References of "Vandenbol, Micheline"
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See detailEnrichment of anhydrous milk fat in polyunsaturated fatty acid residues from linseed and rapeseed oils through enzymatic interesterification
Aguedo, Mario ULg; Hanon, EMILIEN ULg; Danthine, Sabine ULg et al

in Journal of Agricultural and Food Chemistry (2008), 56(5), 1757-1765

Lipozyme TL IM was used in a solvent-free batch and microaqueous system for enzymatic interesterification of anhydrous milkfat (AMF) with linseed oil (LO) in binary blends and with rapeseed oil (RO) in ... [more ▼]

Lipozyme TL IM was used in a solvent-free batch and microaqueous system for enzymatic interesterification of anhydrous milkfat (AMF) with linseed oil (LO) in binary blends and with rapeseed oil (RO) in one ternary blend. The aim was to obtain and characterize physicochemically fats enriched with unsaturated C-18 fatty acids (oleic, linoleic, and, especially, linolenic acids) from natural vegetable oils. Binary blends of AMF/LO 100/0, 90/10, 80/20, 70/30, and 60/40 (w/w) were interesterified. The change in triacylglycerol (TAG) profiles showed that quasi-equilibrium conditions were reached after 4-6 h of reaction. Free fatty acid contents < 1%. The decrease in solid fat content and in dropping point temperature obtained with increasing content of LO and interesterification resulted in good plastic properties for the products originating from the blends 70/30 and 60/40. This was confirmed by textural measurements. Melting profiles determined by differential scanning calorimetry showed complete disappearance of low-melting TAGs from LO and the formation of intermediary species with a lower melting temperature. Oxidative stability of the interesterified products was diminished with increasing LO content, resulting in low oxidation induction times. A ternary blend composed of AMF/RO/LO 70/20/10 gave satisfactory rheological and oxidative properties, fulfilling the requirements for a marketable spread and, moreover, offering increased potential health benefits due to the enriched content in polyunsatured fatty acid residues. [less ▲]

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See detailCharacterization of a novel aphid prenyltransferase displaying dual geranyl/farnesyl diphosphate synthase activity
Vandermoten, Sophie ULg; Charloteaux, Benoît ULg; Santini, S. et al

in FEBS Letters (2008), 582(16), 19281934

We report on the cDNA cloning and characterization of a novel short-chain isoprenyl diphosphate synthase from the aphid Myzus persicae. Of the three IPPS cDNAs we cloned, two yielded prenyltransferase ... [more ▼]

We report on the cDNA cloning and characterization of a novel short-chain isoprenyl diphosphate synthase from the aphid Myzus persicae. Of the three IPPS cDNAs we cloned, two yielded prenyltransferase activity following expression in Escherichia coli; these cDNAs encode identical proteins except for the presence, in one of them, of an N-terminal mitochondrial targeting peptide. Although the aphid enzyme was predicted to be a farnesyl diphosphate synthase by BLASTP analysis, rMpIPPS, when isopentenyl diphosphate and dimethylallyl diphosphate are supplied as substrates, typically generated geranyl diphosphate (C10) as its main product, along with significant quantities of farnesyl diphosphate (C15). Analysis of an MpIPPS homology model pointed to substitutions that could confer GPP/FPP synthase activity to the aphid enzyme. [less ▲]

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See detailSeparate And Combined Disruptions Of Two Exo-Beta-1,3-Glucanase Genes Decrease The Efficiency Of Pichia Anomala (Strain K) Biocontrol Against Botrytis Cinerea On Apple
Friel, D.; Pessoa, Nmg.; Vandenbol, Micheline ULg et al

in Molecular Plant-Microbe Interactions [=MPMI] (2007), 20(4), 371-379

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See detailEnrichment of anhydrous milk fat in polyunsatured fatty acid residues from linseed and rapeseed oil through enzymatic interesterification
Aguedo, Mario ULg; Hanon, Emilien ULg; Danthine, Sabine ULg et al

Poster (2007)

The interesterification, or ester exchange, between two fats leads to the rearrangement of acyl moieties in both. The use of a sn-1,3-specific lipase confines the exchange of fatty acid residues to the sn ... [more ▼]

The interesterification, or ester exchange, between two fats leads to the rearrangement of acyl moieties in both. The use of a sn-1,3-specific lipase confines the exchange of fatty acid residues to the sn-1 and sn-3 positions of triacylglycerides (TAG), generating products with characteristics that cannot be obtained through a chemical process or a blending. Such reactions require mild conditions with no solvent needed and they yield no unhealthful trans fatty acids, justifying the stepped-up interest of enzymatic interesterification for the production of margarines and other food fats. The aim of this work was to use enzymatic interesterification to enrich anhydrous milk fat (AMF) with unsaturated fatty acid C18 residues from linseed oil (LO) and eventually from rapeseed oil (RO) through some binary blends and one ternary blend. For that, the 1,3-specific lipase from Thermomyces lanuginosa (Lipozyme TL IM) was used in solvent-free batch and micro-aqueous reactions and fat blends with different mass ratios were tested. The evolution of TAG profiles, of interesterification degre (ID) and of free fatty acids (FFA), was followed along the reactions. Determination of dropping points (DP) and solid fat contents (SFC) enabled a rheological characterization of the products. The end products were also characterized for their oxidative stability and their textural properties. [less ▲]

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See detailMutational Analysis Of The Tre2 Oncogene Encoding An Inactive Rabgap
Bizimungu, C.; Thomas, Annick ULg; Brasseur, Robert ULg et al

in Biotechnology Letters (2007), 29(12), 1927-37

The TRE2 oncoprotein is structurally related to the RabGAP (GTPase-activating protein) family. However, TRE2 seems enzymatically inactive. Two regions are important for its lack of GAP activity. First ... [more ▼]

The TRE2 oncoprotein is structurally related to the RabGAP (GTPase-activating protein) family. However, TRE2 seems enzymatically inactive. Two regions are important for its lack of GAP activity. First, the TBC domain, forming the catalytically active domain of RabGAPs, is non-functional in the oncoprotein. Also involved in TRE2 inactivity is the 93-aa region flanking the TBC domain on the C-terminal side. In order to identify the residues responsible for non-functionality, we performed hydrophobic cluster analysis of the oncoprotein sequence, combined with secondary structure prediction, receptor-binding domain analysis, and a tilted peptide calculation. These analyses were complemented with site-directed and random mutagenesis experiments. On the basis of our data, we hypothesize that the lack of secondary structure of the region flanking the TBC domain in TRE2 may explain why this region plays a role in the lack of GAP activity, even when a potentially functional TBC domain is present. [less ▲]

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See detailMolecular cloning and functional expression of a new aphid isoprenyl diphosphate synthase
Vandermoten, Sophie ULg; Beliveau, Catherine; Sen, Stephanie et al

Poster (2006, December 18)

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See detailMolecular cloning and functional expression of a new aphid isoprenyl diphosphate synthase
Vandermoten, Sophie ULg; Beliveau, C.; Sen, S. et al

in Archives Internationales de Physiologie et de Biochimie (2006, December), 190

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See detailQuantification of Bifidobacterium spp. and Lactobacillus spp. in rat fecal samples by real-time PCR.
Delroisse, Jean-Marc; Boulvin, Anne-Lise; Parmentier, Isabelle et al

in Microbiological research (2006), (5),

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See detailThe Tre2 Oncoprotein, Implicated In Ewing'S Sarcoma, Interacts With Two Components Of The Cytoskeleton
Dechamps, C.; Bach, S.; Portetelle, Daniel ULg et al

in Biotechnology Letters (2006), 28(4),

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See detailExpression and purification of the human Tre2 product, a putative Ypt/Rab GTPase activating protein.
Bizimungu, Christelle; Stroobants, Aurore ULg; Tricot, Catherine et al

in Archives Internationales de Physiologie et de Biochimie (2005), 191

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See detailQuantification of Bifidobacterium ssp and Lactobacillus spp in rat fecal samples by real-time PCR
Delroisse, Jean-Marc; Boulvin, Anne-Lise; Parmentier, Isabelle et al

in Archives Internationales de Physiologie et de Biochimie (2005), 191

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See detailExpression of a synthetic gene encoding a Tribolium castaneum carboxylesterase in Pichia pastoris
Delroisse, Jean-Marc; Dannau, Marie; Gilsoul, Jean-Jacques et al

in Protein Expression & Purification (2005), 42(2), 286-294

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See detailEstimation of bioreactor efficiency through structured hydrodynamic modeling case study of a Pichia pastoris fed-batch process.
Delvigne, Frank ULg; El Mejdoub, Thami ULg; Destain, Jacqueline ULg et al

in Applied Biochemistry and Biotechnology (2005), 121-124

In this article, two theories are unified to investigate the effect of hydrodynamics on a specific bioprocess: the network-of-zones (NOZ) hydrodynamic structured modeling approach (developed by several ... [more ▼]

In this article, two theories are unified to investigate the effect of hydrodynamics on a specific bioprocess: the network-of-zones (NOZ) hydrodynamic structured modeling approach (developed by several researchers but applied to only a few bioprocesses) and the effectiveness factor eta approach. Two process scales were investigated (20 and 500 L), and for each, hydrodynamics were quantified using an NOZ validated by homogeneity time measurements. Several impeller combinations inducing quite different hydrodynamics were tested at the 20-L scale. After this step, effectiveness factors were determined for each fermentation run. To achieve this, a perfectly mixed microbial kinetic model was evaluated by using simple Monod kinetics with a fed-batch mass balance. This methodology permitted determination of the effectiveness factor with more accuracy because of the relation with the perfect case deduced from the Monod kinetics. It appeared that for the small scale, eta decreased until reaching a value of approx 0.7 (30% from the ideal case) for the three impeller systems investigated. However, stirring systems that include hydrofoils seemed to maintain higher effectiveness factors during the course of the fermentation. This effect can be attributed to oxygen transfer performance or to homogenization efficiency exhibited by the hydrofoils. To distinguish the oxygen transfer from the homogenization component of the effectiveness factor, these phenomena were analyzed separately. After determining the evolution of etaO2 linked to oxygen transfer for each of the fermentation runs, the NOZ model was employed to quantify substrate gradient appearance. After this step, another effectiveness factor, etamix, related to mixing was defined. Consequently, it is possible to distinguish the relative importance of the mixing effect and oxygen transfer on a given bioprocess. The results have highlighted an important scale effect on the bioprocess that can be analyzed using the NOZ model. [less ▲]

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