References of "Jijakli, Haissam"
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See detailFungi occurring on waterhyacinth (Eichhornia crassipes (Martius) Solms-Laubach) in Niger River in Mali and their evaluation as mycoherbicides.
Dagno, Karim; Lahlali, Rachid; Diourté, Mamourou et al

in Journal of Aquatic Plant Management (2012), 50

We recovered 116 fungal isolates in 7 genera from waterhyacinth plants having pronounced blight symptoms collected in Mali. Isolation frequency of the genera was Curvularia (60.32%), Fusarium (42.92 ... [more ▼]

We recovered 116 fungal isolates in 7 genera from waterhyacinth plants having pronounced blight symptoms collected in Mali. Isolation frequency of the genera was Curvularia (60.32%), Fusarium (42.92%), Alternaria (11.6%), Coniothyrium (11.6%), Phoma (3.48%), Stemphylium (3.48%), and Cadophora (1.16%). On the basis of in vivo pathogenicity tests in which the diseased leaf area percentage and disease severity were visually estimated using a disease severity index, three isolates, Fusarium sp. Mln799, Cadophora sp. Mln715, and Alternaria sp. Mlb684 caused severe disease. These were later identified as Gibberella sacchari Summerell & J.F. Leslie, Cadophora malorum (Kidd & Beaumont) W. Grams, and Alternaria sp. respectively. This is the first report to highlight C. malorum as a candidate biocontrol agent against waterhyacinth. Neither C. malorum Mln715 nor Alternaria sp. Mlb684 in host specificity tests showed any pathogenicity toward 17 crop plants of economic importance in Mali. [less ▲]

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See detailCharacterization of a novel chitinase from a moderately halophilic bacterium, Virgibacillus marismortui strain M3-23
Essghaier, Badiaa; Hedi, Abdeljabbar; Bajji, Mohammed et al

in Annals of Microbiology (2012), 62(2), 835-841

A new chitinase produced by the moderately halophilic bacterium Virgibacillus marismortui strain M3- 23 was identified and characterized. Distinguishable characteristics of high activity and stability at ... [more ▼]

A new chitinase produced by the moderately halophilic bacterium Virgibacillus marismortui strain M3- 23 was identified and characterized. Distinguishable characteristics of high activity and stability at different pH, temperatures and salinity of M3-23 chitinase are reported. Analysis of the catalytic domain sequence from the enzyme highlighted its relationship to glycosyl hydrolase family 18. Comparison of the deduced chitinase sequence from strain M3-23 to known chitinases from Bacillus species showed low similarity (82%), suggested its novelty. This is the first report of the characterization of chitinase from the species V. marismortui. The halo- and thermo-tolerant nature of the chitinolytic enzyme allows its potential use in agricultural and industrial applications. [less ▲]

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See detailBiopesticides: Feedback from distributors and users
Jijakli, Haissam ULg

Conference (2011, December)

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See detailBiocontrol proteomics:Implication of the pentoses phosphates pathway in the antagonist effect of Pichia anomala against Botrytis cinerea on apple
Kwasiborski, Anthony ULg; Renaut, Jenny; Lepoivre, Philippe ULg et al

Poster (2011, September 21)

The growing interest of the consumers for the wholesome food and the protection of the environment as well as the development of resistant pathogens to pesticides, stimulate the interest of growers to ... [more ▼]

The growing interest of the consumers for the wholesome food and the protection of the environment as well as the development of resistant pathogens to pesticides, stimulate the interest of growers to apply biological control methods. Pichia anomala strain K was previously identified as an efficient biocontrol agent of the main apple pathogens, Botrytis cinerea and Penicillum expansum. Further study demonstrated the complexicity of the mode of action of P. anomala against B. cinerea. A cDNA-AFLP and gene disruption study revealed implication of exo-β-1,3-glucanases in the mode of action of P. anomala strain Kh6 (a haploid form of P. anomala strain K displaying the same biocontrol properties). However, these studies suggested also implication of other factors. The present study aims to increase our knowledge of the mode of action of P. anomala strain Kh6 against B. cinerea using an in situ approach allowing the triple interaction, host/pathogen/antagonist and the proteomic tool allowing to study the ultime expression of the genome without a priori. One 50mm wound per apple were covered by a membrane and inoculated by a P. anomala suspension then by B. cinerea or not. Samples were collected during the exponential and stationary phase to identify the early and later responses to the presence of B. cinerea. After extraction, proteins were separated on 2-D gels. Spots influenced by the presence of B. cinerea in exponential and stationary phases were identified by MALDI-ToF. One hundred five and sixty spots of proteins were influenced by the presence of B. cinerea in exponential and stationary phases respectively. In exponential phase, P. anomala Kh6 in absence of B. cinerea uses mainly the glycolysis pathway, whereas in presence of pathogen, it orientates its energetic metabolism to the oxidative phosphorylation and sets up the pentose phosphate pathway. Thanks to this new orientation, P. anomala Kh6 probably obtains energy and nucleic acids allowing to colonize the wound as fast as in absence of B. cinerea and prevents the use of nutrients by the pathogen. In stationary phase, no differences in the P. anomala Kh6 energetic metabolism, in absence and in presence of B. cinerea were observed. During that phase, P. anomala Kh6 seems to use the alcoholic fermentation in order to face the nutrients impoverishment of the substrate. [less ▲]

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See detailBiocontrol proteomics:Implication of the pentoses phosphates pathway in the antagonist effect of Pichia anomala against Botrytis cinerea on apple.
Kwasiborski, Anthony ULg; renaut, Jenny; Delaplace, Pierre ULg et al

Conference (2011, August 31)

Pichia anomala strain K was previously identified as an efficient biocontrol agent of the apple pathogen, Botrytis cinerea. Further study demonstrated the complexicity of the mode of action of P. anomala ... [more ▼]

Pichia anomala strain K was previously identified as an efficient biocontrol agent of the apple pathogen, Botrytis cinerea. Further study demonstrated the complexicity of the mode of action of P. anomala against B. cinerea. A molecular study revealed implication of exo-β-1,3-glucanases in the mode of action of P. anomala but suggested implication of other factors. The present study aims to increase our knowledge of the mode of action of P. anomala strain Kh6 against B. cinerea using an in situ approach allowing interactions between organisms, and the proteomic tool allowing to study the ultime expression of the genome. One wound per apple were covered by a membrane and inoculated by P. anomala then by B. cinerea or not. Samples were collected at different incubation times to identify the responses of P. anomala to the presence of B. cinerea. After extraction, proteins were separated on 2-D gels. Spots influenced were identified by MALDI-ToF. In exponential phase, P. anomala Kh6 orientates its energetic metabolism from the glycolysis to the oxidative phosphorylation and sets up the pentose phosphate pathway. Thanks to this new pathway, P. anomala probably obtains energy and nucleic acids allowing to colonize the wound as fast as in absence of B. cinerea. In stationary phase, no differences in the P. anomala energetic metabolism, in absence and in presence of B. cinerea were observed. During that phase, P. anomala seems to use the alcoholic fermentation in order to face the nutrients impoverishment of the substrate. [less ▲]

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See detailAlternaria jacinthicola, a new fungal species causing blight leaf disease on water hyacinth (Eichhornia crassipes (Martius) Solms-Laubach)
Dagno, Karim ULg; Crovadore, Julien; Lefort, François et al

in Journal of Yeast and Fungal Research (2011), 2(7), 99-105

Water hyacinth (Eichhornia crassipes) causes environmental, agricultural and health problems in Mali. This is particularly severe in the District of Bamako and the irrigation systems of the “Office du ... [more ▼]

Water hyacinth (Eichhornia crassipes) causes environmental, agricultural and health problems in Mali. This is particularly severe in the District of Bamako and the irrigation systems of the “Office du Niger”area. During two years survey for fungal pathogens of water hyacinth infested areas, isolate Mlb684 was collected from diseased plant. This fungal isolate was identified as a potential mycoherbicide for sustainable management for water hyacinth. The aim of this study was to characterize isolate Mlb684. The characterization was based on a morphological description and a DNA sequence analysis. Various genes amplified from isolate Mlb684 were compared to those existing in Genbank. These genes were 18S ribosomal rDNA gene, ITS rDNA gene, elongation factor-1 alpha (EF1a) gene, calmodulin and actin genes. DNA sequence comparisons and morphological description provided enough evidences to show that isolate Mlb684 belonged to the Alternaria genus and was distinct from any other known Alternaria species. Based on these evidences, the new fungal isolate was called “Alternaria jacinthicola Dagno & M.H. Jijakli”. A specimen culture has been deposited in the Gembloux Agro Bio Tech Plant Pathology unit fungal collection, with Mlb684 reference and in the Industrial Fungal and Yeast Collection (BCCM/MUCL, Belgium) under the accession number: MUCL 53159 and all DNA sequences were deposited in GenBank (NCBI). [less ▲]

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See detailPre-harvest conditions affect the banana susceptibility to post-hervest disease.
Lassois, Ludivine ULg; Ewane, Cecile; Forret, Marie et al

Conference (2011, May 24)

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See detailIn situ proteome study of Pichia anomala strain K, an antagonist of the apple pathogen Botrytis cinerea
Kwasiborski, Anthony ULg; Renaut, Jenny; Delaplace, Pierre ULg et al

Conference (2011, May 24)

Postharvest fungal pathogens, mainly Botrytis cinerea, Penicillum expansum and Gloeosporium spp., annually cause 5-20% losses of fruit. Control measures against these diseases include chemical fungicide ... [more ▼]

Postharvest fungal pathogens, mainly Botrytis cinerea, Penicillum expansum and Gloeosporium spp., annually cause 5-20% losses of fruit. Control measures against these diseases include chemical fungicide applications, but the development of resistant fungal explains the growing interest for biological control. Pichia anomala strain K was previously identified as an efficient antagonist of pathogens on apples. Indeed, the percentage of protection of P.anomala against B.cinerea reached from 90 to 100% on apple wounds according to the experimental conditions. Microbiological, biochemical and molecular approaches demonstrated the implication of exo-β-1,3-glucanases in the mechanism of action of P.anomala. However, study of these mechanisms could be improved by observations under natural infection conditions in order to take into account the tripartite interactions host/antagonist/pathogen. The proteomic tool allowed an overview of process implicated in the antagonism against B.cinerea in such conditions. One 50mm wound per apple were covered by a membrane and inoculated by a P.anomala suspension then by B.cinerea or not. Samples were collected during the exponential and stationary phase to identify the early and later responses to the presence of B.cinerea. After extraction, proteins were separated on 2DE gels. Spots influenced by the presence of B.cinerea in exponential and stationary phases were identified by MALDI-ToF. One hundred five and sixty spots of proteins were influenced by the presence of B.cinerea in exponential and stationary phase respectively. In exponential phase, influenced proteins were implicated in the different steps of the proteins biosynthesis: amino acid synthesis, translation or mRNA maturation and in energy synthesis. On the other hand, in stationary phase, influenced proteins were mainly implicated in energy metabolic pathway: glycolysis, alcoholic fermentation or gluconeogenesis. The presence of B.cinerea seemed to induce a slowdown in the metabolism of P.anomala without influenced its growth. Further studies have to be realized to understand the complexity of these modes of action. [less ▲]

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See detailScreening Elisa method to assess in vitro efficacy of new agents based on Lactoperoxydase system against phytopathogens
Bafort, Françoise ULg; Lepoivre, Philippe ULg; Jijakli, Haissam ULg et al

Poster (2011, May 24)

The lactoperoxydasesystem (LPS) is a natural biological protection system in human saliva, milk and tears. Lactoperoxydase catalyzes the oxidation of iodide (I-) and thiocyanate (SCN-) in presence of ... [more ▼]

The lactoperoxydasesystem (LPS) is a natural biological protection system in human saliva, milk and tears. Lactoperoxydase catalyzes the oxidation of iodide (I-) and thiocyanate (SCN-) in presence of hydrogen peroxide in hypoiodite (OI-) and hypothiocyanite (OSCN-) ions. Both ions have inhibitory action against pathogenic bacteria, fungi and viruses. Until now, the ions OI- and OSCN- applied separately from the LPS were not tested against plant pathogens. Seventeen KI/KSCN/H2O2 ratios with 3 dilutions for each one were tested against Botrytiscinerea. Results showed that the ions OI- and OSCN- gives a better % of inhibition with: -high concentration of KI+KSCN, -a ratio of KI/KSCN of 4.5 and -a ratioof (KI+KSCN)/H2O2 near 1. Increased dilution combined with lower KI+KSCN concentration reduced the efficacy of the ions. From the screening against B.cinerea, 4 ratios of KI+KSCN were selected and tested against 6 other phytopathogens. Results showed that the OI- and OSCN- ions give 87 and 100% inhibition against Penicillium expansum and Verticillium dahlia respectively. The inhibitory activity of the ions solution was ranged between 70 and 79% regarding Fusarium avenaceum, Phytophthora infestans and Colletotrichum lindemuthanium. The ions OI- and OSCN- showed an insufficient inhibitory activity against Septoria tritici. The screening method highlighted that high KI/KSCN ratios and low dilution were more efficient against phytopathogens. The efficient ratios will be further evaluated in vivo. [less ▲]

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See detailProduction and oil-emulsion formulation of Cadophora malorum and Alternaria jacinthicola, two biocontrol agents against Water Hyacinth (Eichhornia crassipes)
Dagno, Karim ULg; Lahlali, Rachid; Diourté, Mamourou et al

in African Journal of Microbiology Research [=AJMR] (2011), 5(8), 924-929

Cadophora malorum isolate Mln715 and Alternaria jacinthicola strain MUCL 53159 are under <br />development as biocontrol agents against Water Hyacinth (Eichhornia crassipes) in Mali. Production of spores ... [more ▼]

Cadophora malorum isolate Mln715 and Alternaria jacinthicola strain MUCL 53159 are under <br />development as biocontrol agents against Water Hyacinth (Eichhornia crassipes) in Mali. Production of spores of these agents on locally available substrates (Water Hyacinth, powdered paddy rice chaff, wheat semolina) was assessed with a view to mass production. The C. malorum isolate sporulated best on Water Hyacinth (4.08 × 107 spores ml-1), followed by wheat (1.06 ×107 spores ml-1), whereas A. jacinthicola produced more spores on paddy rice chaff and wheat (0.24 x 107 spores ml-1). The severity of the damage caused by each pathogen was evaluated in the greenhouse and in the field. Under both greenhouse and field conditions, the biocontrol efficacy of the fungal isolates was improved with (unrefined) Carapa procera (L.) oil or (refined) palm oil, supplemented with soybean lecithin and Tween 20. When such a formulation was used, the incubation time was 4 to 5 days in the greenhouse and 7 to 9 days on the field, and the damage severity (DS) recorded 6 weeks after treatment varied from 87.02 to 93.13% in the greenhouse and from 59.11 to 63.00% in the field. For unformulated C. malorum and A. jacinthicola respectively, the incubation times were longer and the DS values were only 22.11 and 29.05% in the greenhouse and 12.05 and 15.15% on the field. Our results highlight good substrates for mass production of these mycoherbicides and demonstrate the ability of vegetable oil formulations to improve their efficacy. [less ▲]

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See detailRôle des acides aminés dans l'activité antagoniste d'Aureobasidium Pullulans vis-à-vis de la pourriture bleue des pommes en post-récolte
Krimi Bencheqroun, Sanae; Bajji, Mohammed; Laghilili, Mustapha et al

Conference (2011, March 23)

Aureobasidium pullulans (souche Ach1-1) a montré une grande efficacité vis-à-vis de Penicillium expansum agent de la pourriture bleue des pommes en conservation. Le présent travail a été réalisé dans le ... [more ▼]

Aureobasidium pullulans (souche Ach1-1) a montré une grande efficacité vis-à-vis de Penicillium expansum agent de la pourriture bleue des pommes en conservation. Le présent travail a été réalisé dans le cadre de l’analyse des mécanismes d’action qui sont les plus impliqués dans son activité antagoniste. Dans des essais in vivo sur pommes blessées, l’effet protecteur de la souche Ach1-1 vis-à-vis de P. expansum a été significativement affaibli par l’ajout dans les blessures de concentrations élevées en acides aminés. L’importance de la réduction étant dépendante de la concentration appliquée, a montré que la compétition pour les acides aminés joue un rôle important dans la suppression de P. expansum. Ce résultat a été appuyé par l’analyse biochimique de la cinétique de l’épuisement des acides aminés dans les blessures des pommes qui a dévoilé que ces composés et particulièrement la sérine, la glycine et l’acide glutamique sont mieux métabolisés par la souche antagoniste que par le pathogène. L’ajout en excès de ces trois acides aminés individuellement dans les blessures des pommes a fortement réduit l’efficacité de la souche Ach1-1 vis-à-vis de P. expansum. Ainsi, ces acides aminés semble être parmi les éléments les plus limitants dans le mécanisme de la compétition. Ces résultats indiquent que l’antagoniste A. pullulans souche Ach 1-1 exerce une activité fongistatique plus que fongicide vis-à-vis de P. expansum et agit par une compétition efficace pour les éléments nutritifs limitants des blessures des pommes et particulièrement les acides aminés sans affecter la viabilité du pathogène. [less ▲]

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See detailControl of apple blue mold by the antagonistic yeast pichia anomala strain K: screening of UV protectants for preharvest application
Lahlali, Rachid; Brostaux, Yves; Jijakli, Haissam ULg

in Plant Disease (2011), 95(3), 311-316

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See detailEffect of temperature and water activity on spore germination and mycelial growth of three fungal biocontrol agents against water hyacinth (Eichhornia crassipes)
Dagno, Karim ULg; Lahlali, Rachid; Diourté, M. et al

in Journal of Applied Microbiology (2011), 110

The fungi were grown in vitro on plates containing potato dextrose agar medium at different aw values (glycerol being added to adjust the aw). The percentage of viable conidia and radial growth rate ... [more ▼]

The fungi were grown in vitro on plates containing potato dextrose agar medium at different aw values (glycerol being added to adjust the aw). The percentage of viable conidia and radial growth rate decreased with decreasing water activity. Statistical analysis showed a significant effect of aw, temperature and the aw temperature interaction on mycelial growth (P < 0Æ0001). Water activity emerged as the factor exerting the greatest influence. Differences were observed between the fungi tested, the C. malorum appearing more tolerant to low aw and the F. sacchari more tolerant to high temperature (35 C). Growth models predicting the combined effect of aw and temperature were developed and response surfaces generated, showing fairly good agreement with the experimental values. Conclusions: Our results confirm the previous finding that aw has a greater influence than temperature on fungal growth. Under most conditions, variation of environmental factors has a detrimental influence on the percentage of viable conidia and mycelial growth rate of fungal isolates. [less ▲]

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See detailDevelopment of a Quick Quantitative Real-Time PCR for the In Vivo Detection and Quantification of Peach latent mosaic viroid
Parisi, Olivier ULg; Lepoivre, Philippe ULg; Jijakli, Haissam ULg

in Plant Disease (2011), 95(2), 137-142

Viroids are plant pathogens infecting a broad range of herbaceous and tree crops. Among them, the Peach latent mosaic viroid (PLMVd) infects mainly peach trees, causing a loss of production with no ... [more ▼]

Viroids are plant pathogens infecting a broad range of herbaceous and tree crops. Among them, the Peach latent mosaic viroid (PLMVd) infects mainly peach trees, causing a loss of production with no curative options. Detecting this viroid is thus important for certification procedures aiming to avoid the release of infected material into orchards. Presented here is a complete detection method based on reverse transcription (RT) followed by a quantitative real-time polymerase chain reaction (PCR). New primers were selected and optimal reaction conditions determined for routine application of the method. The technique is 105 times more sensitive than the endpoint RT-PCR used for PLMVd detection, and permits earlier detection of PLMVd in infected plants. The quick, low-cost extraction procedure used and the quality of the results obtained make this method suitable for routine testing. [less ▲]

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