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Papers by leila Chebil Ajjabi

... Pergammon Press, Oxford. 173 pp. Pitta P., Karakassis I., Tsapakis M., Zivanovic S., 1999.Nat... more ... Pergammon Press, Oxford. 173 pp. Pitta P., Karakassis I., Tsapakis M., Zivanovic S., 1999.Natural vs mariculture induced variability in nutrients and plankton in the easternMediterranean. Hydrobiologia 391, 181-194. Shpigel M. & Blaylock RA, 1991. ...

L'activité aquacole est accompagnée d'une pollution causée principalement par le déversement des ... more L'activité aquacole est accompagnée d'une pollution causée principalement par le déversement des nutriments générés par les organismes en élevages. Les macroalgues sont capables d'absorber ces nutriments pour leur croissance favorisant ainsi un revenu supplémentaire à l'aquaculteur en utilisant des espèces à importance économique. Cette étude a pour but de comparer l'efficacité de l'algue rouge Gracilaria bursa-pastoris et l'algue verte Ulva sp. dans le traitement des effluents piscicoles tout en transformant la charge polluante en biomasse algale utilisable. L'étude de la croissance et de la capacité épuratoire de ces deux algues a été menée, pendant deux semaines, sous des conditions contrôlées de laboratoire. Les résultats ont montré que pendant les huit premières heures, les deux algues ont réduit significativement les concentrations des trois nutriments analysés (NH 4 + , NO 3 et PO 4 3+). Ce pendant Ulva sp. s'est montrée plus performante. Parallèlement, les deux algues ont enregistrées un accroissement notable de leur biomasse. Les taux de croissance spécifique de G. bursa-pastoris et Ulva sp. sont respectivement de 1,97 et 2,74%J-1. Ces deux espèces pourraient être utilisées en aquaculture comme filtre biologique et cette biomasse algale produite offre des possibilités de son utilisation dans le domaine biotechnologique.

Journal of Environmental Management, Aug 1, 2009

The biosorption of the heavy metals Cu 2þ and Zn 2þ by dried marine green macroalga (Chaetomorpha... more The biosorption of the heavy metals Cu 2þ and Zn 2þ by dried marine green macroalga (Chaetomorpha linum) was investigated. The biosorption capacities of the dried alga for copper and zinc were studied at different solution pH values (2-6), different algal particle sizes (100-800 mm) and different initial metal solution concentrations (0.5-10 mM). An optimum pH value of 5 was found suitable for both metal ions biosorption for both metal ions. At the optimum particle size (100-315 mm), biosorbent dosage (20 g/l) and initial solution pH (pH 5), the dried alga produced maximum copper and zinc uptakes values (q max) of 1.46 and 1.97 mmol/g respectively (according to the Langmuir model). The kinetic data obtained at different initial metal concentrations indicated that the biosorption rate was fast and most of the process was completed within 120 min. This study illustrated an alternative technique for the management of unwanted biological materials using processed algal material. C. linum is one of the fast-growing marine algae in the lake of Tunis and could be utilized as a biosorbent for the treatment of Cu 2þ and Zn 2þ contaminated wastewater streams.

Aquacultural Engineering, Feb 1, 1998

Abstract An ecosystem culture with a consumer-producer relationship based on the cycle of substan... more Abstract An ecosystem culture with a consumer-producer relationship based on the cycle of substances in the natural ecosystem was constructed in order to study the feasibility of economical cultivation of the marine microalga Nannochloropsis sp. in rotifer waste water. To promote algal growth, the following points were investigated to determine: (1) whether micronutrients necessary for Nannochloropsis culture are generated by rotifers, (2) the favorable and optimal ranges of nutrient concentrations in aged rotifer culture water involved in the optimal growth of Nannochloropsis sp., and (3) the suitability of some economical organic fertilizers in rotifer waste water at earlier stages. In new rotifer waste water, the growth of Nannochloropsis was equal to that in enriched sea water with Enriched Sea Water Provasoli (ESP) nutrients. Micronutrients could be recycled rapidly through feeding and excretion of rotifers. Using aged rotifer waste water, the maximum cellular density was obtained in a waste water with nitrogen and phosphorus concentrations of 364 and 179 μg at. 1 −1 , respectively. This growth was 23% higher than that obtained in enriched sea water with ESP nutrients (control). On the other hand, the organic fertilizers used in this experiment (chicken manure extract and decomposed shark meat) were found to be suitable for enhancing growth of Nannochloropsis sp. in rotifer waste water at earlier stages. The use of chicken manure with an additional inorganic nitrogen source to rotifer waste water resulted in a 50% increase in cellular density of Nannochloropsis sp. compared with that obtained in the control. However, addition of decomposed shark meat to rotifer waste water led only to a 20% increase.

Larhyss Journal Issn 1112 3680, Mar 1, 2015

Aquaculture International, 2017

The feasibility of integrating seaweed cultivation with mussel culture in Bizerte lagoon (north T... more The feasibility of integrating seaweed cultivation with mussel culture in Bizerte lagoon (north Tunisia) was investigated during 1 year, in order to exploit mussel excretion nutrients as resource input and to reduce the risk of eutrophication. In parallel, to evaluate nutrients' biofiltering efficiency and uptake rates of the agarophyte Gracilaria verrucosa, growth and nutrient removal from mussel culture water were investigated. In the laboratory, seaweed/mussel co-culture experiments were compared to mussel monoculture systems. The results showed that nitrogen and phosphorus concentrations in monoculture were significantly higher than those in co-culture treatments. Algal growth rate, thallus nutrient contents, and mussel mortality were different between all treatments. The mussel/seaweed biomass ratio of 1:0.28 (treatment 1) was convenient for efficient nutrient uptake and best seaweed growth. Field cultivation trials showed that G. verrucosa grew well in bivalve culturing farm in Bizerte lagoon at a maximum growth rate of 4.45% day −1 attained in spring season. The mean nitrogen content in dry thalli cultured in co-culture with mussel in Bizerte lagoon was 4.19 ± 0.81%. Results indicate that G. verrucosa can efficiently absorb the nutrients from mussel in Bizerte lagoon and can be associated with local mussel farms, mitigating eutrophication, and eventually, increasing economic incomes of farmers.

Frontiers in Marine Science, 2021

Dictyotales, a common taxonomic group of brown seaweeds found in warm and temperate waters, are k... more Dictyotales, a common taxonomic group of brown seaweeds found in warm and temperate waters, are known for their richness in bioactive metabolites. In this study, six species of Dictyotales (Dictyopteris polypodioides, Dictyota dichotoma, Dictyota fasciola, Dictyota spiralis, Padina pavonica, and Taonia atomaria) collected from the Tunisian coasts were investigated for their antioxidant potentials, based on their contents of high added-value bioactive metabolites such as fucoxanthin and polyphenols. Fucoxanthin and polyphenols were analyzed quantitatively by high-performance liquid chromatography (HPLC) and UV spectrophotometer, respectively. The antioxidant property of extracts was also determined based on their ability to scavenge 2,2-Diphenyl-1-picrylhydrazyl (DPPH’s) free radical. Thus, the highest concentrations of fucoxanthin were obtained from T. atomaria and D. polypodioides (5.53 ± 1.2 and 3.43 ± 1.3 mg⋅g–1 dry weight, respectively), while the lowest amount was from D. spira...

Food chemistry, 2018

This study reports, for the first time, data on nutritional quality parameters in Tunisian mussel... more This study reports, for the first time, data on nutritional quality parameters in Tunisian mussels, Mytilus galloprovincialis, with an especial emphasis on lipid compounds. Mussel condition index (CI), proximate composition and fatty acid profiles were investigated for a one year period in order to identify the best harvesting period. Analysis revealed that polyunsaturated fatty acids (PUFA) were the dominant fatty acids with a prevalence of n-3 over n-6 forms. Pearson's correlation indicated a strong relationship between CI and PUFA compound and Principal Components Analysis suggested that, from winter to summer, the product maintained a condition sufficiently good for marketing. The best CI and lipid quantity/quality occurred during summer and this may be used as criteria for product labelling. The study also included a thorough literature review that allowed data comparison on mussels from various Mediterranean sites and allowed the mussels from the Bizerte lagoon (North of T...

Journal of Applied Phycology, 2021

Many western countries show an increased interest in using algae in several sectors such as human... more Many western countries show an increased interest in using algae in several sectors such as human food and animal feed, nutraceuticals, cosmetics and pharmaceuticals, agriculture, or bioenergy. Biomass of marine origin, and especially seaweed, is a key element for blue growth and is expected to contribute to the development of the growing European blue economy. Several Research and Development and Research and Innovation Projects result in the establishment of an emerging seaweed aquaculture in the Northern European countries. However, macroalgal cultivation and bioprocessing is still scarce in the Mediterranean area, particularly in Tunisia, where seaweeds are abundant on its coast, they remain little exploited. Ongoing projects from different research institutes focus on biological activities of macroalgae, the extraction of active compounds, and the potential uses as phycocolloids, pigments, lipids, and bioactive metabolites characterization as well as bioproduct enhancement. The results of these investigations demonstrate that macroalgae from the Tunisian coasts are a source of valuable compounds and that they can be used as a natural renewable resource suitable for a large array of industrial applications. Further to this, specific research activities on seaweed cultivation have been conducted particularly for Gracilaria and Ulva . In this paper, we highlight the potential of the seaweed sector in Tunisia in terms of biodiversity, cultivation, and bioprocessing and discuss the challenges in various sectors, i.e., biology, building capacity, technology, or policy, that currently hinder the expansion of a sustainable Tunisian seaweed industry.

Aquacultural Engineering, 1998

Journal of Environmental Management, 2009

The biosorption of the heavy metals Cu2+ and Zn2+ by dried marine green macroalga (Chaetomorpha l... more The biosorption of the heavy metals Cu2+ and Zn2+ by dried marine green macroalga (Chaetomorpha linum) was investigated. The biosorption capacities of the dried alga for copper and zinc were studied at different solution pH values (2–6), different algal particle sizes (100–800 μm) and different initial metal solution concentrations (0.5–10 mM). An optimum pH value of 5 was found suitable for both metal ions biosorption for both metal ions. At the optimum particle size (100–315 μm), biosorbent dosage (20 g/l) and initial solution pH (pH 5), the dried alga produced maximum copper and zinc uptakes values (qmax) of 1.46 and 1.97 mmol/g respectively (according to the Langmuir model). The kinetic data obtained at different initial metal concentrations indicated that the biosorption rate was fast and most of the process was completed within 120 min. This study illustrated an alternative technique for the management of unwanted biological materials using processed algal material. C. linum is one of the fast-growing marine algae in the lake of Tunis and could be utilized as a biosorbent for the treatment of Cu2+ and Zn2+ contaminated wastewater streams.

The biosorption of the heavy metals Cu 2þ and Zn 2þ by dried marine green macroalga (Chaetomorpha... more The biosorption of the heavy metals Cu 2þ and Zn 2þ by dried marine green macroalga (Chaetomorpha linum) was investigated. The biosorption capacities of the dried alga for copper and zinc were studied at different solution pH values (2-6), different algal particle sizes (100-800 mm) and different initial metal solution concentrations (0.5-10 mM). An optimum pH value of 5 was found suitable for both metal ions biosorption for both metal ions. At the optimum particle size (100-315 mm), biosorbent dosage (20 g/l) and initial solution pH (pH 5), the dried alga produced maximum copper and zinc uptakes values (q max ) of 1.46 and 1.97 mmol/g respectively (according to the Langmuir model). The kinetic data obtained at different initial metal concentrations indicated that the biosorption rate was fast and most of the process was completed within 120 min. This study illustrated an alternative technique for the management of unwanted biological materials using processed algal material. C. linum is one of the fast-growing marine algae in the lake of Tunis and could be utilized as a biosorbent for the treatment of Cu 2þ and Zn 2þ contaminated wastewater streams.

Journal of Environmental Management, Aug 1, 2009

Aquacultural Engineering, Feb 1, 1998

Larhyss Journal Issn 1112 3680, Mar 1, 2015

Aquaculture International, 2017

Frontiers in Marine Science, 2021

Food chemistry, 2018

Journal of Applied Phycology, 2021

Aquacultural Engineering, 1998

Journal of Environmental Management, 2009

The biosorption of the heavy metals Cu 2þ and Zn 2þ by dried marine green macroalga (Chaetomorpha... more The biosorption of the heavy metals Cu 2þ and Zn 2þ by dried marine green macroalga (Chaetomorpha linum) was investigated. The biosorption capacities of the dried alga for copper and zinc were studied at different solution pH values (2-6), different algal particle sizes (100-800 mm) and different initial metal solution concentrations (0.5-10 mM). An optimum pH value of 5 was found suitable for both metal ions biosorption for both metal ions. At the optimum particle size (100-315 mm), biosorbent dosage (20 g/l) and initial solution pH (pH 5), the dried alga produced maximum copper and zinc uptakes values (q max ) of 1.46 and 1.97 mmol/g respectively (according to the Langmuir model). The kinetic data obtained at different initial metal concentrations indicated that the biosorption rate was fast and most of the process was completed within 120 min. This study illustrated an alternative technique for the management of unwanted biological materials using processed algal material. C. linum is one of the fast-growing marine algae in the lake of Tunis and could be utilized as a biosorbent for the treatment of Cu 2þ and Zn 2þ contaminated wastewater streams.