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Auteur Oualida Rached-Mosbah |
Documents disponibles écrits par cet auteur (6)
Affiner la recherche Interroger des sources externesEtude 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. / Ouissem Meghnous
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 de la distribution des métaux lourds dans les ripisylves de l’oued Rhumel." Type de document : texte imprimé Auteurs : Abderrezak Krika, Auteur ; Oualida Rached-Mosbah, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2014 Importance : 160 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : sol, contamination, tamaris, oued Kébir-Rhumel, Pb, Cd, Zn
soil, contamination, tamarisk, Kebir-Rhumel wadi, Pb, Cd, Zn.
التربة ، التلوث ،الطرفاء ، واد كبیر - رمال ، الرصاص،الكادمیوم ، الزنكIndex. décimale : 570 Sciences de la vie. Biologie Résumé : "Wadi Kebir-Rhumel, surrounded by a more or less degraded riparian forest and
interspersed with wide pieces of completely denuded land, is bordered throughout by a main
road probably to be contaminated by heavy metals, particularly lead (Pb), zinc (Zn) and
cadmium (Cd). The present study has for objectives to determine the role of tamarisk grove in
the soil contamination by heavy metals.
For this purpose, ten sites were selected along the Wadi Kebir-Rhumel so as to have
a side by side plot with vegetation and bare plot. In each plot, soil samples were collected in
a central band and, on either side of it, on the side of the road and the edge of the wadi.
Tamarisk leaves have been a sampling means. The concentrations of Pb, Cd and Zn were
determined by ICP-OES in the washed, unwashed leaves and soils. These, have also been the
determination of the organic matter, pH, electrical conductivity, the total limestone (CaCO3),
cation exchange capacity and the particle size.
The results show significant differences between the washed and unwashed leaves of
tamarisk from the viewpoint of the contents of Pb, Zn and Cd, suggesting an atmospheric
origin of their contamination by heavy metals. The determination of the correlation
coefficients shows, for soils with vegetated plots, that the retention of Pb was by the organic
matter and clay, that of Zn by clay and Cd by pH and manganese. In bare plots, retention Pb
and Cd is governed by pH, CEC and silt, whereas Zn is by iron and manganese. The analysis
of variance revealed the contents of Pb, Zn, Cd, organic matter and clay for the plots under
vegetation, particularly in the middle of the tamarisk, significantly greater than in the bare
plots.
It comes out from this study that the efficiency of tamarisk grove in the retention of
metallic trace elements is the results of an important accumulation of Pb and Zn following the
retention of great quantities of clay and organic matter."
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/KRI6560.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9675 "Etude de la distribution des métaux lourds dans les ripisylves de l’oued Rhumel." [texte imprimé] / Abderrezak Krika, Auteur ; Oualida Rached-Mosbah, Directeur de thèse . - constantine [Algérie] : Université Constantine 1, 2014 . - 160 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : sol, contamination, tamaris, oued Kébir-Rhumel, Pb, Cd, Zn
soil, contamination, tamarisk, Kebir-Rhumel wadi, Pb, Cd, Zn.
التربة ، التلوث ،الطرفاء ، واد كبیر - رمال ، الرصاص،الكادمیوم ، الزنكIndex. décimale : 570 Sciences de la vie. Biologie Résumé : "Wadi Kebir-Rhumel, surrounded by a more or less degraded riparian forest and
interspersed with wide pieces of completely denuded land, is bordered throughout by a main
road probably to be contaminated by heavy metals, particularly lead (Pb), zinc (Zn) and
cadmium (Cd). The present study has for objectives to determine the role of tamarisk grove in
the soil contamination by heavy metals.
For this purpose, ten sites were selected along the Wadi Kebir-Rhumel so as to have
a side by side plot with vegetation and bare plot. In each plot, soil samples were collected in
a central band and, on either side of it, on the side of the road and the edge of the wadi.
Tamarisk leaves have been a sampling means. The concentrations of Pb, Cd and Zn were
determined by ICP-OES in the washed, unwashed leaves and soils. These, have also been the
determination of the organic matter, pH, electrical conductivity, the total limestone (CaCO3),
cation exchange capacity and the particle size.
The results show significant differences between the washed and unwashed leaves of
tamarisk from the viewpoint of the contents of Pb, Zn and Cd, suggesting an atmospheric
origin of their contamination by heavy metals. The determination of the correlation
coefficients shows, for soils with vegetated plots, that the retention of Pb was by the organic
matter and clay, that of Zn by clay and Cd by pH and manganese. In bare plots, retention Pb
and Cd is governed by pH, CEC and silt, whereas Zn is by iron and manganese. The analysis
of variance revealed the contents of Pb, Zn, Cd, organic matter and clay for the plots under
vegetation, particularly in the middle of the tamarisk, significantly greater than in the bare
plots.
It comes out from this study that the efficiency of tamarisk grove in the retention of
metallic trace elements is the results of an important accumulation of Pb and Zn following the
retention of great quantities of clay and organic matter."
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/KRI6560.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9675 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité KRI/6560 KRI/6560 Thèse Bibliothèque principale Thèses Disponible 
Titre : Etude écologique de la végétation des bordures d’un oued en région semi aride : cas de l’oued Dahimine (Wilaya de Oum El Bouaghi) Type de document : texte imprimé Auteurs : Alima Mosbah ép Bentellis, Auteur ; Oualida Rached-Mosbah, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2014 Importance : 136 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Sol végétation métaux lourds antimoine arsenic accumulation lygeum spartum L. hedysarum pallidum Desf Soil vegetation Heavy metals antimony تربة نباتات المعادن الثقيلة الأنتيموان الأرسونيك تكثيف Index. décimale : 570 Sciences de la vie. Biologie Diplôme : Doctorat en sciences En ligne : ../theses/biologie/MOS6619.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9741 Etude écologique de la végétation des bordures d’un oued en région semi aride : cas de l’oued Dahimine (Wilaya de Oum El Bouaghi) [texte imprimé] / Alima Mosbah ép Bentellis, Auteur ; Oualida Rached-Mosbah, Directeur de thèse . - constantine [Algérie] : Université Constantine 1, 2014 . - 136 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Sol végétation métaux lourds antimoine arsenic accumulation lygeum spartum L. hedysarum pallidum Desf Soil vegetation Heavy metals antimony تربة نباتات المعادن الثقيلة الأنتيموان الأرسونيك تكثيف Index. décimale : 570 Sciences de la vie. Biologie Diplôme : Doctorat en sciences En ligne : ../theses/biologie/MOS6619.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9741 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MOS/6619 MOS/6619 Thèse Bibliothèque principale Thèses Disponible Documents numériques
texte intégreAdobe Acrobat PDF
Titre : Etude des enzymes de stress oxydatif chez Hedysarum pallidum Desf.et Lygeum spartum L. en réponse à la pollution du sol par l'antimoine. Type de document : texte imprimé Auteurs : Asma Benhamdi, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; Oualida Rached-Mosbah, Auteur Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2014 Importance : 123 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Enzymes, stress oxydatif, Hedysarum pallidum Desf, Lygeum spartum L,antimoine, arsenic, GST, expression des gènes.
Enzymes, oxydatif stress, Hedysarum pallidum Desf, Lygeum spartum L,antimony, arsenic, GST, genes expression.
أنزيمات،الإجهاد المعدني،انتيمون،الزرنيخ،تعبير المورثات، Hedysarum pallidum , Lygeum spartum LIndex. décimale : 570 Sciences de la vie. Biologie Résumé : "The aim of this study is to evaluate the oxidative stress' level and antioxidant defense systems
of plants growing in antimony (Sb) and arsenic (As) contaminated soil, and to analyze the
expression of GST genes. For this, two species Hedysarum pallidum Desf. and Lygeum
spartum L. were collected from different areas around an old mine of antimony located in
Jebel Hamimat (Algeria), according to a concentration gradient of Sb and As in soil, and act
as the subject of analysis related to the oxidative stress markers (malondialdehyde (MDA),
superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX)
and glutathione-S-transferase (GST)). Both species accumulate differently Sb and As in their
aerial and underground parts.
The results show that the oxidative stress level indicator, the MDA, in both plants, increases
significantly with increasing concentrations of Sb and As in the soil, although it is
significantly higher in H. pallidum. The activities of antioxidant enzymes vary from plant to
plant and also from one zone to another. The activities of SOD, APX and GST are the highest
in the most polluted zone in the two parts of H. pallidum. The inhibition of CAT activity in H.
pallidum roots, in all the contaminated zones, is concomitant with the induction of POD
activity in the same tissue. In L. spartum the APX of the upper parts, the CAT and the GST of
the upper parts and the roots are increased to the maximum at zone 5 (the most polluted zone).
However, the activities' decline of SOD and POD in the tissues due to the high concentrations
of Sb and As on the soil , was also observed.. These results suggest that MDA can be used as
a potential soil pollution biomarker by Sb and As for both plants.
Seeds In-vitro culture of two populations of H. pallidum has allowed the cloning and
sequencing of three fragments of actin gene and two of GST tau. The percent identity between
the two genes of GST (tau1 et tau2) is 53% at the nucleotide level and 46% at the protein
level. The analysis of the expression of the two genes by semi-quantitative PCR, in response
to increasing concentrations of Sb in the breeding ground, shows that the expression of GST
tau1 is at its maximum with low concentrations of Sb for the two populations. GST tau2
concentration is more expressed in the population of spoil mine and its expression becomes
more important when the concentration of Sb increases. This allows to deduce that every GST
tau is specific to a substrate and also that GST tau2 has a specific H domain linked to
antimony. This metalloid participates in activation of gene expression that intensifies with
increasing concentration.
The results of the GST and the analysis of the expression of both genes of GST tau in H.
pallidum show that all GST are expressed at low quantities in the absence of the metal stress.
In the metal stress moment, only the GST tau having a specific domain for binding to the
metal are overexpressed."
Diplôme : Doctorat En ligne : ../theses/biologie/BEN6573.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9691 Etude des enzymes de stress oxydatif chez Hedysarum pallidum Desf.et Lygeum spartum L. en réponse à la pollution du sol par l'antimoine. [texte imprimé] / Asma Benhamdi, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; Oualida Rached-Mosbah, Auteur . - constantine [Algérie] : Université Constantine 1, 2014 . - 123 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Enzymes, stress oxydatif, Hedysarum pallidum Desf, Lygeum spartum L,antimoine, arsenic, GST, expression des gènes.
Enzymes, oxydatif stress, Hedysarum pallidum Desf, Lygeum spartum L,antimony, arsenic, GST, genes expression.
أنزيمات،الإجهاد المعدني،انتيمون،الزرنيخ،تعبير المورثات، Hedysarum pallidum , Lygeum spartum LIndex. décimale : 570 Sciences de la vie. Biologie Résumé : "The aim of this study is to evaluate the oxidative stress' level and antioxidant defense systems
of plants growing in antimony (Sb) and arsenic (As) contaminated soil, and to analyze the
expression of GST genes. For this, two species Hedysarum pallidum Desf. and Lygeum
spartum L. were collected from different areas around an old mine of antimony located in
Jebel Hamimat (Algeria), according to a concentration gradient of Sb and As in soil, and act
as the subject of analysis related to the oxidative stress markers (malondialdehyde (MDA),
superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX)
and glutathione-S-transferase (GST)). Both species accumulate differently Sb and As in their
aerial and underground parts.
The results show that the oxidative stress level indicator, the MDA, in both plants, increases
significantly with increasing concentrations of Sb and As in the soil, although it is
significantly higher in H. pallidum. The activities of antioxidant enzymes vary from plant to
plant and also from one zone to another. The activities of SOD, APX and GST are the highest
in the most polluted zone in the two parts of H. pallidum. The inhibition of CAT activity in H.
pallidum roots, in all the contaminated zones, is concomitant with the induction of POD
activity in the same tissue. In L. spartum the APX of the upper parts, the CAT and the GST of
the upper parts and the roots are increased to the maximum at zone 5 (the most polluted zone).
However, the activities' decline of SOD and POD in the tissues due to the high concentrations
of Sb and As on the soil , was also observed.. These results suggest that MDA can be used as
a potential soil pollution biomarker by Sb and As for both plants.
Seeds In-vitro culture of two populations of H. pallidum has allowed the cloning and
sequencing of three fragments of actin gene and two of GST tau. The percent identity between
the two genes of GST (tau1 et tau2) is 53% at the nucleotide level and 46% at the protein
level. The analysis of the expression of the two genes by semi-quantitative PCR, in response
to increasing concentrations of Sb in the breeding ground, shows that the expression of GST
tau1 is at its maximum with low concentrations of Sb for the two populations. GST tau2
concentration is more expressed in the population of spoil mine and its expression becomes
more important when the concentration of Sb increases. This allows to deduce that every GST
tau is specific to a substrate and also that GST tau2 has a specific H domain linked to
antimony. This metalloid participates in activation of gene expression that intensifies with
increasing concentration.
The results of the GST and the analysis of the expression of both genes of GST tau in H.
pallidum show that all GST are expressed at low quantities in the absence of the metal stress.
In the metal stress moment, only the GST tau having a specific domain for binding to the
metal are overexpressed."
Diplôme : Doctorat En ligne : ../theses/biologie/BEN6573.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9691 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/6573 BEN/6573 Thèse Bibliothèque principale Thèses Disponible
Titre : Étude des mécanismes de résistance de bactéries endophytes isolées à partir des racines d’Hedysarum pallidum et de Lygeum spartum poussant sur des déblais de mine d’antimoine. Type de document : texte imprimé Auteurs : Mounia Kassa Laouar ép Chouikh, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; Oualida Rached-Mosbah, Directeur de thèse Mention d'édition : 09/07/2020 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2020 Importance : 183 f. Format : 30 cm. Note générale : 1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Biochimie et Biologie Cellulaire et Moléculaire: Biochimie-Microbiologie appliquée bactéries endophytes métalloïdes stress oxydatif H2O2 MDA proline enzymes
antioxydantes biofilm transformation résistance bacterial endophytes metalloids oxidative stress antioxidant enzymes resistance البكتيريا الداخلية المعادن الثقيلة الإجهاد التأكسدي H2O2البرولين إنزيمات مضادات الأكسدة المقاومة التحولIndex. décimale : 570 Sciences de la vie. Biologie Résumé :
This work focuses on the study of the endophytic bacterial flora of H. pallidum and L. spartum roots, growing on the soil of mining region polluted by Sb and As, and the determination of the physiological, biochemical and molecular defense mechanisms adopted by this microflora to fight against metallic stress. The morphological and biochemical analyzes reveal a high biodiversity of this endophytic microflora. The study of the Sb and As toxicity allows the selection of two strains having the highest MICs, namely 450 mM of Sb and 175 mM of As. The molecular identification of resistant strains via 16S RNA gene sequencing shows that they are identical and belong to the Serratia marcescens species with 99% homology. The batch culture in presence of gradual Sb and As concentrations reveals a progressive decrease in bacterial growth of the two strains. Moreover, the measurement of oxidative stress parameters indicates a significant increase in the H2O2 amount, the MDA amount, the intracellular proline and even the activities of antioxidant enzymes, except at high thresholds in Sb and As. These enzymes permit the detoxification of the bacteria by elimination of the H2O2 and the other free radicals generated by metallic stress. In addition, the study of the resistance of S. marcescens strains to a range of heavy metals and antibiotics shows multiple resistance to nickel and cobalt, as well as to kanamycin, ampicillin and chloramphenicol. To cope with the presence of Sb and As, S. marcescens has adopted life in group mode and form biofilms to reduce their toxicity. The molecular study of the resistance mechanisms of the two strains, using cell transformation methods, reveals that the genetic determinants responsibles for the resistance of S. marcescens to metalloids are carried mainly by the chromosome.Note de contenu : Annexes. Diplôme : Doctorat en sciences En ligne : ../theses/biologie/KAS7638.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11472 Étude des mécanismes de résistance de bactéries endophytes isolées à partir des racines d’Hedysarum pallidum et de Lygeum spartum poussant sur des déblais de mine d’antimoine. [texte imprimé] / Mounia Kassa Laouar ép Chouikh, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; Oualida Rached-Mosbah, Directeur de thèse . - 09/07/2020 . - جامعة الإخوة منتوري قسنطينة, 2020 . - 183 f. ; 30 cm.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Biochimie et Biologie Cellulaire et Moléculaire: Biochimie-Microbiologie appliquée bactéries endophytes métalloïdes stress oxydatif H2O2 MDA proline enzymes
antioxydantes biofilm transformation résistance bacterial endophytes metalloids oxidative stress antioxidant enzymes resistance البكتيريا الداخلية المعادن الثقيلة الإجهاد التأكسدي H2O2البرولين إنزيمات مضادات الأكسدة المقاومة التحولIndex. décimale : 570 Sciences de la vie. Biologie Résumé :
This work focuses on the study of the endophytic bacterial flora of H. pallidum and L. spartum roots, growing on the soil of mining region polluted by Sb and As, and the determination of the physiological, biochemical and molecular defense mechanisms adopted by this microflora to fight against metallic stress. The morphological and biochemical analyzes reveal a high biodiversity of this endophytic microflora. The study of the Sb and As toxicity allows the selection of two strains having the highest MICs, namely 450 mM of Sb and 175 mM of As. The molecular identification of resistant strains via 16S RNA gene sequencing shows that they are identical and belong to the Serratia marcescens species with 99% homology. The batch culture in presence of gradual Sb and As concentrations reveals a progressive decrease in bacterial growth of the two strains. Moreover, the measurement of oxidative stress parameters indicates a significant increase in the H2O2 amount, the MDA amount, the intracellular proline and even the activities of antioxidant enzymes, except at high thresholds in Sb and As. These enzymes permit the detoxification of the bacteria by elimination of the H2O2 and the other free radicals generated by metallic stress. In addition, the study of the resistance of S. marcescens strains to a range of heavy metals and antibiotics shows multiple resistance to nickel and cobalt, as well as to kanamycin, ampicillin and chloramphenicol. To cope with the presence of Sb and As, S. marcescens has adopted life in group mode and form biofilms to reduce their toxicity. The molecular study of the resistance mechanisms of the two strains, using cell transformation methods, reveals that the genetic determinants responsibles for the resistance of S. marcescens to metalloids are carried mainly by the chromosome.Note de contenu : Annexes. Diplôme : Doctorat en sciences En ligne : ../theses/biologie/KAS7638.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11472 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité KAS/7638 KAS/7638 Thèse Bibliothèque principale Thèses Disponible
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