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Auteur Aicha Mechakra (Née Maza) |
Documents disponibles écrits par cet auteur (9)
Affiner la recherche Interroger des sources externesAspects génétiques en relation avec le métabolisme du maltose chez les bactéries à Gram+ / Abdelhamid Mokhtari
Titre : Aspects génétiques en relation avec le métabolisme du maltose chez les bactéries à Gram+ : Bacillus subtilis et Enterococcus faecalis Type de document : texte imprimé Auteurs : Abdelhamid Mokhtari, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; J Deutscher, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2014 Importance : 102 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Enterococcus faecalis système phosphotransferase Maltose-6'-phosphate phosphatase Maltose phosphorylase phosphotransferase systeme Index. décimale : 570 Sciences de la vie. Biologie Résumé :
Similar to Bacillus subtilis, Enterococcus faecalis transports and phosphorylates maltose via a phosphoenolpyruvate (PEP) : maltose phosphotransferasesystem (PTS). The maltose-specific PTS permease is encoded by the malT gene. However, E. faecalis lacks a malA gene encoding a 6-phospho-α-glucosidase, which in B. subtilis hydrolyses maltose 6-P into glucose and glucose 6-P. Instead, an operon encoding a maltose phosphorylase (MalP), a phosphoglucomutaseand a mutarotase starts upstream from malT. MalP was suggested to split maltose 6-P into glucose1-P and glucose 6-P. However, purified MalP phosphorolyses maltose but not maltose 6-P. We discovered that the gene downstream from malT encodes a novel enzyme (MapP) that dephosphorylates maltose 6-P formed by the PTS. The resulting intracellular maltose is cleaved by MalP into glucose and glucose 1-P. Slow uptake of maltose probably via a maltodextrin ABC transporter allows poor growth for the mapP but not the malP mutant. Synthesis of MapP in a B. subtilis mutant accumulating maltose 6-P restored growth on maltose. MapP catalyses the dephosphorylation of intracellular maltose 6-P, and the resulting maltose is converted by the B. subtilis maltose phosphorylase into glucose and glucose 1-P. MapP therefore connects PTS-mediated maltose uptake to maltose phosphorylase-catalysed metabolism. Dephosphorylation assays with a wide variety of phosphosubstrates revealed that MapP preferably dephosphorylates disaccharides containing an O-aglycosyl linkage.
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/MOK6924.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10276 Aspects génétiques en relation avec le métabolisme du maltose chez les bactéries à Gram+ : Bacillus subtilis et Enterococcus faecalis [texte imprimé] / Abdelhamid Mokhtari, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; J Deutscher, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2014 . - 102 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Enterococcus faecalis système phosphotransferase Maltose-6'-phosphate phosphatase Maltose phosphorylase phosphotransferase systeme Index. décimale : 570 Sciences de la vie. Biologie Résumé :
Similar to Bacillus subtilis, Enterococcus faecalis transports and phosphorylates maltose via a phosphoenolpyruvate (PEP) : maltose phosphotransferasesystem (PTS). The maltose-specific PTS permease is encoded by the malT gene. However, E. faecalis lacks a malA gene encoding a 6-phospho-α-glucosidase, which in B. subtilis hydrolyses maltose 6-P into glucose and glucose 6-P. Instead, an operon encoding a maltose phosphorylase (MalP), a phosphoglucomutaseand a mutarotase starts upstream from malT. MalP was suggested to split maltose 6-P into glucose1-P and glucose 6-P. However, purified MalP phosphorolyses maltose but not maltose 6-P. We discovered that the gene downstream from malT encodes a novel enzyme (MapP) that dephosphorylates maltose 6-P formed by the PTS. The resulting intracellular maltose is cleaved by MalP into glucose and glucose 1-P. Slow uptake of maltose probably via a maltodextrin ABC transporter allows poor growth for the mapP but not the malP mutant. Synthesis of MapP in a B. subtilis mutant accumulating maltose 6-P restored growth on maltose. MapP catalyses the dephosphorylation of intracellular maltose 6-P, and the resulting maltose is converted by the B. subtilis maltose phosphorylase into glucose and glucose 1-P. MapP therefore connects PTS-mediated maltose uptake to maltose phosphorylase-catalysed metabolism. Dephosphorylation assays with a wide variety of phosphosubstrates revealed that MapP preferably dephosphorylates disaccharides containing an O-aglycosyl linkage.
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/MOK6924.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10276 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MOK/6924 MOK/6924 Thèse Bibliothèque principale Thèses Disponible
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
Titre : Etude de la production de la protéase par aspergillus oryzae sur milieu solide en fermenteur FUJIWARA : Utilisation des déchets de tomate comme substrat de fermentation Type de document : texte imprimé Auteurs : Hayet Lazzar (Née Boukhalfa), Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; Francis Duchiron, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 109 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : fermentation en milieu solides (FMS) résidus agro-industriels déchets de tomate protéases Aspergillus oryzae optimisation Agro-industrial residues tomato pomace solid-state fermentation (SSF) proteases optimization النفایات الزراعیة مخلفات الطماطم التخمر الصلب (SSF) أنزیم البروتیاز oryzae Aspergillus تحسین التخمر Index. décimale : 570 Sciences de la vie. Biologie Résumé : Agro-industrial residues are rich in organic matter. This makes such wastes very appropriate for transformation by biotechnological processes. Among these, the solid-state fermentation (SSF) have renewed interest worldwide because they provide significant production of various substances compared to submerged cultures. Thus, the objective of this thesis is the use of tomato waste in SSF for production of fungal protease. This substrate is composed of more than 52 % of insoluble fiber, more than 20 % of proteins, 6.52 % ash, and other organic
materials. This composition is used in this type of fermentation as support and nutrients for the microorganism and covers the requirements for inducing production of proteases. Among five strains of Aspergillus grown on tomato pomace SSF in Erlenmeyer flasks, two strains were selected for the development of culture conditions, A. oryzae 5777 and A. oryzae 2220. The study of various parameters on neutral protease production gave a significant effect of moisture, initial pH, age of inoculum and protein content. Two factors (spores rate and
particle size) were found no significant effect on enzyme synthesis. The fermentations performed on a pilot scale by A. oryzae strain 2220, at 50 % initial moisture of substrate and the enrichment of soy flour in an amount of 15 mg / g of substrate, more than 12 U / gds is achieved after 42 hours. Culture with tomato pomace without adding additional protein source allows higher production with 12 % more activity, of 13.55 U / gds. Among the solutions
studied for protease extraction, the 3% NaCl (w / v) gives the maximum activity. The results also showed that the wet fermented substrate provides more neutral protease relative to the dry substrate. The effect of the contact time of the fermented substrate with water gave a maximum activity after stirring for 4 hours with the wet substrate and after 7 hours for the dry one. On the other hand, the pH between 7.6 and 8 and a temperature of 45 ° C allow to obtain maximum catalyst activity. The enzyme retains this activity until a temperature of 55 ° C. The
produced protease has a residual activity of 25 % at 65 ° C after 45 minutes and 34 % at 60 ° C after 60 minutes; it is inhibited at 70% by EDTA and activated by divalent cations of zinc and copper. This indicates that it is a metallo-protease. The enzyme was purified 4-fold by SA precipitation in the 40-80% fraction. The efficiency of this separation is 30%. These results show the potential of tomato pomace as a culture substrate for protease production by SSF.
This would make it very economical synthesis and could meet the demand of growing market for this group of hydrolases with very diverse technological interests
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/BOU6695.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9929 Etude de la production de la protéase par aspergillus oryzae sur milieu solide en fermenteur FUJIWARA : Utilisation des déchets de tomate comme substrat de fermentation [texte imprimé] / Hayet Lazzar (Née Boukhalfa), Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; Francis Duchiron, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2015 . - 109 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : fermentation en milieu solides (FMS) résidus agro-industriels déchets de tomate protéases Aspergillus oryzae optimisation Agro-industrial residues tomato pomace solid-state fermentation (SSF) proteases optimization النفایات الزراعیة مخلفات الطماطم التخمر الصلب (SSF) أنزیم البروتیاز oryzae Aspergillus تحسین التخمر Index. décimale : 570 Sciences de la vie. Biologie Résumé : Agro-industrial residues are rich in organic matter. This makes such wastes very appropriate for transformation by biotechnological processes. Among these, the solid-state fermentation (SSF) have renewed interest worldwide because they provide significant production of various substances compared to submerged cultures. Thus, the objective of this thesis is the use of tomato waste in SSF for production of fungal protease. This substrate is composed of more than 52 % of insoluble fiber, more than 20 % of proteins, 6.52 % ash, and other organic
materials. This composition is used in this type of fermentation as support and nutrients for the microorganism and covers the requirements for inducing production of proteases. Among five strains of Aspergillus grown on tomato pomace SSF in Erlenmeyer flasks, two strains were selected for the development of culture conditions, A. oryzae 5777 and A. oryzae 2220. The study of various parameters on neutral protease production gave a significant effect of moisture, initial pH, age of inoculum and protein content. Two factors (spores rate and
particle size) were found no significant effect on enzyme synthesis. The fermentations performed on a pilot scale by A. oryzae strain 2220, at 50 % initial moisture of substrate and the enrichment of soy flour in an amount of 15 mg / g of substrate, more than 12 U / gds is achieved after 42 hours. Culture with tomato pomace without adding additional protein source allows higher production with 12 % more activity, of 13.55 U / gds. Among the solutions
studied for protease extraction, the 3% NaCl (w / v) gives the maximum activity. The results also showed that the wet fermented substrate provides more neutral protease relative to the dry substrate. The effect of the contact time of the fermented substrate with water gave a maximum activity after stirring for 4 hours with the wet substrate and after 7 hours for the dry one. On the other hand, the pH between 7.6 and 8 and a temperature of 45 ° C allow to obtain maximum catalyst activity. The enzyme retains this activity until a temperature of 55 ° C. The
produced protease has a residual activity of 25 % at 65 ° C after 45 minutes and 34 % at 60 ° C after 60 minutes; it is inhibited at 70% by EDTA and activated by divalent cations of zinc and copper. This indicates that it is a metallo-protease. The enzyme was purified 4-fold by SA precipitation in the 40-80% fraction. The efficiency of this separation is 30%. These results show the potential of tomato pomace as a culture substrate for protease production by SSF.
This would make it very economical synthesis and could meet the demand of growing market for this group of hydrolases with very diverse technological interests
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/BOU6695.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9929 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/6695 BOU/6695 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude des propriétés antidiabétiques, antioxydantes et antiinflammatoires des extraits hydrosolubles d’Anvillea radiataCoss. & Dur. sur le diabète de type 2 expérimental induit par le régime (high fat) chez la souris C57/BL6J. Type de document : texte imprimé Auteurs : Chouaib Kandouli, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; Sylvia Piertri, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 147 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Anvillea radiata plantes médicinales phénoliques totaux cellules bêtapancréatiques souris C57 / BL6J diabète de type 2 Medicinal plants Total phenolics Pancreatic betacells C57/BL6J mice Type 2 diabetes النباتات الطبية محتوى الفينولات السكري نوع 2 الخلايا β البنكرياسية فئران C57B /6J Index. décimale : 570 Sciences de la vie. Biologie Résumé : Ethnopharmacological relevance: According to Saharian traditional medicine, Anvillea radiata Coss. & Dur. (Asteraceae) has been valued for treating a variety of ailments such as gastro-intestinal, liver and pulmonary diseases, and has gained awareness for its beneficial effect on postprandial hyperglycemia. However, to best of our knowledge, no detailed study of the antidiabetic curative effects of this plant has been conducted yet.
Aim of the study: To determine the hypoglycemic and antidiabetic effect of dietary supplementation with Anvillea radiata extracts on high-fat-diet (HFD)-induced obesity and insulin resistance in C57BL/6 J mice in relation with antioxidant, anti-inflammatory, pancreatic beta-cells and skeletal muscle protection, and digestive enzyme inhibiting properties.
Materials and methods: Six extracts (water soluble and organic) from aerial parts of the plant were analyzed phytochemically (total phenolic and flavonoid content) and screened for in vitro superoxide (by chemiluminescence) and hydroxyl radical (by electron paramagnetic resonance spin-trapping) scavenging, antioxidant (DPPH, TRAP and ORAC assays), xanthine oxidase, metal chelating, α-amylase and α-glucosidase inhibitory property, and protective effects on copper-induced lipoprotein oxidation. Then selected
hydroalcoholic and aqueous extracts were assessed for toxicity in normal human lung fibroblasts and A549 cancer cells using FMCA and MTT assays. Two water-soluble extracts having the best overall properties were assessed for their (i) protective effect at 1−15 µg/mL on metabolic activity of rat insulinoma-derived INS-1 cells exposed to
hyperglycemic medium, and (ii) acute hypoglycemic effect on 16-weeks HFD-induced diabetic mice. Then diabetic mice were administered HFD supplemented by extracts (up to 150 mg/kg/day) for 12 additional weeks using standard diet as control and the antidiabetic drug, metformin (150 mg/kg), as positive control. Then the antidiabetic, anti-inflammatory and antioxidant activity of extracts were determined.
Results: Of the highly efficient polyphenolics-enriched hydroalcoholic and ethyl acetate extracts, the lyophilized aqueous (AQL) and butanol extracts were not toxic in cells (≤ 400 µg/mL) or when given orally in normal mice (≤ 2000 mg/kg), exerted a dosedependent hypoglycemic action in diabetic mice, which was maximal at the dose of 150 mg/kg. Upon administering this dose for 12 weeks, both extracts significantly ameliorated
Résumés body weight control capacity, recovery of plasma glucose and insulin level, reduced oxidative stress in blood, myocardial and skeletal muscles, and improved hyperlipidemic and inflammatory status. Moreover, diabetes-related complications were optimally ameliorated by oral therapy based on halved doses (75 mg/kg) of a mixture of AQL andmetformin.
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/KAN7266.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10863 Etude des propriétés antidiabétiques, antioxydantes et antiinflammatoires des extraits hydrosolubles d’Anvillea radiataCoss. & Dur. sur le diabète de type 2 expérimental induit par le régime (high fat) chez la souris C57/BL6J. [texte imprimé] / Chouaib Kandouli, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; Sylvia Piertri, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 147 f. ; 30 cm.
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Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Anvillea radiata plantes médicinales phénoliques totaux cellules bêtapancréatiques souris C57 / BL6J diabète de type 2 Medicinal plants Total phenolics Pancreatic betacells C57/BL6J mice Type 2 diabetes النباتات الطبية محتوى الفينولات السكري نوع 2 الخلايا β البنكرياسية فئران C57B /6J Index. décimale : 570 Sciences de la vie. Biologie Résumé : Ethnopharmacological relevance: According to Saharian traditional medicine, Anvillea radiata Coss. & Dur. (Asteraceae) has been valued for treating a variety of ailments such as gastro-intestinal, liver and pulmonary diseases, and has gained awareness for its beneficial effect on postprandial hyperglycemia. However, to best of our knowledge, no detailed study of the antidiabetic curative effects of this plant has been conducted yet.
Aim of the study: To determine the hypoglycemic and antidiabetic effect of dietary supplementation with Anvillea radiata extracts on high-fat-diet (HFD)-induced obesity and insulin resistance in C57BL/6 J mice in relation with antioxidant, anti-inflammatory, pancreatic beta-cells and skeletal muscle protection, and digestive enzyme inhibiting properties.
Materials and methods: Six extracts (water soluble and organic) from aerial parts of the plant were analyzed phytochemically (total phenolic and flavonoid content) and screened for in vitro superoxide (by chemiluminescence) and hydroxyl radical (by electron paramagnetic resonance spin-trapping) scavenging, antioxidant (DPPH, TRAP and ORAC assays), xanthine oxidase, metal chelating, α-amylase and α-glucosidase inhibitory property, and protective effects on copper-induced lipoprotein oxidation. Then selected
hydroalcoholic and aqueous extracts were assessed for toxicity in normal human lung fibroblasts and A549 cancer cells using FMCA and MTT assays. Two water-soluble extracts having the best overall properties were assessed for their (i) protective effect at 1−15 µg/mL on metabolic activity of rat insulinoma-derived INS-1 cells exposed to
hyperglycemic medium, and (ii) acute hypoglycemic effect on 16-weeks HFD-induced diabetic mice. Then diabetic mice were administered HFD supplemented by extracts (up to 150 mg/kg/day) for 12 additional weeks using standard diet as control and the antidiabetic drug, metformin (150 mg/kg), as positive control. Then the antidiabetic, anti-inflammatory and antioxidant activity of extracts were determined.
Results: Of the highly efficient polyphenolics-enriched hydroalcoholic and ethyl acetate extracts, the lyophilized aqueous (AQL) and butanol extracts were not toxic in cells (≤ 400 µg/mL) or when given orally in normal mice (≤ 2000 mg/kg), exerted a dosedependent hypoglycemic action in diabetic mice, which was maximal at the dose of 150 mg/kg. Upon administering this dose for 12 weeks, both extracts significantly ameliorated
Résumés body weight control capacity, recovery of plasma glucose and insulin level, reduced oxidative stress in blood, myocardial and skeletal muscles, and improved hyperlipidemic and inflammatory status. Moreover, diabetes-related complications were optimally ameliorated by oral therapy based on halved doses (75 mg/kg) of a mixture of AQL andmetformin.
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