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Auteur Mohamed Amine Gomri |
Documents disponibles écrits par cet auteur (3)
Affiner la recherche Interroger des sources externesContribution à l'étude de la diversité des bactéries thermophiles de quelques environnements chauds algériens et essai de de production et de caractérisation de leurs protéases extracellulaires. / Mohamed Amine Gomri
Titre : Contribution à l'étude de la diversité des bactéries thermophiles de quelques environnements chauds algériens et essai de de production et de caractérisation de leurs protéases extracellulaires. Type de document : texte imprimé Auteurs : Mohamed Amine Gomri, Auteur ; Karima Kharroub, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 308 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Biotechnologie:Sciences Alimentaires environnements chauds algériens diversité bactéries thermophiles protéases extracellulaires Algerian hot environments diversity bacteria thermophilic extracellular
proteases بينات ساخنة جزائرية تنوع-بكتيريا محبة للحرارة بروتياز خارج الخليةIndex. décimale : 640 Industrie Alimentaire Résumé :
Natural hot environments can represent an important source of microbial biodiversity and biomolecules with great added value. Among these biomolecules, extracellular hydrolases and in particular proteases are of great interest for the food industry because of their single reactional properties at high temperatures and their stability in various environmental conditions. The primary objective of this thesis is the isolation of thermophilic aerobic bacteria with extracellular proteolytic activities from 7 sites representing different Algerian hot environments: three geothermal sources, two Saharan soils, a sebkha and an oil field. On the
138 isolates selected on the basis of their macroscopic and microscopic morphological characters, 53 isolates able to degrade casein and/or gelatin on solid culture media were characterized by amplified ribosomal DNA restriction analysis. After the elimination of clones, 28 strains were identified by sequencing and analyzing their 16S rRNA genes. These strains belong to 5 genera of aerobic thermophilic endospore-forming bacteria: Anoxybacillus, Bacillus, Geobacillus, Brevibacillus and Thermoactinomyces. The physiological and biochemical characterization of these strains confirm the relationship with these genera. The genomes of two strains, Geobacillus Sah69 and Thermoactinomyces AS95, were then characterized. The production of putative extracellular proteases of industrial interest was revealed. In addition, the biodiversity of the geothermal sources of Debagh and Ouled Ali was studied by metagenomic analysis of the 16S rRNA hypervariable V4 region sequences of environmental DNA collected from sediment samples. The thermophilic aerobic bacterial communities dominate the two sites with a minor presence of the phylum of Firmicutes and the genera isolated by cultural methods. Lastly, the production of extracellular proteases was estimated quantitatively for the 28 selected strains. Study of production kinetics and effect of fermentation conditions on three selected strains, Geobacillus Sah69, Thermoactinomyces AS95 and Brevibacillus OA30, were then carried out. After the extraction of the supernatant, two proteases, metalloprotease 32- F38 and serine-protease 16-F39, were produced and purified from strain Brevibacillus OA30. These proteases were acid, thermoactive and had a great stability in presence of SDS, solvents and other chemical agents tested. Thus revealing a good potential for industrial application.Note de contenu :
Annexes.Diplôme : Doctorat en sciences En ligne : ../theses/agronomie/GOM7444.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11222 Contribution à l'étude de la diversité des bactéries thermophiles de quelques environnements chauds algériens et essai de de production et de caractérisation de leurs protéases extracellulaires. [texte imprimé] / Mohamed Amine Gomri, Auteur ; Karima Kharroub, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2019 . - 308 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Biotechnologie:Sciences Alimentaires environnements chauds algériens diversité bactéries thermophiles protéases extracellulaires Algerian hot environments diversity bacteria thermophilic extracellular
proteases بينات ساخنة جزائرية تنوع-بكتيريا محبة للحرارة بروتياز خارج الخليةIndex. décimale : 640 Industrie Alimentaire Résumé :
Natural hot environments can represent an important source of microbial biodiversity and biomolecules with great added value. Among these biomolecules, extracellular hydrolases and in particular proteases are of great interest for the food industry because of their single reactional properties at high temperatures and their stability in various environmental conditions. The primary objective of this thesis is the isolation of thermophilic aerobic bacteria with extracellular proteolytic activities from 7 sites representing different Algerian hot environments: three geothermal sources, two Saharan soils, a sebkha and an oil field. On the
138 isolates selected on the basis of their macroscopic and microscopic morphological characters, 53 isolates able to degrade casein and/or gelatin on solid culture media were characterized by amplified ribosomal DNA restriction analysis. After the elimination of clones, 28 strains were identified by sequencing and analyzing their 16S rRNA genes. These strains belong to 5 genera of aerobic thermophilic endospore-forming bacteria: Anoxybacillus, Bacillus, Geobacillus, Brevibacillus and Thermoactinomyces. The physiological and biochemical characterization of these strains confirm the relationship with these genera. The genomes of two strains, Geobacillus Sah69 and Thermoactinomyces AS95, were then characterized. The production of putative extracellular proteases of industrial interest was revealed. In addition, the biodiversity of the geothermal sources of Debagh and Ouled Ali was studied by metagenomic analysis of the 16S rRNA hypervariable V4 region sequences of environmental DNA collected from sediment samples. The thermophilic aerobic bacterial communities dominate the two sites with a minor presence of the phylum of Firmicutes and the genera isolated by cultural methods. Lastly, the production of extracellular proteases was estimated quantitatively for the 28 selected strains. Study of production kinetics and effect of fermentation conditions on three selected strains, Geobacillus Sah69, Thermoactinomyces AS95 and Brevibacillus OA30, were then carried out. After the extraction of the supernatant, two proteases, metalloprotease 32- F38 and serine-protease 16-F39, were produced and purified from strain Brevibacillus OA30. These proteases were acid, thermoactive and had a great stability in presence of SDS, solvents and other chemical agents tested. Thus revealing a good potential for industrial application.Note de contenu :
Annexes.Diplôme : Doctorat en sciences En ligne : ../theses/agronomie/GOM7444.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11222 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité GOM/7444 GOM/7444 Thèse Bibliothèque principale Thèses Disponible
Titre : Étude des Archaea halophiles extrêmes isolées d’environnements hypersalins algériens et caractérisation de leurs caroténoïdes. Type de document : texte imprimé Auteurs : Kaouther Sahli, Auteur ; Karima Kharroub, Directeur de thèse ; Mohamed Amine Gomri, Directeur de thèse Mention d'édition : 05/01/2021 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2021 Importance : 214 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : INATAA: Biotechnologie Archaea halophiles extrêmes environnements hypersalins Algérie caroténoïdes caractérisation Extremely halophilic Archaea hypersaline environments Algeria carotenoids characterization العَتَائق المحبة للملوحة البيئَات شَديدَة الملوحة الجزائر الكاروتينات وصف Index. décimale : 640 Industrie Alimentaire Résumé :
Hypersaline lakes constitute a typical example of extreme environments harboring a particular microbial flora, which defies the laws of biology and thrives at the limits of life. Extremely halophilic archaea or haloarchaea dominate the microbial communities found in these environments. These microorganisms represent a deposit of natural resources in biomolecules of industrial interest, in particular pigments. The main objective of this thesis is to isolate extremely halophilic, pigment producers archaeal strains from brine and salt samples collected from 7 different Algerian hypersaline environments. In total, 110 isolates were selected on the basis of their macroscopic morphological characters. Of this total, 43 isolates producing high levels of carotenoids and/or showing highest growth in wide salinity, temperature and pH ranges were selected for phenotypic and molecular characterization. 16S rRNA genes sequencing and analysis revealed that theses strains belong to 7 different archaeal genera of the class Halobaceria: Halorubrum, Haloracula, Haloferax, Natrinema, Halogeometricum, Haloterrigena and Halopiger. Strains Halorubrum sp. BS2 ; Halogeometricum sp. ME3 ; Haloarcula sp. BT9 and Haloferax sp. ME16 were then selected for the study of their carotenoids. Chromatographic and spectrometric analysis of carotenoid extracts revealed a variation in the composition depending on the strain with a predominance of bacterioruberin. The evaluation of antioxidant capacity using in vitro ABTS and DPPH assays showed that these extracts have a strong antioxidant potential, in particular those of Halorubrum sp. BS2 and Haloferax sp. ME16 strains, revealing thus a good potential for biotechnological applications. Antibacterial activity of carotenoid extracts against 4 human‐pathogenic strains and 4 fish pathogenic strains was also evaluated by agar disk diffusion method. The obtained results showed a good antibacterial activity. Lastly, the strain Halorubrum sp. BS2 which showed the highest carotenoid content and interesting biological activities was selected to study the effect of the variation in cultural conditions on its growth and carotenoid production. The results showed that the highest growth and carotenoid contents were obtained at a salinity of 25 % (w/v), under an agitation speed of 300 tpm, at a temperature of 37°C and with a light intensity of 260 µE m-2 s-1.Note de contenu :
Annexes.Diplôme : Doctorat En ligne : ../theses/agronomie/SAH7697.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11531 Étude des Archaea halophiles extrêmes isolées d’environnements hypersalins algériens et caractérisation de leurs caroténoïdes. [texte imprimé] / Kaouther Sahli, Auteur ; Karima Kharroub, Directeur de thèse ; Mohamed Amine Gomri, Directeur de thèse . - 05/01/2021 . - جامعة الإخوة منتوري قسنطينة, 2021 . - 214 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : INATAA: Biotechnologie Archaea halophiles extrêmes environnements hypersalins Algérie caroténoïdes caractérisation Extremely halophilic Archaea hypersaline environments Algeria carotenoids characterization العَتَائق المحبة للملوحة البيئَات شَديدَة الملوحة الجزائر الكاروتينات وصف Index. décimale : 640 Industrie Alimentaire Résumé :
Hypersaline lakes constitute a typical example of extreme environments harboring a particular microbial flora, which defies the laws of biology and thrives at the limits of life. Extremely halophilic archaea or haloarchaea dominate the microbial communities found in these environments. These microorganisms represent a deposit of natural resources in biomolecules of industrial interest, in particular pigments. The main objective of this thesis is to isolate extremely halophilic, pigment producers archaeal strains from brine and salt samples collected from 7 different Algerian hypersaline environments. In total, 110 isolates were selected on the basis of their macroscopic morphological characters. Of this total, 43 isolates producing high levels of carotenoids and/or showing highest growth in wide salinity, temperature and pH ranges were selected for phenotypic and molecular characterization. 16S rRNA genes sequencing and analysis revealed that theses strains belong to 7 different archaeal genera of the class Halobaceria: Halorubrum, Haloracula, Haloferax, Natrinema, Halogeometricum, Haloterrigena and Halopiger. Strains Halorubrum sp. BS2 ; Halogeometricum sp. ME3 ; Haloarcula sp. BT9 and Haloferax sp. ME16 were then selected for the study of their carotenoids. Chromatographic and spectrometric analysis of carotenoid extracts revealed a variation in the composition depending on the strain with a predominance of bacterioruberin. The evaluation of antioxidant capacity using in vitro ABTS and DPPH assays showed that these extracts have a strong antioxidant potential, in particular those of Halorubrum sp. BS2 and Haloferax sp. ME16 strains, revealing thus a good potential for biotechnological applications. Antibacterial activity of carotenoid extracts against 4 human‐pathogenic strains and 4 fish pathogenic strains was also evaluated by agar disk diffusion method. The obtained results showed a good antibacterial activity. Lastly, the strain Halorubrum sp. BS2 which showed the highest carotenoid content and interesting biological activities was selected to study the effect of the variation in cultural conditions on its growth and carotenoid production. The results showed that the highest growth and carotenoid contents were obtained at a salinity of 25 % (w/v), under an agitation speed of 300 tpm, at a temperature of 37°C and with a light intensity of 260 µE m-2 s-1.Note de contenu :
Annexes.Diplôme : Doctorat En ligne : ../theses/agronomie/SAH7697.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11531 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité SAH/7697 SAH/7697 Thèse Bibliothèque principale Thèses Disponible
Titre : Screening d’activités hydrolytiques extracellulaires chez des souches bactériennes aérobies thermophiles isolées à partir de sources thermales terrestres de l’Est Algérien Type de document : texte imprimé Auteurs : Mohamed Amine Gomri, Auteur ; Karima Kharroub, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2012 Importance : 136 f. Format : 31 cm. Note générale : Magister
2 copies imprimées disponiblesLangues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Screening activités hydrolytiques thermophiles source thermales taxonomie numérique Index. décimale : 640 Industrie Alimentaire En ligne : ../theses/agronomie/GOM6158.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=6094 Screening d’activités hydrolytiques extracellulaires chez des souches bactériennes aérobies thermophiles isolées à partir de sources thermales terrestres de l’Est Algérien [texte imprimé] / Mohamed Amine Gomri, Auteur ; Karima Kharroub, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2012 . - 136 f. ; 31 cm.
Magister
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Screening activités hydrolytiques thermophiles source thermales taxonomie numérique Index. décimale : 640 Industrie Alimentaire En ligne : ../theses/agronomie/GOM6158.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=6094 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité GOM/6158 GOM/6158 Thèse Bibliothèque principale Thèses Disponible
