symbionts, multidisciplinary “omics” approaches were here developed including proteomics (ESI-LC-MS-MS, 2D-Dige gel coupled with MALDI-TOF mass spectrometry for protein identification), genomics (with a metagenomic approach based on large cDNA bank construction), metabolomics (LC-MS stragety for carbohydrate degradation product characterization). Moreover, microorganism isolation was used to investigate and characterize glycosyl hydrolases diversity and activity in R. santonensis. The integration of this broad range of “omics” techniques allowed characterizing the role of symbionts in insects in a fundamental approach and to invtigate the chemical ecology of xylophagous insects but also corresponding to an efficient way to promote the selection of efficient enzymatic activities to potentially produce biofuels based on the use of existing lignocellulosic materials. [less ▲]

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See detailEffect of bovine colostrum on the serum insulin-like growth factor-I (IGF-I), the IGF binding proteins-2 and -3 and the thyroid hormones in weaning piglets
Boudry, Christelle ULg; Dehoux, Jean-Paul; Colinet, Frédéric ULg et al

in Archiv Tierzucht (2010), 53(6), 675-688

This study examined the effect of a bovine colostrum supplementation on growth performance, feed intake and the hormonal response of piglets at weaning. Ninety-six newly-weaned piglets were assigned for ... [more ▼]

This study examined the effect of a bovine colostrum supplementation on growth performance, feed intake and the hormonal response of piglets at weaning. Ninety-six newly-weaned piglets were assigned for four weeks to one of the two treatments: Control (diet with bovine milk whey) and Colostrum (diet with bovine colostrum whey) treatments. The supplements were incorporated in a commercial diet at 20 g/kg during the first 2 weeks after weaning and lowered to 10 g/kg for the next 2 weeks. Body weight and feed intake were measured weekly. Blood samples were taken weekly for determination of circulating IGF-I, its binding proteins and the thyroid hormones (T3 and T4). During the first week of the trial, the Colostrum-fed piglets presented improved growth performance, feed intake and feed efficiency and a higher concentration in circulating IGF-I (+ 15 %) compared to the Control piglets. In both treatments, the circulating thyroid hormones were reduced by weaning and the levels measured at weaning were recovered earlier by the Colostrum-fed piglets compared to the Control group (P < 0.05). It is concluded that hormonal response observed after the bovine colostrum supplementation is, at least in part, consequent of the positive action of bovine colostrum on the feed intake. [less ▲]

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