Publications Scientifiques

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Author: search.filters.author.Lenchi, Nesrine

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    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, Nesrine
    Artemisia 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.
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    Simultaneous removal of crude oil and heavy metals by highly adapted bacterial strain Cutibacterium sp. NL2 isolated from Algerian oilfield
    (Springer Science and Business Media Deutschland GmbH, 2024) Lenchi, Nesrine; Ahmedi, Wissam Nour El Houda; Llirós, Marc
    Investigating the ability of bacteria to simultaneously enhance hydrocarbon removal and reduce heavy metals’ toxicity is necessary to design more effective bioremediation strategies. A bacterium (NL2 strain) isolated from an Algerian oilfield was cultivated on crude oil as sole carbon and energy sources. Molecular analyses of the 16S rRNA gene sequence placed the strain within the Cutibacterium genera. This isolate was able to tolerate up to 60% of crude oil as sole carbon source. Chemical analyses (GC-MS) evidenced that strain NL2 was able to degrade 92.22% of crude oil (at optimal growing conditions: pH 10, 44 °C, 50 g L−1 NaCl, and 20% of crude oil (v/v) as sole carbon source) in only 7 days. NL2 isolate was also able to produce biosurfactants with reduction of surface tension of growing media (29.4 mN m−1). On the other hand, NL2 strain was able to tolerate high lead (Pb) and copper (Cu) concentrations (up to 60 mM). In fact, NL2 cultivated in the presence of 20% of crude oil, and 0.48 mM of Pb was able to reduce Pb concentration by a 41.36%. In turn, when cultivated on high Pb concentration (15 mM), the strain was able to remove 35.19% of it and 86.25% of crude oil, both in a time frame of 7 days. Our findings suggest that Cutibacterium strain NL2 is able to efficiently use and remove a wide range of crude oil substrates in presence of high Pb concentration. Accordingly, NL2 strain is of extreme interest from a biotechnological standpoint.
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    Draft Whole-Genome sequences of microbacterium oxydans and microbacterium maritypicum strains
    (American Society for Microbiology, 2023) Lenchi, Nesrine
    Microbacterium 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%
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    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, Marc
    Corrosion 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 strategies
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    Microbacterium algeriense sp. nov., a novel actinobacterium isolated from Algerian oil production waters
    (Microbiology Society, 2020) Lenchi, Nesrine; Anzil, Adriana; Servais, Pierre; Kebbouche-Gana, Salima; Gana, Mohamed Lamine
    A non-motile, straight-rod-shaped, Gram-stain-positive and facultative anaerobic bacterium (i.e., strain G1T) was isolated from production waters from an Algerian oilfield. Growth was observed in the presence of 0.3-3.5 % (w/v) NaCl, at 20-50 °C and at pH 6.0-9.0. Results of phylogenetic analyses based on 16S rRNA gene sequences showed that strain G1T belonged to the genus Microbacterium. Strain G1 T was closely related to Microbacterium oxydans (DSM 20578T) and Microbacterium maritypicum (DSM 12512T) with 99.8 % sequence similarity and to Microbacterium saperdae (DSM 20169T) with 99.6 % sequence similarity. Strain G1 T contained MK9, MK10, MK11, MK12 and MK13 as respiratory quinones, and phosphatidylglycerol, diphosphatidylglycerol and glycolipid as the major polar lipids. The major cellular fatty acids were anteiso-C15:0, iso-C16:0 and anteiso-C17:0. The estimated DNA G+C content was 69.57 mol% based on its draft genome sequence. Genome annotation of strain G1T predicted the presence of 3511 genes, of which 3483 were protein-coding and 47 were tRNA genes. The DNA-DNA hybridization (DDH) and average nucleotide identity (ANI) values between strain G1T and M. oxydans (DSM 20578T) and M. maritypicum (DSM 12512T) were in both cases far below the respective species boundary thresholds (27.5 and 28.0 % for DDH; and 84.40 and 84.82% for ANI, respectively). Based on the data presented above, strain G1T was considered to represent a novel species for which the name Microbacterium algeriense is proposed with the type strain G1T (=DSM 109018T=LMG 31276T)
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    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, Marc
    In 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 industry
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    Comparison of microbial community composition in injection and formation water from Algerian oilfields
    (2012) Lenchi, Nesrine; Inceoğlu, Özgül; Kebbouche-Gana, Salima; Gana, Mohamed Lamine; Llirós, Marc; Servais, Pierre; Garcia-Armisen, Tamara
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    Production of an extracellular lipase from a halophilic isolate, Idiomarina sp.
    (2013) Akmoussi-Toumi, Siham; Kebbouche-Gana, Salima; Lenchi, Nesrine