Browsing by Author "Nawal Mekersi"

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    Effects of single and combined olive mill wastewater and olive mill pomace on the growth, reproduction, and survival of two earthworm species (Aporrectodea trapezoides, Eisenia fetida)
    (journal homepage, 2021) Nawal Mekersi
    The extraction processes of olive oil produce huge amounts of by-products, such as olive mill wastewater (OMWW) and olive mill pomace (OMP), these by-products have significant polluting properties related to their undesirable color and odor, high organic load, acidic pH, high phenolic compounds, high salinity, while their effect on soil organisms is unclear. The study into the effects of these by-products on soil bioindicators, such as earthworms should therefore be prioritized. Indeed, the purpose of this study was to evaluate the effect of environmentally realistic concentrations of olive mill wastewater and olive mill pomace on the growth, reproduction, and survival of the earthworms Aporrectodea trapezoides, and Eisenia fetida. Bioindicators were exposed under laboratory conditions to increasing doses (12.5%, 25%, 50%, 75%, and 100% w/w) of OMWW and OMP separately and in combination. The results showed a higher growth rate on Eisenia fetida when exposed to 12.5% OMP, with a neutral effect on reproduction and survival. Toxicological effects were found at higher doses, namely: there was no cocoon production, growth inhibition, and mortality; these effects were probably due to the higher level of phenolic compounds and higher salinity. In general OMP was found to have toxicity higher than OMWW, the combination of both by-products showed stronger effects on some earthworm endpoints. Comparative responses between the two species showed that Aporrectodea trapezoides proved to be more tolerant. Dilution and bioremediation of these by-products is recommended as a possible solution to reduce their toxicity.
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    Evaluation of the effects of short-term amendment with olive mill pomace on some soil properties
    (SOIL SCIENCE ANNUAL, 2022-01-30) Nawal Mekersi
    The extraction of olive oil produces an enormous quantity of waste, such as olive mill wastewater (OMWW) and olive mill pomace (OMP), The majority of the agricultural wastes, including olive oil mill waste, are used as soil amendments due to their high nutritional value. The purpose of this study was to investigate the effects of the amendment with olive mill pomace from a 3-phase coldpressed system on the characteristics of the soil pH, electrical conductivity (EC), and organic matter content (OM). The experiment was carried out using increasing rates of olive mill pomace (12.5%, 25%, 50%, 75%, and 100% w/w) plus the control untreated soil in microcosms under laboratory conditions. The results showed that the treatment of soil with olive mill pomace has a signifi cant effect on soil properties (pH, EC, OM, OC, and CaCO ) soil pH was decreased under OMP treatment, especially with high doses of PR4 and PR5, and the electrical conductivity of the soil (EC) was increased, as well as soil carbonate content. Moreover, the soil organic matter content and soil organic carbon content were highly increased under the treatment with OMP. As a result, we can consider the olive mill pomace as a soil fertilizer. Pretreatment of olive mill pomace to reduce acidic pH and salt content before use as a soil amendment is also recommended. 3
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    Investigation of Photoprotective, Anti-Inflammatory, Antioxidant Capacities and LC–ESI–MS Phenolic Profile of Astragalus gombiformis Pomel
    (2021) Kenza Kadi; Nawal Mekersi
    Plant-derived compounds have recently been gaining popularity as skincare factors due to their ability to absorb ultraviolet radiations and their anti-inflammatory, and antioxidant properties. In this light, this work aimed to evaluate in vitro the pharmacological activities of the butanolic extract prepared from the aerial parts of Astragalus gombiformis Pomel, an endemic species to southern Algeria. The sun protection factor was used to assess the photoprotective effect (SPF), the protein denaturation method to determine the anti-inflammatory activity, and brine shrimp nauplii and OxHLIA assay, respectively, to assess the cytotoxicity and antioxidant capacity of A. gombiformis. In addition, LC–ESI–MS analysis was employed for the characterization of the phenolic constituents of A. gombiformis. The results showed that A. gombiformis had high capacity for absorbing UV radiations with an SPF of 37.78 0.85 and significant anti-inflammatory activity with a percentage inhibition of 75.38% which is close to that of diclofenac and ketoprofen. In addition, A. gombiformis was found to have effective cytotoxicity against Artemia nauplii with a DC50 value of about 44.7 g/mL, but a weak hemolytic effect against human erythrocytes. LC–ESI–MS results detected the presence of 17 phenolic compounds with a predominance of cirsiliol, silymarin, quercitrin (quercetin-3-Orhamnoside), and kaempferol. Taken together, these results suggest that A. gombiformis extract could be used as a skincare agent in cosmetic formulations, providing excellent antioxidant and anti-inflammatory protection, allowing the treatment of skin conditions, as well as a pharmaceutical agent with multidimensional applications.
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    Soil amendment by olive pomace improving soil quality
    (Journal of Natural Resources and Environment, 2022-03-24) Nawal Mekersi
    The majority of agricultural wastes, including olive oil mill waste, are used as soil amendments due to their high nutritional value. Thepurpose of this study was to investigate the effects of the amendment with olive mill pomace from a 3-phase cold-pressed system on the characteristics fertility of the soil pH, electrical conductivity (EC), and organic matter (OM). The experiment was carried out using twoincreasing rates of olive mill pomace (50% and 100% w/w) plus the control untreated soil in microcosms under laboratory conditions. the results showed that the 50% of olive mill pomace was slightly reduced soil pH and slightly increased on soil (EC), while the 100% of olivemill pomace has a significant decrease on soil pH and a significant increase in soil (EC), Moreover, the amendment of the soil with olivemill pomace has significantly increasing soil organic matter. As a result, we can consider the olive mill pomace as a soil fertilizer.Pretreatment of olive mill pomace to reduce acidic pH and salt content before use as a soil amendment is also recommended.