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Hamouda Beyrem | University Of Carthage - Academia.edu

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Hamouda Beyrem

University Of Carthage, Faculté Des Sciences Bizerte, Emeritus

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Kwantlen Polytechnic University

Victor Camacho-Ibar

Universidad Autonoma de Baja California

University of Patras

Ashoka Trust for Research in Ecology and the Environment (ATREE)

Yusli Wardiatno

Bogor Agricultural University, Indonesia

University of Kerala

UFBA - Federal University of Bahia

Donan Satria Yudha

Universitas Gadjah Mada (Yogyakarta)

Universidad de Colima

BEN SOUISSI JAMILA

Université Gaston Berger de Saint-Louis, Sénégal

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Papers by Hamouda Beyrem

Individual and combined effects of cadmium and diesel on a nematode community in a laboratory microcosm experiment

Ecotoxicology and Environmental Safety, Nov 1, 2007

This article was published in an Elsevier journal. The attached copy is furnished to the author f... more This article was published in an Elsevier journal. The attached copy is furnished to the author for non-commercial research and education use, including for instruction at the author's institution, sharing with colleagues and providing to institution administration. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit:

Trophic restructuring (Wieser 1953) of free-living nematode in marine sediment experimentally enriched to increasing doses of pharmaceutical penicillin G

Ecotoxicology, May 26, 2016

Trophic structure of free living nematode from Bizerte lagoon was tested by a microcosmic study a... more Trophic structure of free living nematode from Bizerte lagoon was tested by a microcosmic study after 30 days of exposure with 5 increasing doses of pharmaceutical penicillin G (D1: 3 mg L(-1), D2: 30 mg L(-1), D3: 300 mg L(-1), D4: 600 mg L(-1), D5: 700 mg L(-1)). Results showed significant differences between nematode assemblages from undisturbed controls and those from penicillin G treatments. Selective deposit-feeders (1A) or nonselective deposit-feeders (1B), very abundant in the control microcosm, were significantly affected and their dominance declined significantly. Epistrate feeders (2A) were significantly gradual increase for all microcosms treated with penicillin G, appeared to be more tolerant to the antibiotic and to take advantage of the growing scarcity of other trophic groups. Compared to the control microcosms, omnivorous-carnivorous (2B) was found to be higher in all treated microcosms, with the exception of those treated with D5. Trophic index (Σθ(2)) was significantly reduced in all microcosms treated whereas trophic ratio 1B/2A appears to be insignificant.

Toxicity of a chromium-enriched superfood, Spirulina platensis, assessed by taxonomic and morpho-functional diversity of marine meiofauna

Environmental Pollution, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Uptake and metabolism of carbamazepine (CBZ) by clam Ruditapes decussatus and its effects in biochemical responses

Xenobiotica; the fate of foreign compounds in biological systems, Jan 25, 2017

1. Laboratory experiments were carried out to assess uptake and metabolism of the epilepsy drug, ... more 1. Laboratory experiments were carried out to assess uptake and metabolism of the epilepsy drug, carbamazepine and its consequent biological responses in marine clam (Ruditapes decussatus) a model non-target organism in ecotoxicology. 2. Clams were exposed to two nominal concentrations (C1 = 30 μg/L and C2 = 50 μg/L) of CBZ for a maximum period of 14 days. Analysis of CBZ and their metabolites in clam and water after exposure to two nominal concentrations of the pharmaceutical drug were performed using UPLC-HRMS analysis. CBZ accumulation reached an average tissue concentration of 1241.59 ng/g dw and 1664.33 ng/g dw at low and high nominal concentration, respectively. 3. Furthermore, a metabolite (3-hydroxy-CBZ) was detected in tissues indicating carbamazepine translocation and metabolism inside clam, suspect screening of CBZ glucuronides was also performed by accurate mass extraction but it could not be detected. 4. Activities of antioxidant enzymes superoxide dismutase, catalase ...

Impac ts of mineral oil and synthetic lubricant on the trophic diversity of marine nematode community: Results from Microcosm Experiments

The effects of two lubricating oils on the trophic diversity of a nematode community of a Tunisia... more The effects of two lubricating oils on the trophic diversity of a nematode community of a Tunisian lagoon were investigated in a microcosm experiment. Sediment from a pristine site in Ghar El Melh lagoon (Western Mediterranean) was treated with mineral oil (Mobil 20 W-50), a synthetic lubricant (Mobil 0 W-40), the same two lubricants after use in a vehicle. Univariate analysis showed significant differences between univariate indices for trophic structure of nematode assemblages from undisturbed control and those from lubricant treatments. Trophic index (2) and the 1B/2A ratio decreased in all microcosms treated with mineral oil or synthetic lubricant. Results from multivariate analyses of the trophic group abundance data demonstrated that the responses of nematode were dependent on the type of lubricant (mineral or synthetic, "clean" or "used") used for the sediment contamination. Non-selective deposit feeders (1B), most abundant in control microcosm, were ver...

New protocols for the selection and rearing of Metoncholaimus pristiurus and the first evaluation of oxidative stress biomarkers in meiobenthic nematodes

Environmental Pollution, Aug 1, 2020

Meiobenthic nematodes have been designated as sensitive global models in the development of biomo... more Meiobenthic nematodes have been designated as sensitive global models in the development of biomonitoring and ecotoxicology monitoring programs howbeit the sensitivity of these organisms against oxidative stress biomarkers have never been addressed. The present study aimed to decipher this research axis after selecting and culturing a single nematode species from an entire community through original laboratory protocols. The purpose of this investigation was to change the grain size of the sediment into the immediate environment of nematodes by progressively adding a biosubstrate made from Sepia officinalis endoskeletton. At the end of the experiment, Metoncholaimus pristiurus became the unique component of the nematode species when the sediment was enriched with 80% of S. officinalis powder. After the mono-species level had been achieved, the selected species was fed on an another biosubstrate made from bodies of Porcellio scaber under the identical laboratory controlled conditions of light and temperature adopted during the selection process. Accordingly, the bioassay protocol this study layed new foundations for the study of meiobenthic nematodes in the biomarker field. Our results revealed that, in case of M. pritiurus, discernible oxidative stress responses are valid for catalase and gluthatione S-transferase. Indeed, for both enzymes, a clear increase in the activity was recorded, and the response was more reinforced when zinc and permethrin were administrated in combination. The relevance of the protocols proposed in this work parallels their global applicability to reach and maintain the monospecific level in laboratory by using biosubstrates made from animals widely distributed. It is true also that our data provided the first results in terms of biochemical biomarkers for meiobenthic nematodes and showed that the selected taxa, M. pristiurus, could be one of the first marine taxa responding early to the tested stressors, zinc and permethrin, even at very low concentrations.

The protective effect of Hibiscus sabdariffa calyxes extract against cypermethrin induced oxidative stress in mice

Pesticide Biochemistry and Physiology, May 1, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Triangular gold nanoparticles modify shell characteristics and increase antioxidant enzyme activities in the clam Ruditapes decussatus

Biomarkers, Apr 19, 2018

Context: Many reports link nanoparticles with adverse environmental effects. However, relatively ... more Context: Many reports link nanoparticles with adverse environmental effects. However, relatively little information is available on how these compounds interact with marine organisms. Objective: Our aim was to examine the effects of triangular gold nanoparticles (Tr-Au NPs) in the clam, Ruditapes decussatus. Materials and methods: Clams were exposed to Tr-Au1 = 5 µg/L and Tr-Au2 = 10 µg/L for 2 and 7 days to study effects of these nanoparticles. Effects on shell structure were investigated. Superoxide dismutase (SOD), catalase (CAT), glutathione transferase (GST) activities, protein carbonyl levels and malondialdehyde content were used to assess biochemical status. Results: Transmission electron microscopy and electron dispersive X-ray microanalysis (EDX) showed that gold leads to modification of shell structure and morphology. Indeed, Tr-Au NPs size were altered forming aggregate particles. Triangular gold NPs increased SOD, CAT and GST activities in gill and digestive gland in a concentration-and time-dependent manner indicating defense against oxidative stress. Lipid peroxidation and protein carbonyl levels indicated that Tr-Au NPs caused significant cellular damage. Conclusion: This study provides a framework for understanding of toxicological effects of nanoparticles on a filter feeding organism. It explores also novel interactions between Tr-Au NPs and bivalve species.

Possible Interaction between ZnS Nanoparticles and Phosphonates on Mediterranean Clams Ruditapes decussatus

Molecules

This study aims to evaluate the toxicity of ZnS nanoparticles (ZnS NP50 = 50 µg/L and ZnS NP100 =... more This study aims to evaluate the toxicity of ZnS nanoparticles (ZnS NP50 = 50 µg/L and ZnS NP100 = 100 µg/L) and diethyl (3-cyano-1-hydroxy-2-methyl-1-phenylpropyl)phosphonate or P (P50 = 50 µg/L and P100 = 100 µg/L) in the clams Ruditapes decussatus using chemical and biochemical approaches. The results demonstrated that clams accumulate ZnS NPs and other metallic elements following exposure. Moreover, ZnS NPs and P separately lead to ROS overproduction, while a mixture of both contaminants has no effect. In addition, data showed that exposure to P100 resulted in increased levels of oxidative stress enzyme activities catalase (CAT) in the gills and digestive glands. A similar trend was also observed in the digestive glands of clams treated with ZnS100. In contrast, CAT activity was decreased in the gills at the same concentration. Exposure to ZnS100 and P100 separately leads to a decrease in acetylcholinesterase (AChE) levels in both gills and digestive glands. Thus, AChE and CAT af...

Physiological Impairment and Biochemical Modifications Induced by Triclosan in Mediterranean Mussels

Animals

The effects of pharmaceutical under aquatic biota are still not well established. In this investi... more The effects of pharmaceutical under aquatic biota are still not well established. In this investigation, we assessed the results of a common pharmaceutical’s, triclosan (TCS), treatment on physiological and biochemical status of the Mediterranean mussels. Filtration and respiration rates were statistically reduced after treatment with highest considered concentration TCS2 = 100 µg·L−1. However, no modification (p > 0.05) was detected after treatment with TCS1 = 50 µg·L−1. For biochemical responses, oxidative stress parameters including H2O2 level and antioxidant enzymes were enhanced following concentration in considered organs. In parallel, Malondialdheyde content was measured in mussels after TCS treatment and lipid peroxidation occurred at high TCS concentration. Neurotoxicity evaluated by acetylcholinesterase (AChE) activity was induced in gills and digestive glands after exposure to TCS2. Overall, physiological impairment, oxidative stress, lipid peroxidation and neurotoxici...

Ecotoxicity of chrysene and phenanthrene on meiobenthic nematodes with a case study of Terschellingia longicaudata: Taxonomics, toxicokinetics, and molecular interactions modelling

Environmental Pollution

The response of meiobenthinc sediment-dwelling nematodes to pyrene: Results from open microcosms, toxicokinetics and in silico molecular interactions

Marine Pollution Bulletin

The Antidepressants Amitriptyline and Paroxetine Induce Changes in the Structure and Functional Traits of Marine Nematodes

Sustainability

Increasing concentrations of the antidepressants amitriptyline and paroxetine were determined rec... more Increasing concentrations of the antidepressants amitriptyline and paroxetine were determined recently in marine habitats. However, their impact on marine biota is understudied, despite multiple undesirable effects they have on the environment. An important behavioral aspect that is increasingly measured following exposure to contaminants is the migration of fauna from contaminated areas. Hence, our aim was to better understand the migration pattern of marine meiobenthic fauna, but with a main focus on nematodes, following the exposure to both antidepressants, alone or in mixture. The experiment was carried out in microcosms, which comprised an uncontaminated upper and a lower contaminated compartment, where amitriptyline was added, alone or mixed with paroxetine, at concentrations of 0.4 and 40 µg L−1. The overall abundance of meiobenthic groups decreased significantly following exposure to amitriptyline in both compartments, a pattern augmented by the mixture with paroxetine. The ...

Ecological interpretation of the distribution, morphometry and energetics of a population of Paracomesoma dubium Filipjev, 1918 (Comesomatidae, Nematoda) from Bizerte Lagoon (Tunisia) Interprétation écologique de la distribution, de la morphométrie et des données énergétiques d'une population de ...

Relative pharyngeal volume (RPV): new index for stress monitoring using meiobenthic nematodes

Meiofauna Marina, 2006

... The authors thank Dr. Naceur Essid (Bizerte Univer-sity) for his help in nematode sampling, D... more

Enhanced pilot bioremediation of oily sludge from petroleum refinery disposal under hot-summer Mediterranean climate

Environmental Technology & Innovation, 2021

Large pilot scale bioremediation approaches were implemented for the treatments of oily sludge (O... more Large pilot scale bioremediation approaches were implemented for the treatments of oily sludge (OS) characterised by alkaline pH (pH > 9), high concentration of metals (3% dry weight) and high total petroleum hydrocarbons content (TPH) ranging between 22,000 and 67,300 mg kg −1 from a Tunisian petroleum refinery. The treatments included bioaugmentation and biostimulation approaches with autochthonous isolated bacterial strains and consortia. Chemical, microbial, and ecotoxicological analyses were performed over a period of 180 days incubation. The bioremediation treatments favoured the development of Proteobacteria, Firmicutes and Bacteroidetes following an ecological succession of specialist bacterial groups, first associated to hydrocarbon degradation (e.g. Marinobacter and Alcanivorax) that resulted in a greater extent of TPH-degradation (up to 80%), and the selection of metal resistant bacteria including Hyphomonas, Phaeobacter, and Desulfuromusa. The best performances were obtained when bioaugmentation and biostimulation were combined. Over 90% of the TPH initial concentration was degraded over 180 days, which was accompanied with a 3-fold reduction of ecotoxicity. Our study demonstrates the efficacy of large pilot scale bioremediation of highly contaminated oily sludge, providing the evidence that the management of autochthonous microbial communities is of paramount importance for the success of the bioremediation process.

Chronic ecotoxicity of ciprofloxacin exposure on taxonomic diversity of a meiobenthic nematode community in microcosm experiments

Journal of King Saud University - Science, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

What Is the Impact of Dexamethasone and Prednisolone Glucocorticoids on the Structure of Meiobenthic Nematode Communities?

Sustainability

The toxic effects of two commonly used glucocorticoids, the dexamethasone and prednisolone, on me... more The toxic effects of two commonly used glucocorticoids, the dexamethasone and prednisolone, on meiobenthic nematodes were assessed in a laboratory experiment for 30 days. Nine treatments were employed, comprised of two single and mixed concentrations of dexamethasone and prednisolone (i.e., 0.14 and 1.4 µg·L−1). The exposure to both glucocorticoids showed significant effects on the abundance and taxonomic diversity of nematodes. Such changes were mainly induced by the decrease in the abundance of the species Microlaimus honestus, considered to be sensitive to prednisolone and by the increase in Enoplolaimus longicaudatus abundance, which can be considered tolerant. The exposure to these glucocorticoids also led to a decrease in 2A feeding groups, 2–4 mm body-size interval, and c-p3 life history type in most treatments, with type of life history and shape of amphids as the most relevant functional traits impacted by these two glucocorticoids. The results could also be explained by th...

Effects of the antidepressant paroxetine on migratory behaviour of meiobenthic nematodes: Computational and open experimental microcosm approach

Marine Pollution Bulletin, 2022

An open experimental setup was established in order to explore the toxic effects of the antidepre... more An open experimental setup was established in order to explore the toxic effects of the antidepressant paroxetine on meiobenthic nematodes. Three types of microcosms made from polyvinyl chloride tubes, each comprising two sediments compartments (upper and lower), were used in a laboratory experiment for 15 days. The experimental setup targeted the migratory behaviour of the nematofauna from the above compartments, which were exposed to paroxetine (0.4 and 40 μg.l-1), towards below compartments. The univariate indices significantly decrease in the contaminated compartments compared to controls. Multivariate analyses revealed also significant taxonomic dissimilarities between contaminated and uncontaminated compartments. Furthermore, SIMPER functional outcomes highlighted a significant decrease in 2A feeding groups, 'co' tail shape, 1-2 mm interval length, 'cr' amphid shape, and c-p2 life history in contaminated compartments. Computational approach showed that paroxetine bound GLD-3 and SDP with high affinities, which together with molecular interactions and toxicokinetics satisfactorily explain the experimental results.

The individual and combined effects of cadmium, polyvinyl chloride (PVC) microplastics and their polyalkylamines modified forms on meiobenthic features in a microcosm

Environmental Pollution, 2020

A microcosm experiment was carried out to study the ecotoxicity and interactions between heavy me... more A microcosm experiment was carried out to study the ecotoxicity and interactions between heavy metals and polyvinyl chloride microplastics. Fifteen treatments were tested and results were examined after one month. In details, this work aims to study the ecotoxicological effects of cadmium (10 and 20 mg kg-1 Dry Weight DW), polyvinyl chloride (PVC) and its modified forms; PVC-DETA (PD) and PVC-TETA (PT) (20 and 40 mg kg-1 DW), separately and in mixtures, on meiofauna from Bizerte lagoon (NE Tunisia) with focus on nematode features. The results obtained showed that individual treatments were toxic for meiofauna and particularly for free-living nematodes. No clear trends characterized the numerical responses but significant reductions were observed for diversity indices. Moreover, the binary combinations of contaminants have a lesser toxic effect compared to their individual effects. This effect could be related to the high-capacity chelating ability of PVC and its polymers against cadmium.

Individual and combined effects of cadmium and diesel on a nematode community in a laboratory microcosm experiment

Ecotoxicology and Environmental Safety, Nov 1, 2007

This article was published in an Elsevier journal. The attached copy is furnished to the author f... more This article was published in an Elsevier journal. The attached copy is furnished to the author for non-commercial research and education use, including for instruction at the author's institution, sharing with colleagues and providing to institution administration. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit:

Trophic restructuring (Wieser 1953) of free-living nematode in marine sediment experimentally enriched to increasing doses of pharmaceutical penicillin G

Ecotoxicology, May 26, 2016

Trophic structure of free living nematode from Bizerte lagoon was tested by a microcosmic study a... more Trophic structure of free living nematode from Bizerte lagoon was tested by a microcosmic study after 30 days of exposure with 5 increasing doses of pharmaceutical penicillin G (D1: 3 mg L(-1), D2: 30 mg L(-1), D3: 300 mg L(-1), D4: 600 mg L(-1), D5: 700 mg L(-1)). Results showed significant differences between nematode assemblages from undisturbed controls and those from penicillin G treatments. Selective deposit-feeders (1A) or nonselective deposit-feeders (1B), very abundant in the control microcosm, were significantly affected and their dominance declined significantly. Epistrate feeders (2A) were significantly gradual increase for all microcosms treated with penicillin G, appeared to be more tolerant to the antibiotic and to take advantage of the growing scarcity of other trophic groups. Compared to the control microcosms, omnivorous-carnivorous (2B) was found to be higher in all treated microcosms, with the exception of those treated with D5. Trophic index (Σθ(2)) was significantly reduced in all microcosms treated whereas trophic ratio 1B/2A appears to be insignificant.

Toxicity of a chromium-enriched superfood, Spirulina platensis, assessed by taxonomic and morpho-functional diversity of marine meiofauna

Environmental Pollution, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Uptake and metabolism of carbamazepine (CBZ) by clam Ruditapes decussatus and its effects in biochemical responses

Xenobiotica; the fate of foreign compounds in biological systems, Jan 25, 2017

1. Laboratory experiments were carried out to assess uptake and metabolism of the epilepsy drug, ... more 1. Laboratory experiments were carried out to assess uptake and metabolism of the epilepsy drug, carbamazepine and its consequent biological responses in marine clam (Ruditapes decussatus) a model non-target organism in ecotoxicology. 2. Clams were exposed to two nominal concentrations (C1 = 30 μg/L and C2 = 50 μg/L) of CBZ for a maximum period of 14 days. Analysis of CBZ and their metabolites in clam and water after exposure to two nominal concentrations of the pharmaceutical drug were performed using UPLC-HRMS analysis. CBZ accumulation reached an average tissue concentration of 1241.59 ng/g dw and 1664.33 ng/g dw at low and high nominal concentration, respectively. 3. Furthermore, a metabolite (3-hydroxy-CBZ) was detected in tissues indicating carbamazepine translocation and metabolism inside clam, suspect screening of CBZ glucuronides was also performed by accurate mass extraction but it could not be detected. 4. Activities of antioxidant enzymes superoxide dismutase, catalase ...

Impac ts of mineral oil and synthetic lubricant on the trophic diversity of marine nematode community: Results from Microcosm Experiments

The effects of two lubricating oils on the trophic diversity of a nematode community of a Tunisia... more The effects of two lubricating oils on the trophic diversity of a nematode community of a Tunisian lagoon were investigated in a microcosm experiment. Sediment from a pristine site in Ghar El Melh lagoon (Western Mediterranean) was treated with mineral oil (Mobil 20 W-50), a synthetic lubricant (Mobil 0 W-40), the same two lubricants after use in a vehicle. Univariate analysis showed significant differences between univariate indices for trophic structure of nematode assemblages from undisturbed control and those from lubricant treatments. Trophic index (2) and the 1B/2A ratio decreased in all microcosms treated with mineral oil or synthetic lubricant. Results from multivariate analyses of the trophic group abundance data demonstrated that the responses of nematode were dependent on the type of lubricant (mineral or synthetic, "clean" or "used") used for the sediment contamination. Non-selective deposit feeders (1B), most abundant in control microcosm, were ver...

New protocols for the selection and rearing of Metoncholaimus pristiurus and the first evaluation of oxidative stress biomarkers in meiobenthic nematodes

Environmental Pollution, Aug 1, 2020

Meiobenthic nematodes have been designated as sensitive global models in the development of biomo... more Meiobenthic nematodes have been designated as sensitive global models in the development of biomonitoring and ecotoxicology monitoring programs howbeit the sensitivity of these organisms against oxidative stress biomarkers have never been addressed. The present study aimed to decipher this research axis after selecting and culturing a single nematode species from an entire community through original laboratory protocols. The purpose of this investigation was to change the grain size of the sediment into the immediate environment of nematodes by progressively adding a biosubstrate made from Sepia officinalis endoskeletton. At the end of the experiment, Metoncholaimus pristiurus became the unique component of the nematode species when the sediment was enriched with 80% of S. officinalis powder. After the mono-species level had been achieved, the selected species was fed on an another biosubstrate made from bodies of Porcellio scaber under the identical laboratory controlled conditions of light and temperature adopted during the selection process. Accordingly, the bioassay protocol this study layed new foundations for the study of meiobenthic nematodes in the biomarker field. Our results revealed that, in case of M. pritiurus, discernible oxidative stress responses are valid for catalase and gluthatione S-transferase. Indeed, for both enzymes, a clear increase in the activity was recorded, and the response was more reinforced when zinc and permethrin were administrated in combination. The relevance of the protocols proposed in this work parallels their global applicability to reach and maintain the monospecific level in laboratory by using biosubstrates made from animals widely distributed. It is true also that our data provided the first results in terms of biochemical biomarkers for meiobenthic nematodes and showed that the selected taxa, M. pristiurus, could be one of the first marine taxa responding early to the tested stressors, zinc and permethrin, even at very low concentrations.

The protective effect of Hibiscus sabdariffa calyxes extract against cypermethrin induced oxidative stress in mice

Pesticide Biochemistry and Physiology, May 1, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Triangular gold nanoparticles modify shell characteristics and increase antioxidant enzyme activities in the clam Ruditapes decussatus

Biomarkers, Apr 19, 2018

Context: Many reports link nanoparticles with adverse environmental effects. However, relatively ... more Context: Many reports link nanoparticles with adverse environmental effects. However, relatively little information is available on how these compounds interact with marine organisms. Objective: Our aim was to examine the effects of triangular gold nanoparticles (Tr-Au NPs) in the clam, Ruditapes decussatus. Materials and methods: Clams were exposed to Tr-Au1 = 5 µg/L and Tr-Au2 = 10 µg/L for 2 and 7 days to study effects of these nanoparticles. Effects on shell structure were investigated. Superoxide dismutase (SOD), catalase (CAT), glutathione transferase (GST) activities, protein carbonyl levels and malondialdehyde content were used to assess biochemical status. Results: Transmission electron microscopy and electron dispersive X-ray microanalysis (EDX) showed that gold leads to modification of shell structure and morphology. Indeed, Tr-Au NPs size were altered forming aggregate particles. Triangular gold NPs increased SOD, CAT and GST activities in gill and digestive gland in a concentration-and time-dependent manner indicating defense against oxidative stress. Lipid peroxidation and protein carbonyl levels indicated that Tr-Au NPs caused significant cellular damage. Conclusion: This study provides a framework for understanding of toxicological effects of nanoparticles on a filter feeding organism. It explores also novel interactions between Tr-Au NPs and bivalve species.

Possible Interaction between ZnS Nanoparticles and Phosphonates on Mediterranean Clams Ruditapes decussatus

Molecules

This study aims to evaluate the toxicity of ZnS nanoparticles (ZnS NP50 = 50 µg/L and ZnS NP100 =... more This study aims to evaluate the toxicity of ZnS nanoparticles (ZnS NP50 = 50 µg/L and ZnS NP100 = 100 µg/L) and diethyl (3-cyano-1-hydroxy-2-methyl-1-phenylpropyl)phosphonate or P (P50 = 50 µg/L and P100 = 100 µg/L) in the clams Ruditapes decussatus using chemical and biochemical approaches. The results demonstrated that clams accumulate ZnS NPs and other metallic elements following exposure. Moreover, ZnS NPs and P separately lead to ROS overproduction, while a mixture of both contaminants has no effect. In addition, data showed that exposure to P100 resulted in increased levels of oxidative stress enzyme activities catalase (CAT) in the gills and digestive glands. A similar trend was also observed in the digestive glands of clams treated with ZnS100. In contrast, CAT activity was decreased in the gills at the same concentration. Exposure to ZnS100 and P100 separately leads to a decrease in acetylcholinesterase (AChE) levels in both gills and digestive glands. Thus, AChE and CAT af...

Physiological Impairment and Biochemical Modifications Induced by Triclosan in Mediterranean Mussels

Animals

The effects of pharmaceutical under aquatic biota are still not well established. In this investi... more The effects of pharmaceutical under aquatic biota are still not well established. In this investigation, we assessed the results of a common pharmaceutical’s, triclosan (TCS), treatment on physiological and biochemical status of the Mediterranean mussels. Filtration and respiration rates were statistically reduced after treatment with highest considered concentration TCS2 = 100 µg·L−1. However, no modification (p > 0.05) was detected after treatment with TCS1 = 50 µg·L−1. For biochemical responses, oxidative stress parameters including H2O2 level and antioxidant enzymes were enhanced following concentration in considered organs. In parallel, Malondialdheyde content was measured in mussels after TCS treatment and lipid peroxidation occurred at high TCS concentration. Neurotoxicity evaluated by acetylcholinesterase (AChE) activity was induced in gills and digestive glands after exposure to TCS2. Overall, physiological impairment, oxidative stress, lipid peroxidation and neurotoxici...

Ecotoxicity of chrysene and phenanthrene on meiobenthic nematodes with a case study of Terschellingia longicaudata: Taxonomics, toxicokinetics, and molecular interactions modelling

Environmental Pollution

The response of meiobenthinc sediment-dwelling nematodes to pyrene: Results from open microcosms, toxicokinetics and in silico molecular interactions

Marine Pollution Bulletin

The Antidepressants Amitriptyline and Paroxetine Induce Changes in the Structure and Functional Traits of Marine Nematodes

Sustainability

Increasing concentrations of the antidepressants amitriptyline and paroxetine were determined rec... more Increasing concentrations of the antidepressants amitriptyline and paroxetine were determined recently in marine habitats. However, their impact on marine biota is understudied, despite multiple undesirable effects they have on the environment. An important behavioral aspect that is increasingly measured following exposure to contaminants is the migration of fauna from contaminated areas. Hence, our aim was to better understand the migration pattern of marine meiobenthic fauna, but with a main focus on nematodes, following the exposure to both antidepressants, alone or in mixture. The experiment was carried out in microcosms, which comprised an uncontaminated upper and a lower contaminated compartment, where amitriptyline was added, alone or mixed with paroxetine, at concentrations of 0.4 and 40 µg L−1. The overall abundance of meiobenthic groups decreased significantly following exposure to amitriptyline in both compartments, a pattern augmented by the mixture with paroxetine. The ...

Ecological interpretation of the distribution, morphometry and energetics of a population of Paracomesoma dubium Filipjev, 1918 (Comesomatidae, Nematoda) from Bizerte Lagoon (Tunisia) Interprétation écologique de la distribution, de la morphométrie et des données énergétiques d'une population de ...

Relative pharyngeal volume (RPV): new index for stress monitoring using meiobenthic nematodes

Meiofauna Marina, 2006

... The authors thank Dr. Naceur Essid (Bizerte Univer-sity) for his help in nematode sampling, D... more

Enhanced pilot bioremediation of oily sludge from petroleum refinery disposal under hot-summer Mediterranean climate

Environmental Technology & Innovation, 2021

Large pilot scale bioremediation approaches were implemented for the treatments of oily sludge (O... more Large pilot scale bioremediation approaches were implemented for the treatments of oily sludge (OS) characterised by alkaline pH (pH > 9), high concentration of metals (3% dry weight) and high total petroleum hydrocarbons content (TPH) ranging between 22,000 and 67,300 mg kg −1 from a Tunisian petroleum refinery. The treatments included bioaugmentation and biostimulation approaches with autochthonous isolated bacterial strains and consortia. Chemical, microbial, and ecotoxicological analyses were performed over a period of 180 days incubation. The bioremediation treatments favoured the development of Proteobacteria, Firmicutes and Bacteroidetes following an ecological succession of specialist bacterial groups, first associated to hydrocarbon degradation (e.g. Marinobacter and Alcanivorax) that resulted in a greater extent of TPH-degradation (up to 80%), and the selection of metal resistant bacteria including Hyphomonas, Phaeobacter, and Desulfuromusa. The best performances were obtained when bioaugmentation and biostimulation were combined. Over 90% of the TPH initial concentration was degraded over 180 days, which was accompanied with a 3-fold reduction of ecotoxicity. Our study demonstrates the efficacy of large pilot scale bioremediation of highly contaminated oily sludge, providing the evidence that the management of autochthonous microbial communities is of paramount importance for the success of the bioremediation process.

Chronic ecotoxicity of ciprofloxacin exposure on taxonomic diversity of a meiobenthic nematode community in microcosm experiments

Journal of King Saud University - Science, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

What Is the Impact of Dexamethasone and Prednisolone Glucocorticoids on the Structure of Meiobenthic Nematode Communities?

Sustainability

The toxic effects of two commonly used glucocorticoids, the dexamethasone and prednisolone, on me... more The toxic effects of two commonly used glucocorticoids, the dexamethasone and prednisolone, on meiobenthic nematodes were assessed in a laboratory experiment for 30 days. Nine treatments were employed, comprised of two single and mixed concentrations of dexamethasone and prednisolone (i.e., 0.14 and 1.4 µg·L−1). The exposure to both glucocorticoids showed significant effects on the abundance and taxonomic diversity of nematodes. Such changes were mainly induced by the decrease in the abundance of the species Microlaimus honestus, considered to be sensitive to prednisolone and by the increase in Enoplolaimus longicaudatus abundance, which can be considered tolerant. The exposure to these glucocorticoids also led to a decrease in 2A feeding groups, 2–4 mm body-size interval, and c-p3 life history type in most treatments, with type of life history and shape of amphids as the most relevant functional traits impacted by these two glucocorticoids. The results could also be explained by th...

Effects of the antidepressant paroxetine on migratory behaviour of meiobenthic nematodes: Computational and open experimental microcosm approach

Marine Pollution Bulletin, 2022

An open experimental setup was established in order to explore the toxic effects of the antidepre... more An open experimental setup was established in order to explore the toxic effects of the antidepressant paroxetine on meiobenthic nematodes. Three types of microcosms made from polyvinyl chloride tubes, each comprising two sediments compartments (upper and lower), were used in a laboratory experiment for 15 days. The experimental setup targeted the migratory behaviour of the nematofauna from the above compartments, which were exposed to paroxetine (0.4 and 40 μg.l-1), towards below compartments. The univariate indices significantly decrease in the contaminated compartments compared to controls. Multivariate analyses revealed also significant taxonomic dissimilarities between contaminated and uncontaminated compartments. Furthermore, SIMPER functional outcomes highlighted a significant decrease in 2A feeding groups, 'co' tail shape, 1-2 mm interval length, 'cr' amphid shape, and c-p2 life history in contaminated compartments. Computational approach showed that paroxetine bound GLD-3 and SDP with high affinities, which together with molecular interactions and toxicokinetics satisfactorily explain the experimental results.

The individual and combined effects of cadmium, polyvinyl chloride (PVC) microplastics and their polyalkylamines modified forms on meiobenthic features in a microcosm

Environmental Pollution, 2020

A microcosm experiment was carried out to study the ecotoxicity and interactions between heavy me... more A microcosm experiment was carried out to study the ecotoxicity and interactions between heavy metals and polyvinyl chloride microplastics. Fifteen treatments were tested and results were examined after one month. In details, this work aims to study the ecotoxicological effects of cadmium (10 and 20 mg kg-1 Dry Weight DW), polyvinyl chloride (PVC) and its modified forms; PVC-DETA (PD) and PVC-TETA (PT) (20 and 40 mg kg-1 DW), separately and in mixtures, on meiofauna from Bizerte lagoon (NE Tunisia) with focus on nematode features. The results obtained showed that individual treatments were toxic for meiofauna and particularly for free-living nematodes. No clear trends characterized the numerical responses but significant reductions were observed for diversity indices. Moreover, the binary combinations of contaminants have a lesser toxic effect compared to their individual effects. This effect could be related to the high-capacity chelating ability of PVC and its polymers against cadmium.