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See detailIsolation of an n-alkylated benzylamine derivative from Pseudomonas putida BTP1 as elicitor of induced systemic resistance in bean
Ongena, MARC ULg; Jourdan, Emmanuel ULg; Schafer, M. et al

in Molecular Plant-Microbe Interactions (2005), 18(6), 562-569

Root treatment of Phaseolus vulgaris with the nonpathogenic Pseudomonas putida BTP1 led to significant reduction of the disease caused by the pathogen Botrytis cinerea on leaves. The molecular determinant ... [more ▼]

Root treatment of Phaseolus vulgaris with the nonpathogenic Pseudomonas putida BTP1 led to significant reduction of the disease caused by the pathogen Botrytis cinerea on leaves. The molecular determinant of P putida BTP1 mainly responsible for the induced systemic resistance (ISR) was isolated from cell-free culture fluid after growth of the strain in the iron-poor casamino acid medium. Mass spectrometry analyses performed on both the bacterial product and synthetic analogues revealed a polyalkylated benzylamine structure, with the quaternary ammonium substituted by methyl, ethyl, and C-13 aliphatic groups responsible for the relative hydrophobicity of the molecule. The specific involvement of the N-alkylated benzylamine derivative (NABD) in ISR elicitation was first evidenced by testing the purified compound that mimicked the protective effect afforded by crude supernatant samples. The evidence was supported by the loss of elicitor activity of mutants impaired in NABD biosynthesis. Our experiments also showed that other iron-regulated metabolites secreted by the strain are not involved in ISR stimulation. Thus, these results indicate a wider variety of Pseudomonas determinants for ISR than reported to date. [less ▲]

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See detailIsolation of bacteriocin-producing lactic acid bacteria from fermented fish product in Senegal.
Dortu, C.; Roblain, D.; Totte, A. et al

Poster (2003, May)

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See detailIsolation of bacteriocin-producing lactic acid bacteria from fermented fish product in Senegal.
Dortu, C.; Roblain, D.; Totte, A. et al

Poster (2003, August)

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See detailIsolation of bioactive peptides from tryptone that modulate lipase production in Yarrowia lipolytica
Turki, Souassen; Ben Kraeim, Ines; Weekers, F. et al

in Bioresource Technology (2009), 100

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See detailIsolation of Bovine Follicular Dendritic Cells Allows the Demonstration of a Particular Cellular Prion Protein
Thielen, Caroline ULg; Mélot, France ULg; Jolois, Olivier ULg et al

in Cell & Tissue Research (2001), 306(1), 49-55

As interaction of cellular prion protein (PrPc) and the infectious agent (PrPres) appears to be a crucial pathogenic step promoted by homology, variation in PrPc isoforms on bovine immune cells may ... [more ▼]

As interaction of cellular prion protein (PrPc) and the infectious agent (PrPres) appears to be a crucial pathogenic step promoted by homology, variation in PrPc isoforms on bovine immune cells may explain the absence of infectivity in most bovine lymph organs. In this study, we examined PrPc expression in bovine lymph organs (tonsils and lymph nodes) and on isolated follicular dendritic cells (FDCs). We used a panel of different monoclonal antibodies (MoAbs) raised against different epitopes of prion protein. Two MoAbs recognise amino acids 79-92 (SAF 34 and SAF 32 Mo-Abs); the 6H4 antibody reacts with a specific peptide comprising the 144-152 amino acids, and the 12F10 MoAb recognises the sequence 142-160. After immunolabelling of frozen sections of lymph organs with 6H4 or 12F10 MoAbs, we detected cellular prion protein in germinal centres. However, using the SAF 34 or SAF 32 antibodies, PrPc was revealed outside the lymphoid tissues. No PrPc was observed in the germinal centres. Therefore, we adapted the method of FDC isolation, making it suitable for the study of PrPc expression on their surface. Using electron microscopy, the presence of PrPc on the surface of FDCs was demonstrated only with 6H4 MoAb. These results suggest that bovine follicular dendritic cells express a particular form of prion protein. Either the N-terminal part of PrPc is cleaved or the accessibility of the specific epitope (79-92) of SAF 34 MoAb is abolished by interaction with other molecules. This particular isoform of PrPc on bovine FDCs might be related to the apparent absence of infectivity in lymph organs in cattle affected by bovine spongiform encephalopathy. [less ▲]

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See detailIsolation of caprine herpesvirus type 1 in Spain
Keuser, V.; Espejo-Serrano, J.; Schynts, F. et al

in Veterinary Record : Journal of the British Veterinary Association (2004), 154(13), 395-399

Two strains of caprine herpesvirus type 1 (CpHV-1) were isolated after the experimental reactivation of two seropositive goats in Spain. Viral DNA from these isolates was compared with DNA from bovine ... [more ▼]

Two strains of caprine herpesvirus type 1 (CpHV-1) were isolated after the experimental reactivation of two seropositive goats in Spain. Viral DNA from these isolates was compared with DNA from bovine herpesvirus type 1 and CpHV-1 reference strains by restriction endonuclease analysis. The two Spanish isolates were closely related but could easily be distinguished from each other and from the reference strains. [less ▲]

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See detailIsolation of Chlamydomonas reinhardtii mutants with altered mitochondrial respiration by chlorophyll fluorescence measurement.
Massoz, Simon; Larosa, Véronique ULg; Horrion, Bastien et al

in Journal of biotechnology (2015)

The unicellular green alga Chlamydomonas reinhardtii is a model organism for studying energetic metabolism. Most mitochondrial respiratory-deficient mutants characterized to date have been isolated on the ... [more ▼]

The unicellular green alga Chlamydomonas reinhardtii is a model organism for studying energetic metabolism. Most mitochondrial respiratory-deficient mutants characterized to date have been isolated on the basis of their reduced ability to grow in heterotrophic conditions. Mitochondrial deficiencies are usually partly compensated by adjustment of photosynthetic activity and more particularly by transition to state 2. In this work, we explored the opportunity to select mutants impaired in respiration and/or altered in dark metabolism by measuring maximum photosynthetic efficiency by chlorophyll fluorescence analyses (FV/FM). Out of about 2900 hygromycin-resistant insertional mutants generated from wild type or from a mutant strain deficient in state transitions (stt7 strain), 22 were found to grow slowly in heterotrophic conditions and 8 of them also showed a lower FV/FM value. Several disrupted coding sequences were identified, including genes coding for three different subunits of respiratory-chain complex I (NUO9, NUOA9, NUOP4) or for isocitrate lyase (ICL1). Overall, the comparison of respiratory mutants obtained in wild-type or stt7 genetic backgrounds indicated that the FV/FM value can be used to isolate mutants severely impaired in dark metabolism. [less ▲]

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See detailIsolation of Clostridium perfringens from three neonatal calves with haemorrhagic abomasitis.
Manteca, C.; Jauniaux, Thierry ULg; Daube, Georges ULg et al

in Revue de Médecine Vétérinaire (2001), 152

Braxy-like disease with sudden death and acute haemorhagic abomasitis was diagnosed in three Belgian Blue calves : one two-day-old and one one month-old calves, in good condition with no clinical signs ... [more ▼]

Braxy-like disease with sudden death and acute haemorhagic abomasitis was diagnosed in three Belgian Blue calves : one two-day-old and one one month-old calves, in good condition with no clinical signs noted a few hours prior to death, and another two day-old calf, which had shown problems of abomasal dilatation and regurgitation prior to death. Histologically, the abomasal wall were oedematous and emphysematous. A pure and abundant growth of Clostridium perfringens was obtained in anaerobic conditions from the abomasal wall of the three Belgian Blue calves. No bacterial growth was obtained in aerobic conditions. The calf with digestive disorders was also positive for BVD virus by immunofluorescence in the abomasal wall and in the spleen. [less ▲]

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See detailIsolation of cultivable viruses from Antarctic wintertime sea ice
Luhtanen, A.-M.; Bamford, D.; De Jong, J. et al

Poster (2015, March)

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See detailIsolation of DD carboxypeptidase from Streptomyces albus G culture filtrates
Ghuysen, Jean-Marie ULg; Leyh-Bouille, Mélina; Bonaly, Roger et al

in Biochemistry (1970), 9(15), 2955-2961

Streptomyces albus G secretes a soluble DD carboxypeptidase whose catalytic activities are similar to those of the particulate DD carboxypeptidase from Escherichia coli. Both enzymes hydrolyze the C ... [more ▼]

Streptomyces albus G secretes a soluble DD carboxypeptidase whose catalytic activities are similar to those of the particulate DD carboxypeptidase from Escherichia coli. Both enzymes hydrolyze the C-terminal D-alanyl-D-alanine linkage of UDP-N-acetylmuramyl-L-alanyl-γ-D-glutamyl-(L)-meso-diaminopimelyl-(L)-D-alanyl-D-aIanine and the enzyme-peptide interactions have identical Michaelis constants. Like the E. coli enzyme, the Streptomyces DD carboxypeptidase exhibits endopeptidase activities. The Streptomyces enzyme is lytic for those walls in which the peptidoglycan interpeptide bonds are mediated through C-terminal D-alanyl-D linkages. There is no strict requirement for a specific structure of the C-terminal D-amino acid residue. The tripeptide Nα , Nє -bisacetyl-L-lysyl-D-alanyl-D-alanine is an excellent substrate for the Streptomyces DD carboxypeptidase. [less ▲]

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See detailIsolation of five new monosomic alien addition lines of Gossypium australe F. Muell in G. hirsutum L. by SSR and GISH analyses
Sarr, D.; Lacape, J.-M.; Rodier-Goud, M. et al

in Plant Breeding (2011), 130

Gossypium australe F. Muell (2n + 2x = 26) is a wild perennial species possessing agronomic useful traits that would be interesting to introgress into G. hirsutum L. (2n = 4x = 52), the main cultivated ... [more ▼]

Gossypium australe F. Muell (2n + 2x = 26) is a wild perennial species possessing agronomic useful traits that would be interesting to introgress into G. hirsutum L. (2n = 4x = 52), the main cultivated cotton species. To isolate monosomic alien addition lines (MAALs) of G. australe in G. hirsutum, the [2(G. hirsutum X G. australe) X G. hirsutum] pentaploid (2n = 5x = 65) was backcrossed as male parent to G. hirsutum. Analysis of 42 BC1 plants and seven alien addition lines, already available, with 150 SSR markers developed from G. hirsutum revealed a cross-species amplification rate of 100% and a polymorphism rate of 56%. Eighty polymorphic SSR markers generated 87 G. australe-specific loci that have been assigned by a hierarchical cluster analysis to 13 linkage groups corresponding to the 13 chromosomes of G. australe. Analysis by SSR markers and genomic in situ hybridization of the self-progeny of disomic alien addition lines, backcross progeny of the pentaploid, allowed the isolation of five new MAALs. [less ▲]

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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. I. Procedure and morphological characterization.
Lilet, C.; Radoux, D.; Heinen, Ernst ULg et al

in Journal of Immunological Methods (1984), 66(2), 235-44

Follicular dendritic cells have been isolated from human tonsils and adenoids and characterized at the ultrastructural level. Follicles were dissected and digested with different hydrolytic enzymes. The ... [more ▼]

Follicular dendritic cells have been isolated from human tonsils and adenoids and characterized at the ultrastructural level. Follicles were dissected and digested with different hydrolytic enzymes. The cells were separated by sedimentation at unit gravity. By this procedure we obtained follicular dendritic cells enveloping lymphocytes with their cytoplasmic extensions in a way analogous to that described for isolated thymic nurse cells. The ultrastructural features of isolated follicular dendritic cells are similar to those observed in situ. Prolonged enzymatic action caused loss of the enveloped lymphocytes. [less ▲]

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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. II. Immunocytochemical characterization.
Heinen, Ernst ULg; Lilet, Chantal ULg; Mason, D. Y. et al

in European Journal of Immunology (1984), 14(3), 267-73

Follicular dendritic cells (FDC) are specialized cells found only within lymphoid follicles. They bind immune complexes and play a role in the presentation of antigen to follicular B cells and in the ... [more ▼]

Follicular dendritic cells (FDC) are specialized cells found only within lymphoid follicles. They bind immune complexes and play a role in the presentation of antigen to follicular B cells and in the generation of B cell memory. In the present report the isolation of FDC from human tonsils and adenoids is described. These isolated cells have an unusual spherical arrangement and enclose lymphocytes within extensions of their membranes. Their ultrastructural features are similar to those observed in situ. The reactivity of isolated FDC with a number of monoclonal antibodies was analyzed by immunofluorescence and by immunostaining (at the electron microscopic level) with colloidal gold. In keeping with the results of previous investigations on tissue sections IgM, IgG and IgA (but not IgD) can be detected on the surface of isolated FDC, as can C3b receptors and the FDC-associated antigen detected by monoclonal antibody R4/23. The immunoglobulins associated with FDC are mostly embedded in an electron-dense material. The majority of the lymphoid cells enclosed within the membrane extensions of FDC are of B cell type. These results suggest that isolated FDC may be suitable for further in vitro investigation of their role in the humoral immune response. [less ▲]

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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. III. Analysis of their Fc receptors.
Heinen, Ernst ULg; Radoux, D.; Kinet-Denoel, C. et al

in Immunology (1985), 54(4), 777-84

Follicular dendritic cells (FDC), isolated from human tonsils or adenoids, were tested for their capacity to retain monomeric, aggregated or antigen-bound human antibodies in the absence of serum. FDC ... [more ▼]

Follicular dendritic cells (FDC), isolated from human tonsils or adenoids, were tested for their capacity to retain monomeric, aggregated or antigen-bound human antibodies in the absence of serum. FDC retain fluorescein-labelled heat-aggregated human immunoglobulins, but not monomeric ones nor fluorescein-labelled F(ab')2 in monomeric or aggregated form. Ultrastructural observations showed that colloidal gold-labelled monomeric, or antigen-bound, antibodies directed against tetanus toxoid are retained by dendrites and membrane infoldings of FDC but are never located in cytoplasmic vesicles. This retention was inhibited by incubating FDC with unlabelled aggregated or antigen-bound antibodies. When gold-labelled anti-tetanus toxoid antibodies were incubated in the presence of protein-A before the contact with FDC, a strong reduction of their retention occurred. This further suggested the presence of Fc receptors on isolated tonsillar FDC. Endocytosis was not observed in isolated FDC, even after prolonged incubation in presence of labelled immune complexes: their Fc receptors are, thus, not related to a phagocytic activity as they are in macrophages. Simultaneous ultrastructural labelling of Fc and C3b receptors with colloidal gold particles of different sizes did not reveal any clear relations between these two receptors on the surface of FDC. [less ▲]

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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. In vitro culture.
Cormann, N.; Heinen, Ernst ULg; Kinet-Denoel, C. et al

in Advances in Experimental Medicine and Biology (1988), 237

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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. V. Effect on lymphocyte proliferation and differentiation.
Cormann, N.; Lesage, F.; Heinen, Ernst ULg et al

in Immunology Letters (1986), 14(1), 29-35

Follicular dendritic cells (FDC) are located only in lymph follicles and are characterized by their capacity to retain high amounts of immune complexes on their plasma membranes. As their functions in ... [more ▼]

Follicular dendritic cells (FDC) are located only in lymph follicles and are characterized by their capacity to retain high amounts of immune complexes on their plasma membranes. As their functions in germinal centres are unknown, we isolated them from human tonsils and cultured them with autologous lymphoid cells. Cultures of lymphoid cells alone or with added macrophages were used as controls. Lymphoid cells incorporated tritiated thymidine only when FDC and lectins were added; this could be shown after several periods of time. However, the Ig secretion by lymphoid cell populations was inhibited by FDC after several days in vitro. In contrast, the supernatants of lymphocytes cultured alone or with macrophages only for the same periods of time contained increasing amounts of immunoglobulins. This inhibitory effect of FDC on immunoglobulin production was observed for all considered isotypes. Our data suggest that FDC stimulate lymphoid cell proliferation but reduce B-cell differentiation. This is the first accessory cell activity definitely shown for FDC in cultures. [less ▲]

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See detailIsolation of follicular dendritic cells from human tonsils and adenoids. VI. Analysis of prostaglandin secretion.
Heinen, Ernst ULg; Cormann, N.; Braun, M. et al

in Annales de l'Institut Pasteur. Immunologie (1986), 137D(3), 369-82

Follicular dendritic cells (FDC) are able to fix high amounts of immune complexes by C3b or Fc receptors without endocytosis and for long periods of time. In order to determine the function of this ... [more ▼]

Follicular dendritic cells (FDC) are able to fix high amounts of immune complexes by C3b or Fc receptors without endocytosis and for long periods of time. In order to determine the function of this retention, we analysed the secretion of prostaglandin E2 (PGE2) by FDC in vitro; indeed, it is well-known that immune complex fixation on cells may induce PGE2 production. FDC were isolated by enzymic digestion of lymph follicles dissected under the biomicroscope from human tonsils or adenoids. Isolated FDC appeared as spherical clusters where they enveloped lymphoid cells with their cytoplasmic extensions. Tests were performed in synthetic culture media or in media supplemented with foetal calf serum. PGE2 production in FDC suspensions was compared to that of lymphocyte or macrophage-enriched populations prepared from the same human tonsils. In all experimental conditions, FDC and macrophage-enriched cell populations produced high levels of PGE2, inversely to lymphoid cell populations. This secretion was inhibited by indomethacin. At the ultrastructural level, we also showed that 3H-arachidonic acid was metabolized in cell membranes of all three cell types. The PGE2 produced in the culture media, according to our experimental conditions, do not influence cell proliferation, as assessed by 3H-thymidine incorporation tests on phytohaemagglutinin-stimulated lymphocytes. [less ▲]

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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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