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In aquatic ecosystems, allelopathic activity depends on the production and secretion of allelopathic compounds and their effective dispersal in the environment. In addition, macroalgae have been found to produce active metabolites that affect other organisms that compete with them for nutrients. However, the allelopathic activity of Baltic red and brown macroalgae on filamentous cyanobacteria is still insufficiently understood. Therefore, the main objective of this study was to demonstrate and compare the allelopathic effects of macroalgae Fucus vesiculosus L. and Coccotylus brodiei (Turner) Kütz. on the growth and photosynthetic activity of two Baltic cyanobacteria Aphanizomenon sp. and Nostoc sp. It was found a stimulating effect of different concentrations (5, 25, and 50 µL mL–1) of the aqueous extract obtained from C. brodiei on the number of cells of Nostoc sp. which constituted 108%, 140%, and 147%, respectively, relative to the control treatment. On the other hand, extracts obtained from F. vesiculosus had no statistically significant effect on the number of cells of the cyanobacteria Aphanizomenon sp. and Nostoc sp. Moreover, the C. brodiei extracts had no significant impact on the growth of Aphanizomenon sp. Furthermore, Baltic macroalgae F. vesiculosus and C. brodiei was able to exert allelopathic effects on photosynthesis performance of Nostoc sp. and Aphanizomenon sp. and compounds produced by them had inhibitory, stimulatory, or no significant effect on the maximum PSII quantum efficiency (Fv/Fm) and the effective quantum yield of PSII photochemistry (ΦPSII). The results obtained in this work constitute an important contribution to the knowledge on the allelopathic activity of Baltic red and brown algae on certain bloom-forming species of filamentous cyanobacteria.

In the Kiel Fjord, western Baltic Sea, an experimental culture of Fucus vesiculosus and Fucus serratus has been established in order to develop a sustainable method for biomass production of these species. The cultivation method includes the unattached rearing of fronds in drifting baskets and their vegetative reproduction by cutting of small vegetative apices. In this study, we performed culture experiments to measure growth rates with this method at different initial stocking densities (1–5 kg m−2) and during different seasons of the year. Using the results, we modelled growth over 1 year for different cultivation scenarios (different initial stocking densities (1–4.75 kg m−2) and harvest densities (1.25–5 kg m−2)) in order to identify optimal scenarios and estimate annual yields and the number of necessary harvests in these scenarios. Fucus vesiculosus showed a parabolic yield–density relationship with decreasing yields at high initial stocking densities (> 2.5 kg m−2). In contrast, F. serratus showed an asymptotic yield–density relationship with rather constant yields at high initial stocking densities. Both species showed a typical seasonal growth pattern with low growth rates during winter and high growth rates during summer; however, F. serratus seemed to be growth limited during summer which was not observed for F. vesiculosus. The modelling results reflected the results of the Density experiment: for F. vesiculosus, optimal cultivation scenarios were found for intermediate cultivation densities (initial stocking densities, 1.75–2.25 kg m−2; harvest densities, 3–4 kg m−2); for F. serratus, optimal cultivation scenarios included higher densities (initial stocking densities, 2.5–4 kg m−2; harvest density, 5 kg m−2). The model scenarios predicted maximal annual yields of 6.65–6.76 kg m−2 for F. vesiculosus and 6.88–6.99 kg m−2 for F. serratus. For both species, the number of harvests necessary to achieve these yields varied depending on the cultivation scenario from 2 to 6. Scenarios with only 1 harvest per year yielded slightly lower annual yields. We conclude that the modelling results offer a valid and helpful orientation for future efforts to produce Fucus species in commercial culture.

The contribution of macroalgae to the removal process of diesel fuel from the Kola Bay of the Barents Sea was estimated. The calculations were based on the results of: 1) recent expeditionary observations of the reserves, spreading, and biomass of algae macrophyte of the phyla Chlorophyta and Rhodophyta, as well as the class Phaeophyceae of the phylum Ochrophyta, inhabiting three bay areas; 2) laboratory research of the ability of macroalgae Ascophyllum nodosum, Fucus vesiculosus, F. distichus, F. serratus, Saccharina latissima, Palmaria palmata, and Ulvaria obscura to neutralize the toxic effect of diesel fuel. As shown, the total contribution of the algae studied into bioremediation of diesel fuel in the bay was of 312 kg·day−1. The differences in the absorption capacity of algae macrophyte were revealed. This process was most efficiently carried out by S. latissima; the minimum efficiency of participation in bioremediation was determined for U. obscura. It was concluded that the existing littoral and sublittoral thickets of marine macroalgae of the Kola Bay can be considered as the key element in the implementation of the preventive, daily cleaning of coastal water from the petroleum products. The inclusion in the calculations of data on the ability of other representatives of the bay phytobenthos to neutralize diesel fuel may increase the role of algae macrophyte in cleaning the coastal marine areas from the petroleum products. As concluded, the thickets of brown algae can be considered as the key component of repair and homeostasis in coastal ecosystems. The destruction of even a part of algae natural communities can change the ecosystem balance.

Seaweeds are a valuable potential source of protein, as well as free amino acids (FAAs) with umami flavour which are in high demand by the food industry. The most commonly used flavouring agents in the food industry are chemically synthesised and therefore are subject to concerns regarding their safety and associated consumer resistance. This study focuses on the effects of extraction time (1 and 2 h) and solvents (0.1 M HCl, 1% citric acid and deionised water) on the extraction of protein and FAAs including umami FAAs from Irish brown seaweeds (Ascophyllum nodosum and Fucus vesiculosus). Extraction yields were influenced by both the extraction solvent and time, and also varied according to the seaweed used. Both seaweeds investigated were found to be good sources of protein, FAAs including umami FAAs, demonstrating potential application as flavouring agents in the food industry. Overall, the use of green solvents (deionised water and citric acid) resulted in higher recoveries of compounds compared to HCl. The results of this study will facilitate the use of more sustainable solvents in industry for the extraction of proteins and flavouring agents from seaweed. European Commission - European Regional Development Fund Science Foundation Ireland BiOrbic SFI Bioeconomy Research Centre Ireland’s European Structural and Investment Programmes

Hypertriglyceridemia is an independent risk factor of coronary heart disease (as established through various previously conducted studies) and it's rising incidence is creating a need for the immediate attention of it's management. Instead of focusing on the controversies involving the toxicity caused due to the long-term use of statin therapy in conventional mode of treatment, opting for a safer alternative system of treatment seems important. Five cases of diagnosed HTG, with triglyceride levels above 200 were treated with homoeopathic medicine - Fucus vesiculosus, in mother tincture form. The primary outcome measure was to evaluate the reduction in the blood triglyceride levels. All the five cases showed a reduction in triglyceride levels to normal range within 4 months of starting the treatment with the Fucus vesiculosus mother tincture. Also, it was observed that the borderline cholesterol levels and high LDL levels in 2 cases were found to reduce to normal. Treatment involving Fucus vesiculosus in cases diagnosed with HTG showed significant reduction in triglyceride levels along with other parameters of lipid profile. Further authentication of results with significant sample sizes may be taken up., Highlights • Traditional use of Fucus vesiculosus in vogue in many countries and basing on previous in-vitro and in-vivo studies, it has been used in the treatment of patients diagnosed with Hypertriglyceridemia. • A case series of 5 treated cases of Hypertriglyceridemia with the homoeopathic remedy “Fucus vesiculosus” with positive outcome has been reported. • Further large sample studies and RCTs are warranted.

Centro de Investigación en Sanidad Animal (CISA), Research on immunotherapeutic agents has become a focus for the treatment of fish diseases. The ability of algae to produce secondary metabolites of potential interest as immunotherapeutics has been documented. The present research intended to assess antiviral and antibacterial activities of macro- and microalgae extracts against viral and bacterial pathogens and explore their immunomodulatory potential using zebrafish (Danio rerio) larvae as a model organism. The cytotoxicity and antiviral activity of eight methanolic and ethanolic extracts from two macroalgae (Fucus vesiculosus, Ulva rigida) and two microalgae (Nannochloropsis gaditana, Chlorella sp.) were analyzed in established fish cell lines. Six extracts were selected to evaluate antibacterial activity by disk diffusion and growth inhibition assays. The three most promising extracts were characterized in terms of fatty acid composition, incorporated at 1% into a plant-based diet, and evaluated their effect on zebrafish immune response and intestinal morphology in a short-term feeding trial. All extracts exhibited in vitro antiviral activity against viral hemorrhagic septicemia and/or infectious pancreatic necrosis viruses. Methanolic extracts from F. vesiculosus and U. rigida were richer in saturated fatty acids and exhibited in vitro antibacterial action against several bacteria. Most promising results were obtained in vivo with F. vesiculosus methanol extract, which exerted an anti-inflammatory action when incorporated alone into diets and induced pro-inflammatory cytokine expression, when combined with the other extracts. Moreover, dietary inclusion of the extracts improved intestinal morphology. In summary, the results obtained in this study support the potential of algae as natural sources of bioactive compounds for the aquaculture industry., M. Monteiro, A. S. Lavrador, R. A. Santos, and F. Rangel were supported by grants SFRH/BD/114995/2016, ZEBRALGRE_BM_2019-003, SFRH/BD/131069/2017, and SFRH/BD/138375/2018, respectively, from FCT — Foundation for Science and Technology, under the POCI program. A. Couto C. Serra and P. Enes have a scientific employment contract supported by national funds through FCT. E. da Costa and M. R. Domingues are financially supported by FCT/MCTES (Portugal) through CESAM (UIDB/50017/2020 + UIDP/50017/2020), QOPNA (FCT UID/QUI/00062/2019), LAQV/REQUIMTE (UIDB/50006/2020), and RNEM (LISBOA-01–0145-FEDER-402–022125). This research was partially supported by the Strategic Funding to UID/Multi/04423/2019 (POCI-01–0145-FEDER-007621) through national funds provided by FCT under the project PTDC/CVT-WEL/5207/2014.

Sorption has been proposed as a promising approach towards a sustainable water decontamination and recently to the recycling of rare earth elements (REE). Although living seaweed have been shown to be capable of removing REE from contaminated solutions, no studies have yet compared the effects of REE competition on sorption onto different groups of seaweed. These effects were analysed in the present study by exposing six living seaweeds (Ulva lactuca, Ulva intestinalis, Fucus spiralis, Fucus vesiculosus, Gracilaria sp. and Osmundea pinnatifida) (3 g/L, fresh weight) to mono-element and multi-element solutions of Y, La, Ce, Pr, Nd, Eu, Gd, Tb and Dy (1 μmol/L). Results show a preference towards light REE in mono-element solutions, which is reduced when in competition with other REE. The competitive effect is less pronounced in heavy REE indicating that these are still able to bind to the macroalgae despite the presence of competing ions. Contrary to water content (%), seaweed specific surface area (cm2/g) shows to be an important factor in the sorption of REE, since larger surface area is associated with higher removal and larger competitive effect.

Background and Objective: The bean seed beetle Bruchidius incarnatus is a major insect pest for stored grains that causes great economic damage. The investigated research aimed to evaluate the efficacy of two species of algae: Fucus vesiculosus and Spirulina platensis as natural alternative pesticides against Bruchidius incarnatus stages. Materials and Methods: The efficacy of two tested algae with amounts of 0.25, 0.35 and 0.50 g were evaluated on B. incarnatus stages. The activities of some biochemical components were assayed to determine the algae effect. Seed germination and growth parameters were studied. Results: F. vesiculosus caused higher potent on larval and adult stages than S. platensis. Antioxidant enzymes Glutathione Peroxidase (GPX) and Superoxide Dismutases (SOD) in treated adults have reached the highest level when compared with control. Some biochemical components in adults were affected also by algae treatment. Treatment with two algaecaused stimulation of seedling and germination development. On the other hand, both types of algae occurred an expansion in the mitotic index and low levels of abnormalities. Conclusion: Both types of algae are considered a promising Bio-insecticide in controlling stored grain pests and it may be considered Bio-eco-friendly in pest management.

Previously it was established that phlorotannins of Arctic brown algae have bactericidal and bacteriostatic effects on Gram-positive and Gram-negative bacteria in aerobic conditions of cultivating in vitro. These effects are due to the presence of active centers in macromolecule (hydroxyl groups) and the degree of polymerization. In this article, the effect of stimulation of the phagocytic activity of human blood neutrophilic leukocytes by studied fractions of Fucus vesiculosus polyphenols was revealed. In vitro, it was found that functional and polymolecular features of polyphenols affect the formation of the complex mechanism of influence on human blood cells. Polyphenols stimulate sorption effects on cells’ surface and cause their agglomeration. Effect of erythrocytes, lymphocytes, epitheliocytes, and neutrophils surface modification without disturbing membrane integrity was revealed. Polyphenols of brown algae increase the intensity of the phagocytic reaction of neutrophilic granulocytes. Additionally, intraperitoneal injection of 5 pg mL−1 in outbred white mice (in 1 mL of saline) increased the migration activity of myeloid and lymphoid elements into the peritoneal space. Studied fractions of polyphenols can provide cell cooperation by increasing cluster formation.

Climate changes in the North Atlantic and Arctic affect the macrophytobenthos along with other components of the ecosystem, resulting in an increase of species diversity and biomass in western Spitsbergen, as has been reported. Gronfjorden is located at the mouth of one of the largest fjords of Spitsbergen, Isfjorden, and is influenced by the recent significant increase in the inflow of Atlantic Water. However, there are nearly no published data on the phytobenthic communities in this area. This research study of the littoral and sublittoral areas of Gronfjorden in 2013–14 documented 68 species, mostly high-boreal and boreal–Arctic species. When compared with species diversity in the other areas of western Spitsbergen, the data show the uniqueness of Gronfjorden’s species composition.

An experimental farm has been installed in the Kiel Fjord, western Baltic Sea, aiming at the development of a sustainable production process for Fucus species (Fucus vesiculosus, Fucus serratus). The envisaged cultivation method includes the unattached rearing of thalli in baskets deployed in the sea and their vegetative reproduction. Fertility (i.e., receptacle formation) is expected to be problematic for this approach, because receptacles are terminated in growth and degrade after gamete release. In culture experiments, natural fertility led to only minimal overall growth in F. vesiculosus and even weight loss in F. serratus. Therefore, we tested if long-term unattached cultivation of formerly attached thalli leads to a lowering of fertility by an acclimatization process. However, fertility after 1 and 2 years of unattached cultivation was statistically equal and still comparable to the high fertility of attached populations. Furthermore, we tested if the only known naturally unattached population in the western Baltic Sea near Glücksburg, which remains largely infertile in the wild, keeps its low fertility if put under culture conditions. During an experimental 1-year cultivation, thalli from this population remained almost entirely vegetative (2.0 ± 3.1% fertile apices). Hence, the Glücksburg population is a promising source of aquacultural seedling biomass. Yet, further tests are necessary to check, if the fertility remains low over several years of cultivation. If unattached populations are used as source for commercial cultures, the collection of seedling material should always be accompanied by strong measures to ensure the continued integrity of these valuable habitats.

Medicinal products of natural origin are widely used by virtue of their pharmacological efficacy and relative safety. Chemical composition of such medicines is usually complex, they may be represented by heteropolymers or mixtures containing peptides, polysaccharides, and other compounds which are endogenous and/or rapidly metabolised in a living organism. Conventional, chromatography-based approaches to evaluation of such medicines are often not applicable. Pharmacokinetics of medicinal products of natural origin may be studied by methods based on assessment of biological action and pharmacodynamic properties of such medicines, which involves determination of biological marker (biomarker) levels. The aim of the study was to summarise the accumulated experimental data on the use of biomarkers in pharmacokinetics studies as illustrated by a few medicinal products of natural origin. Material and methods. The authors studied fucoidan from Fucus vesiculosus , as well as a complex of bioactive compounds and a glycopeptide—both isolated from gonads of green sea urchins ( Strongylocentrotus droebachiensis) . In vitro/ex vivo experiments were used to establish correlation between the concentrations of the test mixtures and the activity/concentration of potential biomarkers. Experiments showing the biomarker concentration in plasma or serum ( in vitro ) and whole blood ( ex vivo ) before and after spiking with the studied products were performed in order to assess specificity, calibration (linear) range of the biomarker response, and its native concentration. The analytical procedures were based on the chromogenic (optical) anti-factor Xa activity (AXA) assay, and determination of dipeptidyl peptidase 4 and lactate dehydrogenase activity by kinetic analysis with spectrophotometric detection of enzymatic reaction products. Results. The analysis of the results of studies of a number of natural products (fucoidan from Fucus vesiculosus ; a complex of bioactive compounds isolated from gonads of green sea urchins S. droebachiensis ; a glycopeptide isolated from internal organs of S. droebachiensis ) demonstrated the feasibility of using biomarkers in pharmacokinetics studies of such products. This approach allowed for accurate calculation of pharmacokinetic parameters. Conclusion. The discussed approach may be used for various biological models and is an effective means of studying compounds that are difficult or impossible to detect by conventional bioassays in pharmacokinetics and bioequivalence studies.

Brown seaweed is an important source of fucoidan, which displays immunomodulatory effects by activating various immune cells. However, these effects of fucoidans from various sources of brown seaweed have not yet been explored in human blood dendritic cells. We studied fucoidans extracted from Ecklonia cava, Macrocystis pyrifera, Undaria pinnatifida, and Fucus vesiculosus for their effects on human monocyte-derived dendritic cells (MODC) and human peripheral blood DC (PBDC) activation. Ecklonia cava fucoidan (ECF) strongly upregulated co-stimulatory molecules, major histocompatibility complex class I and II, and the production of proinflammatory cytokines in MODCs and PBDCs compared to those by the other three fucoidans. Moreover, ECF elicited the strongest effect in the induction of syngeneic T cell proliferation and IFN-γ production compared to those of other fucoidans. These results suggest that ECF could be a suitable candidate molecule for enhancing immune activation in humans compared to that with the other three fucoidans.

In the north Atlantic, rocky intertidal shores with diverse macroalgal assemblages are common. Despite this, the effect of macroalgae on bird use of these habitats is not well understood. We used a single-season, single-species occupancy framework to investigate the influence of the macroalgal assemblage on 3 bird guilds and 2 single-species groups: shorebirds (waders), scavengers, divers, common eiderSomateria mollissimanon-parenting adults, and common eider broods. In particular, we considered whether bird occupancy is more strongly determined by the taxonomic composition of the macroalgal assemblage or by structural characteristics of the collective assemblage. We conducted avian point counts and intertidal habitat surveys at 75 sites along the Maine (USA) coast in 2016 and 2017. Macroalgae increased the probability of site occupancy for 1 guild and 2 single-species groups. Most notably, we found that shorebird occupancy had a positive relationship with the spatial extent and mat depth ofAscophyllum nodosum, indicating a preference for more homogeneous and deeper macroalgal assemblages dominated by this common, tall-canopied taxon. In contrast, common eider presence had a positive relationship with the spatial extent of 2 categories of shorter-canopied macroalgae that are less dominant members of the macroalgal assemblage. Both shorebirds and eiders were less likely to occur in areas with steeper intertidal slopes, which provide less potential habitat during low tides. Overall, our results suggest that macroalgae composition and availability influences bird occupancy in rocky intertidal habitats, but more mechanistic studies (e.g. behavioral) are needed to understand the exact role macroalgae play in coastal bird ecology.

Low-molecular-weight metabolites known as mycotoxins of micromycetes from the genera Fusarium, Alternaria, Penicillium, Aspergillus, etc. were studied using the enzyme immunoassay in the brown algae Ascophyllum nodosum, Pelvetia canaliculata, Fucus vesiculosus, Laminaria digitata, and Saccharina latissima collected from the Kandalaksha Gulf, White Sea. The T-2 toxin, diacetoxyscirpenol, deoxynivalenol, zearalenone, fumonisins of group B, alternariol, ochratoxin A, citrinin, PR-toxin, mycophenolic acid, aflatoxin B1, sterigmatocystin, cyclopiazonic acid, emodin, roridin A, and ergot alkaloids were detected in thalli of A. nodosum, P. canaliculata, and F. vesiculosus. The latter species was found to contain almost all of the above-listed mycotoxins in significant amounts. P. canaliculata had lower levels of PR-toxin, mycophenolic acid, emodin, and roridin A than those recorded from A. nodosum, whereas the levels of the other substances did not differ significantly between these species. L. digitata and S. latissima contained only ergot alkaloids in trace amounts, and no other mycotoxins were detected.

During the tidal cycle, Fucus vesiculosus L. lost moisture (up to 30% of wet weight) and was characterized by a sinusoidal pattern in photosynthetic activity. Three peaks in the photosynthesis capacity were observed at the beginning and middle of low tide and at the beginning of high tide. There were no structural changes in the photosynthetic apparatus. When analyzing the curves of CO2 gas exchange, the processes of photosynthesis in the algae exposed to the air was limited by the activity of the light and dark phases of photosynthesis. The increase in the content of lipid peroxidation products, catalase activity, and accumulation of proline in F. vesiculosus thalli indicated the presence of reversible oxidative stress during low tide.

Fucoxanthin is an oxygenated carotenoid with a broad spectrum of bioactivities, ranging from antioxidant activity to antimicrobial activities. Micro-algae are well-recognized resources for their production of fucoxanthin, which can be enhanced by cell culture and genetic engineering, and macro-algae or seaweeds are readily available natural resources for harvesting and fucoxanthin purification. Prior sample preparation methods from macro-alga matrix are tedious and time-consuming, usually involving repetitive chromatographic purification of fucoxanthin from co-extracted compounds, such as phlorotannins. This study focused on five Icelandic edible seaweeds and reported a novel sample preparation method—sugaring-out for the HPLC analysis of fucoxanthin. We aimed to determine fucoxanthin contents in Icelandic edible seaweeds and to evaluate the effects of drying process on fucoxanthin contents. An aqueous acetonitrile model system was developed to visualize fucoxanthin partition and to select optimal conditions for partition. Glucose was added to trigger phase separation. The highest yield of fucoxanthin was found when it is mixed with 70 mg mL−1 glucose. Among three edible dry seaweeds sold in Icelandic food market, fucoxanthin was detected only in sugar kelp (18.76–38.13 μg g−1 d.w.). Fresh brown algae can be good alternative sources of fucoxanthin (177.74–227.39 μg g−1 d.w. in Ascophyllum nodosum and 120.39–147.86 μg g−1 d.w. in Fucus vesiculosus). Seaweed freshness is critical for fucoxanthin extraction, as post-harvest drying process with light and air exposure can cause approximately 70–90% loss of fucoxanthin after a 4-week drying process.

The polyphenol content in the brown algae of the Barents, White Seas, as well as the water areas of the Northwest Atlantic (the Norwegian Sea, the Faxflow bay of the Atlantic Ocean) located in Russia, Norway, Greenland, and Iceland are compared. Algae of the following species were used for this study: Fucus vesiculosus, Fucus spiralis, Fucus serratus, Ascophyllum nodosum, Fucus evanescens. It was found that the most productive raw materials for the extraction of polyphenolic compounds are brown algae F. vesiculosus, growing in Zavalishin Bay of the Barents Sea (Russia): the highest polyphenol content (14.4%) in the summer of 2019 was noted here. Polyphenols detected in F. vesiculosus in the summer from the White Sea on about. Great burnt (13.3%) (Russia), as well as in the Norwegian Sea, Cape Sydspissen (11.6%) (Norway). The minimum content of polyphenols was found in F. spiralis (0.7% dry mass) on the coast of Iceland (Faxflow bay), a low content of polyphenols was characteristic of all types of algae from this location (0.7–2.4%). Three-way analysis of variance (MANOVA) on the example of three types of algae (F. vesiculosus, F. spiralis, A. nodosum) showed that all the studied factors (place of collection, type of algae, fertile phase) are significant. The most significant factor affecting the accumulation of polyphenols by brown algae is the location of algae growth. The high content of polyphenols in the types of algae we studied from Russian water areas allows us to recommend their use as food and medicinal raw materials, as well as raw materials for biologically active additives.

The seasonal dynamics of catalase activity of two related species of brown macroalgae, Cystoseira crinita (Desf.) Bory (1832) and Fucus vesiculosus L. (1753) was studied. In general, catalase activity (CA) in C. crinita was several times higher than in F. vesiculosus. The maximum values of CA in C. crinita were observed in November and the minimum ones in September. For F. vesiculosus, the maximum CA was found in January and the minimum in April. Abrupt changes in water temperature significantly affected the catalase activity in C. crinita and F. vesiculosus. In both species of algae, a similar seasonal trend in the change of CA was noted: two periods of adaptation adjustment associated with sharp changes in the temperature regime (spring and autumn) were distinguished. In spring, with a rapid increase in the temperature of the water masses, catalase inactivation occurred, whereas during summer to winter transition, accompanied by a sharp water cooling, catalase activity increases. Stabilization of the CA values of the studied macroalgae in the absence of sharp temperature variability was observed. However, this period of “stationary state” varies in time: in Cystoseira crinita it lasts from May to August, and in Fucus vesiculosus it lasts from May to December.

Fouling is a major problem in seaweed aquaculture and one of the main obstacles during the domestication process for new culture species. During first attempts to cultivate Fucus vesiculosus and Fucus serratus in the Kiel fjord (Western Baltic Sea), fouling by the epizoans Electra pilosa, Mytilus sp., and Amphibalanus improvisus rendered the production of marketable biomass impossible. This study tested (1) if regular desiccation by air exposure is effective in decreasing the abundance and size of foulers and (2) if and how regular desiccation affects the growth performance of the cultivated Fucus thalli. For this purpose, thalli of F. vesiculosus and F. serratus were cultivated freely floating in baskets directly deployed in the fjord and desiccated to defined percentages of the wet weight (ww) by air exposure. The treatments comprised controls and desiccations of different intensities (from 90 to 40% of ww) and at different frequencies (1× week−1, 3× week−1). Growth rates of both Fucus species were not or only slightly reduced by the desiccation treatments. The final harvested biomass of F. vesiculosus under frequent mild desiccations (3× week−1 to 80% of ww) was even higher than the biomass of undesiccated controls. The size of the epizoans E. pilosa and A. improvisus was significantly reduced by the desiccation treatments and the abundance of all epizoan species was drastically reduced by the desiccation regimes. Frequent mild desiccations (F. vesiculosus: 3× week−1 to 80% of ww, F. serratus: 3× week−1 to 90% of ww) proved to be most effective and decreased the epizoan ww share of the total harvest from 13.0 ± 4.8% in the control to 1.8 ± 0.2% for F. vesiculosus and from 19.1 ± 2.7 to 1.0 ± 0.1% for F. serratus. Thus, desiccation seems to be an effective measure for the production of clean Fucus biomass in culture which is necessary for further valorization. A technical solution for the implementation of this procedure in large-scale cultures remains to be developed.

Brown algae of the Fucaceae family, collected in the western segment of the Arctic, contain a large number of polyphenolic compounds—phlorotannins—with a unique chemical nature, macromolecular structure, and physicochemical properties, exhibiting bioactive properties. The peculiarity of the biopolymers’ properties and structure, which are an element of fundamental scientific research of the cycle, structure—functional nature—properties, determines the priority of the directions of use of polyphenols as effective biologically active pharmaceutical preparations. This work aims to develop methods for selective extraction of phlorotannins from the Arctic brown alga Fucus vesiculosus, characterization of physicochemical properties, and biological activity of these compounds. The efficiency of solid-phase extraction (SPE) on a hydrophobic sorbent with grafted hexadecyl groups was shown for fractionation of the polyphenolic extract: active fractions were obtained, characterized by a high content of polyphenols (yield of polyphenols up to 98% relative to the content of these components in algae) with mass-average molecular weights of 21.4–35.8 kDa and oligomeric components in the mass range 374–994 Da. The IR spectra of the fractions were characterized, and the tendency of phlorotannins to form aggregates at high concentrations of the extract was shown. During hydrodynamic studies, a strong polyelectrolyte swelling of polyphenols (PP) was noted. The obtained polyphenolic fractions differ in physicochemical characteristics (acid-base and redox properties) and antioxidant activity.

Seaweed valuables have been researched a lot in the last decades but there is a lack of information on brackish seaweed at the eastern part of the Baltic Sea. Previous research shows that Baltic seaweed can be used as a source for phycocolloids as well as for bioenergy. The amount of available usable biomass is not clear, also seaweed in brackish seawater does not reach the dimensions such as the same species in Western parts of the Baltic Sea where the salinity is higher. Therefore, the use of this biomass must be smart to create economic benefit. Three abundant Baltic brackish seaweed species were chosen, to represent green, brown and red seaweed groups and an in-depth information analysis was made to clarify possible focus substances that could be extracted from these species. In this paper we summarize literature of common seaweed components, traditional extraction technology, and potential amount in seaweed and give an overview of novel methods for extraction of seaweed bioactive compounds.

The effect of air drying and freezing at − 25 °C on the total phenolic content, fucoidan, alginate, and amino acids of brown algae Fucus vesiculosus, Fucus distichus, and Ascophyllum nodosum was studied over 365 days of storage every 90 days. The levels of total phenols and polysaccharides in frozen algae samples at 365 days of storage were 75–95% of fresh algae and were higher than in air-dried samples by more than 5–15%. The greatest differences between the fresh and dried samples were in the total phenolic contents. A strong correlation was found between the content of total phenolics and polysaccharides and the water content in frozen samples of F. vesiculosus and A. nodosum. The influence of air drying and freezing processing and storage on the total amino acid content is discussed using F. vesiculosus as an example. The total amino acid content in the air-dried samples increased during storage, but on the 365th day, 99% of the initial content in fresh algae remained. In contrast, the content in the frozen samples had decreased to 82% after the same storage duration. The ratio of the sums of the essential to the total amino acids during storage in the dry and frozen samples increased compared with that in fresh algae from 0.43 to 0.51 after 365 days of storage. Air drying and freezing are suitable procedures in terms of the levels of total phenols, polysaccharides, and amino acids, allowing a shelf life of at least 365 days.

The influence of water-soluble fraction F-55 of brown algae extract Fucus vesiculosus on the development of organotypic tissue culture of different genesis, originating from three germ leaves in young and old rats was studied. The preparation F-55 has a stimulating effect on the processes of cell proliferation in the tissues of ecto-, ento- and mesodermal genesis (cerebral cortex, myocardium, spleen and liver), by regulating the processes of cell proliferation and apoptosis. The revealed strengthening of regeneration processes in explants from both young and old rats under the influence of F-55 preparation in the range of ultra-low concentrations of 10-100 ng/ml can serve as a basis for the creation of new medicinal cytoprotective substances that allow to enhance cell regeneration in various tissues in pathological conditions, including those associated with age.

The fifth basic taste—umami—is based on hydrophilic monosodium L-glutamate (L-Glu), and, to a smaller extent, on L-aspartate (L-Asp), which can be found in free form in seaweeds. The umami taste can be elicited by the synergistic effect of 5′-nucleotides, guanosine-5′-monophosphate (GMP), and inosine-5′-monophosphate (IMP). In this work, twelve edible seaweeds, two green (Codium tomentosum, Ulva rigida), six red (Chondracanthus teedei var. lusitanicus, Chondrus crispus, Gracilaria gracilis, Grateloupia turuturu, Nemalion helminthoides, Osmundea pinnatifida), and four brown (Bifurcaria bifurcata, Fucus vesiculosus, Saccorhiza polyschides, Undaria pinnatifida), from the Portuguese seashore, were selected for the analysis of umami amino acids and 5′-nucleotides. To determine the concentrations of umami free compounds, L-Glu, L-Asp, GMP, and IMP, the usual procedure for the preparation of seaweed’s broth was carried out, and the resulting extracts were analyzed by HPLC-DAD. The effect of the seaweed’s pretreatment, oven-dried and lyophilized, was also studied. Results showed that all seaweed species contained free amino acids in broad range, whereas umami 5′-nucleotides were not detected. The lyophilized C. crispus and G. gracilis contained the highest amounts of free L-Glu (627 ± 109 mg (100 g)−1 and 398 ± 67 mg (100 g)−1, respectively) and L-Asp (520 ± 102 mg (100 g)−1 and 270 ± 10 mg (100 g)−1, respectively). Two-factor PCA explained quantitatively (90%) the variance of seaweed species based on umami L-Glu content after different drying techniques applied. The results indicate that lyophilization constitutes a superior procedure for increasing the umami potential in most of the selected seaweeds.

Recently, in order to assess the quality of water, hydrobiological indicators, in particular various biological characteristics of macroalgae, are widely used along with hydrochemical parameters. Brown alga Fucus vesiculosus due to its ecological plasticity and tolerance to a complex of natural and anthropogenic factors can serve as a model object when studying adaptive reactions of phytocenoses to adverse environmental conditions. The material for the work is the collections of algae during 1999, 2009 and 2019 years within the southern and middle tribes of the Kola Bay. The variability of the age structure of the Fucus vesiculosus on the littoral bay under anthropogenic press in different years has been considered in this work; moreover the environmental assessment of water quality has been also undertaken. Reference data have shown that the waters of the bay contained a wide range of pollutants, due to this an elevated concentrations of oil hydrocarbons and a number of metals have been observed for a long period. A study of the age structure of F. vesiculosus has shown that a long age series have been observed in the littoral cenopopulations of this species, plants of various age groups are presented, while the communities is based on young plants aged from 1 to 3 years. It has been found that the number of individuals of older age groups naturally decreases with increasing age. During the observing period, an increase in algae biomass and a subsequent decrease in its growth have been observed. The presented materials testify the stability of the brown alga F. vesiculosus under conditions of intensive industrial exploitation of the waters of the Kola Bay.

Fucus V e s i culosus (F. Vesiculosus ) by its composition is a unique raw for obtaining of variety substances with a wide range of consumer properties. The composition of the polyphenolic fraction of F.Vesiculosus is characterized by a predominant content of phloroglucinol polymers - phlorotannins, which are the target compound of this study. Microwave assisted pre-treatments of algae were carried out in order to intensify the extraction of target compound. The pre-treatment efficiency was evaluated by determining the yield of extractives, polyphenols and phlorotannins. The chemical composition of the polyphenols fraction of algae was studied. The obtained results show that microwave treatment of F.Vesiculosus allows to increase 1.6 times the yield of target compound with lower energy consumption compared to the reference sample. The obtaining extracts obtained have a high antibacterial effect on gram-positive and gram-negative bacteria, and also stimulate the growth of pea seedlings and can be recommended for use in agriculture as a growth stimulator in preparing seeds for sowing and also as an antibacterial agent, protecting as seeds and seedlings from pathogenic bacteria.

The extraction of polyphenol component of arctic brown algae of the Fucus vesiculosus type and the subsequent fractionation of the extract by column chromatography on a Sephadex LH-20 adsorbent are carried out. The obtained fractions are characterized by size-exclusion chromatography, HPLC with UV and mass spectrometric detection (HPLC–UV-MS), and matrix-assisted laser desorption/ionization mass spectrometry (MALDI–MS). Using the MALDI–MS method, the presence of oligomeric compounds containing up to 13 phloroglucin structural units is detected. Using HPLC–UV-MS, oligomeric compounds in the mass range 374–870 Da (trimers–octamers) are detected, and their ratio is estimated.

The coast of the Arctic seas is rich in reserves of brown algae, which are a source of valuable pharmaceutical substances, in particular polyphenols. The study compared the contents of the total polyphenols of the algae Fucus vesiculosusfrom the Barents, White, Norwegian seas and the Irminger Sea (the western coast of Iceland). A comprehensive extraction technique is proposed and itseffectiveness is shown. Promising areas for the extraction of raw materials with the highest polyphenol content have been identified.

Vanadium-dependent haloperoxidases (V-HPO) are specific enzymes involved in the metabolism of reactive oxygen species in marine algae. These enzymes contribute to early embryogenesis of algae in th...

Numerical models are a suitable tool to quantify impacts of predicted climate change on complex ecosystems but are rarely used to study effects on benthic macroalgal communities. Fucus vesiculosus L. is a habitat-forming macroalga in the Baltic Sea and alarming shifts from the perennial Fucus community to annual filamentous algae are reported. We developed a box model able to simulate the seasonal growth of the Baltic Fucus-grazer-epiphyte system. This required the implementation of two state variables for Fucus biomass in units of carbon (C) and nitrogen (N). Model equations describe relevant physiological and ecological processes, such as storage of C and N assimilates by Fucus, shading effects of epiphytes or grazing by herbivores on both Fucus and epiphytes, but with species-specific rates and preferences. Parametrizations of the model equations and required initial conditions were based on measured parameters and process rates in the near-natural Kiel Outdoor Benthocosm (KOB) experiments during the Biological Impacts of Ocean Acidification project. To validate the model, we compared simulation results with observations in the KOB experiment that lasted from April 2013 until March 2014 under ambient and climate-change scenarios, that is, increased atmospheric temperature and partial pressure of carbon dioxide. The model reproduced the magnitude and seasonal cycles of Fucus growth and other processes in the KOBs over 1 yr under different scenarios. Now having established the Fucus model, it will be possible to better highlight the actual threat of climate change to the Fucus community in the shallow nearshore waters of the Baltic Sea.

Floating algae can be found in high abundances at mid and high latitudes, their prolonged positive buoyancy allowing long-distance dispersal. However, despite their importance to dispersal and ecol...

Poland, a Central European country with a Baltic Sea coastline of 634 km, has no tradition of nearshore cultivation of seaweeds or utilization of this biomass. The Baltic is known for its eutrophication. Numerous attempts are being made to combat this phenomenon as well as to find applications for the beach-cast and free-floating macroalgae, which are a nuisance in many areas. Seaweed harvesting can mitigate eutrophication by the reduction of nutrients – especially nitrogen and phosphorus – in water. Collected biomass can be utilised in agriculture as biofertilisers and used as a valuable raw material for the manufacture of high-value macroalgal products, such as biostimulants of plant growth, feed additives, components of cosmetics, food additives or biogas as a form of renewable energy. The Baltic abounds in green macroalgae (Ulva sp. and Cladophora sp.) with brown (Ectocarpus sp., Pilayella sp., Fucus vesiculosus) and red algae (Vertebrata sp., Ceramium sp., Furcellaria sp.) occurring in much smaller quantities. These seaweeds are also of great interest as bioindicators of environmental pollution. The seaweeds in the southern Baltic Sea still represent an unexploited biomass and can be a huge source of innovation. New approaches towards macroalgal utilisation are in demand.

BackgroundRockweeds are among the most important foundation species of temperate rocky littoral shores. In the Baltic Sea, the rockweedFucus vesiculosusis distributed along a decreasing salinity gradient from the North Atlantic entrance to the low-salinity regions in the north-eastern margins, thus, demonstrating a remarkable tolerance to hyposalinity. The underlying mechanisms for this tolerance are still poorly understood. Here, we exposedF. vesiculosusfrom two range-margin populations to the hyposaline (2.5 PSU - practical salinity unit) conditions that are projected to occur in the region by the end of this century as a result of climate change. We used transcriptome analysis (RNA-seq) to determine the gene expression patterns associated with hyposalinity acclimation, and examined the variation in these patterns between the sampled populations.ResultsHyposalinity induced different responses in the two populations: in one, only 26 genes were differentially expressed between salinity treatments, while the other population demonstrated up- or downregulation in 3072 genes. In the latter population, the projected future hyposalinity induced an acute response in terms of antioxidant production. Genes associated with membrane composition and structure were also heavily involved, with the upregulation of fatty acid and actin production, and the downregulation of ion channels and alginate pathways. Changes in gene expression patterns clearly indicated an inhibition of the photosynthetic machinery, with a consequent downregulation of carbohydrate production. Simultaneously, energy consumption increased, as revealed by the upregulation of genes associated with respiration and ATP synthesis. Overall, the genes that demonstrated the largest increase in expression were ribosomal proteins involved in translation pathways. The fixation rate of SNP:s was higher within genes responding to hyposalinity than elsewhere in the transcriptome.ConclusionsThe high fixation rate in the genes coding for salinity acclimation mechanisms implies strong selection for them. The among-population differentiation that we observed in the transcriptomic response to hyposalinity stress suggests that populations ofF. vesiculosusmay differ in their tolerance to future desalination, possibly as a result of local adaptation to salinity conditions within the Baltic Sea. These results emphasise the importance of considering interspecific genetic variation when evaluating the consequences of environmental change.

Fucoidans are natural polysaccharides with pronounced antitumoral activities. Their modes of action include the antagonization of the chemokine CXCL12, which plays a central role in tumor development and metastasis. However, the usually high molecular mass (Mw) of fucoidans represents an obstacle to their medical application. We therefore investigated two series of degraded fucoidan fractions with regard to their CXCL12 binding and inhibition of CXCL12-induced effects in Raji cells. In addition, semisynthetic β-1,3-glucan sulfates were examined to get more information about the impact of Mw and degree of sulfation (DS). Degradation of the fucoidans from Saccharina latissima (S.l.-SP; 481–77.0 kDa) and Fucus vesiculosus (F.v.-SP; 38.2–20.6 kDa) did not affect the respective binding capacity to CXCL12. Both the Mw independence and the DS dependence were confirmed by the β-1,3-glucan sulfates having significantly higher affinity to CXCL12. The chemokine binding resulted in reduced CXCL12-induced Erk1/2 signaling and chemotaxis of Raji cells which was also independent of the Mw. Solely the oxidatively degraded fucoidan fraction displayed a significantly reduced chemotaxis inhibition. In conclusion, degradation of fucoidans to obtain biopharmaceutically more favorable Mw is possible without impairing their activities targeting CXCL12. Moreover, the β-1,3-glucan sulfates should also be considered as promising candidates for further development.

Coastal ecosystems worldwide are facing intense and diverse pressures caused by anthropogenic climate change, which compromises physiological tolerance of organisms, as well as causes shifts in their biotic interactions. Within-species genetic variation plays an important role in persistence of populations under such changes by providing building blocks for adaptation. The brackish-water Baltic Sea is predicted to experience a significant desalination by the end of this century. The Baltic Sea is dominated, in terms of biomass, by a few species with locally adapted populations, making it a suitable model for studying shifting biotic interactions under changing abiotic conditions. We exposed two foundation species of brown algae, Fucus vesiculosus and Fucus radicans, to end-of-the-century projected salinity together with grazing pressure in experimental tanks. We measured growth, grazing and phlorotannin content and compared these traits between the current and projected future salinity conditions, between Fucus species, and between high and low genotypic diversity groups. Grazing, phlorotannin content and growth of both F. radicans and F. vesiculosus all showed genotypic variation. Future decreased salinity hampered growth of F. vesiculosus irrespective of genotypic diversity of the experimental population. Furthermore, the growth response to desalination showed variation among genotypes. F. radicans was more susceptible to grazing than F. vesiculosus, and, in the high genetic diversity group of the latter, grazing was higher in the future than in current salinity. Climate change induced hyposalinity will thus challenge Fucus populations at their range margins in the Baltic Sea both because of the growth deterioration and changes in grazing. Differences between the species in these responses indicate a better ability of F. radicans to cope with the changing environment. Our results emphasize the complexity of biotic interactions in mediating the climate change influences as well as the importance of genetic diversity in coping with climate change. BONUS (Art 185) - EU, European Union; Swedish Research Council Formas; Linnaeus Centre for Marine Evolutionary Biology at the University of Gothenburg (CeMEB)

The incorporation of macroalgae on aquafeeds has been suggested to increase fish growth and organoleptic characteristics. Moreover, the potential of macroalgae to strengthen fish capacity to cope with different stressors is a challenging topic in the field of applied phycology. The adverse side effects of aqua-medicines, combined with the hypothesis that a macroalgae-enriched diet can minimize that impact, are the starting point for the present study. Hence, a mix of Ulva rigida, Fucus vesiculosus and Gracilaria gracilis was incorporated (5%) in the gilthead seabream (Sparus aurata) diet, to evaluate a possible protection against the chromosomal damage (measured as erythrocytic nuclear abnormalities) induced by the antibiotic oxytetracycline and the antiparasitic formalin as well as by the model genotoxicant cyclophosphamide. A 60-day differential dietary background was implemented (one fish group fed with standard diet and other with macroalgae-supplemented diet), after which fish were challenged by oxytetracycline, formalin and cyclophosphamide, and appraisals carried out 4 and 18 days later. To shed light on the modulation of the erythrocytic population dynamics, the erythrocyte maturity index was assessed. Oxytetracycline and formalin displayed a chromosome-damaging potential that remained for 18 days. The macroalgae-enriched diet evidenced a solid genoprotection against the three agents, revealing a broad-spectrum action. Oxytetracycline and formalin induced an erythrocyte population instability (translated into an aging effect), counteracted by algae supplementation, which seems to convey erythropoiesis promoting factors. Overall, the benefits given by the algae supplementation recommend its adoption within a framework of sustainable aquaculture practices, namely as a prophylactic measure to mitigate productivity losses when oxytetracycline and formalin are used.

Reduced seawater pH due to elevated carbon dioxide (CO2), a process known as ocean acidification (OA), is a globally significant environmental issue. OA is predicted to influence a range of ecosystem processes, but little is known about how changing seawater carbon chemistry could influence the extent and impacts of epiphytism. In the brackish Baltic Sea, increased epiphytism is associated with coastal eutrophication and the potential for OA to interact with this relationship remains unclear. This study focuses on slow-growing perennial algae Fucus vesiculosus—which is one of the most important habitat-forming species in the Baltic Sea—and two of its most common and abundant filamentous epiphytes Ceramium tenuicorne and Pylaiella littoralis. Material for this study was collected from Estonian coastal waters. The aim of the research was to determine which carbon acquisition strategies these species possess, which could indicate how they respond to predicted changes in seawater chemistry due to elevated CO2. Carbon-use strategies in macroalgae were determined by analyzing natural carbon isotope signatures (δ13C), pH drift experiments, and photosynthesis vs. dissolved inorganic carbon (P vs. DIC) curves. Our results showed that although F. vesiculosus and its filamentous epiphytes all possess a carbon concentrating mechanism (CCM), the potential species-specific variation in the CCMs operation will favor C. tenuicorne over F. vesiculosus and P. littoralis in a future high CO2 world.

Life cycle costs of co-digestion plant of cattle farm manure and locally available freshwater macrophyte C. demersum, marine brown algae F. vesiculosus, and marine green algae U. intestinalis; ratio 5:1) are analysed based on Latvian climatic and economic conditions. Biomass collection from nature and pre-treatment of biomass, biogas production, biogas treatment and utilization in combined heat and power plant are included in the boundaries. The weak points of scenarios are large capital investments, electricity sale price (and the application of feed-in tariff). As naturally grown algae and macrophytes are used, they are also sensitive to weather conditions each year as available amounts of biomass might change and decrease. Net Present Value is positive only for C. demersum with Internal Rate of Return of –14 % and Discounted Payback Period of 11 years.

19 Pág. Centro de Investigación en Sanidad Animal (CISA), Marine algae are recognised sources of bioactive compounds that have attracted great interest as nutritional supplements for aquaculture fish. Intensive rearing conditions often expose fish to husbandry-related stressors, rendering fish more susceptible to disease and reducing production yields. The present work evaluated the potential of two marine algae extracts (Fucus vesiculosus and Nannochloropsis gaditana) as nutritional supplements to mitigate stress effects in meagre (Argyrosomus regius) exposed to an acute handling stress (AS). A plant-based diet was used as a control, and three other diets were prepared, which were similar to the control diet but supplemented with 1% of each algal extract or a combination of the two extracts (0.5% each). The effects of supplemented diets on stress biomarkers, antioxidant enzyme activities, and immune response were analysed in fish exposed to AS after 4 weeks of feeding. Supplemented diets did not affect growth performance but the inclusion of F. vesiculosus promoted higher feed efficiency, as compared to the control group. Dietary algal extracts supplementation reduced plasma glucose levels, increased white blood cell counts, and reduced the expression of pro-inflammatory genes when compared with the control. N. gaditana supplementation led to a reduction in hepatic antioxidant enzyme activity and glutathione levels, while F. vesiculosus supplementation increased muscle glutathione reductase activity and reduced lipid peroxidation. These findings support the potential of algal extracts as nutraceuticals in aquafeeds to enhance the ability of fish to cope with husbandry-related stressful conditions and ultimately improve fish health and welfare., This research was funded by U. Porto and SOJA DE PORTUGAL, grant number PP-IJUP2019-SOJA DE PORTUGAL-14 This research was also partially supported by the FCT, grant numbers POCI-01-0145-FEDER-007621 and PTDC/CVT-WEL/5207/2014.

Norovirus infections belong to the most common causes of human gastroenteritis worldwide and epidemic outbreaks are responsible for hundreds of thousands of deaths annually. In humans, noroviruses are known to bind to gastrointestinal epithelia via recognition of blood-group active mucin-type O-glycans. Considering the involvement of l-α-fucose residues in these glycans, their high valency on epithelial surfaces far surpasses the low affinity, though specific interactions of monovalent milk oligosaccharides. Based on these findings, we attempted to identify polyfucoses (fucans) with the capacity to block binding of the currently most prevalent norovirus strain GII.4 (Sydney, 2012, JX459908) to human and animal gastrointestinal mucins. We provide evidence that inhibitory effects on capsid binding are exerted in a competitive manner by α-fucosyl residues on Fucus vesiculosus fucoidan, but also on the galacto-fucan from Undaria pinnatifida and their oligo-fucose processing products. Insight into novel structural aspects of fucoidan and derived oligosaccharides from low-mass Undaria pinnatifida were revealed by GCMS and MALDI mass spectrometry. In targeting noroviral spread attenuation, this study provides first steps towards a prophylactic food additive that is produced from algal species.

Mitomycin C (MMC) is an alkylating chemotherapy drug that could induce DNA damage and genetic alteration. It has been used as a model mutagen for in vivo and in vitro studies. The current study aimed to evaluate the protective role of Zinc oxide alginate–nanocomposites (ZnO-Alg/NCMs) against MMC–induced genotoxicity in mice. Animals were treated as follows: the control group, the groups treated with Algin (400 mg/kg b.w), the groups treated with ZnO-Alg/NCMs (400 mg/kg b.w), the group treated with MMC, and the groups treated with MMC plus Algin or ZnO-Alg/NCMs. Pre-treatment with Algin and ZnO-Alg/NCMs was repeated for one or seven days. Zinc oxide alginate-nanocomposites (ZnO-Alg/NCMs) were synthesized with the aim of incorporating the intrinsic properties of their constituents as an antigenotoxic substance. In this study, alginate was extracted from the brown marine alga Fucus vesiculosus, Zinc oxide nanoparticles were synthesized by using water extract of the same alga, and loaded in alginate to synthesize ZnO-Alg/NCMs. ZnO-NPs and ZnO-Alg/NCMs were characterized by TEM, SEM, EDX, and Zeta potential. The obtained results confirmed that by TEM and SEM, ZnO-NPs are rod shaped which modified, when loaded in alginate matrix, into spherical shape. The physical stability of ZnO-Alg/NCMs was reported to be higher than ZnO-NPs due to the presence of more negative charges on ZnO-Alg/NCMs. The EDX analysis indicated that the amount of zinc was higher in ZnO-NPs than ZnO-Alg/NCMs. The in vivo results showed that treatment with MMC induced genotoxic disturbances. The combined treatment with Algin and ZnO-Alg/NCMs succeeded in inducing significant protection against MMC. It could be concluded that ZnO-Algin/NCMs is a promising candidate to protect against MMC–induced genotoxicity.

RATIONALE Fucus vesiculosus has been described with potential to develop functional foods containing bioactive compounds against various diseases. However, more studies are needed to better understand its functioning and its previously reported bioactivities, mainly at the molecular level. METHODS An untargeted metabolomic study was performed to analyse HepG2 cells exposed to F. vesiculosus aqueous extract, rich in phlorotannins and peptides, during 24 h. This study was carried out using liquid chromatography combined with high-resolution tandem mass spectrometry. RESULTS This metabolomic study showed significant changes in HepG2 metabolites in the presence of the extract, standing out being the increased intensity of various fatty acid amides (oleamide, (Z)-eicos-11-enamide, linoleamide, palmitamide, dodecanamide and stearamide). This group of metabolites is reported in the literature with anticancer and hypocholesterolemic activity, bioactivities also described for F. vesiculosus. The extract induced, likewise, the expression of glutathione indicating its antioxidant effect. CONCLUSIONS This study demonstrated the potential of the compounds present in the F. vesiculosus aqueous extract for the development of natural drugs, nutraceuticals or dietary supplements, justified at the molecular level by changes in cell metabolites related to anticancer and hypocholesterolemic activity. The results here described, using an untargeted metabolomic approach, may contribute to a better understanding of algal behaviour, when used as food, in health-promoting effects.

The enrichment of semolina pasta with nutritionally rich ingredients has been targeted as a health strategy in recent years. In this work, the storage stability of seaweed-enriched pasta was assessed at different combinations of temperature and relative humidity. After six months of storage, pasta samples did not present variations in their sensory properties. The enrichment of durum wheat pasta with 1% of macroalgae Fucus vesiculosus and Ulva rigida flours, or flours of its extracts, was found to be adequate without influencing or modifying the sensory characteristics of pasta samples during the storage period. Water activity was shown to be the main criteria influencing the quality parameters of pasta during shelf life. A higher water activity during storage will lead to higher cooking losses and a lower firmness of cooked pasta, which will damage pasta quality over time.

Enhancing the cholesterol turnover in the brain via activation of liver x receptors can restore memory in a mouse model for Alzheimer's disease. The edible Asian brown alga Sargassum fusiforme (Hijiki) contains high amounts of oxysterols such as (313, 244)-stigmasta-5, 28-dien-3, 24-diol (24[R, S]-saringosterol) that are a potent liver x receptor agonists. We aimed to find native European seaweed species with contents of 24(R, S)-saringosterol that are comparable to those found in Sargassum fusiforme. Additionally, we hypothesize that seasonal variations modify the amount of 24(R, S)-saringosterol in seaweeds. Sterols and oxysterols were extracted with chloroform/ methanol from various seaweed species harvested in the Eastern Scheldt in different seasons between October 2016 and September 2017. Identification and quantification of the lipids was performed by gas chromatographymass spectrometry and gas chromatography- flame ionization detection. We confirmed that brown algae Undaria pinnatifida harvested in February and Sargassum muticum harvested in October contained the highest amounts of 24(R, S)-saringosterol (32.4 +/- 15.25 mu g/g, mean +/- S.D. and 32.95 +/- 2.91 mu g/g, respectively) and its precursor fucosterol (1.48 +/- 0.11 mg/g), higher than Sargassum fusiforme (20.94 +/- 3.00 mu g/g, mean +/- S.D.), while Ascophyllum nodosum and Fucus vesiculosus and Fucus serratus contained amounts of 24(R, S)-saringosterol (22.09 +/- 3.45 mu g/g, 18.04 +/- 0.52 mu g/g and 19.47 +/- 9.01 mu g/g, mean +/- S.D., respectively) comparable to Sargassum fusiforme. In other algae only minor amounts of these sterols were observed. The green algae Ulva lactuca contained only 0.29 mg/g fucosterol and 10.3 mu g/g 24 (R, S)-saringosterol, while all investigated red algae did not contain any 24(R, S)-saringosterol or fucosterol. In the Eastern Scheldt algae harvested in September/October delivered the highest yield for 24(R, S)-saringosterol, with the exception of Undaria pinnatifida that showed the highest levels in February. We showed that exposure of lipid extracts of Ulva lactuca to sunlight at room temperature or in the presence of oxygen to UV-C light lead to the quantitative conversion of fucosterol into 24(R, S)saringosterol. Exposing pure fucosterol to UV-light did not convert any fucosterol into 24(R, S)-saringosterol underscoring the requirement of seaweed constituents in the conversion of fucosterol into 24(R, S)-saringosterol. In conclusion, we showed that brown seaweeds harvested from the Eastern Scheldt contain amounts of 24(R, S)saringosterol comparable to Sargassum fusiforme, varying per season and showing the highest amounts in spring. In accordance with these observations the amount of 24(R, S)-saringosterol in the brown seaweeds can be modulated by light.

Seaweeds are one of the largest producers of biomass in the marine environment and a source of multiple bioactive metabolites with valuable health benefits. Among these, phlorotannins have been widely recognized for their promising bioactive properties. The potential antitumor capacity of Fucus vesiculosus-derived phlorotannins remains, however, poorly explored, especially in gastrointestinal tract-related tumors. Therefore, this work aimed to evaluate the cytotoxic properties and possible mechanisms by which F. vesiculosus crude extract (CRD), phlorotannin-rich extract (EtOAc), and further phlorotannin-purified fractions (F1–F9) trigger cell death on different tumor cell lines of the gastrointestinal tract, using flow cytometry. The results indicate that F. vesiculosus samples exert specific cytotoxicity against tumor cell lines without affecting the viability of normal cells. Moreover, it was found that, among the nine different phlorotannin fractions tested, F5 was the most active against both Caco-2 colorectal and MKN-28 gastric cancer cells, inducing death via activation of both apoptosis and necrosis. The UHPLC-MS analysis of this fraction revealed, among others, the presence of a compound tentatively identified as eckstolonol and another as fucofurodiphlorethol, which could be mainly responsible for the promising cytotoxic effects observed in this sample. Overall, the results herein reported contribute to a better understanding of the mechanisms behind the antitumor properties of F. vesiculosus phlorotannin-rich extracts.

Recent studies indicate that plant polyphenols could be pointed as potential prebiotic candidates since they may interact with the gut microbiota, stimulating its growth and the production of metabolites. However, little is known about the fate of brown seaweeds’ phlorotannins during their passage throughout the gastrointestinal tract. This work aimed to evaluate the stability and bioaccessibility of Fucus vesiculosus phlorotannins after being submitted to a simulated digestive process, as well as their possible modulatory effects on gut microbiota and short-chain fatty acids production following a fermentation procedure using fecal inoculates to mimic the conditions of the large intestine. The stability of phlorotannins throughout the gastrointestinal tract was reduced, with a bioaccessibility index between 2 and 14%. Moreover, slight alterations in the growth of certain commensal bacteria were noticed, with Enterococcus spp. being the most enhanced group. Likewise, F. vesiculosus phlorotannins displayed striking capacity to enhance the levels of propionate and butyrate, which are two important short-chain fatty acids known for their role in intestinal homeostasis. In summary, this work provides valuable information regarding the behavior of F. vesiculosus phlorotannins along the gastrointestinal tract, presenting clear evidence that these compounds can positively contribute to the maintenance of a healthy gastrointestinal condition.