References of "Jacques, Philippe"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailSecond harmonic generation to monitor the interactions of the antimicrobial mycosubtilin with membrane-mimicking interfacial monolayers
Nasir, Mehmet Nail ULg; Benichou, Emmanuel; Guez, Jean-Sébastien et al

in BioNanoScience (2012), 2(2), 108-112

Mycosubtilin is a strong antimicrobial agent belonging to the iturinic lipopeptide family which contains a single tyrosine residue. Its cell target has been shown to be the cytoplasmic membrane. This ... [more ▼]

Mycosubtilin is a strong antimicrobial agent belonging to the iturinic lipopeptide family which contains a single tyrosine residue. Its cell target has been shown to be the cytoplasmic membrane. This tyrosine residue has been previously shown to be essential for the biological activity of mycosubtilin. Since we have previously demonstrated that tyrosine, an aromatic amino acid, can be used as an endogenous probe for the frequency doubling process, the presence of a tyrosine residue in mycosubtilin allowed us to investigate the interactions of mycosubtilin with biomimetic lipid monolayers at the air–water interface by second harmonic generation (SHG). Mycosubtilin was added underneath dipalmitoylphosphatidylcholine or cholesterol monolayers at the air–water interface and significant increases in the surface pressure were observed in both cases. This observation demonstrates that mycosubtilin interacts with these biomimetic membranes. A light polarization resolved analysis of the SHG signals recovered for these two systems was then performed and confirmed that those interactions between the tyrosine residue in mycosubtilin and the membranes could be monitored by SHG. Furthermore, the differences exhibited by the nonlinear optical measurements for different membranes showed that these interactions depend on the nature of the biomimetic membrane present at the air–water interface. [less ▲]

Detailed reference viewed: 23 (4 ULg)
Full Text
Peer Reviewed
See detailSynthesis of amonabactins by Aeromonas hydrophila : implication of NRPS of a unique iterate-alternative type
Leclère, Valérie; Subashkumar, Rathinasamy; Wathelet, Bernard ULg et al

Poster (2011)

Detailed reference viewed: 12 (2 ULg)
Full Text
See detailBioinformatics tools to decrypt pyoverdine biosynthesis in Pseudomonas sp.
Vanvlassenbroeck, Aurélien; Leclère, Valérie; Pupin, Maude et al

Poster (2011)

Detailed reference viewed: 16 (4 ULg)
Full Text
Peer Reviewed
See detailAdenylation domain specificity in pyoverdine NRPS biosynthesis
Vanvlassenbroeck, Aurélien; Leclère, Valérie; Pupin, Maude et al

Poster (2011)

Detailed reference viewed: 18 (3 ULg)
Full Text
Peer Reviewed
See detailSynthesis of amonabactins by Aeromonas hydrophila : implication of NRPS of a unique iterative-alternative type
Leclère, Valérie; Rathisamy, Subashkumar; Wathelet, Bernard ULg et al

Poster (2011)

Detailed reference viewed: 20 (3 ULg)
Full Text
Peer Reviewed
See detailBioinformatics and molecular approaches to detect NRPS genes involved in the biosynthesis of kurstakin from Bacillus thuringiensis
Abderrahmani, Ahmed; Tapi, Arthur; Nateche, Farida et al

in Applied Microbiology & Biotechnology (2011), 92

Detailed reference viewed: 37 (2 ULg)
Full Text
Peer Reviewed
See detailIdentification of surf actin producing strains in Soumbala and Bikalga fermented condiments using polymerase chain reaction and matrix assisted laser desorption/ionization-mass spectrometry methods
Savadogo, A; Tapi, Arthur; Chollet, Marlène et al

in International Journal of Food Microbiology (2011)

Detailed reference viewed: 12 (2 ULg)
Full Text
Peer Reviewed
See detailCellular engineering of Bacillus subtilis to enhance the biosynthesis of highly active anti fungal lipopeptides
Guy, J.; Guez, Jean-Sébastien; Coucheny, F. et al

Poster (2010)

Detailed reference viewed: 9 (4 ULg)
Full Text
Peer Reviewed
See detailHigh-level biosynthesis of the anteiso-C(17) isoform of the antibiotic mycosubtilin in Bacillus subtilis and characterization of its candidacidal activity.
Fickers, Patrick ULg; Guez, Jean-Sebastien; Damblon, Christian ULg et al

in Applied and Environmental Microbiology (2009), 75(13), 4636-40

High-level production (880 mg liter(-1)) and isolation of the anteiso-C(17) isoform of the lipopeptide mycosubtilin produced by a genetically engineered Bacillus subtilis strain are reported. Antifungal ... [more ▼]

High-level production (880 mg liter(-1)) and isolation of the anteiso-C(17) isoform of the lipopeptide mycosubtilin produced by a genetically engineered Bacillus subtilis strain are reported. Antifungal activity of this isoform, as determined via culture and fluorometric and cell leakage assays, suggests its potential therapeutic use as an antifungal agent, in particular against Candida spp. [less ▲]

Detailed reference viewed: 30 (5 ULg)
Full Text
Peer Reviewed
See detailNonribosomal peptides producing strains isolated from Bikalga and Soumbala fermented condiments of Burkina Faso
Savadogo, Aly; Chollet, Marlène; Tapi, Arthur et al

Conference (2009)

Detailed reference viewed: 5 (2 ULg)
Full Text
Peer Reviewed
See detailTemperature dependence of mycosubtilin homologue production in Bacillus subtilis ATCC6633.
Fickers, Patrick ULg; Leclere, Valerie; Guez, Jean*-Sebastien et al

in Research in Microbiology (2008), 159(6), 449-57

Bacillus subtilis ATCC6633 produces mycosubtilin, a non-ribosomally synthesized lipopeptide of the iturin family which presents antagonistic activities toward various phytopathogens. Different homologues ... [more ▼]

Bacillus subtilis ATCC6633 produces mycosubtilin, a non-ribosomally synthesized lipopeptide of the iturin family which presents antagonistic activities toward various phytopathogens. Different homologues with fatty acid moiety varying from C15 to C17 are usually co-produced, with their biological activities increasing with the number of carbons in the fatty acid chain. In the present report, we highlight that growth temperature modulates both the extent of mycosubtilin production and the relative abundance of the different homologues. A 30-fold increase in mycosubtilin production was observed when the temperature was decreased from 37 degrees C to 25 degrees C for both strain ATCC6633 and its derivative BBG100, a constitutive mycosubtilin overproducer. However, no significant difference in either the expression of the mycosubtilin synthetase encoding genes or in the intracellular synthetase concentration could be found, suggesting that the observed phenotype originated from a higher mycosubtilin synthetase turnover at lower temperature. We also point out that lower growth temperature leads to an increased proportion of odd-numbered fatty acid homologues as a consequence of de novo synthesis of C17 anteiso fatty acid following cell adaptation to low temperatures. [less ▲]

Detailed reference viewed: 58 (4 ULg)
Full Text
Peer Reviewed
See detailBacillus lipopeptides: versatile weapons for plant disease biocontrol.
Ongena, MARC ULg; Jacques, Philippe

in Trends in Microbiology (2008), 16(3), 115-25

In the context of biocontrol of plant diseases, the three families of Bacillus lipopeptides - surfactins, iturins and fengycins were at first mostly studied for their antagonistic activity for a wide ... [more ▼]

In the context of biocontrol of plant diseases, the three families of Bacillus lipopeptides - surfactins, iturins and fengycins were at first mostly studied for their antagonistic activity for a wide range of potential phytopathogens, including bacteria, fungi and oomycetes. Recent investigations have shed light on the fact that these lipopeptides can also influence the ecological fitness of the producing strain in terms of root colonization (and thereby persistence in the rhizosphere) and also have a key role in the beneficial interaction of Bacillus species with plants by stimulating host defence mechanisms. The different structural traits and physico-chemical properties of these effective surface- and membrane-active amphiphilic biomolecules explain their involvement in most of the mechanisms developed by bacteria for the biocontrol of different plant pathogens. [less ▲]

Detailed reference viewed: 62 (5 ULg)
Full Text
Peer Reviewed
See detailConditioning Panax vietnamensis cell mass production in bioreactors
Jacques, Philippe; Kevers, Claire ULg; Gaspar, Thomas et al

in Acta Botanica Gallica : Bulletin de la Société Botanique de France (2007), 154

The influence of lighting conditions, culture volume and four different auxins (indoleacetic acid (IAA), indolebutyric acid (IBA), 2,4-dichlorophenoxyacetic acid (2,4-D) or 3-(benzo[b]selenyl)acetic acid ... [more ▼]

The influence of lighting conditions, culture volume and four different auxins (indoleacetic acid (IAA), indolebutyric acid (IBA), 2,4-dichlorophenoxyacetic acid (2,4-D) or 3-(benzo[b]selenyl)acetic acid (BSAA)) on Panax vietnamensis cell growth was evaluated in flasks. The highest biomass productivity was observed under continuous light and in the presence of IBA (0.36 g DW l(-1) d(-1)) or BSAA (0.5 g DW l(-1) d(-1)). Cultures in bioreactors were performed with these two auxins. The final biomass concentration was 107 g FW l(-1) and 373 g FW l(-1) in the presence of IBA or BSAA, respectively. [less ▲]

Detailed reference viewed: 52 (8 ULg)
Full Text
Peer Reviewed
See detailXPS analysis of chemical functions at the surface of Bacillus subtilis
Ahimou, François; Boonaert, Christophe; Adriaensen, Yasmine et al

in Journal of Colloid and Interface Science (2007), 309(1), 49-55

The surface chemical composition of nine strains of Bacillus subtilis was determined by X-ray photoelectron spectroscopy. Regressions between elemental concentrations and concentrations associated with ... [more ▼]

The surface chemical composition of nine strains of Bacillus subtilis was determined by X-ray photoelectron spectroscopy. Regressions between elemental concentrations and concentrations associated with different components of C1s, N1s, and O1s peaks provided a more precise validation of the procedure used for peak decomposition and allowed the assignment of the peak components to be completed or strengthened. The component of the O1s peak appearing around 531.2 eV was shown to contain a contribution of oxygen from phosphate groups (P=O, P–O−), the other contribution being due to oxygen involved in amide functions. The surface negative charge may be fully attributed to phosphate groups, despite the observation of two types of zeta potential vs pH curves. The strains exhibiting a sharp variation of the zeta potential (range of −35 to −55 mV) between pH 2 and 4.7 were characterized by a high phosphate surface concentration and by an excess (about 25%) of phosphate with respect to the sum of potassium, an exchangeable cation, and protonated nitrogen, attributed to protein or to alanine involved in teichoic acids. [less ▲]

Detailed reference viewed: 86 (26 ULg)
Full Text
Peer Reviewed
See detailDirecting the lipopeptide Mycosubtilin biosynthesis toward C17:0 branched isoform influences the expression of cspB and cspC in Bacillus subtilis
Guez, Jean-Sébastien; Drucbert, A.; Müller, C. et al

Poster (2007)

Detailed reference viewed: 26 (0 ULg)
Full Text
Peer Reviewed
See detailMycosubtilin overproduction by Bacillus subtilis BBG100 enhances the organism's antagonistic and biocontrol activities
Leclère, Valérie; Béchet, Max; Adam, Akram et al

in Applied and Environmental Microbiology (2005), 71(8), 4577-4584

A Bacillus subtilis derivative was obtained from strain ATCC 6633 by replacement of the native promoter (if he mycosubtilin operon by a constitutive promoter originating from the replication gene repU of ... [more ▼]

A Bacillus subtilis derivative was obtained from strain ATCC 6633 by replacement of the native promoter (if he mycosubtilin operon by a constitutive promoter originating from the replication gene repU of the Staphylococcus aureus plasmid pUB110. The recombinant strain, designated BBG100, produced up to 15-fold more mycosubtilin than the wild type produced. The overproducing phenotype was related to enhancement of the antagonistic activities against several yeasts and pathogenic fungi. Hemolytic activities were also clearly increased in the modified strain. Mass spectrometry analyses of enriched mycosubtilin extracts showed similar patterns of lipopeptides for BBG100 and the wild type. Interestingly, these analyses also revealed a new form of mycosubtilin which was more easily detected in the BBG100 sample. When tested for its biocontrol potential, wild-type strain ATCC 6633 was almost ineffective for reducing a Pythium infection of tomato seedlings. However, treatment of seeds with the BBG100 overproducing strain resulted in a marked increase in the germination rate of seeds. This protective effect afforded by mycosubtilin overproduction was also visualized by the significantly greater fresh weight of emerging seedlings treated with BBG100 compared to controls or seedlings inoculated with the wild-type strain. [less ▲]

Detailed reference viewed: 31 (3 ULg)
See detailNovel use of lipopeptide preparations
Deleu, Magali ULg; Brans, Alain; Brasseur, Robert ULg et al

Patent (2004)

Detailed reference viewed: 3 (0 ULg)
Full Text
Peer Reviewed
See detailComparative titration of ginsenosides by different techniques in commercial ginseng products and callus cultures
Kevers, Claire ULg; Jacques, Philippe; Gaspar, Thomas ULg et al

in Journal of Chromatographic Science (2004), 42(10, Nov-Dec), 554-558

The ginsenoside content of different ginseng species (Panax ginseng, P. quinquefolium, and P. vietnamensis) from different sources (roots from field-grown plants or from in vitro cultures, cells from ... [more ▼]

The ginsenoside content of different ginseng species (Panax ginseng, P. quinquefolium, and P. vietnamensis) from different sources (roots from field-grown plants or from in vitro cultures, cells from solid calluses or from liquid cultures, commercial powders, and suspensions) is evaluated by means of a new high-performance thin-layer chromatography (HPTLC) technique combining an automatic TLC sampler and scanner. The results are compared with those obtained through more classical gross spectrometric and high-performance liquid chromatography (HPLC) techniques. HPTLC and HPLC allow the separation and estimation of the different ginsenosides. For this, HPTLC is faster and simpler than HPLC. Both techniques determine less amounts of ginsenosides than spectrophotometry, which displays overestimated values caused by light absorption by contaminating osides. In vitro cultured cells and roots contain the same ginsenosides as those produced by their mother plants, although at quite lower levels. The culture media also accumulates ginsenosides. [less ▲]

Detailed reference viewed: 53 (4 ULg)
Full Text
Peer Reviewed
See detailXylanase Production By Penicillium Canescens 10-10c In Solid-State Fermentation
Bakri, Y.; Jacques, Philippe; Thonart, Philippe ULg

in Applied Biochemistry and Biotechnology (2003), 105

Detailed reference viewed: 9 (1 ULg)