References of "Ongena, MARC"
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See detailDevelopment of a biotransformation process of hydroperoxides into green leaf volatiles using sugar beet leaves
Gigot, C.; Ongena, Marc ULg; Fauconnier, Marie-Laure ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010)

Natural green leaf volatiles (GLVs) are commonly sole AS aldehydic and alcoholic flavors; their synthesis is a great challenge for industry. Especially, the bioconversion step of fatty acid hydroperoxides ... [more ▼]

Natural green leaf volatiles (GLVs) are commonly sole AS aldehydic and alcoholic flavors; their synthesis is a great challenge for industry. Especially, the bioconversion step of fatty acid hydroperoxides into aldehydes by the hydroperoxide lyase (HL). This widely studied enzyme is present in cell membranes of green organs from superior plants. Extracted from its natural condition, HL is subject to a suicidal behavior, being irreversibly inhibited by its own substrate. Furthermore, GLVs produced are highly volatile and quickly degraded by other plant enzymes. Thence, high GLVs levels in industrial production are very difficult to obtain, but several biotechnological tools could be developed to enhance this natural synthesis level more than hundred times. This paper will describe a new method for GLVs production in bioreactor using sugar beet leaves as source of HL. One step reaction, including hydroperoxide metabolisation and GLVs extraction, is performed during a short time process. Downstream processing to dispose of natural and pure GLVs molecule will also be discussed. [less ▲]

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See detailModulation of the lipopeptide pattern secreted by Bacillus subtilis upon colonization of different plant roots
Ongena, Marc ULg; Cawoy, H.; Margiassi, M. et al

Conference (2010)

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See detailDifferential roles of lipopeptides(LPs) in plant host defenses and pathogen suppression.
Ongena, Marc ULg; Henry, G.; Jourdan, E. et al

Conference (2010)

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See detailUnraveling the roles of lipopeptides on ISR
Ongena, Marc ULg; Jourdan, E.; Henry, G. et al

Conference (2010)

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See detailDevelopment of a biotransformation process of hydroperoxydes into green leaf volatiles using sugar beet leaves.
Gigot, C.; Ongena, Marc ULg; Fauconnier, Marie-Laure ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14 (S2)

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See detailInsights into the plant defense mechanisms induced by Bacillus lipopeptides
Ongena, Marc ULg; Henry, G.; Adam, A. et al

in Biology of Plant-Microbe Interactions (2010)

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See detailDifferential roles of lipopeptides in plant host defenses and pathogen suppression.
Ongena, Marc ULg; Henry, G.; Jourdan, Emmanuel ULg et al

in Phytopathology (2010), 100

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See detailNatural functions of cyclic lipopeptides from Bacillus and Pseudomonas: more than surfactants and antibiotics
Raaijmakers, Jos; De Bruin, Irene; Nybroe, Ole et al

in FEMS Microbiology Reviews (2010), 34

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See detailBeneficial effects of Bacillus subtilis on field-grown tomato in Burundi : reduction of local Fusarium disease and growth promotion.
Nihorimbere, V.; Ongena, Marc ULg; Cawoy, Hélène ULg et al

in African Journal of Microbiology Research [=AJMR] (2010), 4

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See detailProduction of three anti-listerial peptides by Lactobacillus curvatus in MRS broth.
Ghalfi, H.; Benkerroum, N.; Ongena, Marc ULg et al

in Food Research International (2010), (43), 33-39

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See detailInsights into the plant defense mechanisms induced by Bacillus lipopeptides.
Ongena, Marc ULg; Henry, Guillaume ULg; Adam, Akram et al

Poster (2009, July)

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See detailPilot scale biotransformation of vegetal oil into natural green note flavor using sugar beet leaves as sources of hydroperoxide lyase
Gigot, Cédric ULg; Ongena, Marc ULg; Fauconnier, Marie-Laure ULg et al

Poster (2009, June 02)

Natural green note aromas (GLVs) are highly attractive flavors commonly used in the food industry. These are produced in extremely low levels upon physiological stress in plant organs of any sort. This ... [more ▼]

Natural green note aromas (GLVs) are highly attractive flavors commonly used in the food industry. These are produced in extremely low levels upon physiological stress in plant organs of any sort. This weak sporadic presence entails a very expensive extraction step to obtain pure GLVs. Therefore catalytic biotransformations of fatty acid sources, the initial substrate for GLVs, have been developed. Enzymatic defense pathways and particularly the LOX pathway produce the major part of GLVs. Unlike GLV molecules that are emitted in the atmosphere, the enzymes are extractible from the plant material. Thus, a combination of plant enzyme extracts and substrate preparations provides all the ingredients for GLV production. Besides, sugar beet leaves present high levels of hydroperoxide lyase among plant sources and are available in large amounts during three months. In this enzymatic pathway, fatty acids are successively transformed by lipase, lipoxygenase and hydroperoxide lyase into aldehydes and alcohols, final compounds of GLVs pathway. Limiting and problematic steps occur with the action of hydroperoxide lyase, when enzymatic catalysis is followed by an enzyme destabilization. Alternative substrates bind irreversibly to the heme group of the enzyme and end the reaction. This poster briefly describes the development of a complete bioprocess for natural GLV production, from hydrolysis to purification. A high level of biotransformation could be achieved using optimum experimental conditions and a cheap source of plant materials. [less ▲]

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See detailBacillus-based biocontrol of Fusarium disease on tomato cultures in Burundi
Nihorimbere, Venant; Ongena, Marc ULg; Cawoy, Hélène ULg et al

Poster (2009, May 19)

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See detailPlant growth promotion of tomato under field conditions in Burundi
Cawoy, Hélène ULg; Nihorimbere, Venant; Kakana, Pascal et al

Poster (2009, April 02)

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See detailBacillus amyloliquefaciens GA1 as a source of potent antibiotics and other secondary metabolites for biocontrol of plant pathogens.
Arguelles-Arias, A.; Ongena, MARC ULg; Halimi, B. et al

in Microbial Cell Factories (2009), 8(1), 63

ABSTRACT: BACKGROUND: Phytopathogenic fungi affecting crop and post-harvested vegetables are a major threat to food production and food storage. To face these drawbacks, producers have become increasingly ... [more ▼]

ABSTRACT: BACKGROUND: Phytopathogenic fungi affecting crop and post-harvested vegetables are a major threat to food production and food storage. To face these drawbacks, producers have become increasingly dependent on agrochemicals. However, intensive use of these compounds has led to the emergence of pathogen resistance and severe negative environmental impacts. There are also a number of plant diseases for which chemical solutions are ineffective or non-existent as well as an increasing demand by consumers for pesticide-free food. Thus, biological control through the use of natural antagonistic microorganisms has emerged as a promising alternative to chemical pesticides for more rational and safe crop management. RESULTS: The genome of the plant-associated B. amyloliquefaciens GA1 was sample sequenced. Several gene clusters involved in the synthesis of biocontrol agents were detected. Four gene clusters were shown to direct the synthesis of the cyclic lipopeptides surfactin, iturin A and fengycin as well as the iron-siderophore bacillibactin. Beside these non-ribosomaly synthetised peptides, three additional gene clusters directing the synthesis of the antibacterial polyketides macrolactin, bacillaene and difficidin were identified. Mass spectrometry analysis of culture supernatants led to the identification of these secondary metabolites, hence demonstrating that the corresponding biosynthetic gene clusters are functional in strain GA1. In addition, genes encoding enzymes involved in synthesis and export of the dipeptide antibiotic bacilysin were highlighted. However, only its chlorinated derivative, chlorotetaine, could be detected in culture supernatants. On the contrary, genes involved in ribosome-dependent synthesis of bacteriocin and other antibiotic peptides were not detected as compared to the reference strain B. amyloliquefaciens FZB42. CONCLUSION: The production of all of these antibiotic compounds highlights B. amyloliquefaciens GA1 as a good candidate for the development of biocontrol agents. [less ▲]

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