Publications Scientifiques
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Item Electrocatalytic activity survey of some cathode materials for the reduction of nitrites and nitrates in aqueous solution(Publishing House of the Romanian Academy, 2020) Angar, Yassmina; Daoudi, Sofiane; Kebbouche-Gana, Salima; Djelali, Nacer-EddineThe electrochemical techniques are the subject of increasing interest on the environmental remediation methods thanks to their efficiency and their selectivity. It was classified among the cleanest methods because it does not produce sludge and undesirable intermediate byproducts. For these reasons, we have chosen this technology for the reduction of nitrites and nitrates ions from aqueous solutions. The objective of our study is the comparison of several cathodes materials performances, in order to promote an optimal electro-reduction of these ions. Indeed, we have used the copper, graphite, stainless steel and zinc as cathodes; among them, we have selected the most efficient on which we have optimized the operational conditions. The results suggested that the copper cathode was the most efficient for the reduction of both tested ions compared to the other tested materials. Therefore, the optimization of operational conditions allows us to fixed them at: scan rate=50 mV/s, initial effluent concentration=100 mg/L, pH=7 and potential range of the cyclic voltammetry scanning of [-1,+1]V/SCE for both ions. Under these optimal parameters, the reduction yield after 45min was important that can achieve 96.5% and 99% for nitrites and nitrates respectivelyItem Identification and phylogenetic analyses of anaerobic sulfidogenic bacteria in two Algerian oilfield water injection samples(Taylor & Francis, 2021) Lenchi, Nesrine; Kebbouche-Gana, Salima; Servais, Pierre; Gana, Mohammed Lamine; Llirós, MarcCorrosion of metallic oilfield pipelines by microorganisms is a costly but poorly understood phenomenon. For the first time, sulfidogenic communities in injection waters of two Algerian oilfields, Tin Fuin Tabankort (IT3) and Stah (IS2) were examined using the 16S rRNA gene cloning and sequencing approach. Water samples were inoculated into selective medium for sulfate-reducing bacteria and incubated under anaerobic conditions at 45 °C. The total number of culturable sulfidogenic microorganisms in the samples obtained from the two sampled waters (IT3 and IS2) was 2.4 × 105 cells/mL and 3.9 × 104 cells/mL, respectively. Scanning electron microscopy analyses showed different morphological forms reflecting the diversity of sulfidogenic communities. 16S rRNA gene sequencing and phylogenetic diversity analyses revealed that both water reservoirs harbor large amounts of anaerobic bacteria. However, a majority of all the sequences analyzed (e.g., 34% in the IS2 and 84% in the IT3 samples) were not assigned to any known bacterial group, suggesting that subsurface waters harbor very large sulfidogenic anaerobic microbial communities of as yet undescribed bacterial phyla. Proteobacteria were found to be the most dominant phylum in the IS2 sample (49%); however, no Proteobacteria were detected at the IT3 production well. The Firmicutes phylum (10%) was detected in the two water samples, whereas Bacteroidetes phylum (7%) was retrieved only in IT3. The most abundant related genera were: Desulfotomaculum, Porphyrobacter, Hyphomicrobium, Acidocella, Comamonas, Ramlibacter, Pseudomonas, Enterobacter and Flavitalea. No shared operational taxonomic units were observed among the two samples analyzed, demonstrating the uniqueness of each subsurface water well. This study demonstrates the diversity of the sulfidogenic bacteria that might play a critical role in the souring mediated corrosion of metallic oilfield pipelines. This information could help oilfield companies develop better anticorrosion treatments and strategiesItem A Comprehensive Study on Crude Methanolic Extract of Daphne gnidium L. as Effective Corrosion Inhibitors of Mild Steel Induced by SRB Consortium(Springer, 2019) Djouahra-Fahem, Djamila; Angar, Yassmina; Lamine Mohamed, Gana; Khoukhi, Faiza; Kebbouche-Gana, SalimaThe aim of the present work is the evaluation of effect of methanolic extract obtained from Daphne gnidium against biocorrosion caused by sulphate-reducing bacteria (SRB). Herein, the study of the influence of SRB consortium has been realized on the biological and electrochemical properties of the carbon steel API5LX60 immersed in water sample obtained from an Algerian oil field separator. The monitoring of the treatment effects on the SRB performance using kits test and weight loss methods showed a positive effect of the methanolic extract of D. gnidium as a corrosion inhibitor at a concentration of 0.8 g/L. In the other hand, the weight loss test has generated an efficiency rate of 95.99% at a concentration of 1.6 g/L. A linear polarization resistance approved these results, and they have given a yield of 91.14% with a polarization resistance value of 28.9 kΩ cm2 at a concentration of 0.25 g/L.Item Efficiency Evaluation of Anti-corrosion Treatment of Carbon Steel by Extracts of Red Algae Collected from Mediterranean Coast(Revista de Chimie SRL, 2021) Khoukhi, Faiza; Kebbouche-Gana, Salima; Djelali, Nacer Eddine; Gana, Mohamed LamineThe paper presents the assessment of inhibition effectiveness of biomolecules extracted from red seaweed against biocorrosion in the petroleum industry. The first objective of this study was to obtain extracts (A, B and C, prepared respectively from red algae species: Corallina ellongata, Gymnogongrus crenulatus and Pterocladia capillacea) by ethanol extraction method. The infrared spectra of the three extracts confirmed the presence of amine derivatives molecules known by their anti-corrosion inhibiting powers. The second objective was based on the identification of physico-chemical characteristics of the extracts and thus revealing their inhibitory and / or bactericidal power in bacterial corrosion of carbon steel in injection water contaminated with sulfato-reducing bacteria. Biological test of all extracts gave a concentration upto 10 germs/mL in contaminated water by sulfato-reducing bacteria during 28 days of incubation at 37°C. Evolution in time of the open-circuit potential showed a longer incubation time for electrolyte with extracts, whereas the stabilization time was shorter. Current corrosion density, polarization resistance, charge transfer resistance and double layer capacity were determined by using linear polarizarion resistance technique and electrochemical impedance spectroscopy. The corrosion protection efficiency of extract obtained from Gymnogongrus crenulatus (extract B) reached a maximum protective capacity of 99.69% at 5 ppm in the injection water.Item Biodegradation of Petroleum hydrocarbons and Biosurfactant production by an extremely halophilic Archaea Halovivax sp. A21(Aljest, 2017) Khemili-Talbi, S.; Kebbouche-Gana, Salima; Akmoussi-Toumi, S.; Gana, M.L.; Lahiani,S.; Ferrioune ,I.; Angar,Y.Over the recent few years, biosurfactant has played an important role in the industrial application especially in oil recovery; even in high salinity conditions. The potential of biosurfactant production by the extreme halophilic archaeon Halovivax sp. A21 in the presence of petroleum hydrocarbons (2% v/v) as sole carbon source at high salinity (25% NaCl) has been investigated. The results show the ability of Halovivax sp. A21 to grow and reduce surface tension under an optimum range of pH (7-9), salinities (15-35% NaCl) and temperature (40-45°C) for an optimized volume of 100 ml of the medium for 1000 ml capacity Erlenmeyer flasks with an optimum agitation of 120 rpm. The rates of biosurfactant production on petroleum hydrocarbons were enhanced with increasing NaCl concentration in the medium with an optimum of 25%. Biosurfactant production by Halovivax sp. A21 showed high emulsifying activity (more than 80%) and decreased surface tension (24.5 mN/m). The stability of the produced biosurfactant was determined by different physico-chemical conditions like pH, temperature and salinity. Moreover, the partial purification of the derived biosurfactant by silica gel column chromatography and Thin-layer chromatography revealed that it belongs to the lipopeptide group. Although both catechol dioxygenases participated in the degradation of petroleum hydrocarbons, more induction of catechol 1,2 dioxygenase was observed than the catechol 2,3 dioxygenase which indicated the predominance of the ortho cleavage pathways in the petroleum hydrocarbons degradation by the halophilic strain Halovivax sp. A21. The results demonstrated that strain Halovivax sp. A21 was able to increase the bioavailability of insoluble hydrocarbons, thus facilitating their uptake and their biodegradation even at high salt concentration. Likewise, the search of novel biosurfactants in extremophiles, or the use of microorganisms that present excellentItem Insights into the draft genome sequence of bioactives-producing Bacillus thuringiensis DNG9 isolated from Algerian soil-oil slough(2018) Daas, Mohamed Seghir; Rosana, Albert Remus R.; Acedo, Jeella Z.; Douzane, Malika; Nateche, Farida; Kebbouche-Gana, Salima; Vederas, John C.Bacillus thuringiensisis widely used as a bioinsecticide due to its ability to form parasporal crystals containingproteinaceous toxins. It is a member of theBacillus cereussensulato, a group with low genetic diversity butproduces several promising antimicrobial compounds.B. thuringiensisDNG9, isolated from an oil-contaminatedslough in Algeria, has strong antibacterial, antifungal and biosurfactant properties. Here, we report the 6.06 Mbpdraft genome sequence ofB. thuringiensisDNG9. The genome encodes several gene inventories for thebiosynthesis of bioactive compounds such as zwittermycin A, petrobactin, insecticidal toxins, polyhydroxyalkanoatesand multiple bacteriocins. We expect the genome information of strain DNG9 will provide another model system tostudy pathogenicity against insect pests, plant diseases, and antimicrobial compound mining and comparativephylogenesis among theBacillus cereussensulatogroupItem Valorization of olive tree leaves : phytochemical and pharmacological characterizations, selection of extracts and formulation of herbal cream(2021) Bakdi, Hadjer; Kebbouche-Gana, Salima; Djelali, N.; Louhab, K.; Yahiaoui, K.Olive tree (Olea EuropeaL.) is one of the most important crops in the Mediterranean countries. The global olive oil industry annually generates many tons of olive leaves as waste.The present study aims at a valorisation of Algerian olive leaves harvested from the region of Bouirafor therapeutic use. In order to evaluate the biological effects of the wild olive tree, chemical characterization tests of the leaves were carried out in the Natural Substances Laboratory of Saidal group according to their validated protocols drawn from the French pharmacopoeia. A phytochemical screening has been realized and whose purpose is to refer to the extraction, screening and identification of the medicinally active substances in the plant. Different extractions have been carried out in several solvents in order to extract bioactive molecules from the leaves using several solvents. Subsequently, a pharmacological characterization has been completed by determining the following: antioxidant activity of the extracts was evaluated in vitro by the DPPH method, anti-inflammatory activity was studied in vivo by induction of carrageenan oedema; the antibacterial activity was achieved by the agar medium diffusion method. Finally, we formulated an anti-inflammatory and antibacterial ointments based on the results obtainedItem Diesel Biodegradation Capacities and Biosurfactant Production in Saline-Alkaline Conditions by Delftia sp NL1, Isolated from an Algerian Oilfield(Taylor and Francis Inc., 2020) Lenchi, Nesrine; Kebbouche-Gana, Salima; Servais, Pierre; Gana, Mohamed Lamine; Llirós, MarcIn this study, a diesel oil-degrading bacterium was isolated from an oilfield water injection (water-bearing formations, 1,205 m depth) in Algeria. The bacterial strain, designated NL1, was cultivated on diesel oil as sole carbon and energy sources. Molecular analyses of the 16S rRNA gene sequence (KY397882) placed NL1 strain closely related to distinct cultivated species of the Delftia genus. Optimal diesel oil biodegradation by Delftia sp NL1 strain occurred at pH 11, 40 °C, 2 M NaCl and initial hydrocarbon concentration of 5% (v/v) as sole carbon source. GC-MS analyses evidenced that strain Delftia sp NL1 was able to degrade more than 66.76% of diesel oil within only 7 days. On the other hand, and in the same conditions, biosurfactant production by Delftia sp NL1 was also evaluated evidencing high emulsifying capacity (E24 = 81%), ability to lower the surface tension of growing media (with the value of 25.7 mN m− 1), and production of glycolipids (8.7 g L−1) as biosurfactants. This research presents indigenous strain Delftia sp NL1 for diesel degradation and synthesis of biosurfactant in extreme conditions. In this sense, strain NL1 is a good candidate for possible in situ oil recovery and in wastewater treatment in refineries and oil terminals in petroleum industryItem Kinetic and thermodynamic studies of the ammonium ions adsorption onto natural Algerian bentonite(Taylor & Francis, 2016) Angar, Yassmina; Djelali, Nacer-Eddine; Kebbouche-Gana, SalimaAdsorption processes are the most recommended complementary techniques applied in the wastewater treatment owing to their low economic cost, recyclability, efficiency and low power consumption. Clays known for this treatment are aluminosilicate minerals which contain different exchangeable ions on their surfaces. In the structure of bentonite surface, several cations have the exchange ability such as calcium, sodium, magnesium and potassium. This propriety is responsible for the adsorption of several cationic water pollutants. In this study, natural bentonite particles of 80 μm in diameter were considered and kept stirring at 200 RPM in a contaminated solution with ammonium ions. The effect of contact time and temperature showed that at an optimal temperature of 30°C and during a short stirring time of 50 min, the removal efficiency could reach its maximum of 53.36%. The kinetic study of the ammonium adsorption reaction on natural bentonite allowed concluding that the reaction is obeyed to the first-order model. Determination of various thermodynamic parameters suggests that the reaction is spontaneous and exothermicItem Diversity of Culturable Halophilic Archaea and Bacteria from Chott Tinsilt and El Malah Salt-Lake in Algeria(Science publications, 2020) Akmoussi-Toumi, Siham; Khemili-Talbi, Souad; Kebbouche-Gana, Salima; Lenchi-Izouine, Nesrine; Khelfaoui, Mohamed El Amine; Sayah, Amna; Bouarab, Ghania; Ferrioune, Imen; Mokhtari, Wafa; Najjari, AfefAt the limits of life, hyper-saline aquatic ecosystems; Chott and Sebkha are a model of choice of extreme environments, housing a halophilic microflora that had to adapt to these conditions. In Algeria, these ecosystems are poorly studied. However, our study was carried out on the waters of Chott Tinsilt and Sebkha El Malah. The study of this microflora revealed the presence of a significant morphological, physiological and metabolic diversity. The molecular study allowed us to access to a phylogenetic affiliation including an Archean Species (ATS1) and 7 bacterial species (A1, A2, A3, A4, B1, B4, B5). The results showed that these isolates were related to the genera Haloferax (for the strain ATS1) and Halomonas (strains A1, A2 and A4), Staphylococcus (strain A3), Salinivibrio (strain B1), Planococcus (strain B4) and Halobacillus (strain B5). Most isolates produced hydrolases at high salt concentrations. The Production yields obtained are very promising for applications in the biotechnology and industrial microbiology.