| Titre : |
Etude des exopolysaccharides (EPSs) d'origine bactérienne leurs intérets en bio-industries |
| Type de document : |
texte imprimé |
| Auteurs : |
Mounira Hammadi, Auteur ; Amina Khider, Auteur ; Abdelkrim Chaida, Auteur |
| Editeur : |
Tipaza [Algérie] : Centre universitaire Morsli Abdellah - Tipaza- |
| Année de publication : |
2024/2025 |
| Importance : |
p.89 |
| Présentation : |
couv. en noir et blanc ., ill., fig.,tabl. |
| Format : |
30 cm |
| Accompagnement : |
CD |
| Note générale : |
Bibliographie: p71-81.
Annexes: p82-88. |
| Langues : |
Français (fre) |
| Catégories : |
Microbiologie
|
| Mots-clés : |
Expolysaccharides Screening Optimization Antibacterial activity Antioxidant activity ATR-FTIR. |
| Index. décimale : |
579.49 |
| Résumé : |
Microbial exopolysaccharides (EPS) are attracting growing interest due to their remarkable physicochemical and biological properties. These biopolymers find diverse applications in the pharmaceutical, food, and environmental fields, as texturizing agents, stabilizers, thickeners, and flocculants.
The objective of this study is to explore the biological activities of EPS produced by bacteria isolated from different biotopes, namely antioxidant and antibacterial activity. With this in mind, this study focused on the isolation and characterization of an EPS-producing bacterial strain from environmental samples (river water, red soil, and brown soil). A primary screening was performed on HJL agar at pH 7 after incubation at 30°C for 72 hours.Colonies with a mucoid and shiny appearance were selected for further investigation. Optimization of production conditions was conducted by evaluating the effect of different carbon sources (glucose and sucrose) at various concentrations, as well as different pH and temperature values. This optimization was carried out on liquid HJL agar medium.
Among the 21 isolated strains, the strain designated SR6 proved to be the most efficient in terms of EPS biosynthesis. Its identification based on phenotypic and biochemical tests using the API 50 CH array allowed it to be classified as a fermenting bacteria. Structural analysis of the EPS produced, performed by Fourier Transform Infrared Spectroscopy (ATR-FTIR), revealed the presence of hydroxyl and glycosidic groups, characteristic of exopolysaccharides of bacterial origin.
The antibacterial activity of EPS was demonstrated against pathogenic strains of ATCC. Results showed significant growth inhibition of Staphylococcus aureus ATCC 25923 at concentrations of 15, 30, 60, and 120 mg/ml. However, no antioxidant effect was observed against Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. Furthermore, the antioxidant activity results showed that EPS exhibited no antioxidant effects against DPPH.
These results are quite encouraging for further exploration of bacterial EPS and for highlighting their interesting biological properties, such as antibacterial activity and other potential properties.
|
Etude des exopolysaccharides (EPSs) d'origine bactérienne leurs intérets en bio-industries [texte imprimé] / Mounira Hammadi, Auteur ; Amina Khider, Auteur ; Abdelkrim Chaida, Auteur . - Tipaza [Algérie] : Centre universitaire Morsli Abdellah - Tipaza-, 2024/2025 . - p.89 : couv. en noir et blanc ., ill., fig.,tabl. ; 30 cm + CD. Bibliographie: p71-81.
Annexes: p82-88. Langues : Français ( fre)
| Catégories : |
Microbiologie
|
| Mots-clés : |
Expolysaccharides Screening Optimization Antibacterial activity Antioxidant activity ATR-FTIR. |
| Index. décimale : |
579.49 |
| Résumé : |
Microbial exopolysaccharides (EPS) are attracting growing interest due to their remarkable physicochemical and biological properties. These biopolymers find diverse applications in the pharmaceutical, food, and environmental fields, as texturizing agents, stabilizers, thickeners, and flocculants.
The objective of this study is to explore the biological activities of EPS produced by bacteria isolated from different biotopes, namely antioxidant and antibacterial activity. With this in mind, this study focused on the isolation and characterization of an EPS-producing bacterial strain from environmental samples (river water, red soil, and brown soil). A primary screening was performed on HJL agar at pH 7 after incubation at 30°C for 72 hours.Colonies with a mucoid and shiny appearance were selected for further investigation. Optimization of production conditions was conducted by evaluating the effect of different carbon sources (glucose and sucrose) at various concentrations, as well as different pH and temperature values. This optimization was carried out on liquid HJL agar medium.
Among the 21 isolated strains, the strain designated SR6 proved to be the most efficient in terms of EPS biosynthesis. Its identification based on phenotypic and biochemical tests using the API 50 CH array allowed it to be classified as a fermenting bacteria. Structural analysis of the EPS produced, performed by Fourier Transform Infrared Spectroscopy (ATR-FTIR), revealed the presence of hydroxyl and glycosidic groups, characteristic of exopolysaccharides of bacterial origin.
The antibacterial activity of EPS was demonstrated against pathogenic strains of ATCC. Results showed significant growth inhibition of Staphylococcus aureus ATCC 25923 at concentrations of 15, 30, 60, and 120 mg/ml. However, no antioxidant effect was observed against Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. Furthermore, the antioxidant activity results showed that EPS exhibited no antioxidant effects against DPPH.
These results are quite encouraging for further exploration of bacterial EPS and for highlighting their interesting biological properties, such as antibacterial activity and other potential properties.
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