References of "Thonart, Philippe"
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See detailPrésentation des projets Interreg IVB BIOREFINE et RENEW
Tarayre, Cédric ULg; Delvigne, Frank ULg; Destain, Jacqueline ULg et al

Conference (2013, October 22)

Les projets BioRefine et Renew sont financés par le programme de coopération européen Interreg IVB. Leur but est de promouvoir les transferts de compétences, d'informations et de matières entre les ... [more ▼]

Les projets BioRefine et Renew sont financés par le programme de coopération européen Interreg IVB. Leur but est de promouvoir les transferts de compétences, d'informations et de matières entre les différents pays de la zone européenne du Nord-Ouest. Le projet BioRefine a pour but de récupérer les nutriments (N, P et K) ainsi que les éléments traces métalliques à partir de déchets bien spécifiques: le fumier, le lisier, les digestats de méthanisation et les boues de stations d'épuration. Cette récupération requiert l'élaboration de procédés industriels mis en place après une étude en laboratoire. Le projet Renew, lui, est beaucoup plus général. En ce qui concerne le rôle de Gembloux Agro-Bio Tech dans le projet, le travail sera essentiellement focalisé sur la production d'acide succinique à partir de déchets. Cette production sera assurée par la souche bactérienne Actinobacillus succinogenes. [less ▲]

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See detailProjet Termitofuel: les termites et leurs symbiontes pour mieux valoriser la biomasse ligno-cellulosique
Bauwens, Julien ULg; Tarayre, Cédric ULg; Brasseur, Catherine ULg et al

Poster (2013, October 19)

L’exploitation actuelle de la biomasse ligno-cellulosique, extrêmement abondante sur Terre, est liée à la production de déchets relativement peu valorisables. C’est pourquoi le projet TERMITOFUEL étudie ... [more ▼]

L’exploitation actuelle de la biomasse ligno-cellulosique, extrêmement abondante sur Terre, est liée à la production de déchets relativement peu valorisables. C’est pourquoi le projet TERMITOFUEL étudie la digestion du bois chez les termites, grâce à une approche pluridisciplinaire, en vue d’améliorer la production de bioéthanol de seconde génération. Au sein de l’Unité d’Entomologie Fonctionnelle et Evolutive, l’approche protéomique est employée afin d’identifier les micro-organismes présents dans le tube digestif des termites et caractériser les activités enzymatiques. [less ▲]

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See detailUse of on-line flow cytometry to detect segregation in the microbial population
Brognaux, Alison ULg; Zune, Quentin ULg; Han, Shanshan et al

Poster (2013, October 08)

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See detailANAEROBIC DIGESTION OF ORGANIC WASTES FROM AGRO-FOOD ACTIVITIES IN TUNISIA
Mhiri, F; Hiligsmann, Serge ULg; Sayahi, L. et al

Poster (2013, October 01)

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See detailMONITORING OF ANAEROBIC DIGESTION IN MSW LANDFILLS IN TUNISIA
Mhiri, F.; Hiligsmann, Serge ULg; Sayahi, L. et al

in Proceedings Sardinia 2013 (2013, October)

The monitoring of two controlled landfills in Tunisia was carried out for about 10 years by CITET and CWBI. Both landfills were managed by classical methodology i.e. disposal, compaction and, if any ... [more ▼]

The monitoring of two controlled landfills in Tunisia was carried out for about 10 years by CITET and CWBI. Both landfills were managed by classical methodology i.e. disposal, compaction and, if any, biogas and leachate extraction and treatment. One of them is located near Tunis and the other near Sousse with a warmer climate. They received more than 6,000 and 350 thousand cubic metre of MSW respectively from the two cities. Solid samples were collected by boring at different depths up to 18 m. They were analysed for dry weight and for total organic carbon, nitrogen and (hemi-) cellulose. The boreholes were equipped with 200 mm perforated PEHD tubes for further biogas and leachate sampling and analyses (COD, VFA, CH4 content, …) at different seasons. The results indicate an efficient mesophilic anaerobic digestion in both landfills. The high dry weight content (70 – 92%) of 13 solid samples collected in Sousse landfill contrasts however with the high leachate production in the Tunis landfill, filling about completely the majority of boreholes. The results of this monitoring confirm the trends formerly described about biological activity and environmental impact of landfills in Tunisia. Moreover a 200 L pilot-scale anaerobic digester was operated for about 3 years with solid wastes from Tunis landfill to assess the evolution of moisture content and organic matter. [less ▲]

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See detailANAEROBIC DIGESTION WITH BIOHYDROGEN PRODUCTION FROM ORGANIC WASTES : STATE-OF-THE ART
Hiligsmann, Serge ULg; Beckers, L.; Hamilton, C. et al

in Proceedings Sardinia 2013 (2013, October)

Hydrogen (H2) is being considered as an ideal and clean energy carrier since the utilization of hydrogen, either via combustion or via fuel cells, results in pure water. However, currently its production ... [more ▼]

Hydrogen (H2) is being considered as an ideal and clean energy carrier since the utilization of hydrogen, either via combustion or via fuel cells, results in pure water. However, currently its production relies mainly (i.e. 95%) on fossil fuels. The recent advances to produce biohydrogen from renewable sources such as biomass and particularly by fermentation of carbohydrate-rich substrates from agriculture and agro-industries appear promising. Such a process called “dark fermentation” enables both organic waste treatment and renewable energy production to be coupled. The soluble metabolites, mainly acetate and butyrate, contained in the spent medium of the dark fermentation bioreactor may be efficiently converted to methane in a second anaerobic digester treating other carbon sources. The paper reviews the state-of-the art on the challenges and prospective applications of dark fermentation as a first step of anaerobic digestion of municipal solid wastes to produce H2 and CH4. [less ▲]

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See detailStudy of the sorption behavior of Hibscus sabdariffa anthocyanins on a macroporous resin
Beye, Cheikh ULg; Souk Tounkara, Lat; Destain, Jacqueline ULg et al

in Journal of Food Process Engineering (2013), 36(5), 579-590

The adsorption of Hibiscus sabdariffa sp. anthocyanins onto a macroporous resin was studied in laboratory experiments. The anthocyanin aqueous extracts obtained from the calyces were used in agitated ... [more ▼]

The adsorption of Hibiscus sabdariffa sp. anthocyanins onto a macroporous resin was studied in laboratory experiments. The anthocyanin aqueous extracts obtained from the calyces were used in agitated batch experiments with a macroporous resin. The adsorption kinetics and isotherms of H. sabdariffa anthocyanins on a selected macroporous resin was studied to determine the parameters that have to be optimized to recover the anthocyanins from aqueous extracts of the calyces. The adsorption kinetic experimental data were fit into a pseudo second order kinetic model, which was then used to determine several parameters such as the contact time necessary to reach equilibrium as well as the maximum adsorption capacity. The best fit for the equilibrium adsorption isotherm experimental data was obtained with the Langmuir isotherm model. Based on qualitative and quantitative interpretation of the experimental data, the resin that was tested here appeared to have good adsorption capacity for the anthocyanins even though the necessary time to reach equilibrium was particularly long. Three aspects of the desorption of anthocyanins from the resin were studied: the speed of release of the anthocyanins (desorption kinetics), the extent of the anthocyanin desorption depending on the adsorption contact time and finally, the influence of the mobile phase's characteristics [less ▲]

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See detailStress microbien lors du processus d’extrapolation: Approche physique et biologique
Lejeune, Annick ULg; Thonart, Philippe ULg; Delvigne, Frank ULg

in Cerevisia : Belgian Journal of Brewing and Biotechnology (2013), 38(3), 89-101

Les micro-organismes sont utilisés dans de nombreux domaines (agro-alimentaire, pharmaceutique, environnemental, énergétique,…) que ce soit pour la production de biomasse ou de métabolites particuliers ... [more ▼]

Les micro-organismes sont utilisés dans de nombreux domaines (agro-alimentaire, pharmaceutique, environnemental, énergétique,…) que ce soit pour la production de biomasse ou de métabolites particuliers. Le passage de l’échelle du laboratoire à l’échelle industrielle est souvent problématique car les micro-organismes sont sensibles aux conditions environnementales développées au sein du volume réactionnel. De plus, la perte de l’efficacité d’homogénéisation des bioréacteurs industriels entraîne des perturbations au niveau du métabolisme des cellules. C’est pourquoi il est important d’étudier les conditions hydrodynamiques développées au sein du réacteur. Cet article présente des méthodes de calcul et de modélisation de ces conditions. L’impact de l’hydrodynamique sur le métabolisme microbien peut être étudié par l’utilisation de réacteurs scale-down. Les techniques nouvelles permettant de réaliser un scale-up prennent en compte des caractères physiologiques des cellules, qui estiment l’impact des conditions environnementales sur le métabolisme microbien et donc la bonne réussite du procédé. Enfin, l’étude de Saccharomyces cerevisiae, micro-organisme de grand intérêt biotechnologique, est réalisée. [less ▲]

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See detailDéveloppement d'un dispositif de trajectographie optique nécessaire pour la caractérisation expérimentale par une approche Euler-Lagrange des écoulements dans des bioréacteurs à cuve agitée
Collignon, Marie-Laure ULg; Delafosse, Angélique ULg; Delvigne, Frank ULg et al

in Récents Progrès en Génie des Procédés (2013, October)

Les bioréacteurs à cuve agitée sont des dispositifs largement utilisés dans l’industrie pharmaceutique. Les performances globales des cultures menées dans ces bioréacteurs dépendent fortement de ... [more ▼]

Les bioréacteurs à cuve agitée sont des dispositifs largement utilisés dans l’industrie pharmaceutique. Les performances globales des cultures menées dans ces bioréacteurs dépendent fortement de l’environnement physico-chimique et hydrodynamique local rencontré par les microorganismes et ce au cours du temps. Pour parvenir à caractériser cet historique de conditions locales rencontrées, une approche Euler-Lagrange doit être adoptée. La difficulté dans ce type d’approche est d’être capable de mesurer de manière fiable la trajectoire suivie par le microorganisme au sein du bioréacteur. Pour ce faire, le Laboratoire de Génie Chimique de l’Université de Liège a conçu un dispositif de trajectographie optique. L’objectif de cet article est de présenter ce dispositif, les développements qui ont été nécessaire à sa mise en œuvre et les résultats obtenus. Le dispositif se compose de deux caméras observant selon deux axes de l’espace un bioréacteur rétro-éclairé par des panneaux leds. La trajectoire suivie par une particule noire en gel d’alginate de calcium de 491 µm de diamètre est construite à partir des images acquises par ces deux caméras préalablement modélisée par un modèle pinhole et traitées par une approche rationnée. La validité des trajectoires mesurées a été prouvée dans un bioréacteur de 20 L mélangé par une hélice TTP en comparant les champs de vitesse moyen et d’énergie cinétique turbulent extraits de la trajectoire avec ceux obtenus par la technique eulérienne Stéréo P.I.V. La convergence de ces deux champs avec le temps d’acquisition de la trajectoire a également été démontrée. [less ▲]

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See detailProteomic Investigation of Aphid Honeydew Reveals an Unexpected Diversity of Proteins
Sabri, Ahmed; Vandermoten, Sophie ULg; Leroy, Pascal et al

in PLoS ONE (2013), 8(9),

Aphids feed on the phloem sap of plants, and are the most common honeydew-producing insects. While aphid honeydew is primarily considered to comprise sugars and amino acids, its protein diversity has yet ... [more ▼]

Aphids feed on the phloem sap of plants, and are the most common honeydew-producing insects. While aphid honeydew is primarily considered to comprise sugars and amino acids, its protein diversity has yet to be documented. Here, we report on the investigation of the honeydew proteome from the pea aphid Acyrthosiphon pisum. Using a two-Dimensional <br />Differential in-Gel Electrophoresis (2D-Dige) approach, more than 140 spots were isolated, demonstrating that aphid honeydew also represents a diverse source of proteins. About 66% of the isolated spots were identified through mass spectrometry analysis, revealing that the protein diversity of aphid honeydew originates from several organisms (i.e. the host aphid and its microbiota, including endosymbiotic bacteria and gut flora). Interestingly, our experiments also allowed to identify some proteins like chaperonin, GroEL and Dnak chaperones, elongation factor Tu (EF-Tu), and flagellin that might act as mediators in the plant-aphid interaction. In addition to providing the first aphid honeydew proteome analysis, we propose to reconsider the importance of this substance, mainly acknowledged to be a waste product, from the aphid <br />ecology perspective. [less ▲]

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See detailSemi-Continuous Fermentation for Gluconic acid Production at High Temperature
Zarmehrkhorshid, Raziyeh ULg; Shafiei, Rasoul ULg; Thonart, Philippe ULg

in World Acadamy of Science, Engineering and Technology (2013, July 31)

Gluconic acid (GA) is a multifunctional organic acid with versatile applications in food, beverage and pharmaceutical industries. Recently, owing to increasing demand for cheaper gluconic acid and its ... [more ▼]

Gluconic acid (GA) is a multifunctional organic acid with versatile applications in food, beverage and pharmaceutical industries. Recently, owing to increasing demand for cheaper gluconic acid and its salts; studies have mainly focused on more economical production process through using cheaper carbohydrate sources and isolation of appropriate microorganism. Despite progress towards its microbial production, fewer studies are available regarding its bacterial production at high temperature. It is believed that, withstanding high temperature during production of this acid can provide a new option for industrially cost effective production through reduction in cost of cooling. Results: A major challenge associated with semi-continuous process of gluconate production using A. senegalensis was inability in glucose consumption during the late stationary phase and next fermentation cycles. Inactivation of respiration system (total dehydrogenases activity) and entrance of cells into viable but nonculturable (VBNC) state during stationary phase were the main reasons of this inability. Conclusions: To improve gluconic acid fermentation at high temperature, it is necessary to induce the activity of total dehydrogenases as they carry the oxidation reaction of glucose. Supplementing the feed with ethanol, successfully conferred ability to cells for further glucose consumption. [less ▲]

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See detailEliciteurs dérivés de rhamnolipides : synthèses, modélisations et activités biologiques
Mayon, Patrick; Ait Barka, Essaid; Baillieul, Fabienne et al

Poster (2013, July 04)

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See detailSuitability of the Weibull 4-parameters model to predict the induction phase of α-amylase production during red sorghum malting when a steep in dilute NaOH is used prior to a resteep in a Bacillus subtilis-S499 based treatment
Bwanganga Tawaba, Jean-Claude ULg; Benjamin Pondo Kouadio; Malumba Kamba, Paul ULg et al

in Journal of the Institute of Brewing (2013)

In previous studies, Bacillus subtilis has been used to control mould growth during red sorghum malting. The use of this biocontrol in steeping liquor has been optimized with some success and the combined ... [more ▼]

In previous studies, Bacillus subtilis has been used to control mould growth during red sorghum malting. The use of this biocontrol in steeping liquor has been optimized with some success and the combined use of a 0.2% NaOH steep, followed by a resteep in a Bacillus subtilis-based biocontrol, has been proposed. The sharpness and variability of the β-amylase peak and the higher levels of β-glucanase obtained in the presence of B. subtilis cells were highlighted. In this work, the suitability of the Weibull 4 Parameters Model to predict sorghum malt α-amylase activity during the enzyme induction stage of red sorghum germination has been compared with those of a 2nd Order Polynomial Model and a General Linear Model. Results obtained showed that the Weibull 4 Parameters Model could be used to predict α-amylase activity, with significant goodness of fit when compared to the 2nd Order Polynomial Model and to the General Linear Model. The effects of steeping treatment (combined use of 0.2% NaOH and Bacillus subtilis S499 starters) and the germination temperature are presented. When the Bacillus subtilis culture used as a starter was diluted, the treatment efficacy to develop α-amylase activity was lost. This study also showed that the germination temperature affected the α-amylase activity rate increase during the induction phase. [less ▲]

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See detailIsolation and Cultivation of a Xylanolytic Bacillus subtilis Extracted from the Gut of the Termite Reticulitermes santonensis
Tarayre, Cédric ULg; Brognaux, Alison ULg; Brasseur, Catherine ULg et al

in Applied Biochemistry and Biotechnology (2013)

The aim of this work was the isolation of xylanolytic microorganisms from the digestive tract of the termite Reticulitermes santonensis. The reducing sugars released after the hydrolysis of xylans can be ... [more ▼]

The aim of this work was the isolation of xylanolytic microorganisms from the digestive tract of the termite Reticulitermes santonensis. The reducing sugars released after the hydrolysis of xylans can be further fermented to provide bioethanol. A xylanolytic strain of Bacillus subtilis was isolated from the hindgut of the termite and displayed amylase and xylanase activities. The bacterium was grown on media containing agricultural residues: wheat bran, wheat distiller’s grains, and rapeseed oil cake. Wheat bran led to the highest induction of xylanase activity, although the development of the strain was less fast than in the other media. It was possible to reach maximal xylanase activities of 44.3, 33.5, and 29.1 I.U./ml in the media containing wheat bran, wheat distiller’s grains, and rapeseed oil cake, respectively. Mass spectrometry identified a wide range of xylose oligomers, highlighting an endoxylanase activity. The enzyme was stable up to 45 °C and displayed an optimal pH close to 8. [less ▲]

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See detailPhysiological response of yeast to process perturbations: A mini-bioreactor approach
Lejeune, Annick ULg; Delvigne, Frank ULg; Thonart, Philippe ULg

in Cerevisia : Belgian Journal of Brewing and Biotechnology (2013), 38(1), 15-19

Large-scale production of yeast (Saccharomyces cerevisiae) is difficult to control, considering the drop of mixing and mass transfer efficiency during scale-up. The drop of hydrodynamic efficiency in ... [more ▼]

Large-scale production of yeast (Saccharomyces cerevisiae) is difficult to control, considering the drop of mixing and mass transfer efficiency during scale-up. The drop of hydrodynamic efficiency in large-scale bioreactors induces the formation of heterogeneities, i.e. mainly substrate and dissolved oxygen in process conditions. These extracellular fluctuations have several impacts at the level of the physiology of microorganisms, from metabolic shift to specific gene expression (stress response). Microbial cell responses to extracellular fluctuations are actually not fully understood. In this work, we propose to reproduce the main extracellular fluctuations at the level of a mini bioreactor platform. These mini-reactors are shake flasks equipped with dissolved oxygen probes. The cultures are realized with different fed-batch control strategies. A scale-down approach has been developed by considering slow release techniques and intermittent feeding, in order to reproduce the glucose and dissolved oxygen fluctuations experienced in large-scale reactors. The mini-reactor has been used to screen the response of several green fluorescent protein (GFP) reporter strains (adh2, tps2, pdc6 and hxt2). The GFP content of cells has been determined by flow cytometry in order to take into account population heterogeneity. In front of these results, the methodology presented in this work can be proposed as a scale-down tool. [less ▲]

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