35 results on '"Sabour, Brahim"'
Search Results
2. Lipophilic toxins occurrence in non-traditional invertebrate vectors from North Atlantic Waters (Azores, Madeira, and Morocco): Update on geographical tendencies and new challenges for monitoring routines
- Author
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Silva, Marisa, Rodríguez, Inés, Barreiro, Aldo, Kaufmann, Manfred, Neto, Ana Isabel, Hassouani, Meryem, Sabour, Brahim, Alfonso, Amparo, Botana, Luis M., and Vasconcelos, Vitor
- Published
- 2020
- Full Text
- View/download PDF
3. Feasibility of ex-situ recruitment and outplanting of Gongolaria nodicaulis (Fucales, Phaeophyceae) for restoration of warm temperate marine forests in Atlantic Morocco.
- Author
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Khaya, Khaoula, Falace, Annalisa, Serrão, Ester A., Neiva, João, Reani, Abdeltif, Sabour, Brahim, and Belattmania, Zahira
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TEMPERATE forests ,FUCALES ,INTERTIDAL zonation ,CONSERVATION & restoration ,CYSTOSEIRA ,BROWN algae ,BROMELIACEAE - Abstract
Brown algal forests provide many ecosystem services but are declining worldwide, prompting a growing number of conservation and restoration efforts. Recent attempts to recover Cystoseira forests are encouraging in the Mediterranean, but whether this is possible in more challenging Atlantic conditions has not yet been investigated. In this study, we assess the feasibility of cultivating Gongolaria nodicaulis by producing ex-situ recruits for reforestation on the Atlantic coast of Morocco. Embryos of G. nodicaulis were cultured on clay tiles for 26 days under controlled conditions without water motion, reaching an average length of 3 mm before being outplanted on the intertidal zone. The transplants were monitored for six months. Recruits experienced high loss rates, approximately 47 % of zygotes within 7 days in culture and 75 % of outplanted seedlings within 10 days in the field. The latter might result from natural self-thinning (competition), but our observations suggested that it was also largely due to the weak attachment of recruits to the tiles resulting from cultivation under calm conditions. Six months after the transplants, the surviving individuals reached the size of wild adult algae (average length of 13.5 cm), and some even became reproductive. Globally, survival rates, growth, physiological condition and fertility in this restoration pilot suggest that ex-situ recruitment and outplanting of G. nodicaulis is a promising approach to recover forests in Atlantic Morocco. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
- View/download PDF
4. Spatiotemporal variation of the epifaunal assemblages associated to Sargassum muticum on the NW Atlantic coast of Morocco
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Belattmania, Zahira, Chaouti, Abdellatif, Engelen, Aschwin H., Serrao, Ester A., Machado, Margarida, Reani, Abdeltif, and Sabour, Brahim
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- 2020
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5. Brown Seaweed Sargassum muticum as Low-Cost Biosorbent of Methylene Blue
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El Atouani, Samir, Belattmania, Zahira, Reani, Abdeltif, Tahiri, Soufiane, Aarfane, Abdellatif, Bentiss, Fouad, Jama, Charafeddine, Zrid, Rachid, and Sabour, Brahim
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- 2019
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6. Distribution, health and threats to Mediterranean macroalgal forests: defining the baselines for their conservation and restoration.
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Verdura, Jana, Rehues, Lluc, Mangialajo, Luisa, Fraschetti, Simonetta, Belattmania, Zahira, Bianchelli, Silvia, Blanfuné, Aurélie, Sabour, Brahim, Chiarore, Antonia, Danovaro, Roberto, Fabbrizzi, Erika, Giakoumi, Sylvaine, Iveša, Ljiljana, Katsanevakis, Stelios, Kytinou, Eleni, Nasto, Ina, Nikolaou, Athanasios, Orfanidis, Sotiris, Rilov, Gil, and Rindi, Fabio
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CONSERVATION & restoration ,MARINE algae ,FOREST restoration ,FOREST degradation ,CYSTOSEIRA ,ALGAL communities ,ECOSYSTEMS - Abstract
The worldwide decline of macroalgal forests is raising major concerns for the potentially negative consequences on biodiversity and ecosystem functions, pushing for the definition of specific conservation and restoration measures. Protecting and restoring these habitats requires detailed information on their distribution, ecological status, and drivers of decline. Here, we provide the most updated available information on the distribution of Mediterranean Cystoseira s.l. forests by conducting a comprehensive bibliographic survey of literature published from 2009 to 2021, complemented by unpublished data. We also provide insights into the ecological status of these forests and the stressors affecting them across the Mediterranean basin. Our results show that most Mediterranean coasts remain un(der)studied and that the available information is concentrated in spatially limited coastal areas, restricted to very few species. When the ecological status is reported, data is highly heterogeneous, making any comparisons problematic, what claims for the description and use of easy and standardized monitoring methods for comparative purposes. Drivers of decline of Cystoseira s.l. forest have been even less investigated and, therefore, still poorly characterized. Our results highlight that our current knowledge is still insufficient to implement effective conservation and restoration strategies at the basin scale but also regionally. We call for the urgent need for mapping and standardized monitoring of Cystoseira s.l. forests to obtain baseline information for future management strategies involving their conservation, the mitigation of the stressors threatening them and the restoration of the degraded forests. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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7. The paranthurid isopod crustacean Paranthura nigropunctata (Lucas, 1846): first record from the Atlantic coast of Morocco
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Belattmania, Zahira, Chaouti, Abdellatif, Reani, Abdeltif, Machado, Margarida, Engelen, Aschwin H., Serrão, Ester A., and Sabour, Brahim
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- 2018
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8. Biosynthesis and Characterization of Silver Nanoparticles Using Sodium Alginate from the Invasive Macroalga Sargassum muticum
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Belattmania, Zahira, Bentiss, Fouad, Jama, Charafeddine, Barakate, Mustapha, Katif, Chaimaa, Reani, Abdeltif, and Sabour, Brahim
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- 2018
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9. The Invasive Seaweed Agarophyton vermiculophyllum from Oualidia Lagoon (Northwestern Moroccan Atlantic Coast) as a Source of Agar: Yield, Chemical Characteristics, and Rheological Properties.
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Nadri, Amal, Belattmania, Zahira, Chaouti, Abdellatif, Bentiss, Fouad, Jama, Charafeddine, Hmimid, Fouzia, Reani, Abdeltif, and Sabour, Brahim
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RHEOLOGY ,AGAR ,MARINE algae ,LAGOONS ,CHEMICAL properties ,AGAROSE - Abstract
Agar is a hydrophilic biopolymer extracted from red seaweed. This phycocolloid consists of two components: agarose and agaropectin. In the present work, agar extracted from the invasive red seaweed Agarophyton vermiculophyllum was characterized using physical, chemical, and spectroscopic analyses to investigate the effect of alkaline pretreatment on agar properties. Two extraction conditions, native and alkali-pretreated agars, were comparatively studied. The native yield (28.4 ± 0.9%) was higher than that of the alkaline-pretreated agar (20.4 ± 0.8%). The alkali-pretreated agar showed higher gel strength (763.8 ± 57.0g cm
−2 ), gelling (36.5 ± 0.9 °C), and melting (83.2 ± 0.6 °C) temperatures and increased 3,6-anhydrogalactose (26.2 ± 1.9%) and decreased sulfate contents (6.2 ± 0.8%) compared with native agar (gel strength: 204.8 ± 17.10g cm−2 , gelling temperature: 29.5 ± 0.9 °C, melting temperature: 73.4 ± 0.7 °C, 3,6-AG content: 13.8 ± 0.7%, sulfate content: 10.5 ± 0.5%). The alkaline pretreatment improved the agar's gelling properties and significantly influenced its chemical properties. In view of the obtained results, A. vermiculophyllum might potentially be thought of as a viable source for the agar industry in Morocco, serving as a local source of agar. [ABSTRACT FROM AUTHOR]- Published
- 2023
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10. DNA barcoding reveals cryptic diversity, taxonomic conflicts and novel biogeographical insights in Cystoseira s.l. (Phaeophyceae).
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Neiva, João, Bermejo, Ricardo, Medrano, Alba, Capdevila, Pol, Milla-Figueras, David, Afonso, Pedro, Ballesteros, Enric, Sabour, Brahim, Serio, Donatella, Nóbrega, Eduardo, Soares, João, Valdazo, José, Tuya, Fernando, Mulas, Martina, Israel, Álvaro, Sadogurska, Sofia S., Guiry, Michael D., Pearson, Gareth A., and Serrão, Ester A.
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CYSTOSEIRA ,GENETIC barcoding ,MARINE algae ,BIOGEOGRAPHY ,ALGAE ,LAMINARIA ,BROWN algae - Abstract
Cystoseira sensu lato (s.l.) – encompassing the genera Cystoseira sensu stricto (s.s.), Ericaria and Gongolaria – is a diverse group of forest-forming brown macroalgae endemic to the warm-temperate North-east Atlantic. These algae have immense biogeographic and ecological significance and have been experiencing recent regional declines. Most Cystoseira s.l. display important morphological plasticity and can be confused with similar species. Therefore, species boundaries, geographic ranges and phylogenetic affinities remain imprecise for most. In the face of persistent taxonomic difficulties, several authors underlined the necessity for new molecular-based approaches, but studies so far lacked representativity, resolution and standardization. To fill in these gaps, in this study we sequenced a comprehensive collection of Cystoseira s.l. spanning its entire North-east Atlantic range for a ~1200 bp cox1 barcode, and sequenced selected individuals representing major genetic entities for a few additional plastid markers. Phylogeographic, phylogenetic and species delimitation methods revealed 27 Molecular Operational Taxonomic Units, including unaccounted cryptic diversity, and elucidated with unprecedented resolution species compositions and phylogenetic relationships within each genus. Some entities within the lineages Cystoseira compressa/humilis, Ericaria brachycarpa/crinita, E. selaginoides and tophulose Gongolaria, as well as among free-living algae, conflicted with a priori taxonomic assignments, and required the redefinition, reinstatement and recognition of new taxa. For some, diagnostic mutations and biogeography were more useful for species identifications than morphological characters or conventional barcoding gaps. A few species showed narrow geographic ranges and others were the sole representatives of their respective lineages. Several sister-species showed Atlantic vs Mediterranean complementary ranges. Phylogenetic signal of cox1 was nevertheless insufficient to confidently determine patterns of lineage splitting in several lineages and species complexes and did not improve significantly with additional plastid markers. We discuss novel systematics and biogeography insights considering the advantages and shortcomings of the barcoding approach employed, and how this comprehensive baseline study can be expanded to address multiple questions still left unanswered. HIGHLIGHTS Identification of major genetic entities of Cystoseira s.s., Ericaria and Gongolaria. A comprehensive reference cox1 barcode library for Cystoseira s.l. Updated systematics and biogeography of Cystoseira s.l. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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- View/download PDF
11. Latitudinal incidence of phototrophic shell-degrading endoliths and their effects on mussel bed microclimates
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Lourenço, Carla R., Nicastro, Katy R., McQuaid, Christopher D., Sabour, Brahim, and Zardi, Gerardo I.
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- 2017
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12. The invasive Atlantic blue crab Callinectes sapidus Rathbun, 1896 expands its distributional range southward to Atlantic African shores: first records along the Atlantic coast of Morocco.
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Chaouti, Abdellatif, Belattmania, Zahira, Nadri, Amal, Serrão, Ester A., Encarnação, Joao, Teodósio, Alexandra, Reani, Abdeltif, and Sabour, Brahim
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BLUE crab ,TERRITORIAL waters ,PORTUNIDAE ,COASTS ,CRUSTACEA ,DECAPODA ,SOUND recordings - Abstract
The occurrence of the exotic Atlantic blue crab Callinectes sapidus Rathbun, 1896 (Crustacea: Decapoda: Portunidae) is reported for the first time from the Moroccan Atlantic coast. Working with local fishermen, we gathered 160 records of the Atlantic blue crab from several estuarine, coastal and marine areas, in the period between June and August 2021. These new records confirm its establishment in the Atlantic coasts of North Africa, suggesting a southern range expansion. These findings, likely exacerbated by growing populations along the Atlantic coast of Morocco and temperate coastal waters, provide new insights into the invasion dynamics of this species in the northeast Atlantic Ocean. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
13. Synthesis and Characterization of Silver Nanoparticles Using Alginate from the Brown Seaweed Laminaria ochroleuca: Structural Features and Antibacterial Activity
- Author
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Kaidi, S, Belattmania, Zahira, Bentiss, Fouad, Jama, Charafeddine, Reani, Abdeltif, Sabour, Brahim, Université Chouaib Doukkali (UCD), Unité Matériaux et Transformations - UMR 8207 (UMET), and Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
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silver nanoparticles ,[CHIM.POLY]Chemical Sciences/Polymers ,Molecular Medicine ,[CHIM.MATE]Chemical Sciences/Material chemistry ,biosynthesis ,Molecular Biology ,Biochemistry ,Biotechnology ,sodium alginate ,Laminaria ochroleuca - Abstract
International audience; In this study, inexpensive and eco-friendly production of the silver nanoparticles (AgNPs) was explored using Laminaria ochroleuca sodium alginate as stabilizing and reducing agent. The synthesized nanoparticles were characterized by various analytical techniques such as UV–Vis spectroscopy, Energy dispersive X-ray spectrometer (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM), TEM selected area electron diffraction (SAED), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The synthesis of AgNPs was elucidated by characteristic absorption peaks in the UV–Vis test. The FTIR analysis revealed the involvement of many functional groups in the bioreduction and the stabilization of AgNPs, while TEM images illustrated the spherical shape with maximum particles found in the size range of 10-20 nm. Prominent peaks and silver diffraction rings shown by the XRD spectrum and SAED pattern, respectively, confirmed the crystalline nature (fcc) of the synthesized AgNPs, which were found to be thermally stable based on TGA analysis. The AgNPs exhibited strong antibacterial activity against Gram+ and Gram– bacteria. The synthesized silver nanoparticles using Laminaria ochroleuca sodium alginate revealed interesting properties that could be potentially used for pharmaceutical applications.
- Published
- 2021
14. Isolation and Structural Characterization of Alginates from the Kelp Species Laminaria ochroleuca and Saccorhiza polyschides from the Atlantic Coast of Morocco.
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Kaidi, Soukaina, Bentiss, Fouad, Jama, Charafeddine, Khaya, Khaoula, Belattmania, Zahira, Reani, Abdeltif, and Sabour, Brahim
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KELPS ,SACCORHIZA polyschides ,NUCLEAR magnetic resonance spectroscopy ,VISCOSITY ,CHEMICAL structure - Abstract
Alginates are linear unbranched polysaccharides produced by brown seaweeds. The gel properties of this phycocolloid are mainly linked to the monomer composition, sequential structure and molecular weight of the polymeric chain. Nevertheless, these structural parameters are also dependent on the age and tissue of the thalli used. In this work, the kelp species Laminaria ochroleuca and Saccorhiza polyschides harvested from the Moroccan coast were analyzed for their alginates content and composition in different thalli parts (blade and stipe). Spectroscopic characterization (
1 H NMR and FT-IR), viscosity, and molecular weight of the extracted alginates were investigated. The obtained results showed that the alginate contents ranged from 20.19 ± 2 to 49.8 ± 2.4% dw. FT-IR spectroscopy exhibited similar spectra between the alginates extracted from both species and the commercial alginate. The1 H-NMR results revealed interesting variations in block composition between species, and less disparity with regard to the tissue type (M/G values ranging from 0.89 to 2.14). High mannuronate content was found in all alginates except for those extracted from the blade of L. ochroleuca. The homopolymeric fractions FMM are remarkably high compared to the FGG and heteropolymeric fractions (FGM /FMG ) in S. polyschides. However, for L. ochroleuca, the heteropolymeric fractions are quite abundant, accounting for more than 34% of the polymer diads. The alginates extracted from both species indicated low values for the intrinsic viscosity. Based on the yield and the structural properties of their alginates, this study suggests that both L. ochroleuca and S.polyschides could be considered potential alginophytes to be incorporated into the industry of alginates. It also proposes an optimization of the yield, using the different thalli parts in the extraction (blade and stipe). The chemical structure and viscosity of their alginates may contribute to expanding their applications, especially in biotechnology and medical fields. [ABSTRACT FROM AUTHOR]- Published
- 2022
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15. Mechanistic Insights into the Selective Synthesis of 4 H -Pyran Derivatives On-Water Using Naturally Occurring Alginate from Sargassum muticum: Experimental and DFT Study.
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Oudghiri, Khaoula, Belattmania, Zahira, Elmouli, Hamid, Guesmi, Salaheddine, Bentiss, Fouad, Sabour, Brahim, Bahsis, Lahoucine, and Taourirte, Moha
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PYRAN derivatives ,CHEMICAL synthesis ,ALGINATES ,WIREWEED ,DENSITY functional theory - Abstract
The naturally occurring sodium alginate (SA) biopolymer from the Sargassum muticum (Yendo) Fensholt was employed as a green organocatalyst for the synthesis of 4H-pyran derivatives. The naturally extracted macromolecule was fully characterized using different analyses, including nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Energy Dispersive X-ray Analysis (EDX). The catalytic activity of SA was investigated in the one-pot reaction between aldehydes, malononitrile, and 1,3-dicarbonyl compounds in water at room temperature, and the corresponding 2-amino-3-cyano-4H-pyran derivatives were obtained with good to excellent yields. This organocatalyst was easily separated from the reaction mixture and reused for at least two consecutive cycles without a significant loss of its catalytic activity or selectivity. From the mechanistic point of view, density functional theory (DFT) and NCI analyses were performed for the first time to explain the regioselectivity outcomes for the synthesis of 2-amino-3-cyano-4H-pyran derivatives using SA as a green organocatalyst. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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- View/download PDF
16. The invasive Atlantic blue crab Callinectes sapidus Rathbun, 1896 expands its distributional range southward to Atlantic African shores: first records along the Atlantic coast of Morocco.
- Author
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Chaouti, Abdellatif, Belattmania, Zahira, Nadri, Amal, Serrão, Ester A., Encarnação, Joao, Teodósio, Alexandra, Reani, Abdeltif, and Sabour, Brahim
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BLUE crab ,PORTUNIDAE ,COASTS ,CRUSTACEA ,SOUND recordings ,DECAPODA - Abstract
The occurrence of the exotic Atlantic blue crab Callinectes sapidus Rathbun, 1896 (Crustacea: Decapoda: Portunidae) is reported for the first time from the Moroccan Atlantic coast. Working with local fishermen, we gathered 160 records of the Atlantic blue crab from several estuarine, coastal and marine areas, in the period between June and August 2021. These new records confirm its establishment in the Atlantic coasts of North Africa, suggesting a southern range expansion. These findings, likely exacerbated by growing populations along the Atlantic coast of Morocco and temperate coastal waters, provide new insights into the invasion dynamics of this species in the northeast Atlantic Ocean. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
17. Chemical Composition and In Vitro Antioxidant and Antimicrobial Activities of the Marine Cyanolichen Lichina pygmaea Volatile Compounds.
- Author
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Sanad, Hiba, Belattmania, Zahira, Nafis, Ahmed, Hassouani, Meryem, Mazoir, Noureddine, Reani, Abdeltif, Hassani, Lahcen, Vasconcelos, Vitor, and Sabour, Brahim
- Abstract
Volatile compounds from the marine cyanolichen Lichina pygmaea, collected from the Moroccan Atlantic coast, were extracted by hydrodistillation and their putative chemical composition was investigated by gas chromatography coupled to mass spectrometry (GC/MS). Based on the obtained results, Lichina pygmaea volatile compounds (LPVCs) were mainly dominated by sesquiterpenes compounds, where γ-himachalene, β-himachalene, (2E,4E)-2,4 decadienal and α-himachalene were assumed to be the most abundant constituents, with percentage of 37.51%, 11.71%, 8.59% and 7.62%, respectively. LPVCs depicted significant antimicrobial activity against all tested strains (Staphylococcus aureus CCMM B3, Pseudomonas aeruginosa DSM 50090, Escherichia coli ATCC 8739 and Candida albicans CCMM-L4) with minimum inhibitory concentration (MIC) values within the range of 1.69–13.5 mg/mL. Moreover, this LPVC showed interesting scavenging effects on the 2,2-diphenyl-1-picrylhydrazyl radical with an IC
50 of 0.21 mg/mL. LPVCs could be an approving resource with moderate antimicrobial potential and interesting antioxidant activity for cosmetics and pharmaceutical applications. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
18. Seasonal patterns of growth, alginate content and block structure of the alien invader Sargassum muticum (Fucales, Ochrophyta) from the Atlantic coast of Morocco.
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Belattmania, Zahira, El Atouani, Samir, Bentiss, Fouad, Jama, Charafeddine, Falace, Annalisa, Chaouti, Abdellatif, Reani, Abdeltif, and Sabour, Brahim
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ALGINIC acid ,SARGASSUM ,FUCALES ,SEASONS ,MOLE fraction ,ALGINATES ,BROWN algae - Abstract
In the present study, alginate yield and composition were investigated during the seasonal life cycle of the alien brown alga Sargassum muticum harvested from the Atlantic coast of Morocco. Alginate yield ranged from 11.14% in winter to 25.62% in spring/early summer, coinciding with maximum vegetative growth. Monthly monitoring of the alginate block structure showed that the highest mannuronate (M)/guluronate (G) ratio was recorded during the maximum development of S. muticum, before sexual maturity and during resumption of vegetative growth, giving maximum flexibility to the alga. The unusually high molar monad fractions (F
G ) and dyad fractions (FGG ) of guluronic acid in late summer/early autumn appeared to be related to stiffness of senescent thalli. Rheological characterisation showed that the alginate of S. muticum exhibited pseudoplastic behaviour, with the highest apparent viscosities measured in late summer/early autumn when the G blocks dominated the alginate structure. This study suggests that S. muticum could be exploited as an alginophyte for commercial applications. The best harvest time is May-June, which corresponds to the highest alginate yield, maximum thallus growth, and largely completed sexual reproduction, ensuring sustainable exploitation of the species. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
19. New invertebrate vectors of Okadaic acid from the North Atlantic Waters - Portugal (Azores and Madeira) and Morocco
- Author
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Silva, Marisa, Rodriguez, Inés, Barreiro, Aldo, Kaufmann, Manfred Josef, Neto, Ana Isabel, Hassouani, Meryem, Sabour, Brahim, Alfonso, Amparo, Botana, Luis M., and Vasconcelos, Vitor
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Faculdade de Ciências da Vida ,Okadaic acid ,Morocco ,New vectors ,Madeira Island (Portugal) ,São Miguel Island ,São Miguel Island, Açores (Portugal) ,Madeira Island - Abstract
Okadaic acid and its analogues are potent phosphatase inhibitors that cause Diarrheic Shellfish Poisoning (DSP) through the ingestion of contaminated shellfish by humans. This group of toxins is transmitted worldwide but the number of poisoning incidents has declined over the last 20 years due to legislation and monitoring programs that were implemented for bivalves. In the summer of 2012 and 2013, we collected a total of 101 samples of 22 different species that were made up of benthic and subtidal organisms such echinoderms, crustaceans, bivalves and gastropods from Madeira, São Miguel Island (Azores archipelago) and the northwestern coast of Morocco. The samples were analyzed by UPLC-MS/MS. Our main objective was to detect new vectors for these biotoxins. We can report nine new vectors for these toxins in the North Atlantic: Astropecten aranciacus, Arbacia lixula, Echinaster sepositus, Holothuria sanctori, Ophidiaster ophidianus, Onchidella celtica, Aplysia depilans, Patella spp., and Stramonita haemostoma. Differences in toxin contents among the species were found. Even though low concentrations were detected, the levels of toxins that were present, especially in edible species, indicate the importance of these types of studies. Routine monitoring should be extended to comprise a wider number of vectors other than for bivalves of okadaic acid and its analogues.
- Published
- 2015
20. The invasive brown seaweed Sargassum muticum as new resource for alginate in Morocco: Spectroscopic and rheological characterization.
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El Atouani, Samir, Bentiss, Fouad, Reani, Abdeltif, Zrid, Rachid, Belattmania, Zahira, Pereira, Leonel, Mortadi, Abdelhadi, Cherkaoui, Omar, and Sabour, Brahim
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WIREWEED ,ALGINATES ,RHEOLOGY ,SHORELINES ,PHYCOLOGY ,BIOPOLYMERS - Abstract
SUMMARY The Japanese brown seaweed Sargassum muticum, recently invaded several shorelines worldwide including the Atlantic coast of Morocco with large well-established populations. Within the framework of a sustainable strategy to control this invasive seaweed, we report on extraction yield, spectroscopic characterization and rheological properties of alginate, a commercially valuable colloid, from harvested biomass of S. muticum. Extraction yield was about 25.6% on dry weight basis. Infrared spectroscopy analysis shows that the obtained Fourier transform infrared spectra of the extracted biopolymer exhibit strong similarities with that of the commercial alginate. Furthermore, Proton nuclear magnetic resonance spectroscopy revealed that S. muticum alginate has almost equal amounts of β-D-mannuronic acid (M; 49%) and α-L-guluronic acid (G; 51%) with an M/G ratio of 1.04 and a high content of heteropolymeric MG GM diads suggesting a sequence distribution of an alternated polymer type. Rheological measurements were performed at different sodium alginate concentrations, temperatures and shear rates. The hydrocolloid exhibited pseudoplastic behavior and showed shear thinning, particularly at high solution concentration and low temperature which is consistent with the rheological behavior reported for commercial alginates. Considering the abundance of S. muticum in the Northwestern Atlantic coast of Morocco and the quality of the extracted hydrogel, this invasive species could be considered as a potential source of alginates. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
21. New Invertebrate Vectors of Okadaic Acid from the North AtlanticWaters--Portugal (Azores and Madeira) and Morocco.
- Author
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Silva, Marisa, Rodriguez, Inés, Barreiro, Aldo, Kaufmann, Manfred, Neto, Ana Isabel, Hassouani, Meryem, Sabour, Brahim, Alfonso, Amparo, Botana, Luis M., and Vasconcelos, Vitor
- Subjects
INVERTEBRATES as carriers of disease ,PHOSPHATASE inhibitors ,SHELLFISH ,GASTROPODA ,TOXINS - Abstract
Okadaic acid and its analogues are potent phosphatase inhibitors that cause Diarrheic Shellfish Poisoning (DSP) through the ingestion of contaminated shellfish by humans. This group of toxins is transmitted worldwide but the number of poisoning incidents has declined over the last 20 years due to legislation and monitoring programs that were implemented for bivalves. In the summer of 2012 and 2013, we collected a total of 101 samples of 22 different species that were made up of benthic and subtidal organisms such echinoderms, crustaceans, bivalves and gastropods from Madeira, São Miguel Island (Azores archipelago) and the northwestern coast of Morocco. The samples were analyzed by UPLC-MS/MS. Our main objective was to detect new vectors for these biotoxins. We can report nine new vectors for these toxins in the North Atlantic: Astropecten aranciacus, Arbacia lixula, Echinaster sepositus, Holothuria sanctori, Ophidiaster ophidianus, Onchidella celtica, Aplysia depilans, Patella spp., and Stramonita haemostoma. Differences in toxin contents among the species were found. Even though low concentrations were detected, the levels of toxins that were present, especially in edible species, indicate the importance of these types of studies. Routine monitoring should be extended to comprise a wider number of vectors other than for bivalves of okadaic acid and its analogues. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
22. First Report of Ciguatoxins in Two Starfish Species: Ophidiaster ophidianus and Marthasterias glacialis.
- Author
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Silva, Marisa, Rodriguez, Inés, Barreiro, Aldo, Kaufmann, Manfred, Neto, Ana Isabel, Hassouani, Meryem, Sabour, Brahim, Alfonso, Amparo, Botana, Luis M., and Vasconcelos, Vitor
- Subjects
STARFISHES ,CIGUATERA poisoning ,ALGAL toxins ,BIVALVES ,ECHINODERMATA - Abstract
Ciguatera fish poisoning (CFP) is a syndrome caused by the ingestion of fish contaminated with Ciguatoxins (CTXs). These phycotoxins are produced mainly by dinoflagellates that belong to the genus Gambierdiscus that are transformed in more toxic forms in predatory fish guts, and are more present in the Indo-Pacific and Caribbean areas. It is estimated that CFP causes per year more than 10,000 intoxications worldwide. With the rise of water temperature and anthropogenic intervention, it is important to study the prevalence of CFP in more temperate waters. Through inter- and subtidal sampling, 22 species of organisms were collected, in Madeira and Azores archipelagos and in the northwestern Moroccan coast, during September of 2012 and June and July of 2013. A total of 94 samples of 22 different species of bivalves, gastropods, echinoderms and crustaceans where analyzed by Ultra Performance Liquid Chromatography-Mass Spectometry-Ion Trap-Time of Flight (UPLC-MS-IT-TOF) and Ultra Performance Chromatography- Mass Spectrometry (UPLC-MS). Our main aim was to detect new vectors and ascertain if there were some geographical differences. We detected for the first time putative CTXs in echinoderms, in two starfish species—M. glacialis and O. ophidianus. We detected differences regarding uptake values by organisms and geographical location. Toxin amounts were significant, showing the importance and the need for continuity of these studies to gain more knowledge about the prevalence of these toxins, in order to better access human health risk. In addition, we suggest monitoring of these toxins should be extended to other vectors, starfish being a good alternative for protecting and accessing human health risk. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
23. Sargassum muticum (Yendo) Fensholt (Fucales, Phaeophyta) in Morocco, an invasive marine species new to the Atlantic coast of Africa.
- Author
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Sabour, Brahim, Reani, Abdeltif, EL Magouri, Hachem, and Haroun, Ricardo
- Subjects
WIREWEED ,HOME range (Animal geography) ,EXOTIC marine organisms ,PLANT phenology ,MARINE ecology ,OYSTERS ,COASTS - Abstract
The Japanese brown seaweed Sargassum muticum (Yendo) Fensholt (Fucales, Phaeophyta) is reported for the first time in Atlantic Morocco, along the shoreline of Doukkala (S of Casablanca). This record, the first in the African continent, represents a remarkable range expansion of this invasive marine species. Indeed, it is the southern-most occurrence of the species in the Atlantic. Preliminary phenological and ecological data of this non-native species were provided from the Doukkala coast. The major effects on benthic structure and composition of this invasive brown macroalga were also evaluated from published data. Oyster transfers from the French coast were the most likely primary introduction vector, but maritime vectors linked to shipping and navigation cannot be ruled out. Guidelines for prevention of further expansion of this highly invasive marine species along the Moroccan coasts are described. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
24. Growth responses of Microcystis ichthyoblabe Kutzing and Anabaena aphanizomenoides Forti (cyanobacteria) under different nitrogen and phosphorus conditions.
- Author
-
Sabour, Brahim, Loudiki, Mohammed, and Vasconcelos, Vitor
- Subjects
- *
EXPERIMENTS , *CYANOBACTERIAL blooms , *PROKARYOTES , *CYANOBACTERIAL evolution , *PHOSPHORUS , *NITROGEN , *NONMETALS , *DENSITY , *PLANKTON blooms - Abstract
Experiments in batch cultures under controlled sub-optimal light and temperature conditions were undertaken to determine the effect of nitrogen, phosphorus and N:P ratios on the growth of Microcystis ichthyoblabe Kutz. 1843 and Anabaena aphanizomenoides Forti 1912, two toxic cyanobacteria forming blooms from Oued Mellah lake. Phosphorus experiments show that densities of M. ichthyoblabe and A. aphanizomenoides increased differently in the various media. Under non-limiting phosphorus conditions (1000-6960 μg P l-1), 5-7 days of exponential growth was observed, while in P-free and in P-deficient media (0-500 μg l-1), the growth was limited. As with phosphorus experiments, cell growth of M. ichthyoblabe was substantially favoured under high nitrate concentrations (50-84 mg l-1), whereas cultures under N-free or N-deficient conditions (0-10 mg l-1) seemed to be limited. Nitrate-nitrogen at all tested concentrations was not limiting for the growth of A. aphanizomenoides cultures, which reached high density during an exponential growth of 8-9 days. Under low nitrate concentrations (0-5 mg l-1), an increased number of heterocysts was observed. There was a markedly diminished growth with the lower N:P ratio experiments (≤5) only for Microcystis and on the highest N:P ratio experiments (≥30) for both Microcystis and Anabaena aphanizomenoides. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
25. Gracilaria gracilis (Gracilariales, Rhodophyta) from Dakhla (Southern Moroccan Atlantic Coast) as Source of Agar: Content, Chemical Characteristics, and Gelling Properties.
- Author
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Belattmania, Zahira, Bhaby, Sanaa, Nadri, Amal, Khaya, Khaoulaa, Bentiss, Fouad, Jama, Charafeddine, Reani, Abdeltif, Vasconcelos, Vitor, and Sabour, Brahim
- Abstract
Agar is a sulfated polysaccharide extracted from certain marine red algae, and its gel properties depend on the seaweed source and extraction conditions. In the present study, the seaweed Gracilaria gracilis (Gracilariales, Rhodophyta) from Dakhla (Moroccan Atlantic Coast) was investigated for its agar content, structure, and gel properties. The agar yields of G. gracilis were 20.5% and 15.6% from alkaline pretreatment and native extraction, respectively. Agar with alkaline pretreatment showed a better gelling property supported by higher gel strength (377 g·cm
−2 ), gelling (35.4 °C), and melting (82.1 °C) temperatures with a notable increase in 3,6-anhydro-galactose (11.85%) and decrease in sulphate (0.32%) contents. The sulfate falling subsequent to alkaline pretreatment was verified through FT-IR spectroscopy. The13 C NMR spectroscopy showed that alkaline-pretreated agar has a typical unsubstituted agar pattern. However, native agar had a partially methylated agarose structure. Overall, this study suggested the possibility of the exploitation of G. gracilis to produce a fine-quality agar. Yet, further investigation may need to determine the seasonal variability of this biopolymer according to the life cycle of G. gracilis. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
26. Contributed Article Dynamics and toxicity of Anabaena aphanizomenoides (Cyanobacteria) waterblooms in the shallow brackish Oued Mellah lake (Morocco).
- Author
-
Sabour, Brahim, Loudiki, Mohammed, Oudra, Brahim, Vasconcelos, Vitor, Oubraim, Said, and Fawzi, Brahim
- Subjects
- *
MICROCYSTINS , *BACTERIAL toxins , *PHYTOPLANKTON , *BIOMASS , *ALGAL blooms , *HIGH temperatures - Abstract
The structure and abundance of phytoplankton communities were investigated during 1997 to 1999 in Oued Mellah, a shallow brackish and hypertrophic lake, with particular regard to Anabaena aphanizomenoides dynamics. Important events of algal blooms were observed mostly by the cyanobacteria Microcystis ichthyoblabe, Anabaena aphanizomenoides and Oscillatoria chlorina and by the ichthyotoxic haptophyceae Prymnesium parvum. Anabaena aphanizomenoides proliferated during late summer after the Microcystis ichthyoblabe blooms. The percentage of Anabaena aphanizomenoides of the phytoplankton biomass varied from 88 to 94 percent during bloom periods. Maximum biomass was 146 and 120 mg fresh weight l -1 during the 1997 and 1999 summer periods, respectively. The main environmental factors leading to the ecological success of A. aphanizomenoides were high temperature (25–28 C), high incident light intensities (1488–1912 µ E m -2 s -1 , high nutrient deficiency (0 µ g P-PO -4 l -1 ; 0–0.18 mg N-NO 3 l -1 ) and decrease of alkalinity (329–494 mg HCO 3 - l -1 ). The toxicity of the Anabaena aphanizomenoides bloom was evaluated by bioassays and analyses. The lethal dose 50 of the bloom sample tested in mice was 254 mg DW kg -1 body weight while toxicity (24 h LC -50 ) in the brine shrimp Artemia salina was 3.68 mg DW ml -1 . The low microcystin content (3.28 µ g g DW -1 ) determined by ELISA was not consistent with the tested bioassays and is suggestive of the presence of other toxic compounds in the bloom extracts. Four toxic fractions were separated by HPLC-PDA and identified as microcystins according to their UV spectra. The production of microcystins by Anabaena aphanizomenoides bloom was confirmed by the analysis of the isolated strain which, in Z8 medium under controlled laboratory conditions, produced three variants of microcystins, two of them being similar to those produced by the natural bloom. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
27. Impact of wastewater effluent on the diatom assemblages structure of a brackish small stream: Oued Hassar (Morocco).
- Author
-
Fawzi, Brahim, Loudiki, Mohamed, Oubraim, Said, Sabour, Brahim, and Chlaida, Mohamed
- Subjects
COMPOSITION of water ,WASTE spills ,DIATOMS ,WATER pollution ,RIVERS - Abstract
Abstract: The impact of the wastewater input of Médiouna agglomeration (southeastern area of Casablanca) on the diatom flora and water quality of Oued Hassar stream (Morocco) was studied from July 1997 to August 1998. This wastewater effluent, which was highly loaded with ammonia, orthophosphates and organic matters, had disturbed the diatom assemblages structure and water quality of this stream. The study of the epilithic algal assemblages revealed the presence of 130 taxa of diatoms, 21 of which, according to the available literature, were recorded for the first time in the Moroccan inland waters. Almost all the latter taxa are mesohalobic or oligohalobic-indifferent. Nitzschia inconspicua Grun. was the most abundant species (47.7%) and grows particularly at the source of the stream. Navicula subminuscula Manguin, Nitzschia capitellata Hust. and Nitzschia desertorum Hust. have their dominance in the highly polluted zones, especially downstream the wastewater input. [Copyright &y& Elsevier]
- Published
- 2002
- Full Text
- View/download PDF
28. Toxicology of a Microcystic ichthyoblabe Waterbloom from lake Oued Mellah (Morocco).
- Author
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Sabour, Brahim, Loudiki, Mohammed, Oudra, Brahim, Vasconcelos, Vitor, Martins, Rosario, Oubraim, Sail, and Fawzi, Brahim
- Subjects
TOXICITY testing ,CYANOBACTERIAL blooms ,LIQUID chromatography ,MICROCYSTINS - Abstract
Examines the toxicity of the cyanobacterial waterblooms in Morocco. Level of maximal biomass; Use of liquid chromatography-photodiode array detection; Identification of microcystin variants.
- Published
- 2002
- Full Text
- View/download PDF
29. Isolation and FTIR-ATR and 1H NMR Characterization of Alginates from the Main Alginophyte Species of the Atlantic Coast of Morocco.
- Author
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Belattmania, Zahira, Kaidi, Soukaina, El Atouani, Samir, Katif, Chaimaa, Bentiss, Fouad, Jama, Charafeddine, Reani, Abdeltif, Sabour, Brahim, Vasconcelos, Vitor, and Zoumpoulakis, Panagiotis
- Subjects
ALGINATES ,LAMINARIA ,FUCUS vesiculosus ,SODIUM alginate ,DENTAL materials ,NUCLEAR magnetic resonance spectroscopy ,ALGINIC acid - Abstract
Alginates are widely used as gelling agents in textile print pastes, medical industries, impression material in dentistry, and anticoagulant material in toothpaste. In the present study, the content and spectroscopic characterization (
1 H NMR and FT-IR) of the sodium alginates were investigated in the eight brown seaweeds Sargassum muticum, Fucus vesiculosus f. volubilis, Carpodesmia tamariscifolia, Bifurcaria bifurcata, Laminaria ochroleuca, Cystoseira humilis, Saccorhiza polyschides, and Fucus guiryi harvested from the NW Atlantic coast of Morocco. The results proved that the most studied algae depicted alginate yields higher than 18% dry weight. The FT-IR analysis showed that the spectra of the extracted alginates exhibited significant similarities to the commercial alginate from Sigma-Aldrich. The1 H NMR spectroscopy indicated that the extracted alginates have a high content of β-d-mannuronic (M) than α-l-guluronic acid (G) with M/G ratio values ranging from 1.04 to 4.41. The homopolymeric fractions FMM are remarkably high compared to the FGG and heteropolymeric fractions (FGM = FMG ) especially for F. guiryi, C humilis, C. tamariscifolia, L. ochroleuca, and S. polyschides. Nevertheless, the heteropolymeric fractions (FGM /FMG ) are quite abundant in the alginates of S. muticum, F. vesiculosus f. volubilis, and B. bifurcata accounting for more than 52% of the polymer diads. Based on these results, the investigated algal species (except Fucus guiryi and Bifurcaria bifurcata) could be regarded as potential sources of alginates for industrial uses. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
30. A baseline assessment of beach macrolitter and microplastics along northeastern Atlantic shores.
- Author
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Velez, Nadja, Zardi, Gerardo I., Lo Savio, Roberto, McQuaid, Christopher D., Valbusa, Ugo, Sabour, Brahim, and Nicastro, Katy R.
- Subjects
PLASTIC marine debris ,MARINE debris ,FOOD packaging ,POLLUTANTS ,LITTER (Trash) ,POLYMERS ,POLYPROPYLENE ,BIODEGRADABLE plastics - Abstract
Marine litter is widely dispersed throughout coastal environments. Assessing the distribution and accumulation of such contaminants is crucial to understand their environmental impacts. This study presents a baseline for the monitoring of litter and microplastics in intertidal sediments along the Atlantic shores of southern Portugal and Morocco and identifies potential sources of contamination. Although variable, distribution and composition of both litter and microplastics did not follow a latitudinal pattern. Most of the litter had an undifferentiated source. Within the identifiable sources of litter, food packaging, fishing and tobacco were the most abundant, with variable contributions among sites. Over 97% of marine litter retrieved was plastic. Fragments and filaments were the most abundant categories of plastics at sites with the highest and lowest microplastic abundance respectively. Filaments were mainly made of Polypropylene (PP,50%) and Polyethylene terephthalate (PET,29%) while the predominant polymers for fragments were Polyethene (PE, 75%) and PP (25%). • Although spatially variable, distribution and composition of litter and microplastics did not follow a latitudinal pattern. • Plastic and microplastics were ubiquitous and the most abundant debris. • Most of the microplastic found were fragments, followed by filaments. • Polyethylene and Polypropylene were the most common polymer types in microplastic. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
31. Tetrodotoxins Occurrence in Non-Traditional Vectors of the North Atlantic Waters (Portuguese Maritime Territory, and Morocco Coast).
- Author
-
Silva, Marisa, Rodríguez, Inés, Barreiro, Aldo, Kaufmann, Manfred, Neto, Ana Isabel, Hassouani, Meryem, Sabour, Brahim, Alfonso, Amparo, Botana, Luis M., and Vasconcelos, Vitor
- Subjects
HIGH performance liquid chromatography ,COASTS ,PUFFERS (Fish) ,MASS spectrometry - Abstract
Tetrodotoxin (TTX) is a potent alkaloid typically from tropical ecosystems, but in the last decade its presence has been more pronounced in the temperate waters of the Atlantic. In its last scientific opinion, the European Food Safety Authority (EFSA) stressed the need for data regarding TTX prevalence in European waters. To address EFSA's concerns, benthic organisms such as mollusks, crustaceans, echinoderms and fish with different feeding habits were collected along the Portuguese continental coast, islands (São Miguel, Azores, and Madeira) and the northwestern Moroccan coast. A total of 165 samples were analyzed by ultra high performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS) and ultra high performance chromatography mass spectrometry (UHPLC-MS/MS). Geographical tendencies were detected as follows, by descending order: S. Miguel Island (Azores), Moroccan coast, Madeira Island and Portuguese continental coast. The toxin amounts detected were significant, above the Dutch limit value established in 2017, showing the importance and the need for continuity of these studies to gain more knowledge about the prevalence of these toxins, unraveling new vectors, in order to better assess human health risk. This work represents a general overview of new TTX bearers (7) most of them in gastropods (Patella depressa, Nucella lapillus, Onchidella celtica and Aplysia depilans), followed by echinoderms (Echinus esculentus and Ophidiaster ophidianus) and puffer fish Sphoeroides marmoratus. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
32. Paralytic Shellfish Toxins Occurrence in Non-Traditional Invertebrate Vectors from North Atlantic Waters (Azores, Madeira, and Morocco).
- Author
-
Silva, Marisa, Rey, Verónica, Barreiro, Aldo, Kaufmann, Manfred, Neto, Ana Isabel, Hassouani, Meryem, Sabour, Brahim, Botana, Ana, Botana, Luis M., and Vasconcelos, Vitor
- Subjects
PARALYTIC shellfish poisoning ,INVERTEBRATE communities ,CYANOBACTERIAL toxins ,MICROALGAE - Abstract
Paralytic shellfish toxins (PSTs) are potent alkaloids of microalgal and cyanobacterial origin, with worldwide distribution. Over the last 20 years, the number of poisoning incidents has declined as a result of the implementation of legislation and monitoring programs based on bivalves. In the summer of 2012 and 2013, we collected a total of 98 samples from 23 different species belonging to benthic and subtidal organisms, such as echinoderms, crustaceans, bivalves, and gastropods. The sampling locations were Madeira, São Miguel Island (Azores archipelago), and the northwestern coast of Morocco. The samples were analyzed using post-column oxidation liquid chromatography with a fluorescence detection method. Our main goal was to detect new vectors for these biotoxins. After reporting a total of 59 positive results for PSTs with 14 new vectors identified, we verified that some of the amounts exceeded the limit value established in the EU. These results suggest that routine monitoring of saxitoxin and its analogs should be extended to more potential vectors other than bivalves, including other edible organisms, for a better protection of public health. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
33. Similar Epiphytic Macrofauna Inhabiting the Introduced Sargassum muticum and Native Fucoids on the Atlantic Coast of Morocco
- Author
-
Belattmania, Zahira, Chaouti, Abdellatif, Reani, Abdeltif, Machado, Margarida, Engelen, Aschwin H., Serrão, Ester Á., and Sabour, Brahim
- Published
- 2018
- Full Text
- View/download PDF
34. Isolation and FTIR-ATR and 1 H NMR Characterization of Alginates from the Main Alginophyte Species of the Atlantic Coast of Morocco.
- Author
-
Belattmania Z, Kaidi S, El Atouani S, Katif C, Bentiss F, Jama C, Reani A, Sabour B, and Vasconcelos V
- Subjects
- Atlantic Ocean, Morocco, Alginates chemistry, Alginates isolation & purification, Magnetic Resonance Spectroscopy, Seaweed chemistry, Spectroscopy, Fourier Transform Infrared
- Abstract
Alginates are widely used as gelling agents in textile print pastes, medical industries, impression material in dentistry, and anticoagulant material in toothpaste. In the present study, the content and spectroscopic characterization (
1 H NMR and FT-IR) of the sodium alginates were investigated in the eight brown seaweeds Sargassum muticum , Fucus vesiculosus f. volubilis , Carpodesmia tamariscifolia , Bifurcaria bifurcata , Laminaria ochroleuca , Cystoseira humilis , Saccorhiza polyschides , and Fucus guiryi harvested from the NW Atlantic coast of Morocco. The results proved that the most studied algae depicted alginate yields higher than 18% dry weight. The FT-IR analysis showed that the spectra of the extracted alginates exhibited significant similarities to the commercial alginate from Sigma-Aldrich. The1 H NMR spectroscopy indicated that the extracted alginates have a high content of β-d-mannuronic (M) than α-l-guluronic acid (G) with M/G ratio values ranging from 1.04 to 4.41. The homopolymeric fractions FMM are remarkably high compared to the FGG and heteropolymeric fractions (FGM = FMG ) especially for F. guiryi , C humilis , C. tamariscifolia , L. ochroleuca , and S. polyschides . Nevertheless, the heteropolymeric fractions (FGM /FMG ) are quite abundant in the alginates of S. muticum , F. vesiculosus f. volubilis , and B. bifurcata accounting for more than 52% of the polymer diads. Based on these results, the investigated algal species (except Fucus guiryi and Bifurcaria bifurcata ) could be regarded as potential sources of alginates for industrial uses.- Published
- 2020
- Full Text
- View/download PDF
35. New Invertebrate Vectors of Okadaic Acid from the North Atlantic Waters--Portugal (Azores and Madeira) and Morocco.
- Author
-
Silva M, Rodriguez I, Barreiro A, Kaufmann M, Isabel Neto A, Hassouani M, Sabour B, Alfonso A, Botana LM, and Vasconcelos V
- Subjects
- Animals, Atlantic Islands, Atlantic Ocean, Chromatography, Liquid methods, Environmental Monitoring, Food Contamination analysis, Morocco, Portugal, Tandem Mass Spectrometry, Invertebrates, Marine Toxins analysis, Okadaic Acid analysis
- Abstract
Okadaic acid and its analogues are potent phosphatase inhibitors that cause Diarrheic Shellfish Poisoning (DSP) through the ingestion of contaminated shellfish by humans. This group of toxins is transmitted worldwide but the number of poisoning incidents has declined over the last 20 years due to legislation and monitoring programs that were implemented for bivalves. In the summer of 2012 and 2013, we collected a total of 101 samples of 22 different species that were made up of benthic and subtidal organisms such echinoderms, crustaceans, bivalves and gastropods from Madeira, São Miguel Island (Azores archipelago) and the northwestern coast of Morocco. The samples were analyzed by UPLC-MS/MS. Our main objective was to detect new vectors for these biotoxins. We can report nine new vectors for these toxins in the North Atlantic: Astropecten aranciacus, Arbacia lixula, Echinaster sepositus, Holothuria sanctori, Ophidiaster ophidianus, Onchidella celtica, Aplysia depilans, Patella spp., and Stramonita haemostoma. Differences in toxin contents among the species were found. Even though low concentrations were detected, the levels of toxins that were present, especially in edible species, indicate the importance of these types of studies. Routine monitoring should be extended to comprise a wider number of vectors other than for bivalves of okadaic acid and its analogues.
- Published
- 2015
- Full Text
- View/download PDF
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