References of "Ongena, Marc"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailMALDI Mass Spectrometry Imaging: a new tool to decipher the antibiome of Bacillus amyloliquefaciens
Debois, Delphine ULg; Jourdan, Emmanuel; Cawoy, Hélène et al

Conference (2014, June 05)

Soil Bacillus isolates may devote up to 8% of their genome to nonribosomal synthesis of lipopeptide (LP)- and polyketide (PK)-type antibiotics. LPs from surfactin, iturin and fengycin families are known ... [more ▼]

Soil Bacillus isolates may devote up to 8% of their genome to nonribosomal synthesis of lipopeptide (LP)- and polyketide (PK)-type antibiotics. LPs from surfactin, iturin and fengycin families are known to exert different actions on the wellness of the producing strain such as fungitoxicity (iturin, fengycin) or motility, root colonization and immune stimulating agent (surfactin). Nevertheless, few is reported about the actual antibiome secreted in situ by Bacillus cells during confrontation with phytopathogens or plant root colonization. We developed a method mimicking the conditions prevailing in the rhizosphere and, taking advantage of the versatility of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging, we were able to localize and identify antibiotics produced in situ by bacterial cells. First, we applied this new methodology to bioassays in which Bacillus amyloliquefaciens 98S were grown together with Fusarium oxysporum, with the aim of deciphering the role of the different LP families during the phytopathogen growth inhibition. Our results showed that the three LP families were readily produced in different proportions. Especially, images of surfactins, iturins and fengycins demonstrated that iturins are the antibiotic family actually involved in the antagonism against Fusarium oxysporum. In a second approach, we used a “in planta” model in which Bacillus amyloliquefaciens S499 was simultaneously grown with Tomato and Arabidopsis thaliana roots. Imaging results, obtained during a time course analysis, showed that surfactin is always the major lipopeptide detected. In further experiments involving a refined time-window, we observed that surfactin is actually produced as soon as 24h post inoculation. These results were the starting point of a wider study showing that the early accumulation of surfactin is a complex phenomenon involving, among other mechanisms, cell-well components recognition by bacteria, and that this interaction is a win-win association for both plant and bacterial cells. [less ▲]

Detailed reference viewed: 36 (1 ULg)
Full Text
See detailA methodology for elicitor screening of winter wheat infected by STB and FHB
Le Mire, Géraldine ULg; SIAH, Ali; Deleu, Magali ULg et al

Poster (2014, May 20)

Un doctorat au sein de Gembloux Agro Bio-Tech (Plateforme Agriculture Is Life) vise à développer une méthode à base d'éliciteurs bio-sourcés pour protéger le blé d'hivers contre la Septoriose (STB) et la ... [more ▼]

Un doctorat au sein de Gembloux Agro Bio-Tech (Plateforme Agriculture Is Life) vise à développer une méthode à base d'éliciteurs bio-sourcés pour protéger le blé d'hivers contre la Septoriose (STB) et la Fusariose (FHB). Dans ce cadre, la mise au point d'un protocole efficace d'infection du blé est élémentaire avant de pouvoir entamer les tests de screening d'éliciteurs. Nous présentons ici une méthode d'infection du blé par Septoria tritici et les résultats de ces tests de reproduction de symptômes. [less ▲]

Detailed reference viewed: 18 (5 ULg)
Full Text
Peer Reviewed
See detailSpatiotemporal monitoring of the antibiome secreted by Bacillus biofilms on plant roots using MALDI mass spectrometry imaging
Debois, Delphine ULg; Jourdan, Emmanuel; Smargiasso, Nicolas ULg et al

in Analytical Chemistry (2014), 86(9), 4431-4438

Some soil Bacilli living in association with plant roots can protect their host from infection by pathogenic microbes and are therefore being developed as biological agents to control plant diseases. The ... [more ▼]

Some soil Bacilli living in association with plant roots can protect their host from infection by pathogenic microbes and are therefore being developed as biological agents to control plant diseases. The plant protective activity of these bacteria has been correlated with the potential to secrete a wide array of antibiotic compounds upon growth as planktonic cells in isolated cultures under laboratory conditions. However, in situ expression of these antibiotics in the rhizosphere where bacterial cells naturally colonize root tissues is still poorly understood. In this work, we used Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI MSI) to examine spatio-temporal changes in the secreted antibiome of B. amyloliquefaciens developing as biofilms on roots. Non-ribosomal lipopeptides such as the plant immunity elicitor surfactin or the highly fungitoxic iturins and fengycins were readily produced albeit in different time-frames and quantities in the surrounding medium. Interestingly, MS/MS experiments performed directly from the gelified culture medium, also allowed to identify a new variant of surfactins released at later time points. However, no other bioactive compounds such as polyketides were detected at any time, strongly suggesting that the antibiome expressed in planta by B. amyloliquefaciens does not reflect the vast genetic arsenal devoted to the formation of such compounds. This first dynamic study reveals the power of MALDI MSI as tool to identify and map antibiotics synthesized by root-associated bacteria and more generally, to investigate plant-microbe interactions at the molecular level. [less ▲]

Detailed reference viewed: 15 (2 ULg)
Full Text
Peer Reviewed
See detailAltered Desferrioxamine-mediated Iron Utilization is a Common Trait of bald Mutants of Streptomyces coelicolor
Lambert, Stéphany ULg; Traxler, Matthew F; Craig, Matthias et al

in Metallomics (2014)

Detailed reference viewed: 4 (2 ULg)
Full Text
See detailImaging MS: strategies for the identification of analytes
Debois, Delphine ULg; Smargiasso, Nicolas ULg; Jourdan, Emmanuel et al

Scientific conference (2014, April 04)

Detailed reference viewed: 27 (5 ULg)
Full Text
See detailDevelopment of formulated elicitors to control bioagressors of wheat: which interests?
Le Mire, Géraldine ULg; Deleu, Magali ULg; Ongena, Marc ULg et al

Poster (2014, February 07)

Crop plants are constantly exposed to a wide range of environmental stresses that can cause major productivity loss. Fungicide treatments are the most efficient disease control methods used up to now ... [more ▼]

Crop plants are constantly exposed to a wide range of environmental stresses that can cause major productivity loss. Fungicide treatments are the most efficient disease control methods used up to now. However, the environmental and health issues caused by these chemicals make it urgent to develop safer methods for pathogen control. In the optic of a sustainable agriculture, several biocontrol tools have been developed during the last decades. Elicitors are increasingly subject to research as interesting alternatives to phytosanitary products. Yet, few efficient formulations exist on the market, and no product has been designed specifically to protect wheat crops. This study will thus focus on the the manipulation of host natural defenses through the use of elicitors as a preventive treatment against major wheat diseases such as Septoria tritici, Fusarium graminearum and Fusarium culmorum. [less ▲]

Detailed reference viewed: 55 (5 ULg)
Peer Reviewed
See detailInteractions of a potential plant elicitor mannolipid with plant model membranes
Polo Lozano, Damien ULg; Lins, Laurence ULg; Ongena, Marc ULg et al

Poster (2014, February 07)

The use of chemical pesticides causes problems for human health and environment. In this context, there is an increasing interest for alternative products such as biopesticides. Among them, elicitors act ... [more ▼]

The use of chemical pesticides causes problems for human health and environment. In this context, there is an increasing interest for alternative products such as biopesticides. Among them, elicitors act on the plants by inducing systemic resistance against diseases caused by fungal, viral, bacterial agents and insects. The target of the elicitors is supposed to be the plant plasma membranes (PPM). The main mechanisms of interaction of many elicitors involve proteic receptors but lipid-based elicitors (LBE) may preferably interact with the lipidic fractions of PPM. However there is no detailed information at the molecular level on the PPM-LBE interactions. Our work is focused on a original synthetic LBE composed of a mannoside linked to a myristic acid. It has potential elicitor activities as shown by the assays on tobacco root cells. These activities could be related to its interaction with the lipidic phase of PPM. Since PPM are complex entities, the analyses of the PPM- molecule interactions are quite difficult. In this context, these interactions were carried out using biomimetic membranes of PPM such as Langmuir monolayers and multilayers. The effects of our molecule on these membranar systems were investigated by biophysical and in silico approaches. [less ▲]

Detailed reference viewed: 65 (10 ULg)
Peer Reviewed
See detailNew alternatives to chemical pesticides: deciphering the action mechanisms of lipid based plant elicitors via complementary biophysical and biological approaches.
Nasir, Mehmet Nail ULg; Polo Lozano, Damien ULg; Luzuriaga Loaiza, Walter ULg et al

Poster (2014, February)

Nowadays, many health and environmental problems are caused by the use of chemical pesticides. In this context, an increasing demand for alternative products such as biopesticides has been observed. Among ... [more ▼]

Nowadays, many health and environmental problems are caused by the use of chemical pesticides. In this context, an increasing demand for alternative products such as biopesticides has been observed. Among biopesticides, elicitor molecules which are able to trigger immune defense responses in plants are one of the most promising options. Although numerous elicitors have been discovered, the mechanisms involved in the perception, by plants, of only a few molecules have been identified. These elicitors usually interact with proteic receptors but we have recently shown that they may also act on the lipid phase of the plasma membrane. This project first aims to improve our understanding of the molecular mechanisms involved in the recognition of specific lipid based elicitors (LBE). On that basis, the FIELD project will contribute to the design and the development of innovative compounds derived natural LBE. A multi-disciplinary approach, based on chemistry, bio-physics, bio-chemistry, and phytopathology will be followed by a consortium of different research groups from Gembloux Agro-Bio Tech in close collaboration with teams from foreign institutions. [less ▲]

Detailed reference viewed: 36 (5 ULg)
Full Text
Peer Reviewed
See detailLes lipopeptides d’origine microbienne, des agents de biocontrôle aux multiples facettes
Jacques, P.; Deravel, J.; Coutte, F. et al

in Phytoma (2014), 672

Detailed reference viewed: 10 (0 ULg)
Full Text
Peer Reviewed
See detailAltered Desferrioxamine-mediated Iron Utilization is a Common Trait of bald Mutants of Streptomyces coelicolor
Lambert, Stéphanie ULg; Traxler, M. F.; Craig, M. et al

in Metallomics (2014)

Detailed reference viewed: 16 (1 ULg)
Full Text
Peer Reviewed
See detailTo settle or to move? The interplay between two classes of cyclic lipopeptides in the biocontrol strain Pseudomonas CMR12a
D’aes, J.; Phuong Kieu, N.; Leclère, V. et al

in Environmental Microbiology (2014), In press

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailHost-induced bacterial cell wall decomposition mediates pattern-triggered immunity in Arabidopsis
Liu, X.; Grabherr, H.; Willmann, R. et al

in eLife (2014)

Detailed reference viewed: 3 (1 ULg)
Full Text
Peer Reviewed
See detailHigh-energy X-ray tomography analysis of a metal packing biofilm reactor for the production of lipopeptides by Bacillus subtilis
Zune, Quentin ULg; Soyeurt, Delphine; Toye, Dominique ULg et al

in Journal of Chemical Technology & Biotechnology (2014), 89

BACKGROUND: Whereas multi-species biofilm reactors are commonly used for the treatment of liquid and solid wastes, new strategies are progressing for the development of single species biofilm for the ... [more ▼]

BACKGROUND: Whereas multi-species biofilm reactors are commonly used for the treatment of liquid and solid wastes, new strategies are progressing for the development of single species biofilm for the production of high-value metabolites. Technically, this new concept relies on the design of bioreactors able to promote biofilm formation and on the identification of the key physico-chemical parameters involved in biofilm formation. RESULTS: An experimental setting comprising a liquid continuously recirculated on a metal structured packing has been used to promote Bacillus subtilis GA1 biofilm formation. The colonization of the packing has been visualized non-invasively by X-ray tomography. This analysis revealed an uneven, conical, distribution of the biofilm inside the packing. Compared with a submerged culture carried out in a stirred tank reactor, significant modification of the lipopeptide profile has been observed in the biofilm reactorwith the disappearance of fengycin and iturin fractions and an increase of the surfactin fraction. In addition, considering the biofilm reactor design, no foam formation has been observed during the culture. CONCLUSIONS: The configuration of this biofilm reactor set-up allows for a higher surfactin production by comparison with a submerged culture while avoiding foam formation. Additionally, scale-up could easily be performed by increasing the number of packing elements. [less ▲]

Detailed reference viewed: 50 (28 ULg)
Full Text
Peer Reviewed
See detailIn Vitro and In Vivo Characterization of Plant Growth Promoting Bacillus Strains Isolated from Extreme Environments of Eastern Algeria.
Ait-Kaki, Asma; Kacem-Chaouche, Noreddine; Ongena, Marc ULg et al

in Applied biochemistry and biotechnology (2014), 172

This report is to our knowledge the first to study plant growth promotion and biocontrol characteristics of Bacillus isolates from extreme environments of Eastern Algeria. Seven isolates of 14 (50 %) were ... [more ▼]

This report is to our knowledge the first to study plant growth promotion and biocontrol characteristics of Bacillus isolates from extreme environments of Eastern Algeria. Seven isolates of 14 (50 %) were screened for their ability to inhibit growth of some phytopathogenic fungi on PDA and some roots exudates. The bacteria identification based on 16S r-RNA and gyrase-A gene sequence analysis showed that 71 % of the screened isolates belonged to Bacillus amyloliquefaciens and the rest were closely related to B. atrophaeus and B. mojavensis. Most of them had high spore yields (22 x 108-27 x 108 spores/ml). They produced protease and cellulase cell wall-degrading enzymes while the chitinase activity was only observed in the B. atrophaeus (6SEL). A wide variety of lipopeptides homologous was detected by liquid chromatography-electrospray ionization-mass spectrometry analysis. Interestingly, some additional peaks with new masses were characterized, which may correspond to new fengycin classes. The isolates produced siderophores and indole-3- acetic acid phytohormone. The greenhouse experiment using a naturally infested soil with Sclerotonia sclerotiorum showed that the B. atrophaeus (6SEL) significantly increased the size of the chickpea plants and reduced the stem rot disease (P < 0.05). These results suggest that these isolates may be used further as bio-inoculants to improve crop systems. [less ▲]

Detailed reference viewed: 20 (2 ULg)
Full Text
Peer Reviewed
See detailPlant defense stimulation by natural isolates of Bacillus depends on efficient surfactin production
Cawoy, Hélène ULg; Mariutto, Martin; Henry, Guillaume et al

in Molecular Plant-Microbe Interactions [=MPMI] (2014), 27

Detailed reference viewed: 106 (40 ULg)