Publications Scientifiques
Permanent URI for this communityhttps://dspace.univ-boumerdes.dz/handle/123456789/10
Browse
7 results
Search Results
Item Chemical composition, antimicrobial and antioxidant activities of methanolic extracts of the Algerian Artemisia campestris L. at different stage of growth(Springer, 2024) Brahmi, Fairouz; Berrached, Rachda; Kebbouche Gana, Salima; Kadik, Leila; Lenchi, NesrineArtemisia campestris, widely abundant in North Africa, is usually used as a decoction to treat several diseases; but its chemical composition at different growth stages and along a climatic gradient has never been investigated. In this study, phytochemical content, antioxidant and antimicrobial activities of crude methanolic fractions from dry aerial parts of A. campestris, growing in two different bioclimatic conditions, were compared. The growth stages, vegetative and reproductive, were also taken into consideration. The HPLC analysis revealed the presence of several compounds like ascorbic, isovannilic, ferrulic and cinnapic acids. The antioxidant activity was evaluated with two different methods: DPPH and FRAP essay. The four samples showed very high antioxidant activity. The in vitro antimicrobial activity shows a strong inhibitory effect against gram positive bacteria. But, they were resistant to gram negative bacteria and yeast. The biggest inhibition diameter was recorded against S. aureus and B. cereus.Item Draft Whole-Genome sequences of microbacterium oxydans and microbacterium maritypicum strains(American Society for Microbiology, 2023) Lenchi, NesrineMicrobacterium spp. are a group of microbes that have been recovered from a wide variety of environments in nature. Here, I report the complete genomic data for Microbacterium oxydans and Microbacterium maritypicum type strains that are already present in public culture repositories. The genome of the M. oxydans strain was 3,894,869 bp long, with a G1C content of 68.26%. The genome of the M. maritypicum strain was 3,668,377 bp long, with a G1C content of 68.44%Item 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 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 Valorisation de sous produits agroalimentaires pour la production de biosurfactants(2014) Kebbouche-Gana, Salima; Khemili, Souad; Akmoussi-Toumi, Siham; Lenchi, NesrineItem 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-EddineA 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 costItem Diversity of microbial communities in production and injection waters of algerian oilfields revealed by 16S rRNA gene amplicon 454 pyrosequencing(2013) Lenchi, Nesrine; Kebbouche-Gana, Salima; Gana, M.A.; Lliro, M.; Servais, P.The microorganisms inhabiting many petroleum reservoirs are multi-extremophiles capable of surviving in environments with high temperature, pressure and salinity. Their activity influences oil quality and they are an important reservoir of enzymes of industrial interest. To study these microbial assemblages and to assess any modifications that may be caused by industrial practices, the bacterial and archaeal communities in waters from four Algerian oilfields were described and compared. Three different types of samples were analyzed: production waters from flooded wells, production waters from non-flooded wells and injection waters used for flooding (water - bearing formations). Microbial communities of production and injection waters appeared to be significantly different. From a quantitative point of view, injection waters harbored roughly ten times more microbial cells than production waters. Bacteria dominated in injection waters, while Archaea dominated in production waters. Statistical analysis based on the relative abundance and bacterial community composition (BCC) revealed significant differences between production and injection waters at both OTUs 0.03 and phylum level. However, no significant difference was found between production waters from flooded and non-flooded wells, suggesting that most of the microorganisms introduced by the injection waters were unable to survive in the production waters. Furthermore, a Venn diagram generated to compare the BCC of production and injection waters of one flooded well revealed only 4% of shared bacterial OTUs. Phylogenetic analysis of bacterial sequences indicated that Alpha- , Beta- and Gammaproteobacteria were the main classes in most of the water samples. Archaeal sequences were only obtained from production wells and each well had a unique archaeal community composition, mainly belonging to Methanobacteria , Methanomicrobia , Thermoprotei and Halobacteria classes. Many of the bacterial genera retrieved had already been reported as degraders of complex organic molecules and pollutants. Nevertheless, a large number of unclassified bacterial and archaeal sequences were found in the analyzed samples, indicating that subsurface waters in oilfields could harbor new and still-non-described microbial species