Publications Scientifiques

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    Valorization Of Brown Algae (cystoseira Caespitosa) From Local Region In Algeria For Sodium Alginate Extraction And Their Application In The Immobilization Of Microbial Pectinases
    (Université M'Hamed Bougara Boumerdes, 2019) Benmalek, N.; Nouani, A.; Benchabane, A.
    Sodium alginate were extracted from brown algae (Cystoseira Caespitosa) collected from Algerian Mediterranean coast. the physicochemical characteristic of sodium alginate showed that the average yield was 12% and the average molecular masse was 9000Da calculated using intrinsic viscosity data. Fourier transform infrared spectroscopy was used to characterize the extracted powder of sodium alginate, COO- and C-O-C were evident in the finger print region, the ratio of guluronic acid (G) / mannuronic acid (M) was recorded to be 0.91. This polysaccharide were used to immobilize crude pectinolytic enzymes synthesized by a strain of Aspergillus niger sp. The immobilization was carried out by dropwise introduction of alginate-enzyme mixture into a 0.2M CaCl 2 solution, by this technique, alginates shrinking in the form of spherical beads. The calcium alginate beads have been analyzed using scanning electron microscopy (SEM), observation under SEM showed that the beads have a rough surface and the enzymes were successfully included in the beads. The immobilization efficiency was about 83.9% and the immobilized enzyme could be reused in 4 cycles keeping 42,14% of its initial activity. The beads were successfully used for apple juice clarification.
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    Kinetic and equilibrium studies of salicylic acid adsorption from contaminated water by (alginate/chitosan/cobalt ferrite) nanocomposites
    (Aljest, 2019) Aroun, I.; Bensacia, N.; Seffah, K.; Benyahia, S.
    The main objective of this study is the synthesis of the (Alginate / Chitosan/ Cobalt ferrite) nanocomposites. The asdsorbent was characterized via Fourrier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (DRX) and zeta potential. The adsorption tests of salicylic acid on the (Alginate / chitosan / cobalt ferrite) adsorbent were carried out at a temperature of 25°C, pH equal to 4, a mass of 10 mg and a concentration of 10 mg /L. Under these conditions, the adsorption capacity was found to be of the order of 10 mg /g, which corresponds to an equilibrium time of 90 min. The kinetics of adsorption is correctly written by the kinetic model of the pseudo second order. The adsorption data were fitted using the Langmuir and Freundlich isotherms, and the obtained modeling equilibrium adsorption data suggested that the (Alginate / Chitosan/ Cobalt ferrite) nanocomposites sample contained homogeneous adsorption sites that fit the Langmuir adsorption model well
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    Valorization of brown algae (Cystoseira caespitosa) from local region in Algeria for sodium alginate extraction and their application in the immobilization of microbial pectinases
    (Aljest, 2019) Hachemi-Benmalek, N.; Nouani, A.; Benchabane, A.
    Sodium alginate were extracted from brown algae (Cystoseira Caespitosa) collected from Algerian Mediterranean coast. the physicochemical characteristic of sodium alginate showed that the average yield was 12% and the average molecular masse was 9000Da calculated using intrinsic viscosity data. Fourier transform infrared spectroscopy was used to characterize the extracted powder of sodium alginate, COO- and C-O-C were evident in the finger print region, the ratio of guluronic acid (G) / mannuronic acid (M) was recorded to be 0.91. This polysaccharide were used to immobilize crude pectinolytic enzymes synthesized by a strain of Aspergillus niger sp. The immobilization was carried out by dropwise introduction of alginate-enzyme mixture into a 0.2M CaCl 2 solution, by this technique, alginates shrinking in the form of spherical beads. The calcium alginate beads have been analyzed using scanning electron microscopy (SEM), observation under SEM showed that the beads have a rough surface and the enzymes were successfully included in the beads. The immobilization efficiency was about 83.9% and the immobilized enzyme could be reused in 4 cycles keeping 42,14% of its initial activity. The beads were successfully used for apple juice clarification.
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    Production of biosurfactant on crude date syrup under saline conditions by entrapped cells of Natrialba sp. strain E21, an extremely halophilic bacterium isolated from a solar saltern (Ain Salah, Algeria)
    (Springer, 2013) Kebbouche-Gana, Salima; Gana, Mohamed Lamine; Ferrioune, Imen; Khemili, Souad; Lenchi, Nesrine; Akmoussi-Toumi, Siham; Bouanane-Darenfed, Nabila Amel; Djelali, Nacer-Eddine
    A bacterial strain E21 was isolated from a sample of water collected in the salt lake located close to Ain Salah, Algeria. The analysis of 16S rRNA gene sequence had indicated that the strain had 93 % sequence similarity with the genus Natrialba sp. strain E21 (Gen- Bank, FR750525.1) and was considered extremely halo- philic. Production of biosurfactant by the strain E21 with free and entrapped cells was investigated using soluble starch in the saline conditions. Biosurfactant synthesis was followed by measuring the surface tension and emulsifying index 9 days under optimal conditions (40 C, pH 7). Some diffusional limitations in alginate and agar beads affected the kinetics of biosurfactant production when compared to that obtained with free cells culture. The minimum values of surface tension were 27 and 30 mN m - 1 achieved after 9 days with free and immobilized cells, respectively, while the corresponding maximum E24 values were 65.3 and 62.3 %, respectively. The re-use of bacterial cells along with the limited cell losses provided by the immobilized system might lead to significant reduction of the biosur- factant production cost