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Auteur Zahia Meraihi |
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Titre : Activité biochimique des extraits flavonoiques de la plante Ranunculus repens L. : effet sur le diabLte expérimental et l'hépatotoxicité induite par l'Epirubicine. Type de document : texte imprimé Auteurs : Mohamed Kebieche, Auteur ; Zahia Meraihi, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2009 Importance : 129 f. Format : 30 cm. Note générale : 01 Disponible à la salle de recherche 02 Disponibles au magazin de la B.U.C. 01 CD Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Biochimie - Microbiologie: Biochimie diabète flavonoïdes Stress oxydant Alloxane Ranunculus repens L. Effet antidiabétique Epirubicine Hépatotoxicité Quercétine Chémoprotecteur stress oxydant flavonoids extract Ranunculus repens L alloxane antidiabetic effect épirubicin Hepatotoxicity Oxidative stress Quercetin Hepatoprotective effect. Index. décimale : 570 Sciences de la vie. Biologie Résumé : In the present study, the antihyperglycemic, anti-diabetic and antioxidant effects of the n-Butanol extract (BE) obtained from air part of Ranunculus repens L plant and quercetin were investigated in normal glucose-fed hyperglycemia, in alloxan induced diabetes and in epirubicin (EPI) toxicity of the rats. The results of this study show antihyperglycemic and antidiabetic activity of the phenolic compounds. And to elucidate a possible mechanism of action of this plant extract, the glycogen liver rate, insulin secretion and the in vitro chelating effect of glucose by plant compounds were also investigated. The flavonoids reduced significantly blood glucose in a dose-dependant manner (200,400,600 mg/kg) in both hyperglycemic and diabetic rats after oral administration as oral hypoglycemic drug, glibenclamide (2.5 mg/kg). We show that flavonoids extracts was able significantly to complex the glucose in vitro, induce insulin secretion of beta cells and to active glycogenesis in liver as shown by the abundance of glycogen granulation in liver histochemical preparation after administration of flavonoids extract. In addition these flavonoids extract and quercetin possess a chemoprotector power against malondialdehyde formation (MDA, lipid peroxidation product) and reduction of antioxidant systems such SOD, CAT and GSH in alloxan-induced diabetic rats. The equilibrium disorder of redox status after alloxan administration is reestablished by flavonoids pretreatment of alloxanised rats. The flavonoids markedly inhibited lipid peroxidation process in pancreatic cells and the proportioning of cytosolic SOD, CAT and GSH showed a significant elevation to establish equilibrium of redox status and consequently protect beta cells and prevent diabetes. The anticancer therapy with EPI produces acute hepatotoxicityby generation of free radicals. However, the oxidative status of the liver cells and mitochondria has been investigated in EPI toxicity of the rats. In this present study, we investigated in first the prooxidant effect of EPI and its implication on both hepatic cells and mitochondria function. EPI injection in rats at dose of 9 mg/kg induced hepatic dysfunction revealed by a significant increase in serum of glutamate oxaloacetate transaminases and glutamate pyruvate transaminases. Oxidative stress in liver cells and mitochondria was provoked by EPI since a statistically significant reduction of CAT, SOD and GSH levels, and significant increase of MDA level, indicator of lipid peroxidation which could perforate the biologic
membranes, were observed. In second, the protective effect of quercetin (33 mg/kg) and flavonoids extract of RRL (100 mg/kg) against oxidative stress induced by EPI was also investigated. Indeed, the pretreatment of rats with flavonoids protected liver cells and mitochondria from oxidative stress permitting, on one hand, the prevention of hepatic dysfunction on maintaining the normal level of serum transaminases following inhibition of their hepatic leakage by preventing lipid peroxidation Thus, the prevention of the cellular membranes perforation, and in the other hand maintaining also antioxidant defense system in mitochondria and cytosol of hepatocytes. Taken together, this data reveal that flavonoids extract of Ranunculus repens L extract and quercetin possess an interesting virtue to be antihyperglycemic and antidiabetic with positive action on liver glycogenesis and insulin secretion. These phenolic compounds have also antiradical and antioxidant power that confers them chemoprotection role against oxidative stress generated in pancreas cells and liver respectively by alloxan and epirubicin.
Note de contenu :
Annexes.Diplôme : Doctorat En ligne : ../theses/biologie/KEB5525.pdf Permalink : index.php?lvl=notice_display&id=1794 Activité biochimique des extraits flavonoiques de la plante Ranunculus repens L. : effet sur le diabLte expérimental et l'hépatotoxicité induite par l'Epirubicine. [texte imprimé] / Mohamed Kebieche, Auteur ; Zahia Meraihi, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2009 . - 129 f. ; 30 cm.
01 Disponible à la salle de recherche 02 Disponibles au magazin de la B.U.C. 01 CD
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Biochimie - Microbiologie: Biochimie diabète flavonoïdes Stress oxydant Alloxane Ranunculus repens L. Effet antidiabétique Epirubicine Hépatotoxicité Quercétine Chémoprotecteur stress oxydant flavonoids extract Ranunculus repens L alloxane antidiabetic effect épirubicin Hepatotoxicity Oxidative stress Quercetin Hepatoprotective effect. Index. décimale : 570 Sciences de la vie. Biologie Résumé : In the present study, the antihyperglycemic, anti-diabetic and antioxidant effects of the n-Butanol extract (BE) obtained from air part of Ranunculus repens L plant and quercetin were investigated in normal glucose-fed hyperglycemia, in alloxan induced diabetes and in epirubicin (EPI) toxicity of the rats. The results of this study show antihyperglycemic and antidiabetic activity of the phenolic compounds. And to elucidate a possible mechanism of action of this plant extract, the glycogen liver rate, insulin secretion and the in vitro chelating effect of glucose by plant compounds were also investigated. The flavonoids reduced significantly blood glucose in a dose-dependant manner (200,400,600 mg/kg) in both hyperglycemic and diabetic rats after oral administration as oral hypoglycemic drug, glibenclamide (2.5 mg/kg). We show that flavonoids extracts was able significantly to complex the glucose in vitro, induce insulin secretion of beta cells and to active glycogenesis in liver as shown by the abundance of glycogen granulation in liver histochemical preparation after administration of flavonoids extract. In addition these flavonoids extract and quercetin possess a chemoprotector power against malondialdehyde formation (MDA, lipid peroxidation product) and reduction of antioxidant systems such SOD, CAT and GSH in alloxan-induced diabetic rats. The equilibrium disorder of redox status after alloxan administration is reestablished by flavonoids pretreatment of alloxanised rats. The flavonoids markedly inhibited lipid peroxidation process in pancreatic cells and the proportioning of cytosolic SOD, CAT and GSH showed a significant elevation to establish equilibrium of redox status and consequently protect beta cells and prevent diabetes. The anticancer therapy with EPI produces acute hepatotoxicityby generation of free radicals. However, the oxidative status of the liver cells and mitochondria has been investigated in EPI toxicity of the rats. In this present study, we investigated in first the prooxidant effect of EPI and its implication on both hepatic cells and mitochondria function. EPI injection in rats at dose of 9 mg/kg induced hepatic dysfunction revealed by a significant increase in serum of glutamate oxaloacetate transaminases and glutamate pyruvate transaminases. Oxidative stress in liver cells and mitochondria was provoked by EPI since a statistically significant reduction of CAT, SOD and GSH levels, and significant increase of MDA level, indicator of lipid peroxidation which could perforate the biologic
membranes, were observed. In second, the protective effect of quercetin (33 mg/kg) and flavonoids extract of RRL (100 mg/kg) against oxidative stress induced by EPI was also investigated. Indeed, the pretreatment of rats with flavonoids protected liver cells and mitochondria from oxidative stress permitting, on one hand, the prevention of hepatic dysfunction on maintaining the normal level of serum transaminases following inhibition of their hepatic leakage by preventing lipid peroxidation Thus, the prevention of the cellular membranes perforation, and in the other hand maintaining also antioxidant defense system in mitochondria and cytosol of hepatocytes. Taken together, this data reveal that flavonoids extract of Ranunculus repens L extract and quercetin possess an interesting virtue to be antihyperglycemic and antidiabetic with positive action on liver glycogenesis and insulin secretion. These phenolic compounds have also antiradical and antioxidant power that confers them chemoprotection role against oxidative stress generated in pancreas cells and liver respectively by alloxan and epirubicin.
Note de contenu :
Annexes.Diplôme : Doctorat En ligne : ../theses/biologie/KEB5525.pdf Permalink : index.php?lvl=notice_display&id=1794 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité KEB/5525 KEB/5525 Thèse Bibliothèque principale Thèses Disponible
Titre : Activité Killer chez des levures isolées des sols du Nord-Est Algérien : Purification, caractérisation et effet sur les souches de levures indésirables. Type de document : texte imprimé Auteurs : Fatima-Zohra-Kenza Labbani, Auteur ; Zahia Meraihi, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 103 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : levures isolement Pichia kluyveri toxine killer biocontrôle levures indésirables Yeast isolation killer toxin biocontrol undesirable yeasts خمائر عزل سم قاتل مكافحة حيوية خمائر غير مرغوب فيها Index. décimale : 570 Sciences de la vie. Biologie Résumé : The general purpose of this thesis is to search for killer activity in yeast strains isolated from agricultural and forest soil in the region of Constantine for biotechnological applications.The isolation of yeasts allows to list 15 strains. The molecular taxonomy based on the sequences of D1/D2 domain of the 26S ribosomal ARN gene groups these isolates into 6 different species: Cryptococcus aerius, Hanseniaspora opuntiae, Hanseniaspora uvarum, Pichia kluyveri, Meyerozyma guilliermondii and Saccharomyces cerevisiae. Morphological, physiological and biochemical characteristics of the strains are in agreement with those cited in
literature. Preliminary testing for killer activity reveals that only the strain L5 is able to produce killer activity. The killer strain is belonging to the species P. kluyveri. The crude killer protein produced by the strain P. kluyveri reveals that the toxin is active against food and beverage spoilage yeast strains belonging to the genera: Dekkera, Kluyveromyces, Pichia, Saccharomyces, Torulaspora, Wickerhamomyces and Zygosaccharomyces. The highest killer activity is obtained against the strain Dekkera bruxellensis DBVPG 6706. Both the heat shock (30 min at 100°C) and the enzymatic treatment with pronase demonstrate the complete loss of the initial killer activity of the toxin, and hence its proteinaceous nature is apparently confirmed. The active protein migrates as a single band in SDS-PAGE and has a molecular mass of 54 kDa. The purified killer toxin has an optimal pH between 4.0-4.5, while the optimal of temperature is 25°C.The determination of minimum inhibitory concentrations (MICs) shows that the purified killer protein has a high in vitro activity against D.bruxellensis (MICs from 64 000- to 256 000-fold lower than that exhibited by potassium metabisulphite) and Saccharomyces cerevisiae (MICs from 32 000- to 64 000-fold lower than potassium sorbate).
No in vitro synergistic interactions (calculated by FIC index -Σ FIC) are observed when killer protein is used in combination with the active compounds : potassium metabisulphite, potassium sorbate, or ethanol. The killer protein exhibited a dose–response effect against D.
bruxellensis and S. cerevisiae in a soft drink « Campari MIXX » (Milan, Italy) and pear juice « Santal » (Parma, Italy), respectively. The results of the present study suggest that the killer protein could be proposed as a novel food-grade compound useful for the control of food and beverage spoilage yeasts. Additionally, the purified killer protein maintains its killing action at
least for 3 days against S. cerevisiae DBVPG 6500 inoculated in pear juice and for 10 days against D. bruxellensis DBVPG 6706 in soft drink. The results of the present study suggest that the killer protein produced by the strain P. kluyveri (L5) could be proposed as a novel natural agent for the biocontrole of beverage spoilage yeasts.
Diplôme : Doctorat En ligne : ../theses/biologie/LAB6794.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10026 Activité Killer chez des levures isolées des sols du Nord-Est Algérien : Purification, caractérisation et effet sur les souches de levures indésirables. [texte imprimé] / Fatima-Zohra-Kenza Labbani, Auteur ; Zahia Meraihi, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2015 . - 103 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : levures isolement Pichia kluyveri toxine killer biocontrôle levures indésirables Yeast isolation killer toxin biocontrol undesirable yeasts خمائر عزل سم قاتل مكافحة حيوية خمائر غير مرغوب فيها Index. décimale : 570 Sciences de la vie. Biologie Résumé : The general purpose of this thesis is to search for killer activity in yeast strains isolated from agricultural and forest soil in the region of Constantine for biotechnological applications.The isolation of yeasts allows to list 15 strains. The molecular taxonomy based on the sequences of D1/D2 domain of the 26S ribosomal ARN gene groups these isolates into 6 different species: Cryptococcus aerius, Hanseniaspora opuntiae, Hanseniaspora uvarum, Pichia kluyveri, Meyerozyma guilliermondii and Saccharomyces cerevisiae. Morphological, physiological and biochemical characteristics of the strains are in agreement with those cited in
literature. Preliminary testing for killer activity reveals that only the strain L5 is able to produce killer activity. The killer strain is belonging to the species P. kluyveri. The crude killer protein produced by the strain P. kluyveri reveals that the toxin is active against food and beverage spoilage yeast strains belonging to the genera: Dekkera, Kluyveromyces, Pichia, Saccharomyces, Torulaspora, Wickerhamomyces and Zygosaccharomyces. The highest killer activity is obtained against the strain Dekkera bruxellensis DBVPG 6706. Both the heat shock (30 min at 100°C) and the enzymatic treatment with pronase demonstrate the complete loss of the initial killer activity of the toxin, and hence its proteinaceous nature is apparently confirmed. The active protein migrates as a single band in SDS-PAGE and has a molecular mass of 54 kDa. The purified killer toxin has an optimal pH between 4.0-4.5, while the optimal of temperature is 25°C.The determination of minimum inhibitory concentrations (MICs) shows that the purified killer protein has a high in vitro activity against D.bruxellensis (MICs from 64 000- to 256 000-fold lower than that exhibited by potassium metabisulphite) and Saccharomyces cerevisiae (MICs from 32 000- to 64 000-fold lower than potassium sorbate).
No in vitro synergistic interactions (calculated by FIC index -Σ FIC) are observed when killer protein is used in combination with the active compounds : potassium metabisulphite, potassium sorbate, or ethanol. The killer protein exhibited a dose–response effect against D.
bruxellensis and S. cerevisiae in a soft drink « Campari MIXX » (Milan, Italy) and pear juice « Santal » (Parma, Italy), respectively. The results of the present study suggest that the killer protein could be proposed as a novel food-grade compound useful for the control of food and beverage spoilage yeasts. Additionally, the purified killer protein maintains its killing action at
least for 3 days against S. cerevisiae DBVPG 6500 inoculated in pear juice and for 10 days against D. bruxellensis DBVPG 6706 in soft drink. The results of the present study suggest that the killer protein produced by the strain P. kluyveri (L5) could be proposed as a novel natural agent for the biocontrole of beverage spoilage yeasts.
Diplôme : Doctorat En ligne : ../theses/biologie/LAB6794.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10026 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité LAB/6794 LAB/6794 Thèse Bibliothèque principale Thèses Disponible Activité de la lipoprotéine lipase et de la lipase hépatique sur les émulsions lipidiques parenterales influence d'une infection bactérienne / Zahia Meraihi
Titre : Activité de la lipoprotéine lipase et de la lipase hépatique sur les émulsions lipidiques parenterales influence d'une infection bactérienne Type de document : texte imprimé Auteurs : Zahia Meraihi, Auteur ; C. Lutton, Directeur de thèse ; G. Rebel, Directeur de thèse ; Université de starsbourg, Éditeur scientifique Année de publication : 1990 Importance : 194 f. Note générale : 01 Disponible au magasin de la bibliothèque centrale Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Lipoprotéine Lipase hépatique Index. décimale : 570 Sciences de la vie. Biologie Diplôme : Doctorat en sciences Permalink : index.php?lvl=notice_display&id=1565 Activité de la lipoprotéine lipase et de la lipase hépatique sur les émulsions lipidiques parenterales influence d'une infection bactérienne [texte imprimé] / Zahia Meraihi, Auteur ; C. Lutton, Directeur de thèse ; G. Rebel, Directeur de thèse ; Université de starsbourg, Éditeur scientifique . - 1990 . - 194 f.
01 Disponible au magasin de la bibliothèque centrale
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Lipoprotéine Lipase hépatique Index. décimale : 570 Sciences de la vie. Biologie Diplôme : Doctorat en sciences Permalink : index.php?lvl=notice_display&id=1565 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MER/2163 MER/2163 Thèse Bibliothèque principale Thèses Disponible 
Titre : Cellulases de souches fongiques issues du sol d'un milieu extreme (sol proche de sources thermales) : Sélection des souches et étude des caractéristiques des enzymes. Type de document : texte imprimé Auteurs : Hind Leghlimi, Auteur ; Zahia Meraihi, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2013 Autre Editeur : Ardenne : Université de Reims Importance : 135 f. Format : 30 cm Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Moisissures isolement écosystèmes extrêmes cellulase ß-glucosidase thermostabilité Fungi isolation extreme ecosystems thermostability فطریات خیطیة عزل مناطق قاسیة إنزیم ال beta "glucosidase "
الثبات الحراريIndex. décimale : 570 Sciences de la vie. Biologie Résumé : Filamentous fungi found in soils surrounding the hydrothermal stations of regions in the east of Algeria: Guelma (Hammam Debagh) and Mila (Hammam Grouz-Atmania, Hammam Safsaf-Teleghma), are screened for the presence of cellulase activity. 88 fungal strains were
isolated and identified as belonging to six genera: Aspergillus, Alternaria, Emericella, Fusarium, Penicillium and Trichoderma. Their selection (filter paper test and test of perforated plates) shows that only the strain J2 has a significant cellulolytic activity. This
isolate belongs to the species of Trichoderma longibrachiatum Rifai. At 35°C, our isolate shows equivalent activities filter paper and endoglucanase than T. reesei. On the other hand the β-glucosidase activity of our isolate was until twice more important than T. reseei one.
With an inoculum size of 106 spores/ml the strain produces the maximum enzyme activities.
A good yield of enzyme is obtained with spores aged of six days. The strain D allowed from subcloning cultivated in 4 liters fermenter on Mandels medium with cellulose Avicel (1%) produces maximum activities of filter paper (1.88UI/ml), endoglucanase (11.22UI/ml) and β-
glucosidase (0.66UI/ml) after 128 hours, 144 hours and 120 hours, respectively. The optimum temperatures were 55°C and 60°C for endoglucanase and FPA, respectively. The endoglucanase was optimally active at pH 4.0, and the FPA was optimal at pH 4.0 and 5.0.
The endoglucanase was thermostable at 70°C after 5 hours incubation, preserved 80% of the original activity. The half-life of the filter paper activity appeared to be 3 hours at 60°C.
These activities were stable at 50°C after 5 hours incubation in a pH range of 3.0 to 6.0 and 4.0 to 6.0, respectively. The EDTA (5mM) causes a significant diminution of the cellulasic activity, while the β-mercaptoethanol (5mM) leading to their activation. Divalent cations calcium (Ca2+) and zinc (Zn2+) cause an increase and improvement of enzymes activities in the presence of EDTA (5mM). The crude enzyme extract is able to hydrolyse insoluble cellulosic substrates. This enzyme can be classified as an endo and exo type of the cellulase.
These results suggested that the no-mutated strain Trichoderma longibrachiatum should be an attractive producer for cellulases production.Diplôme : Doctorat en sciences En ligne : ..//theses/biologie/LEG6420.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9439 Cellulases de souches fongiques issues du sol d'un milieu extreme (sol proche de sources thermales) : Sélection des souches et étude des caractéristiques des enzymes. [texte imprimé] / Hind Leghlimi, Auteur ; Zahia Meraihi, Directeur de thèse . - constantine [Algérie] : Université Constantine 1 : Ardenne : Université de Reims, 2013 . - 135 f. ; 30 cm.
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Moisissures isolement écosystèmes extrêmes cellulase ß-glucosidase thermostabilité Fungi isolation extreme ecosystems thermostability فطریات خیطیة عزل مناطق قاسیة إنزیم ال beta "glucosidase "
الثبات الحراريIndex. décimale : 570 Sciences de la vie. Biologie Résumé : Filamentous fungi found in soils surrounding the hydrothermal stations of regions in the east of Algeria: Guelma (Hammam Debagh) and Mila (Hammam Grouz-Atmania, Hammam Safsaf-Teleghma), are screened for the presence of cellulase activity. 88 fungal strains were
isolated and identified as belonging to six genera: Aspergillus, Alternaria, Emericella, Fusarium, Penicillium and Trichoderma. Their selection (filter paper test and test of perforated plates) shows that only the strain J2 has a significant cellulolytic activity. This
isolate belongs to the species of Trichoderma longibrachiatum Rifai. At 35°C, our isolate shows equivalent activities filter paper and endoglucanase than T. reesei. On the other hand the β-glucosidase activity of our isolate was until twice more important than T. reseei one.
With an inoculum size of 106 spores/ml the strain produces the maximum enzyme activities.
A good yield of enzyme is obtained with spores aged of six days. The strain D allowed from subcloning cultivated in 4 liters fermenter on Mandels medium with cellulose Avicel (1%) produces maximum activities of filter paper (1.88UI/ml), endoglucanase (11.22UI/ml) and β-
glucosidase (0.66UI/ml) after 128 hours, 144 hours and 120 hours, respectively. The optimum temperatures were 55°C and 60°C for endoglucanase and FPA, respectively. The endoglucanase was optimally active at pH 4.0, and the FPA was optimal at pH 4.0 and 5.0.
The endoglucanase was thermostable at 70°C after 5 hours incubation, preserved 80% of the original activity. The half-life of the filter paper activity appeared to be 3 hours at 60°C.
These activities were stable at 50°C after 5 hours incubation in a pH range of 3.0 to 6.0 and 4.0 to 6.0, respectively. The EDTA (5mM) causes a significant diminution of the cellulasic activity, while the β-mercaptoethanol (5mM) leading to their activation. Divalent cations calcium (Ca2+) and zinc (Zn2+) cause an increase and improvement of enzymes activities in the presence of EDTA (5mM). The crude enzyme extract is able to hydrolyse insoluble cellulosic substrates. This enzyme can be classified as an endo and exo type of the cellulase.
These results suggested that the no-mutated strain Trichoderma longibrachiatum should be an attractive producer for cellulases production.Diplôme : Doctorat en sciences En ligne : ..//theses/biologie/LEG6420.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9439 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité LEG/6420 LEG/6420 Thèse Bibliothèque principale Thèses Disponible Documents numériques
texte integraleAdobe Acrobat PDF
Titre : Isolement et caractérisation de souches fongiques de milieux extremes (sol et sebkha de la région de Biskra) productrices de cellulase themostable à interet industriel Type de document : texte imprimé Auteurs : Soumia Bensmira, Auteur ; Zahia Meraihi, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2006 Importance : 88 f. Note générale : 01 Disponible à la salle de recherche 02 Disponibles au magazin de la B.U.C. Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Déchets de dattes Identification Thermostabilité Cellulase Isolemen Milieux extremes Moisissures Isolation extreme medium fungi date scrap cellulase thermostability عزل تعريف وسط اقصى بقايا التمور سلولاز مقاومة الحرارة Index. décimale : 570 Sciences de la vie. Biologie Résumé : The microscopic study of the moulds isolated from Sebkhas of Biskra area allowed, to identify 7 different kinds from 10 potentially cellulolytic strains: Aspergillus, Penicillium, Geotrichum, Altarnaria, Cladosporium, Altarnaria and Trichoderma.
The fermentation of the 10 strains selected and cultivated on a medium containing date scrap (under product of pheonicical industry) as a substrate of fermentation, allowed to select hypercellulolytic strains with a cellulasic activity of 775 U. The strain (R3), isolated from the ground soil of palm plantations of Biskra corresponds to the Trichoderma kind. This train is retained for the kinetic study of the biomass, the cellulasic activity, sugar, proteins like that of the pH. This study reveals that the synthesis of the enzyme reaches its maximum after 60 hours of fermentation during the stationary phase of the growth.
A partial purification with ammonia sulphate 40 % of saturetion reduced the content of proteins of 78.4 % and increased the specific activity to 94.35 % which reached the degree of purification to 17.70. The enzyme was found very thermostable with a half-life of 170 , 140, 120 and 50 munites at 60, 70, 80 and 90°C respectively. The corresponding temperature for the maximum cellulolytic activity was 55°C whereas the optimim pH was 4.8.Diplôme : Magistère En ligne : ../theses/biologie/BEN4503.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=1348 Isolement et caractérisation de souches fongiques de milieux extremes (sol et sebkha de la région de Biskra) productrices de cellulase themostable à interet industriel [texte imprimé] / Soumia Bensmira, Auteur ; Zahia Meraihi, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2006 . - 88 f.
01 Disponible à la salle de recherche 02 Disponibles au magazin de la B.U.C.
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Déchets de dattes Identification Thermostabilité Cellulase Isolemen Milieux extremes Moisissures Isolation extreme medium fungi date scrap cellulase thermostability عزل تعريف وسط اقصى بقايا التمور سلولاز مقاومة الحرارة Index. décimale : 570 Sciences de la vie. Biologie Résumé : The microscopic study of the moulds isolated from Sebkhas of Biskra area allowed, to identify 7 different kinds from 10 potentially cellulolytic strains: Aspergillus, Penicillium, Geotrichum, Altarnaria, Cladosporium, Altarnaria and Trichoderma.
The fermentation of the 10 strains selected and cultivated on a medium containing date scrap (under product of pheonicical industry) as a substrate of fermentation, allowed to select hypercellulolytic strains with a cellulasic activity of 775 U. The strain (R3), isolated from the ground soil of palm plantations of Biskra corresponds to the Trichoderma kind. This train is retained for the kinetic study of the biomass, the cellulasic activity, sugar, proteins like that of the pH. This study reveals that the synthesis of the enzyme reaches its maximum after 60 hours of fermentation during the stationary phase of the growth.
A partial purification with ammonia sulphate 40 % of saturetion reduced the content of proteins of 78.4 % and increased the specific activity to 94.35 % which reached the degree of purification to 17.70. The enzyme was found very thermostable with a half-life of 170 , 140, 120 and 50 munites at 60, 70, 80 and 90°C respectively. The corresponding temperature for the maximum cellulolytic activity was 55°C whereas the optimim pH was 4.8.Diplôme : Magistère En ligne : ../theses/biologie/BEN4503.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=1348 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/4503 BEN/4503 Thèse Bibliothèque principale Thèses Disponible
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