Seaweed Fucus Spiralis Research Articles

Unveiling the Antioxidant Potential of Halophyte Plants and Seaweeds for Health Applications

Halophyte plants and seaweed are described in the literature as rich sources of antioxidant compounds that can be used in the pharmaceutical and food industries. In this work, we studied the antioxidant composition of five species of halophytic plants (Suaeda vera Forssk, Portulaca oleracea L., Inula crithmoides L., Salicornia ramosissima (Hook.f.) J. Woods and Sarcocornia perennis (Mill.) A.J.Scott) and three seaweeds (Gracilaria gracilis (Stackhouse) Steentoft, L.Irvine and Farnham, Fucus spiralis L. and Ulva rigida C. Agardh) collected in Sado Estuary, Portugal. In the case of the plants, different parts of the plant were also assessed. Various extraction procedures were also performed to understand which methods were most suitable for extracting the various antioxidant compounds. Therefore, the aim of this study was to characterize the antioxidant compounds in halophytes and seaweed using various methods (ABTS, DPPH and FRAP), as well as the phenolic (TPC) and flavonoid (TFC) contents in the different extracts obtained. The amount of soluble protein in each extract was also determined. The results show that methanolic extracts generally have a higher antioxidant capacity, while the highest soluble protein content was observed in aqueous extracts. The seaweed Fucus Spiralis showed the highest antioxidant content, while in halophytic plants the highest antioxidant content was detected in the leaves. In general, this work confirms the potential of halophytes and seaweed as sources of antioxidant compounds for use in the food and pharmaceutical industries.

Biochemical composition, antiradical potential and human health risk of the Arctic edible brown seaweed Fucus spiralis L

Biochemical composition, antiradical potential and human health risk of the Arctic edible brown seaweed Fucus spiralis L

Highlighting the Biological Potential of the Brown Seaweed Fucus spiralis for Skin Applications.

Skin aging is a biological process influenced by intrinsic and extrinsic factors. The last ones, mainly exposure to UV radiation, increases reactive oxygen species (ROS) production leading to a loss of extracellular matrix, also enhanced by enzymatic degradation of matrix supporting molecules. Thus, and with the growing demand for eco-friendly skin products, natural compounds extracted from brown seaweeds revealed to be good candidates due to their broad range of bioactivities, especially as antioxidants. The aim of this study was to assess the dermo-cosmetic potential of different fractions obtained from the brown seaweed Fucus spiralis. For this purpose, in vitro antioxidant (Total Phenolic Content (TPC), 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, Ferric Reducing Antioxidant Power (FRAP), Oxygen Radical Absorbance Capacity (ORAC)), anti-enzymatic (collagenase, elastase and hyaluronidase), antimicrobial, anti-inflammatory (NO production) and photoprotective (ROS production) capacities were evaluated. Although nearly all fractions evidenced antioxidant effects, fraction F10 demonstrated the highest antioxidant ability (EC50 of 38.5 µg/mL, DPPH assay), and exhibited a strong effect as an inhibitor of collagenase (0.037 µg/mL) and elastase (3.0 µg/mL). Moreover, this fraction was also the most potent on reducing ROS production promoted by H2O2 (IC50 of 41.3 µg/mL) and by UVB (IC50 of 31.3 µg/mL). These bioactivities can be attributed to its high content of phlorotannins, as evaluated by LC-MS analysis, reinforcing the potential of F. spiralis for further dermatological applications.

Unveiling the microbial community associated with the marine seaweed Fucus spiralis

Event Abstract Back to Event Unveiling the microbial community associated with the marine seaweed Fucus spiralis Joana Ribeiro1, Susete G. Pinteus1, Celso Alves1, Joana Silva1 and Rui P. Pedrosa1* 1 MARE – Marine and Environmental Sciences Centre, ESTM, Polytechnic Institute of Leiria, Portugal The marine environment offers an immense biodiversity still mostly unexplored. Within, marine organisms stablish close associations as strategy to survive and prosper, creating complex networks where seaweeds play an important role. As photosynthetic organisms, they are in the base of the food chain providing food and shelter for a wide number of organisms such as sea urchins, sea snails, crustaceans and young fish, and by other side, they contribute to the establishment of specific microbiological communities [1,2]. These symbiotic relationships provide a variety of advantages to the host such as vitamins and nitrogen fixation, and studies suggest that these microbiological communities are also involved in the defence against predators through the production of bioactive secondary metabolites. On the other hand, seaweeds provide the surfaces for microbial colonization and a source of nutrients [2,3]. Within this framework, in this work, bacteria associated with Fucus spiralis (Brown seaweed) collected in Peniche coast, were selected according to their phenotype and isolated by the streak technique. The identification was carried out by the RNA ribossomal 16s gene amplification through PCR techniques using the 27F and 1392R primers, which resulted in the identification of 63 bacteria. The genera Pseudoalteromonas sp, Bacillus sp., Vibrio sp., Halomonas sp., Idiomarina sp., and Staphylococcus sp. were verified, however Idiomarina sp. was the most abundant genus corresponding to 36% of the total isolates. Some of these genera are reported to have biotechnological relevance as producers of bioactive metabolites [4-7]. The exploration of the microbiological biodiversity associated with the seaweed Fucus spiralis resulted in the discovery of new possible sources of bioactive compounds. Acknowledgements Authors would like to acknowledge the financial support of the Portuguese Foundation for Science and Technology (FCT) through Strategic Project UID/MAR/04292/2013 granted to MARE – Marine and Environmental Sciences Centre, through Red2Discovery Project (PTDC/MAR-BIO/6149/2014), co-financed by COMPETE (POCI-01-0145-FEDER-016791), and through Oncologia de Precisão: Terapias e Tecnologias Inovadoras project (POINT4PAC) (SAICTPAC/0019/2015 - LISBOA-01-0145-FEDER-016405).

Antioxidant and Cytoprotective Activities of Fucus spiralis Seaweed on a Human Cell in Vitro Model.

Antioxidants play an important role as Reactive Oxygen Species (ROS) chelating agents and, therefore, the screening for potent antioxidants from natural sources as potential protective agents is of great relevance. The main aim of this study was to obtain antioxidant-enriched fractions from the common seaweed Fucus spiralis and evaluate their activity and efficiency in protecting human cells (MCF-7 cells) on an oxidative stress condition induced by H2O2. Five fractions, F1–F5, were obtained by reversed-phase vacuum liquid chromatography. F3, F4 and F5 revealed the highest phlorotannin content, also showing the strongest antioxidant effects. The cell death induced by H2O2 was reduced by all fractions following the potency order F4 > F2 > F3 > F5 > F1. Only fraction F4 completely inhibited the H2O2 effect. To understand the possible mechanisms of action of these fractions, the cellular production of H2O2, the mitochondrial membrane potential and the caspase 9 activity were studied. Fractions F3 and F4 presented the highest reduction on H2O2 cell production. All fractions decreased both caspase-9 activity and cell membrane depolarization (except F1). Taken all together, the edible F. spiralis reveal that they provide protection against oxidative stress induced by H2O2 on the human MCF-7 cellular model, probably acting as upstream blockers of apoptosis.

Mechanisms associated to cytotoxicity and antimicrobial activities of VLC fractions isolated from brown seaweed Fucus spiralis

Mechanisms associated to cytotoxicity and antimicrobial activities of VLC fractions isolated from brown seaweed Fucus spiralis

Anti-inflammatory potential of monogalactosyl diacylglycerols and a monoacylglycerol from the edible brown seaweed Fucus spiralis Linnaeus.

A monoacylglycerol (1) and a 1:1 mixture of two monogalactosyl diacylglycerols (MGDGs) (2 and 3) were isolated from the brown seaweed Fucus spiralis Linnaeus. The structures were elucidated by spectroscopic means (NMR and MS) and by comparison with the literature. Compound 1 was composed of a glycerol moiety linked to oleic acid (C18:1 Ω9). Compounds 2 and 3 contained a glycerol moiety linked to a galactose unit and eicosapentaenoic acid (C20:5 Ω3) combined with octadecatetraenoic acid (C18:4 Ω3) or linolenic acid (C18:3 Ω3), respectively. The isolated compounds were tested for their cytotoxic and anti-inflammatory activity in RAW 264.7 macrophage cells. All of them inhibited NO production at non-cytotoxic concentrations. The fraction consisting of compounds 2 and 3, in a ratio of 1:1, was slightly more effective than compound 1 (IC50 of 60.06 and 65.70 µg/mL, respectively). To our knowledge, this is the first report of these compounds from F. spiralis and on their anti-inflammatory capacity.

Cytotoxicity and antiproliferative activity of fractions isolated from Fucus spiralis seaweed

Event Abstract Back to Event Cytotoxicity and antiproliferative activity of fractions isolated from Fucus spiralis seaweed Celso Alves1*, Susete Pinteus1, André Horta1, Joana Silva1, Nádia Fino1, Olivier Thomas2 and Rui Pedrosa1 1 School of Tourism and Maritime Technology, Portugal 2 ICN - University of Nice-Sophia Antipolis, France In the last decades, nature has played a significant role as source of new drugs and recent trends in medicines research emphasize that marine environment has a high potential for discovery of new pharmaceutical compounds. Harsh chemical and physical conditions in the marine environment provide a production of quite specific and potent active molecules. The aim of this study was to evaluate the antitumor activity of isolated fractions obtained from seaweed Fucus spiralis on three human tumor cell lines (HepG-2; MCF-7; SH-SY5Y). In this study, five fractions obtained by Vacuum Liquid Chromatography (VLC) from Fucus spiralis methanolic extracts were tested on HepG-2, MCF-7 and SH-SY5Y cells through cytotoxicity and anti-proliferative assays. The results were obtained the according MTT method. The highest cytotoxicity was exhibited by F3 fraction on HepG-2 cells and by F1 and F5 fractions on SH-SY5Y cells, reduced the cells viability (1 mg/ml; 24 hours) in 83%, 97% and 91%, respectively. The smallest IC50 was exhibited by F1 fraction on SH-SY5Y with 308.0µg/ml. In cell proliferation assays, F1, F3, F4 and F5 fractions showed anti-proliferative activity on all cell lines tested. (1 mg/ml; 24 hours). However, the effects were more marked on HepG-2 and SH-SY5Y cells. The smallest IC50 was exhibited on SH-SY5Y cells by F1 and F3 fraction with an IC50 of 153.2 and 136.4µg/ml, respectively. In conclusion, Fucus spiralis is a promising source of new molecules with therapeutically applications in cancer. Acknowledgements This work was supported through funding provided by the European Commission Collaborative Project FP7 KBBE 2010–4 BAMMBO (Project Number 265896). Keywords: algae, antitumor activity, bioactive compounds, Marine Natural Products, MCF-7 Cells, HepG2 cells, SH-SY5Y cells Conference: IMMR | International Meeting on Marine Research 2014, Peniche, Portugal, 10 Jul - 11 Jul, 2014. Presentation Type: Poster Presentation Topic: BLUE BIOTECH Citation: Alves C, Pinteus S, Horta A, Silva J, Fino N, Thomas O and Pedrosa R (2014). Cytotoxicity and antiproliferative activity of fractions isolated from Fucus spiralis seaweed. Front. Mar. Sci. Conference Abstract: IMMR | International Meeting on Marine Research 2014. doi: 10.3389/conf.fmars.2014.02.00067 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 10 May 2014; Published Online: 18 Jul 2014. * Correspondence: Dr. Celso Alves, School of Tourism and Maritime Technology, Peniche, Portugal, celso.alves@ipleiria.pt Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Celso Alves Susete Pinteus André Horta Joana Silva Nádia Fino Olivier Thomas Rui Pedrosa Google Celso Alves Susete Pinteus André Horta Joana Silva Nádia Fino Olivier Thomas Rui Pedrosa Google Scholar Celso Alves Susete Pinteus André Horta Joana Silva Nádia Fino Olivier Thomas Rui Pedrosa PubMed Celso Alves Susete Pinteus André Horta Joana Silva Nádia Fino Olivier Thomas Rui Pedrosa Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Extraction of essential oils from native plants and algae from the coast of Peniche (Portugal): antimicrobial and antioxidant activity.

Event Abstract Back to Event Extraction of essential oils from native plants and algae from the coast of Peniche (Portugal): antimicrobial and antioxidant activity. Carlos Pena1, Teresa M. Mouga1, Maria M. Sampaio1 and Clélia N. Afonso1* 1 School of Tourism and Maritime Technology, GIRM - Marine Resources Research Group, Polytechnic Institute of Leiria, Portugal Coastal areas are highly complex and dynamic ecosystem of interface between land, sea and atmosphere, which also suffer biotic influences. These areas play several important ecological functions, and here we can find an enormous biodiversity. The coastline of Portugal features a high number of endemic flora and vegetation with the potential to provide functional compounds that may provide physiological benefits at nutritional and therapeutic levels, as sources of bioactive substances with antimicrobial, antioxidant, antifungal, antitumalr and anti-inflammatory activity. Among these compounds, we find essential oils, also known as volatile oils, which are a result of secondary metabolism of aromatic plants, containing a large number of substances with varied chemical composition that can be obtained by different methods of extraction. The aim of this study was to extract essential oils of native plants and seaweeds from the coast of Peniche by hydrodistillation in Clevenger apparatus, with optimization of the purification process. Extracted essential oils were tested as to their ability as antibacterial and antifungal agents, and also as antioxidants. The plants studied for this purpose were Inula chritmoides L., Juniperus phoenicea subsp. turbinata (Guss.) Nyman, Daucus carota spp. halophilus and the seaweeds Fucus spiralis L., Codium tomentosum Stackhouse, Stypocaulon scoparium (Linnaeus) Kützing and Plocamium cartilagineum (Linnaeus) P.S.Dixon. The antimicrobial ability was tested in two bacteria species, Bacillus subtilis and Escherichia coli and in the yeast Saccharomyces cerevisiae, using standard procedures. The antioxidant potential was evaluated and from the results obtained, we can conclude that the essential oils extracted by the hydrodistillation method of plants and algae contain bioactive compounds present in its constitution with interesting bio-activity that can offer significant benefits and biotechnological relevance. Acknowledgements The authors wish to thank all the colleagues from ESTM who assisted in field and laboratory work in some steps of this work. Keywords: Hydrodistillation, ; Essential oils, ; Antioxidant activity, ; Antimicrobial activity, ; Bioactive compounds Conference: IMMR | International Meeting on Marine Research 2014, Peniche, Portugal, 10 Jul - 11 Jul, 2014. Presentation Type: Poster Presentation Topic: BLUE BIOTECH Citation: Pena C, Mouga TM, Sampaio MM and Afonso CN (2014). Extraction of essential oils from native plants and algae from the coast of Peniche (Portugal): antimicrobial and antioxidant activity.. Front. Mar. Sci. Conference Abstract: IMMR | International Meeting on Marine Research 2014. doi: 10.3389/conf.fmars.2014.02.00001 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 09 May 2014; Published Online: 18 Jul 2014. * Correspondence: Prof. Clélia N Afonso, School of Tourism and Maritime Technology, GIRM - Marine Resources Research Group, Polytechnic Institute of Leiria, Peniche, 2520-641, Portugal, clelia@ipleiria.pt Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Carlos Pena Teresa M Mouga Maria M Sampaio Clélia N Afonso Google Carlos Pena Teresa M Mouga Maria M Sampaio Clélia N Afonso Google Scholar Carlos Pena Teresa M Mouga Maria M Sampaio Clélia N Afonso PubMed Carlos Pena Teresa M Mouga Maria M Sampaio Clélia N Afonso Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Development of an ointment for burns based in dry extract of the seaweed Fucus spiralis

Event Abstract Back to Event Development of an ointment for burns based in dry extract of the seaweed Fucus spiralis Gonçalo M. Bernardo1, Gonçalo Castro1, Marcia S. Santos1, Maria M. Sampaio1 and Clélia N. Afonso1* 1 School of Tourism and Maritime Technology, Marine Resources Research Group (GIRM), Polytechnic Institute of Leiria, Portugal The Fucus spiralis is a brown seaweed found on the Portuguese coast used as wound healing in traditional medicine were their antioxidant, immunostimulant, anticoagulant, antibacterial properties and also remineralizing, smoothing, moisturizing capacities and anti-tumor action were studied with proved results. These seaweed are one of the several described in the European Pharmacopoeia, making F.spiralis a seaweed with great potential for the development of new drugs and/or pharmaceuticals. The objective of this project was to formulate an ointment with F. spiralis dry extracts using vaseline as a base for the treatment of burns. Fucus spiralis was collected on the coast of Peniche (west coast of Portugal), washed, sorted, lyophilized and crushed for the dry extract preparation. The ash (g/g) and iodine (%) content in F. spiralis were determined. The ointment was prepared and homogenized with three concentrations of dry extract (1%, 2% and 5%) and were analyzed over time in parallel with the observation of the physical, chemical, organoleptic and rheological characteristics. The results showed that the F. spiralis presented a iodine content of 0,0076%, a low concentration in comparison with the Farmacopeia europea directives. The ointment prepared is a non-Newtonian fluid, and the absorption spectrum in ultraviolet light (UV) detected that it behaves as UVB and UVC blocker, despite of not having the same effect on UVA radiation. With these results and the many properties of Fucus spiralis we conclude that the ointment with dry extract of F. spiralis with the three concentrations of dry extract established is likely to have a great potential in the area of pharmaceutical and medicine, especially for burns application or other skins disorders. Acknowledgements The first two authors contributed equally to this work. The authors wish to thank all the colleagues from ESTM who assisted in field and laboratory work in some steps of this work. Keywords: Fucus spiralis, ointment, Burns, seaweed extract, Brown algae Conference: IMMR | International Meeting on Marine Research 2014, Peniche, Portugal, 10 Jul - 11 Jul, 2014. Presentation Type: Poster Presentation Topic: BLUE BIOTECH Citation: Bernardo GM, Castro G, Santos MS, Sampaio MM and Afonso CN (2014). Development of an ointment for burns based in dry extract of the seaweed Fucus spiralis. Front. Mar. Sci. Conference Abstract: IMMR | International Meeting on Marine Research 2014. doi: 10.3389/conf.fmars.2014.02.00002 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 23 May 2014; Published Online: 18 Jul 2014. * Correspondence: Prof. Clélia N Afonso, School of Tourism and Maritime Technology, Marine Resources Research Group (GIRM), Polytechnic Institute of Leiria, Peniche, 2520-641, Portugal, clelia@ipleiria.pt Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Gonçalo M Bernardo Gonçalo Castro Marcia S Santos Maria M Sampaio Clélia N Afonso Google Gonçalo M Bernardo Gonçalo Castro Marcia S Santos Maria M Sampaio Clélia N Afonso Google Scholar Gonçalo M Bernardo Gonçalo Castro Marcia S Santos Maria M Sampaio Clélia N Afonso PubMed Gonçalo M Bernardo Gonçalo Castro Marcia S Santos Maria M Sampaio Clélia N Afonso Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Drought stress, rain and recovery of the intertidal seaweed Fucus spiralis

Non-motile organisms of intertidal shores such as seaweeds have to cope with a great variability of environmental factors. In this survey, we studied whether different morphotypes of the intertidal seaweed Fucus spiralis L. are also reflected in a characteristic performance. Desiccation and recovery of this Phaeophyceae were investigated in field experiments near Aljezur, Portugal. Fucus spiralis is exposed to serious desiccation during periods of falling tide, resulting in a tissue water loss of about 90%. Due to large semidiurnal tidal ranges in this area, two morphotypes can be distinguished: F. spiralis growing in the lower intertidal (LZ) is thicker and fleshier compared with plants in the upper intertidal (HZ), and this is reflected in a significant difference in fresh and dry mass. During sunny days and at low tide, effective quantum yields (ΦPSII) decreased significantly after 2 h desiccation. This continued until re-submersion. The photosynthetic performances of HZ and LZ plants also differed significantly after LZ plants were already submerged and photosynthetisizing, but the HZ specimens still exposed to air. Recovery experiments after desiccation treatments showed fast recovery within 6 min after re-submersion in both morphotypes. HZ specimens showed a slower recovery, which indicates a protection measure to the adverse conditions in the upper intertidal. In 24 h desiccation treatments, however, HZ specimens expressed a significantly higher maximum fluorescence yield Fv/Fm recovery. Simulated rainfalls during low tides caused photosynthetic activity to drop to 50% of initial Fv/Fm, independent of the length of the rain period. Treated plants also fully recovered after 6 min re-submersion in seawater. A comparison of single fronds and tufts clearly indicated advantages of the tuft growth strategy: tufts showed higher ΦPSII at prolonged emersion times. Our study indicated a clear relationship between size and drought resistance, which was primarily due to the smaller and hardy HZ plants that withstand longer desiccation times without damage.

Arsenic is not stored as arsenite - phytochelatin complexes in the seaweeds Fucus spiralis and Hizikia fusiforme

Environmental context Seaweeds hyperaccumulate the toxic metalloid arsenic, but seemingly achieve detoxification by transformation to arsenosugars. The edible seaweed hijiki is a notable exception because it contains high levels of toxic arsenate and arsenite. Terrestrial plants detoxify arsenic by forming arsenite–phytochelatin complexes. The hypothesis that seaweeds also synthesise phytochelatins to bind arsenite as a means of detoxification before arsenosugar synthesis is tested in this investigation. Abstract Phytochelatins (PCs), generic structure [γ-Glu-Cys]n-Gly, are peptides synthesised by terrestrial plants to bind toxic metal(loid)s such as cadmium and arsenic. Seaweeds are arsenic hyperaccumulators, seemingly achieving detoxification via arsenosugar biosynthesis. Whether seaweeds synthesise PCs to aid detoxification during arsenic exposure is unknown. Hizikia fusiforme (hijiki) and Fucus spiralis were used as model seaweeds: the former is known for its large inorganic arsenic concentration, whereas the latter contains mainly arsenosugars. F. spiralis was exposed to 0, 1 and 10 mg L–1 arsenate solutions for 24 h, whereas hijiki was analysed fresh. All samples contained AsIII, glutathione and reduced PC2, identified using HPLC-ICP-MS/ES-MS. Although hijiki contained no AsIII–PC complexes, arsenate exposed F. spiralis generated traces of numerous arsenic compounds that might be AsIII–GS or AsIII–PC2 complexes. AsIII–PC complexes seem not to be a principal storage form for long-term arsenic storage within seaweeds. However, 40 times higher glutathione concentrations were found in hijiki than F. spiralis, which may explain how hijiki deals with its high inorganic arsenic burden.

Emission rates of C 8–C 15 VOCs from seaweed and sand in the inter-tidal zone at Mace Head, Ireland

Emission fluxes for a range of C 8–C 15 volatile organic compounds (VOCs) were determined from the seaweed Fucus spiralis (spiral wrack) and an adjacent sand surface during low tide on the coastline of Mace Head, Ireland. These two surface types, assessed using dynamic flux chamber systems, are typical of the Mace Head inter-tidal zone. A range of n-alkanes and oxygenates were routinely identified in the measurement of chamber air. Examination of the odd/even n-alkane ratios and use of the carbon preference index (CPI) suggested a biogenic source for these compounds (CPIs >2 in for all samples). Fluxes of n-pentadecane, the most predominant n-alkane, ranged from 0.2 to 5.1 μg m −2 h −1 (0.9–24 nmol m −2 h −1), while oxygenates such as nonanal and decanal had fluxes ranging from <0.1 to 4.4 μg m −2 h −1 (<0.1–31 nmol m −2 h −1) and <0.1 to 4.6 μg m −2 h −1 (<0.1–30 nmol m −2 h −1), respectively. Seaweed emission rates for n-pentadecane were correlated with photosynthetically active radiation (PAR) ( r s=0.94) while emissions from sand showed correlation with temperature ( r s=0.85). This suggests a possible biochemical route controlling the release of n-pentadecane from spiral wrack, and temperature-driven volatilisation from sand. Volatilisation from residual seawater trapped in the sand may explain the comparable flux of both n-alkanes and oxygenates from this surface. Unlike the n-alkanes, oxygenate fluxes from sand correlate with PAR, suggesting a photodependent production from organic carbon residues present in seawater. Comparison with previous flux estimates from coastal seawater indicates that the two source types ( Fucus spiralis and bare sand) are significant but not dominant sources of these VOCs.

A method for the assessment of light-induced oxidative stress in embryos of fucoid algae via confocal laserscan microscopy

A method was developed for measurement of active oxygen production in embryonic stages of the brown seaweed Fucus spiralis, using the label CM-DCFH-DA. Active oxygen species convert the label into the green fluorescent CM-DCF (exc/em 488/530 nm) that is detected via confocal laserscan microscopy and quantitative image analysis. Loading of the label did not harm the embryos; loading efficiency was age-independent, and the esterases needed for conversion to CM-DCFH were not inhibited by the effective UV dose (2 W m−2) applied in the experiments. After correction for daily variation of the laser power, and calibration with DCF standard solutions, this automated analysis of confocal images rendered active oxygen concentrations in fucoid embryos (μM DCF). An experiment was designed for the assessment of active oxygen production following irradiance stress in the light-sensitive embryos. Dim-light-acclimated, 1-, 2- and 4-day-old embryos were transferred for 60 min to defined high-light conditions (4π-irradiance 300 μmol photons m−2 s−1), optionally without UV radiation, including UVA, or including UVA plus UVB. PSII yield measurements (PAM fluorometer) were carried out in order to assess the degree of photoinhibition under these light conditions. The imposed light stress initially caused a rapid decrease of the PSII yields (ΦP). With increasing embryo age, minimum ΦP values attained under light stress remained higher. Consequently, electron transport rates (ETR) would increase with embryo age, i.e., with the development of their photosynthetic apparatus. Active oxygen production increased with ETR, and when UVB was included, relatively greater amounts of active oxygen were produced. A slow, second-phase decrease of ΦP under light stress that was proportional to active oxygen production indicated that some photooxidative damage was caused, in particular during UVB exposure. Recovery from light stress was a rapid process in the absence of UVB; in such cases ΦP was almost restored to the initial values within 60 min. The relative state of recovery of ΦP was correlated with both the effective UV dose and active oxygen production rate (DCF). Recovery was slowest in embryos exposed for 60 min to an experimental UVB dose, which was representative of a situation at low tide, on a sunny day. The results suggest that active oxygen may cause an in situ inhibition of growth of the earliest life stages of F. spiralis.

REACTIVE OXYGEN PRODUCTION AND DAMAGE IN INTERTIDAL FUCUS SPP. (PHAEOPHYCEAE)

The research described in this paper was designed to test the hypothesis that the differential stress tolerance associated with the vertical zonation of intertidal seaweeds is attributable to reactive oxygen metabolism. To do so, we measured the production of, and damage caused by, reactive oxygen in three species of intertidal brown seaweeds—Fucus spiralis L., F. evanescens C. Ag., and F. distichus L.— that differ in their ability to withstand freezing, desiccation, and high light stress. Fucus spiralis is the most stress‐tolerant species and F. distichus the least. Reactive oxygen production was determined by measuring the production of H2O2 and the oxidation of dichlorohydrofluorescein diacetate to dichlorofluorescein. Damage caused by freezing, desiccation, and high‐light stress was assessed by measuring variable fluorescence (Fv/Fm) and lipid peroxidation. Production of reactive oxygen increased following freezing, desiccation, or high‐light stress. In general, the data were consistent with the hypothesis that reactive oxygen metabolism is involved in stress tolerance. The production of reactive oxygen was relatively low in unstressed seaweeds, and there was little difference between species. Fucus distichus showed the greatest increase in reactive oxygen production after desiccation and freezing stress. Fucus evanescens produced more reactive oxygen production after desiccation than F. spiralis. Although F. evanescens and F. spiralis produced similar amounts of reactive oxygen after freezing, this treatment resulted in an increase in lipid peroxidation only in F. evanescens (and F. distichus).

Characteristics of arsenic accumulation by the seaweeds Fucus spiralis and Ascophyllum nodosum

This study examines the accumulation of 74As-arsenic in the seaweeds Fucus spiralis (L.) and Ascophyllum nodosum (L.) collected from Restronguet Creek in southwest England during 1978. Also, the influence of environmental factors (valence state of arsenic, pH, salinity, temperature, phosphate concentration) and metabolic inhibitors on the uptake of arsenic by F. spiralis is examined. Most of the arsenic in the seaweeds was non-exchangeable with labelled arsenic in the medium. The accumulation of 74As reached a steady state in 1 to 8 d, depending on the species and external arsenic concentration. At steady state the accumulated arsenic is proportional to external arsenate concentration. F. spiralis accumulated 4 times more arsenate than arsenite. The short-term uptake of arsenic increased in proportion to the external arsenic concentration up to a level of 1000 μg l-1; it then remained constant at higher levels of arsenic. Arsenic uptake increased in direct proportion to increasing temperature. Variation of pH or salinity had no effect on arsenic incorporation. The accumulation of arsenic occurred only in living tissue and was inhibited by KCN in a concentration-dependent manner. The uptake of arsenic by F. spiralis in the presence of photo-synthetic inhibitors (DCMU or CMU) or in the dark was greater than in the light controls. Thus, it was concluded that energy is required for arsenic uptake and this is derived from respiration rather than photosynthesis. There was no evidence for a common mechanism of phosphate and arsenate uptake by macroalgae, although high concentrations of phosphate (40 to 400 μM) initially inhibited arsenate uptake.

Drought-Hardening in the Upper-Shore Seaweeds Fucus Spiralis and Pelvetia Canaliculata

Drought-Hardening in the Upper-Shore Seaweeds Fucus Spiralis and Pelvetia Canaliculata