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Auteur L. Dehimat |
Documents disponibles écrits par cet auteur (5)
Affiner la recherche Interroger des sources externesL’effet inhibiteur depythium sp. sur la croissance mycélienne de fusarium roseum et d’alternaria alternata / Samai Batoul Bouneghou
Titre : L’effet inhibiteur depythium sp. sur la croissance mycélienne de fusarium roseum et d’alternaria alternata Type de document : texte imprimé Auteurs : Samai Batoul Bouneghou, Auteur ; L. Dehimat, Directeur de thèse ; Zahira Bouziane, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2010 Importance : 36 f. Format : 31 cm Note générale : Master
2 copies imprimées disponiblesLangues : Français (fre) Catégories : Français - Anglais
BiologieTags : Pythium sp. Fusarium roseum Alternaria alternata lutte biologique antagonisme. Biologie Index. décimale : 570 Sciences de la vie. Biologie En ligne : ../theses/biologie/BOU10003.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=5826 L’effet inhibiteur depythium sp. sur la croissance mycélienne de fusarium roseum et d’alternaria alternata [texte imprimé] / Samai Batoul Bouneghou, Auteur ; L. Dehimat, Directeur de thèse ; Zahira Bouziane, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2010 . - 36 f. ; 31 cm.
Master
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Pythium sp. Fusarium roseum Alternaria alternata lutte biologique antagonisme. Biologie Index. décimale : 570 Sciences de la vie. Biologie En ligne : ../theses/biologie/BOU10003.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=5826 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/10003 BOU/10003 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude de l’aptitude des souches fongiques, isolées de la rhizosphère de deux plantes steppiques de la région minière d’Ain-Babouche, à la remédiation des sols métallifères. Type de document : texte imprimé Auteurs : Ouissem Meghnous, Auteur ; L. Dehimat, Directeur de thèse ; Oualida Rached-Mosbah, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2020 Importance : 175 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
1 copies imprimées disponiblesLangues : Français (fre) Catégories : Français - Anglais
BiologieTags : Microbiologie :Biotechnologie et Bioprocédés, Applications Mycologiques Mycoendophytes Hedysarum pallidum Desf. Lygeum spartum. L antimoine arsenic résistance bioaccumulation stress oxydatif bioremédiation antimony resistance oxidative stress bioremedation الفطریات الداخلیة الإثمد الزرنیخ المقاومة الامتصاص الحیوي الإجھاد الأكسدي الإصلاح الحیوي Index. décimale : 570 Sciences de la vie. Biologie Résumé : The aim of this work is to highlight a resistant endophytic mycoflora in the roots of two metallophylic species Hedysarum pallidum Desf. and Lygeum spartum L. growing on soil contaminated with antimony (Sb) and arsenic (As) in Djebel Hamimat (Algeria) region, to study the toxicity of mycoendophytes with respect to toxicity of Sb and As, to evaluate the level of oxidative stress and the antioxidant defense systems of Aspergillus tubingensis and Fusarium oxyporum induced by metalloid toxicity. Our work demonstrates, the presence of mycoendophytes associated with the roots of the two plant species studied for the first time in Algeria; H. pallidum, and L. spartum. This latter have a colonization frequencies of 64.58% and 96.87% respectively. among the isolated mycoendophytes, only Aspergillus tubingensis was resistant to 500 mM Sb, and Fusarium oxysporum tolerated 30 mM As. The toxicity tests in vitro on A. tubingensis and F. oxysporum revealed that these strains accumulated a significant amounts of Sb in their biomass, in contrast to As. As regards the indicators of the oxidative stress level and the antioxidant responses of the two endophytic species, MDA, H2O2 and intracellular proline content increase significantly with increasing doses of Sb and As in the culture medium. Antioxidant responses vary quantitatively and qualitatively from a fungal species to another, and from a metalloid to another. This suggests that these endophytic strains may be potential agents for the bioremediation of soil and aquatic environments contaminated with antimony and arsenic.
Note de contenu : Annexe 1 : Les milieux de cultures
Annexe 2 : Extraction d’ADN génomique des mycoendophytes Résistants
Annexe 3 : Courbes étalons
Annexe 4 : Matrices de corrélation
article: Oxidative and antioxidative responses to antimony stress by endophytic fungus Aspergillus tubingensis isolated from antimony accumulator Hedysarum pallidum Desf.
Ouissem Meghnous1 & Laid Dehimat2 & Patrick Doumas3 & Mounia Kassa-Laouar1 & Fawzia Mosbah1 &
Oualida RachedDiplôme : Doctorat En ligne : ../theses/biologie/MEG7633.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11334 Etude de l’aptitude des souches fongiques, isolées de la rhizosphère de deux plantes steppiques de la région minière d’Ain-Babouche, à la remédiation des sols métallifères. [texte imprimé] / Ouissem Meghnous, Auteur ; L. Dehimat, Directeur de thèse ; Oualida Rached-Mosbah, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2020 . - 175 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Microbiologie :Biotechnologie et Bioprocédés, Applications Mycologiques Mycoendophytes Hedysarum pallidum Desf. Lygeum spartum. L antimoine arsenic résistance bioaccumulation stress oxydatif bioremédiation antimony resistance oxidative stress bioremedation الفطریات الداخلیة الإثمد الزرنیخ المقاومة الامتصاص الحیوي الإجھاد الأكسدي الإصلاح الحیوي Index. décimale : 570 Sciences de la vie. Biologie Résumé : The aim of this work is to highlight a resistant endophytic mycoflora in the roots of two metallophylic species Hedysarum pallidum Desf. and Lygeum spartum L. growing on soil contaminated with antimony (Sb) and arsenic (As) in Djebel Hamimat (Algeria) region, to study the toxicity of mycoendophytes with respect to toxicity of Sb and As, to evaluate the level of oxidative stress and the antioxidant defense systems of Aspergillus tubingensis and Fusarium oxyporum induced by metalloid toxicity. Our work demonstrates, the presence of mycoendophytes associated with the roots of the two plant species studied for the first time in Algeria; H. pallidum, and L. spartum. This latter have a colonization frequencies of 64.58% and 96.87% respectively. among the isolated mycoendophytes, only Aspergillus tubingensis was resistant to 500 mM Sb, and Fusarium oxysporum tolerated 30 mM As. The toxicity tests in vitro on A. tubingensis and F. oxysporum revealed that these strains accumulated a significant amounts of Sb in their biomass, in contrast to As. As regards the indicators of the oxidative stress level and the antioxidant responses of the two endophytic species, MDA, H2O2 and intracellular proline content increase significantly with increasing doses of Sb and As in the culture medium. Antioxidant responses vary quantitatively and qualitatively from a fungal species to another, and from a metalloid to another. This suggests that these endophytic strains may be potential agents for the bioremediation of soil and aquatic environments contaminated with antimony and arsenic.
Note de contenu : Annexe 1 : Les milieux de cultures
Annexe 2 : Extraction d’ADN génomique des mycoendophytes Résistants
Annexe 3 : Courbes étalons
Annexe 4 : Matrices de corrélation
article: Oxidative and antioxidative responses to antimony stress by endophytic fungus Aspergillus tubingensis isolated from antimony accumulator Hedysarum pallidum Desf.
Ouissem Meghnous1 & Laid Dehimat2 & Patrick Doumas3 & Mounia Kassa-Laouar1 & Fawzia Mosbah1 &
Oualida RachedDiplôme : Doctorat En ligne : ../theses/biologie/MEG7633.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11334 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MEG/7633 MEG/7633 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude des myco-pathogènes de Lens culinaris et évaluation de l’effet de deux souches de Trichoderma harzianum : cas de la Fusariose et de la Cylindrosporiose. Type de document : texte imprimé Auteurs : Hiba Almi, Auteur ; L. Dehimat, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 119 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : " Lens culinaris, Cylindrosporium sp, Fusarium solani, Trichoderma harzianum,
fermentation liquide, fermentation solide, antagonisme."
Lens culinaris Cylindrosporium sp Fusarium solani Trichoderma harzianum liquid fermentation solid state fermenttion antagonism
Lens culinaris, Cylindrosporium sp, Fusarium solani, Trichoderma harzianum,التخمر الصلب-التخمر-التنافسIndex. décimale : 570 Sciences de la vie. Biologie Résumé : In order to evaluate the bio protector effect of two strains of Trichoderma harzianum on two
Cylindrosporium sp and Fusarium solani phytopatogens, a pathosystem using the model
legume Lens culinaris has been chosen. The isolation of mycetes allowed us to obtain 197
fungal isolates of the different samples taken from BARAOUIA and AIN SEMARA sites, in
the region of Constantine. In fact, 87 fungal isolates were obtained from different soil depths,
with a fungal dominance in the depths 5 and 10. The rest of isolates (110) were obtained from
different levels of plants, with a homogeneous distribution in terms of the number of isolates
between the air and the underground surface. The macroscopic and microscopic identification
of the set of isolates allowed for trying them into 25 genus, whose 55.34% of trains taken
from BARAOUIA site and 46.30% of AIN SEMARA site are phytopatogens. Two fungal
isolates with an antagonist activity were preselected after having developed important zones
of inhibition on the PDA medium. The preliminary and molecular identification of these
isolates has shown that they belong to Trichoderma harzianum 127a and Trichoderma
harzianum 127b. The conducted tests In vitro antagonism against both pathogens Lens
culinaris, namely Cylindrosporium sp and Fusarium solani; have revealed that the inhibition
rate by the volatile metabolites is 62.70% in average, and those by diffusible metabolites is
86.34% in average. The evaluation of the rate competition exerted by T-T-127b and 127a,
revealed that our Trichoderma strains have the ability to reduce from 70 to 83% growth C.SP
and from 67 to 82% F of growth .solani.From these results, it seems that the efficiency of the
strains of Trichoderma is more important when gathering all the ways of action (the use of
spores). The optimisation of the fermentation medium (FL) has revaluated that the optimal
conditions of the biomass production of T-127a and T-127b are: pH 5, temperature of 30°C
and a culture medium on a malt extract (M2). The cultivation of biomass T- 127a and T-127b
on wheat bran (FMS) has achieved a smooth greenish powder, whose concentration before
purification is 3.27 109C/mL for T-127a and 3.33 109C/mL for T-127b. Moreover, the
application of these spores on lentil plants, has revaluated that, in case of no treatment with
antagonist strains, the inoculated plants with one of the pathogens (C. sp or F. solani) receive
a hydric deficit leading to rise in the prolin content, a decrease in the chlorophyll content, in
the concentration of the total sugars and in the growth. However, the plants stimulated by the
strains of Trichoderma, had a stable content of prolin, a high content of chlorophyll and
sugars as well as a rapid growth. The other treatments were able to conserve values of sugars,
chlorophyll, prolin and a growth similar to the samples. In conclusion, our strains of
Trichoderma harzianum prodycing at the laboratory level have important antifungal activities,
which allow them of being exploited and the industrial level.
Diplôme : Doctorat En ligne : ../theses/biologie/ALM6793.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10014 Etude des myco-pathogènes de Lens culinaris et évaluation de l’effet de deux souches de Trichoderma harzianum : cas de la Fusariose et de la Cylindrosporiose. [texte imprimé] / Hiba Almi, Auteur ; L. Dehimat, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2015 . - 119 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : " Lens culinaris, Cylindrosporium sp, Fusarium solani, Trichoderma harzianum,
fermentation liquide, fermentation solide, antagonisme."
Lens culinaris Cylindrosporium sp Fusarium solani Trichoderma harzianum liquid fermentation solid state fermenttion antagonism
Lens culinaris, Cylindrosporium sp, Fusarium solani, Trichoderma harzianum,التخمر الصلب-التخمر-التنافسIndex. décimale : 570 Sciences de la vie. Biologie Résumé : In order to evaluate the bio protector effect of two strains of Trichoderma harzianum on two
Cylindrosporium sp and Fusarium solani phytopatogens, a pathosystem using the model
legume Lens culinaris has been chosen. The isolation of mycetes allowed us to obtain 197
fungal isolates of the different samples taken from BARAOUIA and AIN SEMARA sites, in
the region of Constantine. In fact, 87 fungal isolates were obtained from different soil depths,
with a fungal dominance in the depths 5 and 10. The rest of isolates (110) were obtained from
different levels of plants, with a homogeneous distribution in terms of the number of isolates
between the air and the underground surface. The macroscopic and microscopic identification
of the set of isolates allowed for trying them into 25 genus, whose 55.34% of trains taken
from BARAOUIA site and 46.30% of AIN SEMARA site are phytopatogens. Two fungal
isolates with an antagonist activity were preselected after having developed important zones
of inhibition on the PDA medium. The preliminary and molecular identification of these
isolates has shown that they belong to Trichoderma harzianum 127a and Trichoderma
harzianum 127b. The conducted tests In vitro antagonism against both pathogens Lens
culinaris, namely Cylindrosporium sp and Fusarium solani; have revealed that the inhibition
rate by the volatile metabolites is 62.70% in average, and those by diffusible metabolites is
86.34% in average. The evaluation of the rate competition exerted by T-T-127b and 127a,
revealed that our Trichoderma strains have the ability to reduce from 70 to 83% growth C.SP
and from 67 to 82% F of growth .solani.From these results, it seems that the efficiency of the
strains of Trichoderma is more important when gathering all the ways of action (the use of
spores). The optimisation of the fermentation medium (FL) has revaluated that the optimal
conditions of the biomass production of T-127a and T-127b are: pH 5, temperature of 30°C
and a culture medium on a malt extract (M2). The cultivation of biomass T- 127a and T-127b
on wheat bran (FMS) has achieved a smooth greenish powder, whose concentration before
purification is 3.27 109C/mL for T-127a and 3.33 109C/mL for T-127b. Moreover, the
application of these spores on lentil plants, has revaluated that, in case of no treatment with
antagonist strains, the inoculated plants with one of the pathogens (C. sp or F. solani) receive
a hydric deficit leading to rise in the prolin content, a decrease in the chlorophyll content, in
the concentration of the total sugars and in the growth. However, the plants stimulated by the
strains of Trichoderma, had a stable content of prolin, a high content of chlorophyll and
sugars as well as a rapid growth. The other treatments were able to conserve values of sugars,
chlorophyll, prolin and a growth similar to the samples. In conclusion, our strains of
Trichoderma harzianum prodycing at the laboratory level have important antifungal activities,
which allow them of being exploited and the industrial level.
Diplôme : Doctorat En ligne : ../theses/biologie/ALM6793.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10014 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité ALM/6793 ALM/6793 Thèse Bibliothèque principale Thèses Disponible
Titre : Isolement et identification de souches d’Aspergillus de différents écosystèmes productrices de substances à activité antibactérienne et caractérisation partielle des molécules élaborées. Type de document : texte imprimé Auteurs : Amina Bramki, Auteur ; L. Dehimat, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 150 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
2 copies imprimées disponiblesLangues : Français (fre) Catégories : Français - Anglais
BiologieTags : Biochimie et Biologie Cellulaire et Moléculaire: Biochimie Appliquée Aspergillus écosystèmes particuliers activité antibactérienne molécules bioactives antibacterial activity bioactive molecules نظم بيتية خاصة نشاط مضاد للبكتيري جزيئات نشطة حيويا Index. décimale : 570 Sciences de la vie. Biologie Résumé :
In the interest of discovering new antibiotic molecules, the antibacterial activity of ten fungal species of Aspergillus genus isolated from soils taken from particular ecosystems (Laghouat and Teleghma) was sought against six bacterial strains; three with Gram + staining and three with Gram - staining. The results of the demonstration by different techniques (cylinders, disks and wells) have allowed us to select for the rest of our work three fungal species (A. quadrilineatus, A. niveus and A. wentii) that have a considerable antibacterial effect, and which are not well developed by researchers in the field of secondary metabolites with antibacterial activity. In order to optimize the extraction conditions of the bioactive molecules of these strains, five solvents in different polarities were tested, of which chloroform turned out to be the best one. After the selection of this solvent, four culture media of various compositions were used to determine the most adequate medium for the production of antibacterial substances. The results show that the nature of the components of these media (carbon source, nitrogen, and mineral source) greatly influences the production capacity of antibiotics in fungi. Moreover, the study of the stability of bioactive molecules reveals that the majority of active extracts maintain their activity after heat treatment (up to 100 °C) and exposure to light. In addition, the separation of antibacterial molecules by chromatographic techniques allowed us to select an active fraction. After the analysis of this fraction by UPLCMS, 24 peaks corresponding to 24 molecules were revealed with determination of their chemical characteristics: m/z ratios, formulas, retention time and intensities.
Note de contenu :
Annexes.Diplôme : Doctorat En ligne : ../theses/biologie/BRA7540.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11380 Isolement et identification de souches d’Aspergillus de différents écosystèmes productrices de substances à activité antibactérienne et caractérisation partielle des molécules élaborées. [texte imprimé] / Amina Bramki, Auteur ; L. Dehimat, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2019 . - 150 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Biochimie et Biologie Cellulaire et Moléculaire: Biochimie Appliquée Aspergillus écosystèmes particuliers activité antibactérienne molécules bioactives antibacterial activity bioactive molecules نظم بيتية خاصة نشاط مضاد للبكتيري جزيئات نشطة حيويا Index. décimale : 570 Sciences de la vie. Biologie Résumé :
In the interest of discovering new antibiotic molecules, the antibacterial activity of ten fungal species of Aspergillus genus isolated from soils taken from particular ecosystems (Laghouat and Teleghma) was sought against six bacterial strains; three with Gram + staining and three with Gram - staining. The results of the demonstration by different techniques (cylinders, disks and wells) have allowed us to select for the rest of our work three fungal species (A. quadrilineatus, A. niveus and A. wentii) that have a considerable antibacterial effect, and which are not well developed by researchers in the field of secondary metabolites with antibacterial activity. In order to optimize the extraction conditions of the bioactive molecules of these strains, five solvents in different polarities were tested, of which chloroform turned out to be the best one. After the selection of this solvent, four culture media of various compositions were used to determine the most adequate medium for the production of antibacterial substances. The results show that the nature of the components of these media (carbon source, nitrogen, and mineral source) greatly influences the production capacity of antibiotics in fungi. Moreover, the study of the stability of bioactive molecules reveals that the majority of active extracts maintain their activity after heat treatment (up to 100 °C) and exposure to light. In addition, the separation of antibacterial molecules by chromatographic techniques allowed us to select an active fraction. After the analysis of this fraction by UPLCMS, 24 peaks corresponding to 24 molecules were revealed with determination of their chemical characteristics: m/z ratios, formulas, retention time and intensities.
Note de contenu :
Annexes.Diplôme : Doctorat En ligne : ../theses/biologie/BRA7540.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11380 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BRA/7540 BRA/7540 Thèse Bibliothèque principale Thèses Disponible
Titre : Isolement des microorganismes possédant une activité anti- Fusarium Type de document : texte imprimé Auteurs : Sana Ghorri, Auteur ; L. Dehimat, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 140 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Fusarium Fusariose lutte biologique Trichoderma BIOLOG extraits fongiques biological control fungal extracts المكافحة البيولوجيةة المستخلصات الفطرية Index. décimale : 570 Sciences de la vie. Biologie Résumé : This study was carried out in order to fight against the phytopathogenic fungus ""Fusarium"".
eight species from the genus Fusarium have been isolated from different organs of infected
plants. genus identification was conducted using morphological characters, while the
identification of species was performed by molecular pathway within the LMBA Laboratory
(Laboratory of Microbiology and Biomolecules Assets).
Indeed, according to affiliation results, the eight pathogenic strains belong to three Fusarium
species in the circumstances; Fusarium verticillioides, Fusarium solani and Fusarium
oxysporum.
Biological control against the phytopathogens is highlighted using seven strains from the
genus Trichoderma isolated from three Algerian agricultural soils.
The molecular identification of isolats conducted in the laboratory of LMBA has divided
the seven strains into five main species: Trichoderma album, Trichoderma harzianum,
Trichoderma virens, Trichoderma longibrachiatum, Trichoderma viride. Indeed, This study
showed a significant diversity of Trichoderma species in Algeria. However, to our
knowledge, there are no previous published studies on the isolation of Trichoderma album,
Trichoderma virens and Trichoderma longibrachiatum, from the Algerian soil.
The effect of the antagonist activity of Trichoderma strains against the eight isolated
Fusarium species was studied using two methods, direct and indirect confrontation. Direct
confrontation results show a percentage of inhibition ranging from 55% to 72% depending on
the tested pathogenic and antagonists species, while the results of the confrontation from
distance reveals low percentage of inhibition varied from 2% to 43%.
The seven tested Trichoderma strains show considerable capacity of resistance on the media
with a different pH from 2 to 9. Enzymatic activity test of antagonistic strains shows that the
seven tested strains represent very important sources of lytic enzymes namely chitinase,
cellulase, protease, lipase and laccase.
Both test for anti-Fusarium activity, and culture filtrates antagonistic strains show a low
inhibition of mycelial growth of pathogenic strains. Furthermore, this study showed a
remarkable change of color and appearance of the Fusarium strains due to antagonistic
metabolits.
chloroformic extract effect of the seven antagonistic strains, was tested by the BIOLOG
technic and by the technical soaked disks, both techniques show a good inhibitory activity of
the extracts, no matter what the concentration used is (50 mg / ml , 25 mg / ml and 1mg / ml)
Diplôme : Doctorat En ligne : ../theses/biologie/GHO6792.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10015 Isolement des microorganismes possédant une activité anti- Fusarium [texte imprimé] / Sana Ghorri, Auteur ; L. Dehimat, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2015 . - 140 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Fusarium Fusariose lutte biologique Trichoderma BIOLOG extraits fongiques biological control fungal extracts المكافحة البيولوجيةة المستخلصات الفطرية Index. décimale : 570 Sciences de la vie. Biologie Résumé : This study was carried out in order to fight against the phytopathogenic fungus ""Fusarium"".
eight species from the genus Fusarium have been isolated from different organs of infected
plants. genus identification was conducted using morphological characters, while the
identification of species was performed by molecular pathway within the LMBA Laboratory
(Laboratory of Microbiology and Biomolecules Assets).
Indeed, according to affiliation results, the eight pathogenic strains belong to three Fusarium
species in the circumstances; Fusarium verticillioides, Fusarium solani and Fusarium
oxysporum.
Biological control against the phytopathogens is highlighted using seven strains from the
genus Trichoderma isolated from three Algerian agricultural soils.
The molecular identification of isolats conducted in the laboratory of LMBA has divided
the seven strains into five main species: Trichoderma album, Trichoderma harzianum,
Trichoderma virens, Trichoderma longibrachiatum, Trichoderma viride. Indeed, This study
showed a significant diversity of Trichoderma species in Algeria. However, to our
knowledge, there are no previous published studies on the isolation of Trichoderma album,
Trichoderma virens and Trichoderma longibrachiatum, from the Algerian soil.
The effect of the antagonist activity of Trichoderma strains against the eight isolated
Fusarium species was studied using two methods, direct and indirect confrontation. Direct
confrontation results show a percentage of inhibition ranging from 55% to 72% depending on
the tested pathogenic and antagonists species, while the results of the confrontation from
distance reveals low percentage of inhibition varied from 2% to 43%.
The seven tested Trichoderma strains show considerable capacity of resistance on the media
with a different pH from 2 to 9. Enzymatic activity test of antagonistic strains shows that the
seven tested strains represent very important sources of lytic enzymes namely chitinase,
cellulase, protease, lipase and laccase.
Both test for anti-Fusarium activity, and culture filtrates antagonistic strains show a low
inhibition of mycelial growth of pathogenic strains. Furthermore, this study showed a
remarkable change of color and appearance of the Fusarium strains due to antagonistic
metabolits.
chloroformic extract effect of the seven antagonistic strains, was tested by the BIOLOG
technic and by the technical soaked disks, both techniques show a good inhibitory activity of
the extracts, no matter what the concentration used is (50 mg / ml , 25 mg / ml and 1mg / ml)
Diplôme : Doctorat En ligne : ../theses/biologie/GHO6792.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10015 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité GHO/6792 GHO/6792 Thèse Bibliothèque principale Thèses Disponible
