References of "Thonart, Philippe"
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See detailIn vitro root cultures of Panax ginseng and P-quinquefolium
Kevers, Claire ULg; Jacques, Philippe; Thonart, Philippe ULg et al

in Plant Growth Regulation (1999), 27(3), 173-178

The paper describes a procedure for the initiation, subculture and continued proliferation of adventitious roots of Panax ginseng and Panax quinquefolium, which resemble hairy roots. The technique took ... [more ▼]

The paper describes a procedure for the initiation, subculture and continued proliferation of adventitious roots of Panax ginseng and Panax quinquefolium, which resemble hairy roots. The technique took advantage of the high powerful activity of a new synthetic auxin: benzo[b]selenienyl acetic acid (BSAA). Such initiation from root explants was dependent upon the season, the type and concentration of auxin. The hairy-like roots of ginseng could be subcultured by transfer every 4 weeks to fresh liquid medium either in agitated Erlenmeyer flasks or in bioreactors. Optimal conditions for a continued multiplication (up to 14 per month) were determined. The only practical problem was the limitation of the fresh mass as inoculum: the multiplication rate decreased with the increased quantity of roots. It is postulated that a root growth inhibiting substance was released into the media by the proliferating ginseng hairy roots. [less ▲]

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See detailOptimization of biosurfactant lipopeptide production from Bacillus subtilis S499 by Plackett-Burman design
Jacques, P.; Hbid, C.; Destain, Jacqueline ULg et al

in Applied Biochemistry and Biotechnology (1999), 77-9

Bacillus subtilis S499 is well-known for its ability to produce two families of surfactant lipopeptides: Iturin A and Surfactin S1. Fermentation optimization for this strain was performed to amplify the ... [more ▼]

Bacillus subtilis S499 is well-known for its ability to produce two families of surfactant lipopeptides: Iturin A and Surfactin S1. Fermentation optimization for this strain was performed to amplify the surfactant production. Ten active variables were analyzed by two successive Plackett-Burman designs, consisting respectively of 12 and 16 experiments to give an optimized medium. The amount of biosurfactant lipopeptides in the supernatant of a culture carried out in this optimized medium was about five times higher than that obtained in nonoptimized rich medium. The analysis of the surfactant molecules produced in such optimized conditions has revealed the presence of a third family of lipopeptides: the fengycins. The time-dependent production of these three families of molecules in bioreactors showed that surfactin S1 is produced during the exponential phase and iturin A and fengycins during the stationary phase. [less ▲]

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See detailProtection Of Cucumber Against Pythium Root Rot By Fluorescent Pseudomonads: Predominant Role Of Induced Resistance Over Siderophores And Antibiosis
Ongena, MARC ULg; Daayf, F.; Jacques, P. et al

in Plant Pathology (1999), 48(1),

Four Pseudomonas strains were evaluated for their intrinsic properties conferring their ability to protect long English cucumber against Pythium aphanidermatum in hydroponic culture. Two of the strains ... [more ▼]

Four Pseudomonas strains were evaluated for their intrinsic properties conferring their ability to protect long English cucumber against Pythium aphanidermatum in hydroponic culture. Two of the strains, BTP1 and its siderophorenegative mutant M3, increased plant yield as compared with the non-inoculated control plants. Strain BTP7 was intermediate in its biocontrol activity while strain ATCC 17400 failed to reduce disease development. The role of pyoverdines could not be confirmed since treatment with either BTP1 or its siderophore-negative mutant M3 provided similar suppression of Pythium disease. In addition, no siderophores were detected in the nutrient solution. BTP1 did not inhibit pathogen growth in vitro on several media, suggesting that antibiosis was not a mechanism of suppression. Quantification of root bacterial populations did not indicate differences among the strains. On the other hand, roots treated with either BTP1 or its sid¹ mutant M3 contained more antifungal phenolics than roots from any other treatments including controls. These results suggest that antifungal compounds induced by inoculation of cucumber roots with the fluorescent Pseudomonas strains BTP1 and M3 participate actively in the protection of cucumber plants against P. aphanidermatum [less ▲]

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See detailImproving The Catabolic Functions Of Desiccation-Tolerant Soil Bacteria
Weekers, F.; Jacques, P.; Springael, D. et al

in Applied Biochemistry and Biotechnology (1999), 77-9

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See detailComputer Simulation Of Surfactin Conformation At A Hydrophobic/Hydrophilic Interface
Gallet, X.; Deleu, Magali ULg; Razafindralambo, Hary ULg et al

in Langmuir (1999), 15(7), 2409-13

Using a molecular modeling method, different conformations of surfactin at a hydrophobic/hydrophilic interface are established. Two conformations of the peptide ring (S1 and S2) provided by NMR ... [more ▼]

Using a molecular modeling method, different conformations of surfactin at a hydrophobic/hydrophilic interface are established. Two conformations of the peptide ring (S1 and S2) provided by NMR experiments built with three different aliphatic chains in folded or extended configurations were studied. For the structures including the S2 peptide ring conformation, the theoretical interfacial molecular area corresponds to the experimental limiting area A0 value obtained with a Langmuir film balance. The peptide ring is positioned in the plane of the interface with the two acidic chains close to each other and protruding in the aqueous phase, and the β-hydroxy fatty acid chain, folded to interact mainly with the Leu2 side chain and also with the Val4 side chain. This design has the largest calculated molecular area and would correspond to the most stable amphipathic structure representing the surfactin experimental behavior in weak compression. [less ▲]

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See detailInterfacial and emulsifying properties of lipopeptides from Bacillus subtilis
Deleu, Magali ULg; Razafindralambo, Hary ULg; Popineau, Y. et al

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (1999), 152(1-2), 3-10

The fundamental surface-active properties at the oil/water interface and emulsifying properties of surfactin, iturin A and fengycin, lipopeptides from Bacillus subtilis, were investigated. All ... [more ▼]

The fundamental surface-active properties at the oil/water interface and emulsifying properties of surfactin, iturin A and fengycin, lipopeptides from Bacillus subtilis, were investigated. All lipopeptides reduce rapidly the dynamic interfacial tension. Among lipopeptide families, surfactin is the most effective in terms of fundamental dynamic and equilibrium interfacial properties. Lipopeptides present intermediate properties in comparison with sodium dodecyl sulfate and beta-lactoglobulin concerning the stabilizing effect towards creaming-flocculation and the resistance to coalescence. Among lipopeptides, iturin A seems to show the best resistance to creaming-flocculation whereas fengycin exhibits the highest resistance to coalescence properties. (C) 1999 Elsevier Science B.V. All rights reserved. [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 detailProtection des pommes Jona Gold par Bacillus subtilis GA1 et S499 contre Botrytis cinerea
Toure, Y.; Jacques, Ph.; Thonart, Philippe ULg

Poster (1998, May 08)

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See detailImproving the catabolic functions in desiccation-tolerant soil bacteria in view of their use in bioaugmentation.
Weekers, F.; Jacques, Ph.; 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 detailOptimization of biosurfactant lipopeptide production from Bacillus subtilis S499 by plackett-burman design
Jacques, Ph.; Hbid, Ch.; Razafindralambo, Hary ULg et al

Poster (1998, May)

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

Poster (1998, May)

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

in Biodegradation (1998)

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

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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

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See detailIsolation Of Highly Performant Sulfate Reducers From Sulfate-Rich Environments
Hiligsmann, Serge ULg; Jacques, Philippe; 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 detailStructural analysis of two pyoverdins by electrospray and FAB mass spectrometry
Ongena, MARC ULg; Jacques, Philippe; 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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