3 résultat(s) recherche sur le tag 'Fungi'    

Isolement de moisissures productrices de protéases coagulantes.Production et purification des enzymes et étude de leur effet sur la coagulation de lait / Aicha Benlounissi  

Public ISBD Titre : Isolement de moisissures productrices de protéases coagulantes.Production et purification des enzymes et étude de leur effet sur la coagulation de lait Type de document : texte imprimé Auteurs : Aicha Benlounissi, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; A.Christophe Marquette, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2012 Importance : 181 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles Langues : Français (fre) Tags : Moisisissures  aspergillus  penicillium  optimisation et modélisation  protéases et coagulation  Fungi  Aspergillus  modeling and optimization  proteinases and coagulation ?????? ??????????  ?????????  ???????? ??????  ??????? Index. décimale : 570 Sciences de la vie. Biologie Résumé : Six strains of fungi isolated from Algerian soil, five of the genus Aspergillus and one of the genus Penicillium are identified and are used to produce clotting proteases: A.Niger, A.flavus,A.awamori, A.tubingensis,A.tamarii and P.pinophilum. Enzymes are synthesized by fermentation of whey-based media enriched and optimized in two phases by using two experimental designs.The first plan Plackett-Burman(11 factors and 12 experiments) was used to select factors with a positive and significant effect on the production of proteases.7 factors are real [pH,agitation,yeast extract,lactose,peptone ,CaCl2 and salts(MgSO4 and FeSO4)] and four errors.The second plan, Box and Wilson gave the optimum factors selected whose number varies form one strain to another.The optimization showed that each strain is able to produce an extracellular acid protease and coagulating milk with important activities(between 1822.21 U.and 2583.83 U.). The enzymes are then purified in three steps: molecular filtration on Sephadex G25, ion-exchange chromatography on DEAE-Sepharose and affinity chromatography on pepstatin A-agarose.The latter has eliminated up to 92% of non-active protein with purification factors between 2.84 and 6.19. The separation of the purified enzymes by SDS-PAGE showed molecular weight of the acid protease from each strain:30 kDa for P.pinophilum,35kDa for A.flavus and A.tamarii and 55kDa for A.Niger, A.awamori and A.tubingensis.The study of the properties has allwed the determination of an optimum pH of between 4 and 5.5 and a temperature optimum between 30 and 50°C.All enzymes are stable 1 h at the temperature of optimum activity. Coagulation tests are performed on three different milks at 35°C after each purification step.The coagulation time,the appearance and texture of curdled are different depending on the origin of the protease. All enzymes cause a very rapid coagulation of fresh cow's milk in a very short time: 2 min. For the A.tomarii enzyme and 5 min for all other enzymes. Diplôme : Doctorat en sciences En ligne : ../theses/biologie/BEN6309.pdf Format de la ressource électronique : pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=6257 Isolement de moisissures productrices de protéases coagulantes.Production et purification des enzymes et étude de leur effet sur la coagulation de lait [texte imprimé] / Aicha Benlounissi, Auteur ; Aicha Mechakra (Née Maza), Directeur de thèse ; A.Christophe Marquette, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2012 . - 181 f. ; 30 cm. 2 copies imprimées disponibles Langues : Français (fre) Tags : Moisisissures  aspergillus  penicillium  optimisation et modélisation  protéases et coagulation  Fungi  Aspergillus  modeling and optimization  proteinases and coagulation ?????? ??????????  ?????????  ???????? ??????  ??????? Index. décimale : 570 Sciences de la vie. Biologie Résumé : Six strains of fungi isolated from Algerian soil, five of the genus Aspergillus and one of the genus Penicillium are identified and are used to produce clotting proteases: A.Niger, A.flavus,A.awamori, A.tubingensis,A.tamarii and P.pinophilum. Enzymes are synthesized by fermentation of whey-based media enriched and optimized in two phases by using two experimental designs.The first plan Plackett-Burman(11 factors and 12 experiments) was used to select factors with a positive and significant effect on the production of proteases.7 factors are real [pH,agitation,yeast extract,lactose,peptone ,CaCl2 and salts(MgSO4 and FeSO4)] and four errors.The second plan, Box and Wilson gave the optimum factors selected whose number varies form one strain to another.The optimization showed that each strain is able to produce an extracellular acid protease and coagulating milk with important activities(between 1822.21 U.and 2583.83 U.). The enzymes are then purified in three steps: molecular filtration on Sephadex G25, ion-exchange chromatography on DEAE-Sepharose and affinity chromatography on pepstatin A-agarose.The latter has eliminated up to 92% of non-active protein with purification factors between 2.84 and 6.19. The separation of the purified enzymes by SDS-PAGE showed molecular weight of the acid protease from each strain:30 kDa for P.pinophilum,35kDa for A.flavus and A.tamarii and 55kDa for A.Niger, A.awamori and A.tubingensis.The study of the properties has allwed the determination of an optimum pH of between 4 and 5.5 and a temperature optimum between 30 and 50°C.All enzymes are stable 1 h at the temperature of optimum activity. Coagulation tests are performed on three different milks at 35°C after each purification step.The coagulation time,the appearance and texture of curdled are different depending on the origin of the protease. All enzymes cause a very rapid coagulation of fresh cow's milk in a very short time: 2 min. For the A.tomarii enzyme and 5 min for all other enzymes. Diplôme : Doctorat en sciences En ligne : ../theses/biologie/BEN6309.pdf Format de la ressource électronique : pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=6257

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Cellulases de souches fongiques issues du sol d'un milieu extreme (sol proche de sources thermales) / Hind Leghlimi    

Public ISBD 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) Tags : Moisissures  isolement  écosystèmes extrêmes  cellulase  ß-glucosidase  thermostabilité  Fungi  isolation  extreme ecosystems  thermostability  ?????? ?????  ???  ????? ?????  ????? ?? beta "glucosidase " ?????? ??????? Index. 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 : pdf Permalink : https://bu.umc.edu.dz/md/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 (Route ain el bey, Algérie) : Université Constantine 1 : Ardenne : Université de Reims, 2013 . - 135 f. ; 30 cm. Langues : Français (fre) Tags : Moisissures  isolement  écosystèmes extrêmes  cellulase  ß-glucosidase  thermostabilité  Fungi  isolation  extreme ecosystems  thermostability  ?????? ?????  ???  ????? ?????  ????? ?? beta "glucosidase " ?????? ??????? Index. 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 : pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9439

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Isolement et caractérisation de souches fongiques de milieux extremes (sol et sebkha de la région de Biskra) productrices de cellulase themostable à interet industriel / Soumia Bensmira  

Public ISBD 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) Tags : Déchets de dattes  Identification  Thermostabilité  Cellulase  Isolemen  Milieux extremes  Moisissures  Isolation  extreme medium  fungi  date scrap  cellulase  thermostability  ???  ?????  ??? ????  ????? ??????  ??????  ?????? ??????? 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 : pdf Permalink : https://bu.umc.edu.dz/md/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) Tags : Déchets de dattes  Identification  Thermostabilité  Cellulase  Isolemen  Milieux extremes  Moisissures  Isolation  extreme medium  fungi  date scrap  cellulase  thermostability  ???  ?????  ??? ????  ????? ??????  ??????  ?????? ??????? 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 : pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=1348

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