References of "Thonart, Philippe"
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See detailMicroencapsulation Of Erythromycin And Clarithromycin Using A Spray-Drying Technique
Zgoulli, S.; Grek, V.; Barre, G. et al

in Journal of Microencapsulation (1999), 16(5), 565-71

Previous methods of microencapsulation are unable to process particles smaller than 100 microm without organic solvents or the use of multistep processes. The present study investigates the feasiblity of ... [more ▼]

Previous methods of microencapsulation are unable to process particles smaller than 100 microm without organic solvents or the use of multistep processes. The present study investigates the feasiblity of a one-step spray-drying process to microencapsulate erythromycin and clarithromycin, antibiotics known to have an unpleasant, bitter taste. Mixtures of clarithromycin (5% by weight) or erythromycin (30% by weight) with a biodegradable polymer were prepared and spray-dried under specific conditions of temperature and turbine speed. This process resulted in the microencapsulation of 80% of each drug as determined by high pressure liquid chromatography. Particle size ranged from 1 to 80 microm as determined by electron microscopy. These data show that microencapsulation of macrolides using a spray-drying technique is feasible. Spray-drying microencapsulation might be useful in the formulation of palatable oral suspensions of bitter tasting drugs. [less ▲]

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See detailModification of the Thermoresistance to Spray-Drying of a Cold-Adapted Subtilisin by Genetic Engineering
Bare, G.; Diakiese, A.; Zgoulli, S. et al

in Applied Biochemistry and Biotechnology (1999), 77-79(Spring), 857-65

The thermoresistance of a cold-adapted subtilisin dried by spray-drying was studied. Proteolytic activity of this enzyme was measured before and after spray-drying. Without chemical additives, spray ... [more ▼]

The thermoresistance of a cold-adapted subtilisin dried by spray-drying was studied. Proteolytic activity of this enzyme was measured before and after spray-drying. Without chemical additives, spray-drying yields ranged from 2-13%. The use of arabic gum and lactose in the composition of the enzyme solutions allowed the strengthening of the enzyme structures and increased water mobility in the product. Increase of water mobility led to a shorter residence time of the product in the spray-drier and a net yield increase was obtained (yield higher than 50%). The effect of two selective mutations on the thermoresistance to spray-drying of the cold-adapted subtilisin was also investigated. Mutation T85D (introduction of an additional link with an ion Ca2+ necessary for enzyme activity, by substitution of Asp for Thr 85) had no effect on the thermoresistance of the subtilisin to spray-drying. Mutation H121W (introduction of an additional aromatic link by substitution of Trp for His 121) reduced the drying yield from 66% (not modified subtilisin) to 52%. This higher thermosensitivity could be explained by an increase of the hygroscopic character of the modified subtilisin (mutation H121W). [less ▲]

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See detailA biological pluridisciplinary model to predict municipal landfill life
Steyer, E.; Hiligsmann, Serge ULg; Radu, Jean-Pol ULg et al

in Christensen; Cossu; Stegmann (Eds.) Proceedings Sardinia 99, Seventh International Waste Management and Landfill Symposium (1999)

The degradation processes occurring within landfills are the keys to assessment and control of their environmental impact. This degradation results from different microbial activities interacting all ... [more ▼]

The degradation processes occurring within landfills are the keys to assessment and control of their environmental impact. This degradation results from different microbial activities interacting all along the landfill lifetime and influenced by several non-biological factors. Approaching these complex biological and chemical processes requires a multidisciplinary pattern. Thanks to Walloon Region support, we have developed a pattern or model combining the evolution of different key parameters. Such parameters qualify biogas (composition, production rate), leachate (pH, BOD5, COD, volatile fatty acids, redox potential, nitrogen balance, humic acids...), or solid waste (moisture, settlement, cellulose content...). This paper presents relationships, including our model, between these parameters. Variations of pH, BOD5/COD ratio, sulphate concentration in leachates and settlement measures allows to predict landfill age since completion. Evaluation of cellulose and water content in refuse as well as settlement degree are useful to estimate the time required for complete biological degradation. The mathematical model has also been applied, with success, to the case of Anton Sclayn site. [less ▲]

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See detailLandfill management in Africa
Lardinois, M.; Kapepula, D.; Hiligsmann, Serge ULg et al

in Christensen; Cossu; Stegmann (Eds.) Proceedings Sardinia 99, Seventh International Waste Management and Landfill Symposium (1999)

Landfill management is an important matter to study in order to set up techniques respectful of the environment. Before any suggestions of management solutions, behaviour of landfills has to be ... [more ▼]

Landfill management is an important matter to study in order to set up techniques respectful of the environment. Before any suggestions of management solutions, behaviour of landfills has to be characterised. This is necessary to predict future interactions between a landfill and the neighbourhood, and to estimate the landfill lifetime. Water is one of the most important parameter implied in the biological degradation of refuse, which is a substantial source of pollution. Therefore, this parameter is characterised in terms of quantitative and qualitative data. A relationship between climatic conditions, one of the main source of water, and possible evolution of landfills is propounded. [less ▲]

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See detailL’évaluation biologique des décharges en relation avec les propriétés de perméabilité
Steyer, E.; Ourth, A.; Hiligsmann, Serge ULg et al

Scientific conference (1998, September 25)

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See detailImproving the catabolic functions in desiccation-tolerant soil bacteria in view of their use in bioaugmentation.
Weekers, F.; Jacques, Philippe ULg; Springael, D. et al

Poster (1998, May 08)

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See detailModification of the thermoresistance to spray-drying of a cold-adapted subtilisin by genetic engineering
Bare, G.; Diakiese, A.; Zgoulli, S. et al

Poster (1998, May 08)

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See detailDevelopment of a regenerable filter aid for beverages
Bonacchelli, B.; Zgoulli, S.; Harmegnies, F. et al

Poster (1998, May 08)

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See detailImproving the catabolic functions in dessication-tolerant soil bacteria in view of their use in bioaugmentation
Weekers, F.; Jacques, Philippe ULg; Springael, D. et al

Poster (1998, May)

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See detailStructural analysis of two pyoverdins by electrospray and FAB mass spectrometry
Ongena, MARC ULg; Jacques, Philippe ULg; van Vyncht, Gery et al

in Journal of the Mass Spectrometry Society of Japan (1998), 48

Pyoverdins are chromopeptides produced by the so-called fluorescent group of the bacterial genus Pseudomonas. Species or even strain specific they differ in the composition of their peptide chains. For ... [more ▼]

Pyoverdins are chromopeptides produced by the so-called fluorescent group of the bacterial genus Pseudomonas. Species or even strain specific they differ in the composition of their peptide chains. For classification purposes it is of importance to get fast information regarding the nature of the latter. For two new representatives from hydrolysis results and especially from an analysis of the data obtained from electrospray ionization (ESI) and fast atom bombardement (fAn) mass spectrometry measurements the amino acid sequences can be suggested as Asp-BuOHOrn-Dab-aThr-Gly-Ser-Ser-OHAsp-aThr (Pseudomonas putida BTP16) and Ser-SerFoOHOrn-Ser-Ser-Ser-FoOHOrn-Lys-Lys (Pseudomolnas fluorescens BTP7). [less ▲]

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See detailBiological treatment of waste gypsum
Hiligsmann, Serge ULg; Jacques, Philippe ULg; Thonart, Philippe ULg

in Biodegradation (1998)

The presentation presents the investigations about gypsum treatment by sulfate-reducing bacteria

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See detailIsolation Of Highly Performant Sulfate Reducers From Sulfate-Rich Environments
Hiligsmann, Serge ULg; Jacques, Philippe ULg; Thonart, Philippe ULg

in Biodegradation (1998), 9(3-4), 285-292

Eleven pure strains of sulfate-reducing bacteria have been isolated from lab-scale bioreactors or disposal sites, all featuring relatively high concentrations of sulfate, and from natural environments in ... [more ▼]

Eleven pure strains of sulfate-reducing bacteria have been isolated from lab-scale bioreactors or disposal sites, all featuring relatively high concentrations of sulfate, and from natural environments in order to produce sulfide from gypsum using hydrogen as energy source. The properties of the eleven strains have been investigated and compared to these of three collection strains i.e. Desulfovibrio desulfuricans and vulgaris and Desulfotomaculum orientis. Particular attention was paid to the absolute and relative sulfide production rate and to the hydrogen sulfide inhibition level. By comparison to the collection strains, a 75 % higher production rate and a hydrogen sulfide inhibition level about twice higher i.e. 25.1 mM have been achieved with strains isolated from sulfate-rich environments. The strain selection, particularly from sulfate-rich environments, should be considered as an optimization factor for the sulfate reduction processes. [less ▲]

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See detailFoaming properties of lipopeptides produced by Bacillus subtilis: effect of lipid and peptide structural attributes
Razafindralambo, Hary ULg; Popineau, Yves; Deleu, Magali ULg et al

in Journal of Agricultural and Food Chemistry (1998), 46(3), 911-916

To study the effect of lipid and peptide structural attributes of Bacillus subtilis lipopeptides on their foaming properties, the formation, stability, and appearance of foams prepared with surfactins ... [more ▼]

To study the effect of lipid and peptide structural attributes of Bacillus subtilis lipopeptides on their foaming properties, the formation, stability, and appearance of foams prepared with surfactins (C13 C15) and iturins A (C14 C17) were characterized. The density and stability of lipopeptide foams depend on both the alkyl chain hydrophobic character and peptide molecular intrinsic properties. A lipidic chain length of 14 carbon atoms provides lipopeptides with the best foaming properties in terms of foam density and liquid stability in foams. Increases in alkyl chain length above 15 carbon atoms result in a drastic decrease of iturin A foam density. With the same alkyl chain, surfactin produces denser foam whereas iturin A exhibits better foaming stability. These results demonstrate the importance of the peptide structural attributes of B. subtilis on their foaming properties. [less ▲]

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See detailEffect Of Drying On Bioremediation Bacteria Properties
Weekers, F.; Jacques, Philippe ULg; Springael, D. et al

in Applied Biochemistry and Biotechnology (1998), 70-2

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See detailLa gestion biologique d'une decharge.
Thonart, Philippe ULg; Steyer, Emmanuel; Drion, Raphael et al

in Tribune de l'Eau (La) (1998), 590/591

Detailed reference viewed: 122 (8 ULg)