Résultat de la recherche
17 résultat(s) recherche sur le tag 'Purification' 
Affiner la recherche Générer le flux rss de la recherche
Partager le résultat de cette recherche Interroger des sources externes
Titre : Etude des protéases de quelques plantes endémiques. : Purification, propriétés, mécanisme d’action et applications technologiques Type de document : texte imprimé Auteurs : Meriem Benchiheub, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2015 Importance : 105 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Protéases Scolymus maculatus Scolymus hispanicus purification applications technologiques Proteases technological applications ????????? ?????? ??????? ????????? ??????????? Index. décimale : 570 Sciences de la vie. Biologie Résumé : A study was carried out on two local spinous plants of the genus Scolymus in order to extract enzymes having a technological interest. For this, acid proteases were purified from flowers Scolymus maculatus and Scolymus hispanicus in three steps, fractional precipitation with AS, molecular sifting and ion exchange chromatography. The yields activity recovered are 30.56% and 20.97%, with purification degrees of 60.51 and 57.60 for S. maculatus and S. hispanicus respectively. The separation of acid proteases by SDS-PAGE gave a molecular weight of 45
kDa for both enzymes. The study of physicochemical properties allows obtaining an optimum pH of 5, an optimum temperature of 55°C and a stability of 1 hour and a half. These enzymes are inhibited by pepstatin A indicating that it is aspartylprotease; they are activated by Ca+2.
The kinetic parameters of these proteases are Vm 1391 U and 1367 U, KM 4.76 g/L and 5.71 g/L for S. maculatus and S. hispanicus respectively. These enzymes cause a very rapid coagulation of fresh cow's milk in very short times: 7 min for the enzyme of S. maculatus and 10 min to that of S. hispanicus. The coagulant activity of these proteases is optimum at 60 ° C and pH 5, at a concentration of 50 mM in calcium. These coagulases have the ability to hydrolyze , and casein. These results indicate that these enzymes can be used as substitutes for rennet. Other properties tested with alkaline proteases extracted from the same plants showed different technological potential. Thus, these enzymes can act as anticoagulants, detergents and keratinase. Which allows the use in industrial applications.
Diplôme : Doctorat En ligne : ../theses/biologie/BEN6686.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9943 Etude des protéases de quelques plantes endémiques. : Purification, propriétés, mécanisme d’action et applications technologiques [texte imprimé] / Meriem Benchiheub, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse . - constantine (Route ain el bey, Algérie) : Université Constantine 1, 2015 . - 105 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Protéases Scolymus maculatus Scolymus hispanicus purification applications technologiques Proteases technological applications ????????? ?????? ??????? ????????? ??????????? Index. décimale : 570 Sciences de la vie. Biologie Résumé : A study was carried out on two local spinous plants of the genus Scolymus in order to extract enzymes having a technological interest. For this, acid proteases were purified from flowers Scolymus maculatus and Scolymus hispanicus in three steps, fractional precipitation with AS, molecular sifting and ion exchange chromatography. The yields activity recovered are 30.56% and 20.97%, with purification degrees of 60.51 and 57.60 for S. maculatus and S. hispanicus respectively. The separation of acid proteases by SDS-PAGE gave a molecular weight of 45
kDa for both enzymes. The study of physicochemical properties allows obtaining an optimum pH of 5, an optimum temperature of 55°C and a stability of 1 hour and a half. These enzymes are inhibited by pepstatin A indicating that it is aspartylprotease; they are activated by Ca+2.
The kinetic parameters of these proteases are Vm 1391 U and 1367 U, KM 4.76 g/L and 5.71 g/L for S. maculatus and S. hispanicus respectively. These enzymes cause a very rapid coagulation of fresh cow's milk in very short times: 7 min for the enzyme of S. maculatus and 10 min to that of S. hispanicus. The coagulant activity of these proteases is optimum at 60 ° C and pH 5, at a concentration of 50 mM in calcium. These coagulases have the ability to hydrolyze , and casein. These results indicate that these enzymes can be used as substitutes for rennet. Other properties tested with alkaline proteases extracted from the same plants showed different technological potential. Thus, these enzymes can act as anticoagulants, detergents and keratinase. Which allows the use in industrial applications.
Diplôme : Doctorat En ligne : ../theses/biologie/BEN6686.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9943 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/6686 BEN/6686 Thèse Bibliothèque principale Thèses Disponible Isolement, sélection de souches levuriennes de sols arides sahariens (El-M’gheir) productrices de polygalacturonase / Leila Bennamoun
Titre : Isolement, sélection de souches levuriennes de sols arides sahariens (El-M’gheir) productrices de polygalacturonase : Purification et caractérisation enzymatique Type de document : texte imprimé Auteurs : Leila Bennamoun, Auteur ; Zahia Meraihi, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 188 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Exo-polygalacturonase Aureobasidium pullulans Optimisation Déchets de tomates Purification Caractérisation Optimization Tomato pomace Characterization ??????? ?????? ??????? ????? ??? Index. décimale : 570 Sciences de la vie. Biologie Résumé : The general purpose of this study is to search for performing yeasts in the production of thermostable polygalacturonase for possible industrial applications. A total of 20 strains, belonging to the yeast biodiversity of palm and steppe soils in the region of ElM’gheir (Province of El-Oued in the south-east of Algeria), were isolated. Conventional methods coupled with molecular biology (sequencing of the D1/D2 region of the gene
encoding 26S rRNA and ITS) identified five different species: Clavispora lusitaniae, Cryptococcus magnus, Meyerozyma guilliermondii, Aureobasidium pullulan sand Yarrowia lipolytica. The agar plate testing method allowed the isolation of a single pectinolytic strain:
Aureobasidium pullulans (S6). In order to reduce the cost of the polygalacturonase production, tomato pomace was used.
This substrate was targeted by its richness in soluble carbohydrates (20.25%), in mineral matter (5.83%) and in proteins (18.31%). The study showed that the selected yeast Aureobasidium pullulans gives a better production of enzyme with a concentration of 4% in tomato pomace. The inducing substrate is lactose 1% causing an enzyme increase of 642%.Optimization of the medium components was achieved with the aid of response surface methodology. The composition of the optimized medium was as follows: pH 5.16, lactose 1.84 g/L and CaCl2 0.089 g/L. Practical validation of the optimum medium provided polygalacturonase activity of 22.05 U/ml, which was 5-fold higher than in unoptimized conditions. Batch cultivation in a 20 l bioreactor, the maximum production of the PGase was
obtained within 32 of culture corresponding to a maximum of the yeast growth. The mechanism of the enzyme production is therefore of associated type. The chromatographic profile on a Sephacryl S-200 revealed two pectinolytic activities confirmed by the elution of two peaks on DEAE-Sepharose, it is therfore two isoenzymes: the PG1 and the PG2. After these steps, the two forms of isoenzymes were purified respectively with purification rates of
161.1 and 153.4 and yields of 27.39% and 26.45%. The PG1 and PG2 were glycoproteins.
The molecular mass determined with SDS-PAGE was estimated as 113.79 KDa for the PG1 and 71.44 KDa for the PG2. The thin layer chromatography revealed enzymes that hydrolyse polygalacturonic acid to monogalacturonic acid, which shows that the enzymes are exopolygalacturonases (E.C 3.2.1.67). These two isoenzymes have different electrical charges and molecular weights with optimum pH of 10 and 5 for the PG1 and PG2 respectively. The PG1 has a good stability in the pH zone of 7-11 whereas the PG2 is stable in another pH zone varying from 4 to 9 with thermostabilities of 5 h at 60°C. At 80°C and 90°C, the PG1 retains 76.6% and 70% of its activity respectively. As for the PG2, it maintains 88.58% of its activity at 80°C, 70% at 90°C after a 5 h heat treatment. From the point of view of application, the two purified exo-PGases were able to improve the clarification of lemon juice. In view of
these physicochemical properties and the thermostability, the two purified exo-PGases PG1 and PG2 could be applied industrially for the clarification of lemon juice or other industries:
food industries, textile, paper and waste processing.Diplôme : Doctorat en sciences Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10467 Isolement, sélection de souches levuriennes de sols arides sahariens (El-M’gheir) productrices de polygalacturonase : Purification et caractérisation enzymatique [texte imprimé] / Leila Bennamoun, Auteur ; Zahia Meraihi, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 188 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Exo-polygalacturonase Aureobasidium pullulans Optimisation Déchets de tomates Purification Caractérisation Optimization Tomato pomace Characterization ??????? ?????? ??????? ????? ??? Index. décimale : 570 Sciences de la vie. Biologie Résumé : The general purpose of this study is to search for performing yeasts in the production of thermostable polygalacturonase for possible industrial applications. A total of 20 strains, belonging to the yeast biodiversity of palm and steppe soils in the region of ElM’gheir (Province of El-Oued in the south-east of Algeria), were isolated. Conventional methods coupled with molecular biology (sequencing of the D1/D2 region of the gene
encoding 26S rRNA and ITS) identified five different species: Clavispora lusitaniae, Cryptococcus magnus, Meyerozyma guilliermondii, Aureobasidium pullulan sand Yarrowia lipolytica. The agar plate testing method allowed the isolation of a single pectinolytic strain:
Aureobasidium pullulans (S6). In order to reduce the cost of the polygalacturonase production, tomato pomace was used.
This substrate was targeted by its richness in soluble carbohydrates (20.25%), in mineral matter (5.83%) and in proteins (18.31%). The study showed that the selected yeast Aureobasidium pullulans gives a better production of enzyme with a concentration of 4% in tomato pomace. The inducing substrate is lactose 1% causing an enzyme increase of 642%.Optimization of the medium components was achieved with the aid of response surface methodology. The composition of the optimized medium was as follows: pH 5.16, lactose 1.84 g/L and CaCl2 0.089 g/L. Practical validation of the optimum medium provided polygalacturonase activity of 22.05 U/ml, which was 5-fold higher than in unoptimized conditions. Batch cultivation in a 20 l bioreactor, the maximum production of the PGase was
obtained within 32 of culture corresponding to a maximum of the yeast growth. The mechanism of the enzyme production is therefore of associated type. The chromatographic profile on a Sephacryl S-200 revealed two pectinolytic activities confirmed by the elution of two peaks on DEAE-Sepharose, it is therfore two isoenzymes: the PG1 and the PG2. After these steps, the two forms of isoenzymes were purified respectively with purification rates of
161.1 and 153.4 and yields of 27.39% and 26.45%. The PG1 and PG2 were glycoproteins.
The molecular mass determined with SDS-PAGE was estimated as 113.79 KDa for the PG1 and 71.44 KDa for the PG2. The thin layer chromatography revealed enzymes that hydrolyse polygalacturonic acid to monogalacturonic acid, which shows that the enzymes are exopolygalacturonases (E.C 3.2.1.67). These two isoenzymes have different electrical charges and molecular weights with optimum pH of 10 and 5 for the PG1 and PG2 respectively. The PG1 has a good stability in the pH zone of 7-11 whereas the PG2 is stable in another pH zone varying from 4 to 9 with thermostabilities of 5 h at 60°C. At 80°C and 90°C, the PG1 retains 76.6% and 70% of its activity respectively. As for the PG2, it maintains 88.58% of its activity at 80°C, 70% at 90°C after a 5 h heat treatment. From the point of view of application, the two purified exo-PGases were able to improve the clarification of lemon juice. In view of
these physicochemical properties and the thermostability, the two purified exo-PGases PG1 and PG2 could be applied industrially for the clarification of lemon juice or other industries:
food industries, textile, paper and waste processing.Diplôme : Doctorat en sciences Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10467 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/7135 BEN/7135 Thèse Bibliothèque principale Thèses Disponible
Titre : Pectinesterases de mandarine (var citrus nobilislour) : purification et propriétés Type de document : texte imprimé Auteurs : Univ. de Constantine, Editeur scientifique Année de publication : 1988 Importance : 90 f. Note générale : 01 Disponibles au magasin de la bibliothèque centrale Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Purification Enzyme pectique Mandarine Pectinesterase Pectime Jus d'orange Var citrus nobilio loun Index. décimale : 570 Sciences de la vie. Biologie Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=1673 Pectinesterases de mandarine (var citrus nobilislour) : purification et propriétés [texte imprimé] / Univ. de Constantine, Editeur scientifique . - 1988 . - 90 f.
01 Disponibles au magasin de la bibliothèque centrale
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Purification Enzyme pectique Mandarine Pectinesterase Pectime Jus d'orange Var citrus nobilio loun Index. décimale : 570 Sciences de la vie. Biologie Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=1673 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/1085 BEN/1085 Thèse Bibliothèque principale Thèses Disponible
Titre : La Phosphatase alcaline de foetus bovin : purification partielle au cours du développement Type de document : texte imprimé Auteurs : Univ. de Constantine, Editeur scientifique Année de publication : 1984 Importance : 119 f. Note générale : 01 Disponible au magasin de la bibliothèque centrale Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Purification Phosphatase alcaline Foeutus bovin Index. décimale : 570 Sciences de la vie. Biologie Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=1713 La Phosphatase alcaline de foetus bovin : purification partielle au cours du développement [texte imprimé] / Univ. de Constantine, Editeur scientifique . - 1984 . - 119 f.
01 Disponible au magasin de la bibliothèque centrale
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Purification Phosphatase alcaline Foeutus bovin Index. décimale : 570 Sciences de la vie. Biologie Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=1713 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MAZ/1097 MAZ/1097 Thèse Bibliothèque principale Thèses Disponible
Titre : Purification et analyse biochimique des enzymes de conversion de l'angiotensine 1 du poumon et du serum de porc, étude des caines glycaniques de l'enzyme pulmonaire Type de document : texte imprimé Auteurs : Abdelkrim Tahraoui, Auteur ; François Baumann, Directeur de thèse ; Université René Descartes, Editeur scientifique Année de publication : 1990 Importance : 183 f. Note générale : 01 Disponible salle de recherche Langues : (fr) Catégories : Français - Anglais
BiologieTags : Purification Biochimie Enzyme Serum de porc Poumon de porc Index. décimale : 570 Sciences de la vie. Biologie Diplôme : Doctorat Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=1695 Purification et analyse biochimique des enzymes de conversion de l'angiotensine 1 du poumon et du serum de porc, étude des caines glycaniques de l'enzyme pulmonaire [texte imprimé] / Abdelkrim Tahraoui, Auteur ; François Baumann, Directeur de thèse ; Université René Descartes, Editeur scientifique . - 1990 . - 183 f.
01 Disponible salle de recherche
Langues : (fr)
Catégories : Français - Anglais
BiologieTags : Purification Biochimie Enzyme Serum de porc Poumon de porc Index. décimale : 570 Sciences de la vie. Biologie Diplôme : Doctorat Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=1695 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité TAH/2464 TAH/2464 Thèse Bibliothèque principale Thèses Disponible 
PermalinkPermalink
Permalink
Permalink
Permalink
Permalink
Permalink
Permalink
Permalink
Permalink
PermalinkPermalink
