References of "Ongena, MARC"
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See detailBiodegradation of Polycyclic Aromatic Hydrocarbons in Mangrove Sediments Under Different Strategies: Natural Attenuation, Biostimulation, and Bioaugmentation with Rhodococcus erythropolis T902.1
Lang, F. S.; Destain, Jacqueline ULg; Delvigne, Frank ULg et al

in Water, Air & Soil Pollution (2016), 227(9),

Polycyclic aromatic hydrocarbons (PAHs) are pollutants that occur in mangrove sediments. Their removal by bacteria often depends on specific characteristics as the number of benzene rings they possess and ... [more ▼]

Polycyclic aromatic hydrocarbons (PAHs) are pollutants that occur in mangrove sediments. Their removal by bacteria often depends on specific characteristics as the number of benzene rings they possess and their solubility. Their removal also depends on environmental factors, such as pH, temperature, oxygen, and the ability of the endogenous or exogenous microflora to metabolize hydrocarbons. With the aim of treating mangrove sediments polluted by hydrocarbons in a biological way, a biodegradation experiment was conducted using mangrove sediments artificially contaminated with a mixture of four PAHs. The study used Rhodococcus erythropolis as an exogenous bacterial strain in order to assess the biodegradation of the PAH mixture by natural attenuation, biostimulation, bioaugmentation, and a combination of biostimulation and bioaugmentation. The results showed that the last three treatments were more efficient than natural attenuation. The biostimulation/bioaugmentation combination proved to be the most effective PAH degradation treatment. © 2016, Springer International Publishing Switzerland. [less ▲]

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See detailRole of phenazines and cyclic lipopeptides produced by pseudomonas sp. CMR12a in induced systemic resistance on rice and bean
Ma, Z.; Hua, G. K. H.; Ongena, Marc ULg et al

in Environmental Microbiology Reports (2016)

Pseudomonas sp. CMR12a produces two different classes of cyclic lipopeptides (CLPs) (orfamides and sessilins), which all play a role in direct antagonism against soilborne pathogens. Here we show that ... [more ▼]

Pseudomonas sp. CMR12a produces two different classes of cyclic lipopeptides (CLPs) (orfamides and sessilins), which all play a role in direct antagonism against soilborne pathogens. Here we show that Pseudomonas sp. CMR12a is also able to induce systemic resistance to Magnaporthe oryzae on rice and to the web blight pathogen Rhizoctonia solani AG2-2 on bean. Plant assays with biosynthesis mutants of Pseudomonas sp. CMR12a impaired in the production of phenazines and/or CLPs and purified metabolites revealed that distinct bacterial determinants are responsible for inducing systemic resistance in these two pathosystems. In rice, mutants impaired in phenazine production completely lost their ability to induce systemic resistance, while a soil drench with pure phenazine-1-carboxamide (PCN) at a concentration of 0.1 or 1 μM was active in inducing resistance against M. oryzae. In bean, mutants that only produced phenazines, sessilins or orfamides were still able to induce systemic resistance against Rhizoctonia web blight, but a balanced production of these metabolites was needed. This study not only shows that Pseudomonas sp. CMR12a can protect rice to blast disease and bean to web blight disease, but also displays that the determinants involved in induced systemic resistance are plant, pathogen and concentration dependent. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd. [less ▲]

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See detailComplete genome sequence of Bacillus amyloliquefaciens subsp. plantarum S499, a rhizobacterium that triggers plant defences and inhibits fungal phytopathogens
Molinatto, G.; Puopolo, G.; Sonego, P. et al

in Journal of Biotechnology (2016), 238

Bacillus amyloliquefaciens subsp. plantarum S499 is a plant beneficial rhizobacterium with a good antagonistic potential against phytopathogens through the release of active secondary metabolites ... [more ▼]

Bacillus amyloliquefaciens subsp. plantarum S499 is a plant beneficial rhizobacterium with a good antagonistic potential against phytopathogens through the release of active secondary metabolites. Moreover, it can induce systemic resistance in plants by producing considerable amounts of surfactins. The complete genome sequence of B. amyloliquefaciens subsp. plantarum S499 includes a circular chromosome of 3,927,922 bp and a plasmid of 8,008 bp. A remarkable abundance in genomic regions of putative horizontal origin emerged from the analysis. Furthermore, we highlighted the presence of genes involved in the establishment of interactions with the host plants at the root level and in the competition with other soil-borne microorganisms. More specifically, genes related to the synthesis of amylolysin, amylocyclicin, and butirosin were identified. These antimicrobials were not known before to be part of the antibiotic arsenal of the strain. The information embedded in the genome will support the upcoming studies regarding the application of B. amyloliquefaciens isolates as plant-growth promoters and biocontrol agents. © 2016 Elsevier B.V. [less ▲]

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See detailPyoverdine and histicorrugatin-mediated iron acquisition in Pseudomonas thivervalensis
Matthijs, Sandra; Brandt, Nathalie; Ongena, Marc ULg et al

in Biometals (2016), 29(3), 467-485

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See detailIn Situ Analysis of Bacterial Lipopeptide Antibiotics by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging
Debois, Delphine ULg; Ongena, Marc ULg; Cawoy, H. et al

in Nonribosomal Peptide and Polyketide Biosynthesis : Methods and Protocols (2016)

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See detailBiosynthesis, Chemical Structure, and Structure-Activity Relationship of Orfamide Lipopeptides Produced by Pseudomonas protegens and Related Species
Ma, Zongwang; Geudens, Niels; Kieu, Nam P. et al

in Frontiers in Microbiology (2016), 7

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See detailEffects of Plant Growth-Promoting Rhizobacteria on Wheat Growth under Greenhouse and Field Conditions in combination with different nitrogen fertilizer levels
Nguyen, Minh ULg; Ongena, Marc ULg; Colinet, Gilles ULg et al

Poster (2015, November 23)

Many Plant Growth-Promoting Rhizobacteria (PGPR) are able to enhance root growth, mineral availability, and nutrient use efficiency of crops. The aim of this project is to screen commercially available ... [more ▼]

Many Plant Growth-Promoting Rhizobacteria (PGPR) are able to enhance root growth, mineral availability, and nutrient use efficiency of crops. The aim of this project is to screen commercially available PGPR formulations and lab strains to increase wheat growth and yield in combination with an optimized nitrogen (N) fertilizer application scheme. This could lead to a significant reduction of N fertilizer application without affecting the subsequent grain yields. The screened products collection includes (1) Mix1 (a mix of Azospirillum sp., Azorhizobium sp., and Azoarcus sp.), (2) Mix2 (a mix of Mix1 complemented with two strains of phosphorus-solubilizing Bacillus sp.), (3) Bacillus amyloliquefaciens a, (4) B. subtilis, and (5) B. amyloliquefaciens b. These products were screened under greenhouse and field conditions in 2014 by using spring and winter wheat varieties, respectively. Under greenhouse conditions, there was a significant increase in root dry weight and in root per shoot ratio of plants inoculated with Mix1. Under field conditions, the interaction between PGPR inoculation and different N fertilizer doses was assessed. The grain yield was negatively impacted by low N fertilizer applications. Under such conditions, the inoculation of the wheat rhizosphere with B. subtilis increased the grain yield by 15% relative to the water control. However, in the field trial, the variability between plot replicates was high and lead to non-significant results. Based on these results, modified screening strategies for PGPR selection were set up for the next trials. [less ▲]

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See detailImpacts of Plant Growth-Promoting Rhizobacteria-based Biostimulants on Wheat Growth under Greenhouse and Field Conditions
Nguyen, Minh ULg; Ongena, Marc ULg; Colinet, Gilles ULg et al

Poster (2015, November 16)

Plant Growth-Promoting Rhizobacteria (PGPR) are one of the main biostimulant classes due to their capacity of stimulating root growth and enhancing soil mineral availability, hence increasing nutrient use ... [more ▼]

Plant Growth-Promoting Rhizobacteria (PGPR) are one of the main biostimulant classes due to their capacity of stimulating root growth and enhancing soil mineral availability, hence increasing nutrient use efficiency in crops. The aim of this study is to screen commercially PGPR-containing products to enhance wheat growth and yield in combination with an optimized nitrogen (N) fertilizer application scheme. This could lead to a significant reduction of N fertilizer application without affecting the subsequent grain yields. The screened products collection includes (1) Mix1 (a mix of Azospirillum sp., Azorhizobium sp., and Azoarcus sp.), (2) Mix2 (a mix of Mix1 complemented with two strains of phosphorus-solubilizing Bacillus sp.), (3) Bacillus amyloliquefaciens a, (4) B. subtilis, and (5) B. amyloliquefaciens b. These biostimulants were screened under greenhouse and field conditions in 2014 by using spring and winter wheat varieties respectively. There was a significant increase in root dry weight and in root per shoot ratio of plants inoculated with Mix1. Under field conditions, the interaction between PGPR inoculation and N fertilizer application was assessed. The grain yield was negatively impacted by low N fertilizer applications. Under such conditions, the inoculation of the wheat rhizosphere with Bacillus subtilis increased the grain yield by 15% relative to the water control. However, in the field trial, the variability between plot replicates was high and lead to non-significant results. Based on those results, modified screening strategies for PGPR selection were set up for the 2015 trials to reduce field variability and possibly achieve higher yield increases. [less ▲]

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See detailElicitor screening to protect wheat against Zymoseptoria tritici
Le Mire, Géraldine ULg; SIAH, ALI; Deleu, Magali ULg et al

Conference (2015, August 27)

Plants face an array of biotic and abiotic stresses in their environment, making it necessary to use various chemical inputs to maintain satisfactory yield. Today, conventional agriculture is evolving ... [more ▼]

Plants face an array of biotic and abiotic stresses in their environment, making it necessary to use various chemical inputs to maintain satisfactory yield. Today, conventional agriculture is evolving towards more sustainable practices, out of respect for human health and the environment. Elicitors are considered as promising biological control tools and draw major interest in IPM strategies. These plant-immunity triggering compounds, also called “stimulators of plant natural defenses”, induce a general and systemic resistance in the plant to various diseases. Although numerous elicitors have already been identified and some of them reached the market since the late 1970s, further investigations are still required to better understand the mode of action of these molecules in the plant and ensure a consistent efficiency under various field conditions. Few elicitors have yet been successfully tested and formulated to protect monocotyledonous crop plants such as wheat, which is cultivated over large areas in Europe. This study focuses on the screening of ten potential elicitor products of various origins and structures to protect winter wheat against the fungal pathogen Zymoseptoria tritici. Greenhouse trials were carried out to measure the ability of the different products to reduce disease foliar symptoms (necrosis, chlorosis and pycnidia). Topical spraying treatments with 3 different concentrations of each product were carried out 5 days before pathogen inoculation. Disease severity (% of symptoms on the total surface of the third leaf) was then scored every 2 days up to 28 days post-inoculation. In addition, phytotoxicity and biocide activity of these products was evaluated under greenhouse and laboratory conditions, respectively. The corresponding results will be presented and discussed with the perspective to choose the best elicitor candidates and to undertake investigations on the signaling pathway and the influence of environmental parameters on the elicitation capacity. [less ▲]

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See detailImpacts of Plant Growth-Promoting Rhizobacteria on Wheat Growth under Greenhouse and Field Conditions
Nguyen, Minh ULg; du Jardin, Patrick ULg; Jijakli, Haissam ULg et al

Poster (2015, June 16)

Plant Growth-Promoting Rhizobacteria (PGPR) are well-known on stimulating root growth, enhancing mineral availability, and nutrient use efficiency in crops, and therefore become promising tool for ... [more ▼]

Plant Growth-Promoting Rhizobacteria (PGPR) are well-known on stimulating root growth, enhancing mineral availability, and nutrient use efficiency in crops, and therefore become promising tool for sustainable agriculture. The aim of this project is to screen PGPR strains to enhance wheat growth and yield in combination with an optimised nitrogen (N) fertilizer dose, and thus finally reduce the use of N fertilizer with equivalent yield as the recommended N dose. A list of PGPR has been collected, including (1) Mix1 (a mix of Azospirillum sp., Azorhizobium sp., and Azoarcus sp.), (2) Mix2 (a mix of Mix1 plus with two strains phosphorus-solubilizing Bacillus sp.), (3) Bacillus amyloliquefaciens a, (4) Bacillus subtilis, and (5) Bacillus amyloliquefaciens b. The PGPR were screened in both greenhouse and field condition 2014. There was significant increase in root dry weight and in root per shoot ratio of plants inoculated with Mix1 in the greenhouse. Under field condition, besides the first factor PGPR, an additional factor, i.e. four N fertilizer doses, was applied in the combination with PGPR. Without or at low N fertilizer doses, the results showed that the grain yield declined significantly. The highest grain yield increase was fifteen per cent above the control and achieved by inoculating Bacillus subtilis without application of N fertilizer. However, there was statistically insignificant in all treatments due to variability between plot replicates. Based on these results, a modified protocol plus new strategies for PGPR selection has been built up for 2015 trial to reduce the influence of variability on field and possibly achieve the higher yield increase. [less ▲]

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See detailScreening for interesting elicitors to protect wheat against Zymoseptoria tritici
Le Mire, Géraldine ULg; Siah, Ali; Fauconnier, Marie-Laure ULg et al

Conference (2015, May 19)

Plants face an array of biotic and abiotic stresses in their environment, making it necessary to use various chemical inputs to maintain satisfactory yield. Today, conventional agriculture is evolving ... [more ▼]

Plants face an array of biotic and abiotic stresses in their environment, making it necessary to use various chemical inputs to maintain satisfactory yield. Today, conventional agriculture is evolving towards more sustainable practices, out of respect for human health and the environment. Elicitors are considered as promising biological control tools and draw major interest in IPM strategies. These plant-immunity triggering compounds, also called “stimulators of plant natural defenses”, induce a general and systemic resistance in the plant to various diseases. Although numerous elicitors have already been identified and some of them reached the market since the late 1970s, further investigations are still required to better understand the mode of action of these molecules in the plant and ensure a consistent efficiency under various field conditions. Few elicitors have yet been successfully tested and formulated to protect crop plants such as wheat, which is cultivated over large areas in Europe. This study focuses on the screening of ten potential elicitor products of various origins and structures to protect winter wheat against the fungal pathogen Zymoseptoria tritici. Greenhouse trials were carried out to measure the ability of the different products to reduce disease foliar symptoms (necrosis, chlorosis and pycnidia). In addition, the phytotoxicity and biocide activities of these products were evaluated under greenhouse and laboratory conditions, respectively. The corresponding results will be presented and discussed with the perspective to choose the best elicitor candidates and to undertake investigations on the signaling pathway and the influence of environmental parameters on the elicitation capacity. [less ▲]

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See detailSurfactin: a receptor-independent bacterial elicitor of plant immunity?
Luzuriaga Loaiza, Walter ULg; Legras, Aurelien; Crowet, Jean-Marc ULg et al

Poster (2015, May 13)

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See detailImpact of different plant secondary metabolites addition: saponin, tannic acid, salicin and aloin on glucose anaerobic co-digestion
Mambanzulua Ngoma, Philippe; Hiligsmann, Serge ULg; Sumbu Zola, Eric et al

in Fermentation Technology (2015), 4(1), 1-11

Vegetal waste and some wastewater of agro-food industries contain plant secondary metabolites (PSMs). It was showed in nutritional researches that these substances such as saponins and tannins reduced the ... [more ▼]

Vegetal waste and some wastewater of agro-food industries contain plant secondary metabolites (PSMs). It was showed in nutritional researches that these substances such as saponins and tannins reduced the methane production in the rumen. To our knowledge no study was done in the waste treatment domain to evaluate the inhibitory effect of the principal glycosidic metabolites from the wastewater or vegetal waste on their own methane-producing anaerobic digestion. Therefore in this paper BMP tests were carried out at 30°C with four commercial PSMs (CPSMs) in mixture with glucose monohydrate (Gl) used as control sample. These CPSMs were saponin from Quilaja Saponaria Molina Pract (Sap), tannic acid (Tan), salicin (Sal) and aloin from Curacao Aloe (Alo) representing respectively saponins, tannins, alcoholic glycosides and anthraquinones sources. Acidogenesis and acetogenesis were recorded for all the mixtures of Gl and CPSMs; however their conversion rates decreased with the increase of the concentrations of CPSMs. By contrast, the methanogenesis was inhibited at concentrations of CPSMs above 0.3 g/l. The inhibition degree for aromatic compounds on the anaerobic biodegradation of Gl seemed directly to depend on the numbers of benzene rings in the medium and the synergism. Thus, the highest inhibition of the biogas production from Gl was recorded for Alo, followed by Sap, Tan and Sal. However, the highest inhibition of the methane production from Gl was recorded with Sap, Alo, Tan and Sal. It was supposed that the toxicity potentials of these PSMs on the own biomethanization would be in following decreasing order: Sap or Alo, Tan and Sal. Therefore, the concentration of PSMs alone or in mixture in a digester should be bellow 0.3 g/l. for a better methanization . [less ▲]

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See detailLipopeptides as main ingredients for inhibition of fungal phytopathogens by Bacillus subtilis/amyloliquefaciens
Cawoy, H.; Debois, Delphine ULg; Franzil, Laurent ULg et al

in Microbial Biotechnology (2015), 8(2), 281-295

Summary: Some isolates of the Bacillus subtilis/amyloliquefaciens species are known for their plant protective activity against fungal phytopathogens. It is notably due to their genetic potential to form ... [more ▼]

Summary: Some isolates of the Bacillus subtilis/amyloliquefaciens species are known for their plant protective activity against fungal phytopathogens. It is notably due to their genetic potential to form an impressive array of antibiotics including non-ribosomal lipopeptides (LPs). In the work presented here, we wanted to gain further insights into the relative role of these LPs in the global antifungal activity of B.subtilis/amyloliquefaciens. To that end, a comparative study was conducted involving multiple strains that were tested against four different phytopathogens. We combined various approaches to further exemplify that secretion of those LPs is a crucial trait in direct pathogen ward off and this can actually be generalized to all members of these species. Our data illustrate that for each LP family, the fungitoxic activity varies in function of the target species and that the production of iturins and fengycins is modulated by the presence of pathogens. Our data on the relative involvement of these LPs in the biocontrol activity and modulation of their production are discussed in the context of natural conditions in the rhizosphere. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology. [less ▲]

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