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The Atlantic coastline of El-Jadida, Morocco, is renowned for its plentiful algae, especially brown seaweed, which is rich in active compounds known for their antifungal properties. This valuable resource offers an exciting opportunity to tackle the numerous challenges posed by invasive fungal infections, allergies, mycotoxin-related food poisoning, and drug-resistant strains. Underscoring the urgent need to explore alternative, sustainable, and environmentally friendly antifungal agents derived from algae. This study aimed to evaluate the antifungal activity of total alkaloids and phenolic-rich fractions derived from seven species of Pheophyceae: Sargassum muticum, Sargassum vulgare, Bifurcaria bifurcata, Cystoseira tamariscifolia, Cystoseira humilis, Laminaria ochroleuca, and Fucus spiralis against four fungi: airborne toxigenic isolates of Aspergillus westerdijkiae and Chaetomium globosum as well as nosocomial opportunistic isolates of Aspergillus nidulans and Scopulariopsis brevicaulis. The study also aimed to identify the most effective alga and its specific active compounds through LC–MS and GC–MS analysis. The invasive Sargassum muticum was chosen as the most potent alga in inhibiting the growth of mycelium. For the first time, the alkaloids palmatine and jatrorrhizine, along with caulerpin, have been identified. The chloroform fraction revealed the prevalence of phenolic compounds including, phenolic acids, flavonoids, and phlorotannins. The lowest minimum inhibitory concentrations (MICs), with a maximum fungal load of 108 colony-forming unit (CFU), recorded ranged from 3.12 to 6.25 μg/mL by the phenolic-rich fraction against airborne toxigenic isolates, and from 100 to 200 μg/mL against nosocomial opportunistic isolates by the total alkaloids. In comparison, the positive control, ketoconazole, showed higher MICs and resistance against A. nidulans. The valorization of Sargassum muticum is proposed as a green strategy to preserve the ecological balance, combat antifungal resistance, and address public health challenges. [ABSTRACT FROM AUTHOR]

The present study on the brown seaweeds Sargassum muticum focused on the application of dehydration by pressing or pulsed electric fields (PEF) pretreatment before three drying processes, namely freeze-drying, air impingement drying, and natural convection in an oven. Both pretreatments permitted to reduce significantly the initial moisture of the seaweeds with a reduction up to 50 %. The structural modifications induced by these pretreatments had a direct impact on the mechanisms of moisture retention and distribution within the seaweeds, which consequently exerted an influence on drying kinetics. The apparent moisture diffusivity for freeze-drying was significantly improved by PEF passing from 2.98 10−9 m2 s−1 to 3.62 10−9 m2 s−1 after a total disintegration. Concerning oven drying by natural convection, a dehydration by pressing will be preferred because the drying time to reach 0.45 kg kg−1 in dry basis was reduced by 61 min with this pretreatment. [ABSTRACT FROM AUTHOR]

Sargassum muticum (SM) poses a serious environmental issue since it is a fast-expanding invasive species occupying key areas of the European shoreline, disrupting the autochthonous algae species, and disturbing the ecosystem. This problem has concerned the general population and the scientific community. Nevertheless, as macroalgae are recognized as a source of bioactive molecules, the abundance of SM presents an opportunity as a raw material. In this work, response surface methodology (RSM) was applied as a tool for the optimization of the extraction of bioactive compounds from SM by microwave-assisted extraction (MAE). Five different parameters were used as target functions: yield, total phenolic content (TPC); and the antioxidant measurements of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and β-carotene bleaching (BC). After the optimal extraction conditions were determined (time = 14.00 min; pressure = 11.03 bar; ethanol = 33.31%), the chemical composition and bioactivity of the optimum extract was evaluated to appraise its antioxidant capability to scavenge reactive species and as a potential antibacterial, antidiabetic, antiproliferation, and neuroprotective agent. The results lead to the conclusion that MAE crude extract has bioactive properties, being especially active as an antiproliferation agent and as a nitric oxide and superoxide radical scavenger. [ABSTRACT FROM AUTHOR]

Background and Aims Worldwide, invasive species are spreading through marine systems at an unprecedented rate with both positive and negative consequences for ecosystems and the biological functioning of organisms. Human activities from shipping to habitat damage and modification are known vectors of spread, although biological interactions including epibiosis are increasingly recognized as potentially important to introduction into susceptible habitats. Methods We assessed a novel mechanism of spread – limpets as transporters of an invasive alga, Sargassum muticum , into beds of the seagrass Zostera marina – and the physiological impact of its invasion. The association of S. muticum with three limpet species and other habitats was assessed using intertidal surveys on rocky shores and snorkelling at two seagrass sites in the UK. A 4-year field study tested the effect of S. muticum on Z. marina shoot density, dry weight and phenolic compounds (caffeic and tannic acid) content, and a laboratory experiment tested the impact of S. muticum on nutrient partitioning (C/H/N/P/Si), photosynthetic efficiency (F v/ F m) and growth of Z. marina. Results On rocky shores 15 % of S. muticum occurrences were attached to the shells of live limpets. In seagrass beds 5 % of S. muticum occurrences were attached to the shells of dead limpets. The remainder were attached to rock, to cobblestones, to the seagrass matrix or embedded within the sand. Z. marina density and phenolics content was lower when S. muticum co-occurred with it. Over 3 years, photosynthetic responses of Z. marina to S. muticum were idiosyncratic, and S. muticum had no effect on nutrient partitioning in Z. marina. Conclusions Our results show limpets support S. muticum as an epibiont and may act as a previously unreported transport mechanism introducing invaders into sensitive habitats. S. muticum reduced production of phenolics in Z. marina , which may weaken its defensive capabilities and facilitate proliferation of S. muticum. The effect of S. muticum on Z. marina photosynthesis requires further work but having no effect on the capacity of Z. marina to sequester nutrients suggests a degree of resilience to this invader. [ABSTRACT FROM AUTHOR]

Sargassum muticum (SM) poses a serious environmental issue since it is a fast-expanding invasive species occupying key areas of the European shoreline, disrupting the autochthonous algae species, and disturbing the ecosystem. This problem has concerned the general population and the scientific community. Nevertheless, as macroalgae are recognized as a source of bioactive molecules, the abundance of SM presents an opportunity as a raw material. In this work, response surface methodology (RSM) was applied as a tool for the optimization of the extraction of bioactive compounds from SM by microwave-assisted extraction (MAE). Five different parameters were used as target functions: yield, total phenolic content (TPC); and the antioxidant measurements of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and β-carotene bleaching (BC). After the optimal extraction conditions were determined (time = 14.00 min; pressure = 11.03 bar; ethanol = 33.31%), the chemical composition and bioactivity of the optimum extract was evaluated to appraise its antioxidant capability to scavenge reactive species and as a potential antibacterial, antidiabetic, antiproliferation, and neuroprotective agent. The results lead to the conclusion that MAE crude extract has bioactive properties, being especially active as an antiproliferation agent and as a nitric oxide and superoxide radical scavenger.

Macroalgae, or seaweed, has a long history of use in human diets, especially in Eastern nations. However, the present interest in these species is driven by their remarkable bioactive and nutritional qualities and their significant availability and underutilization, making them incredibly alluring to people following alternative dietary patterns like vegetarianism and veganism. Sargassum muticum, also known as Japanese wireweed or Asian seaweed, is considered edible and has been consumed in some cultures, popular as a soup ingredient in Korea. This brown macroalgae found in marine environments has been introduced in various regions outside its native range, including Europe and North America. Moreover, this species could be helpful in feeding animals or as soil fertilizer. In this study, the nutritional properties of this marine macroalga were investigated. Nutritional parameters such as protein, sugar, and fiber content were analyzed using classical techniques. In addition, its proximate composition was also determined in terms of moisture, fixed and volatile carbon, and ash content using thermogravimetry, and their major minerals, including calcium, potassium, and magnesium, was determined using the ICP-OS technique. In terms of its mineral content, it was found to have a high mineral content (21% of ash), which consisted mainly of calcium (9 g/kg dw), potassium (77 g/kg dw), and magnesium (12 g/kg dw). In addition, this study determined the presence of iodine using ICP-MS, and 106 mg/kg dw of this essential element was quantified in these algae. The results of this study highlighted the potential nutritional benefits of the tested marine algae. Their composition revealed significant concentrations of vital elements, making them highly advantageous for human/animal dietary requirements with possible health benefits. [ABSTRACT FROM AUTHOR]

The pollution of aquatic bodies by synthetic dyes is regarded as one of the most significant environmental issues, which has prompted greater research into effective and sustainable removal techniques. Even though there have been major efforts in the previous few decades, more study is still necessary to fully examine the long-term performance and usable applicability of adsorbents and different adsorption techniques for the removal of dye. In the present study, a brown marine macroalga Sargassum muticum was used as an effective and sustainable biosorbent for the crystal violet (CV) dye removal from aqueous solutions. The biosorbent was characterized by analysis of SEM, EDX, and FTIR. In order to evaluate the optimum conditions of CV biosorption, several parameters have been examined as a function of contact time, algal dose, initial concentration of CV, and pH. The maximum CV removal was obtained at 60 min contact time, 10 g/L algal dosage, 30 mg/L initial concentration of CV, and pH 6. The isothermal models of Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin are best explained the equilibrium data obtained. At the optimum conditions, the maximum biosorption capacity of the algal biomass achieved from the Langmuir model was 39.1 mg/g. The kinetic adsorption models were also better explained using the pseudo-second-order and Elovich model, and the effect of the boundary layer was indicated using the intraparticle diffusion model as well as the chemisorption-controlled biosorption process. Thermodynamically, the process of CV biosorption was shown to be random, spontaneous, and endothermic. Furthermore, the proposed mechanism of CV dye biosorption onto algal biomass is regulated by hydrogen bond formation, electrostatic interaction, and ion exchange. These findings revealed that the biomass of S. muticum is a sustainable and promising material for the biosorption of water pollutants. [ABSTRACT FROM AUTHOR]

This work reports the detailed structure of fucoidan from Sargassum miticum (2SmF2) and its ability to potentiate the inhibitory effect of glycolysis inhibitor 2-deoxy-d-glucose (2-DG). 2SmF2 was shown to be sulfated and acetylated galactofucan containing a main chain of alternating residues of 1,3- and 1,4-linked α-l-fucopyranose, fucose fragments with monotonous 1,3- and 1,4-type linkages (DP up to 3), α-d-Gal-(1→3)-α-L-Fuc disaccharides, and 1,3,4- and 1,2,4-linked fucose branching points. The sulfate groups were found at positions 2 and 4 of fucose and galactose residues. 2SmF2 (up to 800 µg/mL) and 2-DG (up to 8 mM) were not cytotoxic against MDA-MB-231 and SK-MEL-28 as determined by MTS assay. In the soft agar-based model of cancer cell colony formation, fucoidan exhibited weak inhibitory activity at the concentration of 400 µg/mL. However, in combination with low non-cytotoxic concentrations of 2-DG (0.5 or 2 mM), 2SmF2 could effectively inhibit the colony formation of SK-MEL-28 and MDA-MB-231 cells and decreased the number of colonies by more than 50% compared to control at the concentration of 200 µg/mL. Our findings reveal the metabolically oriented effect of fucoidan in combination with a glycolysis inhibitor that may be beneficial for a therapy for aggressive cancers. [ABSTRACT FROM AUTHOR]

Macroalgae are a potentially novel source of nutrition and biologically active molecules. Proliferative species such as Eucheuma denticulatum, Solieria chordalis (red algae) and Sargassum muticum (brown alga) constitute a huge biomass that can be exploited. In this study, we focus on the extraction of polysaccharides from these three macroalgae species and the characterization of cell wall polysaccharides such as carrageenans, fucoidans and alginates by Fourier Transform Infrared spectroscopy with Attenuated Reflectance Module (FTIR-ATR). The comparison of purified extracts with commercial solutions of fucoidans, alginates or carrageenans shows a strong similarity between the spectra. It demonstrates that the methods of extraction that have been used are also suitable purifying technics. Moreover, it validates infrared spectroscopy as a quick, simple and non-destructive method for the accurate analysis of polysaccharides. The FTIR technique applied to samples collected at different periods of the year allowed us to highlight differences in the composition of fucoidans, alginates and carrageenans. Different classes corresponding to the season can be distinguished by statistical multidimensionnal analysis (Principal Component Analysis) showing that the structure of algal polysaccharides, related to bioactivity, depends on the period of harvest. FTIR results showed that S. chordalis and E. denticulatum possess a dominant type of carrageenan called iota-carrageenan. This type of carrageenan is in the majority when the alga is at maturity in its development cycle. During its growth phase, iota-carrageenan precursors can be detected by FTIR spectra, enabling a better control of the extraction and an application of these compounds in various economic sectors. When the alga E. denticulatum is in its juvenile stage, we found traces of kappa-carrageenan and nu-carrageenan polysaccharides in some extracts. [ABSTRACT FROM AUTHOR]

In this study, the total phenolic and flavonoid contents, antioxidant activity and volatile components of brown seaweed Sargassum muticum were investigated after treated with charcoal suspensions at concentrations of 5%, 10%, and 15% (w/v) for 6, 12, 18 and 24 h, respectively. Results revealed that the total phenolic content was reduced by 71.90%, 74.1% and 76.5% respectively compared to the non-charcoal treated control after 6 h of 5%~15% charcoal treatment, while extending treatment time had little impact on it. The total flavonoid content did not differ significantly from the control at 6 h with 5% charcoal treatment (P>0.05) and decreased slightly with longer treatment time, whereas it decreased significantly with both 10% and 15% charcoal treatment to 68.2% and 60.0% of the control after 24 h, respectively (P0.05), whereas decreased gradually with charcoal concentration elevated after 12 h. A total of 25 volatile components were identified from S. muticum, of which the content and types of hydrocarbons dominated. The relative content of volatile components decreased significantly after charcoal treatment (P

A novel solid bio‐electrolyte from seaweed acts as a potential candidate for electrolytes in batteries by solution casting technique. The ethanol extract of seaweed Sargassum Muticum (SME) is blended with PVA to prepare the bio‐membrane and along with MgCl2 as the ionic provider, a solid bio‐electrolyte is produced. The ionic conductivity of the prepared bio‐membrane, 1 g SME+0.8 g PVA is 1.57×10−6 S cm−1. XRD analysis affirms the amorphous nature of the prepared bio‐electrolytes and the highest degree of amorphous nature is apparent for the composition of 1 g SME+0.8 g PVA+0.7 wt% MgCl2. Complex formation between the SME, polyvinyl alcohol, and the added charge carrier has been made evident from the FTIR technique. Thermal properties of the bio‐electrolytes by differential scanning calorimetry (DSC) are supported by the low Tg. Electrochemical impedance analysis for the prepared bio‐electrolytes and the maximum ionic conductivity of 2.22×10−3 S cm−1 is exhibited by 1 g SME+0.8 g PVA+0.7 wt% MgCl2 membrane. A primary magnesium‐ion conducting battery has been constructed with the highest conducting bio‐electrolyte membrane and an open circuit voltage of 2.18 V validates the application of this bio‐membrane as a promising solid electrolyte for energy storage devices. [ABSTRACT FROM AUTHOR]

Seaweed derived biostimulants are gaining attention as an important tool in sustainable agriculture. This offers a unique opportunity to alleviate the environmental impact of Sargassum muticum (Ochrophyta, Phaeophyceae) as an invasive species by finding new applications for its biomass. In this sense, incorporating green extraction technologies is fundamental to ensure environmental-friendly goals. This research was initiated in an attempt to contribute to an integral valorization system of S. muticum biomass, exploring the biostimulant potential of the solubles obtained from pressed solids, through an autohydrolysis treatment. In addition, we compared the effect of three different liquid phase drying techniques (spray-drying, freeze-drying and convective air-drying). Low stress drying techniques as spray-drying showed better conservation of bioactive compounds and biostimulant potential. A bioassay with Nastrium officinale showed no phytotoxic effects despite high electric conductivity in most of the extracts and concentrations. Dried extracts showed mainly an amorphous structure but occasional crystal formation when spray-dried at low temperatures (Tout = 50 ºC) and after convective air drying (T = 40 ºC). Significant increases in root development were achieved at a concentration of 5 mg L−1 of spray-dried extracts and 50 mg L−1 in case of freeze-dried extracts. Munoo-Liisa vitality index showed best results with 50 mg L−1 of freeze-dried extracts. This study provides important information about the influence of different drying techniques on the physicochemical properties and biostimulant potential of S. muticum aqueous extracts and contributes to the integral valorization of its biomass. [ABSTRACT FROM AUTHOR]

Once the tide recedes and leaves a significant amount of stranded seaweed on the coast, marine macroalgae pose a serious threat to the surrounding area. Through this work, we considered a large-scale application of stranded macroalgae in building construction. For the first time we studied the impact of incorporating Sargassum mitucum seaweed fiber in replacement of flax fiber used for a standard structural cob. Thus, cob specimens were elaborated and analyzed to evaluate their compressive and hygrothermal performances. It was found that the compressive strength and water vapor resistance factors of cob decreased with the algae content. Additionally, the obtained results showed that a cob made with Sargassum muticum algae presented better thermal (insulation and inertia) and hygroscopic properties than those of a cob made with a flax fiber. Indeed, the replacement of flax straw by algae lead to a reduction in the thermal conductivity by 38% when compared to the standard cob with 2.5% of flax straw fiber. Consequently, numerical simulation showed a reduction in the energy needs in buildings made with an algae-based cob when compared to those made with a flax-based cob. This study can contribute to a global environmental and economic issue, i.e., the valorization of brown algae on a large scale. Indeed, the worldwide knows the largest sea of sargassum algae extent measures over 8850 km2. This huge mass of brownish algae is expanding every year, which now covers an area from Africa to the Caribbean. It weighs more than 20 million tons and extends from the Gulf of Mexico to the west coast of Africa. We show that stranded algae, which are considered as wastes, have the ability to improve the mechanical and hygrothermal performance of cob-based material. [ABSTRACT FROM AUTHOR]

Graceful kelp crabs (Pugettia gracilis) are abundant consumers in shallow subtidal ecosystems of the Salish Sea. These dynamic habitats are currently experiencing multiple changes including invasion by non-native seaweeds and ocean warming. However, little is known about P. gracilis' foraging ecology, therefore we investigated their feeding preferences between native and invasive food sources, as well as feeding rates at elevated temperatures to better assess their role in changing coastal food webs. To quantify crab feeding preferences, we collected P. gracilis from San Juan Island, WA and conducted no-choice and choice experiments with two food sources: the native kelp, Nereocystis luetkeana, and the invasive seaweed, Sargassum muticum. In no-choice experiments, P. gracilis ate equal amounts of N. luetkeana and S. muticum. However, in choice experiments, P. gracilis preferred N. luetkeana over S. muticum. To test effects of temperature on these feeding rates, we exposed P. gracilis to ambient (11.5 ± 1.3 ℃) or elevated (19.5 ± 1.8 ℃) temperature treatments and measured consumption of the preferred food type, N. luetkeana. Crabs exposed to elevated temperatures ate significantly more than those in the ambient treatment. Our study demonstrates the diet flexibility of P. gracilis, suggesting they may be able to exploit increasing populations of invasive S. muticum in the Salish Sea. Warming ocean temperatures may also prompt P. gracilis to increase feeding, exacerbating harmful impacts on N. luetkeana, which is already vulnerable to warming and invasive competitors. [ABSTRACT FROM AUTHOR]

Graceful kelp crabs (Pugettia gracilis) are abundant consumers in shallow subtidal ecosystems of the Salish Sea. These dynamic habitats are currently experiencing multiple changes including invasion by non-native seaweeds and ocean warming. However, little is known about P. gracilis’ foraging ecology, therefore we investigated their feeding preferences between native and invasive food sources, as well as feeding rates at elevated temperatures to better assess their role in changing coastal food webs. To quantify crab feeding preferences, we collected P. gracilis from San Juan Island, WA and conducted no-choice and choice experiments with two food sources: the native kelp, Nereocystis luetkeana, and the invasive seaweed, Sargassum muticum. In no-choice experiments, P. gracilis ate equal amounts of N. luetkeana and S. muticum. However, in choice experiments, P. gracilis preferred N. luetkeana over S. muticum. To test effects of temperature on these feeding rates, we exposed P. gracilis to ambient (11.5 ± 1.3 °C) or elevated (19.5 ± 1.8 °C) temperature treatments and measured consumption of the preferred food type, N. luetkeana. Crabs exposed to elevated temperatures ate significantly more than those in the ambient treatment. Our study demonstrates the diet flexibility of P. gracilis, suggesting they may be able to exploit increasing populations of invasive S. muticum in the Salish Sea. Warming ocean temperatures may also prompt P. gracilis to increase feeding, exacerbating harmful impacts on N. luetkeana, which is already vulnerable to warming and invasive competitors.

The spread of the brown seaweed Sargassum muticum is one of the best documented invasions of a non-native marine species. Observation of a potentially established population of S. muticum in the Orkney Islands archipelago, located off the northern coast of Scotland, was reported by recreational snorkellers in 2019 and 2020. The present study summarises a focussed investigation to confirm its presence and current local distribution, using data from 46 survey sites monitored as a part of the Orkney Islands Council Harbour Authority monitoring programme. Findings in this study represent the most northerly record of an established population of S. muticum in the United Kingdom, extending the latitudinal range in this country by 1.44° (159 km) northwards, and indicate only localised presence of this species. Analysis of a partial cytochrome oxidase I gene sequence confirmed the visual species identification. Possible vectors of introduction, gaps in the geographic range, local ecological and economic impacts, and the potential ameliorating factor of deep rockpools on wave exposed shores for S. muticum are discussed. [ABSTRACT FROM AUTHOR]

Environmental condition is a significant factor that directly affects the growth, metabolism and productivity of marine algae. This study examined the influences of diluted seawater on the growth, antioxidation capacity and accumulation of bioactive compounds of the marine macroalga, Sargassum muticum. Compared to the natural seawater (30 ppt, parts per thousand) control, the specific growth rate was clearly elevated at diluted seawater with 15 and 20 ppt during the initial 3 days, and was not statistically different at diluted seawater from 15 to 30 ppt at 15 days, while it decreased significantly at a low seawater concentration of 10 ppt. Chlorophyll a, carotenoids and total protein content fluctuated slightly under the different seawater solutions, suggesting that the algal cells underwent metabolic regulation during the period of adaptation to culture media changes. Changes in seawater concentration altered antioxidant enzyme activity, for instance, total superoxide dismutase, catalase and peroxidase, especially at low seawater solutions with 10 and 15 ppt. The malondialdehyde content also increased substantially, indicating that oxidative damage occurred in diluted seawater below 15 ppt. Moreover, the alginate content increased with decreasing seawater concentration, the alginate productivity was significantly increased by 22.32%–54.79% in all dilutions at 3 days and this promotion continued only at 15 and 20 ppt salinities after 7 days. The fucoxanthin content reduced significantly in the 10 and 15 ppt dilutions at 15 days, however, its productivity increased slightly at 10 and 15 ppt salinities in the first 3 days. The phlorotannin content increased slightly in the seawater dilutions with 20 ppt at 3 and 7 days, meanwhile, its productivity was significantly elevated during the initial 3 days at all seawater dilutions and the highest value was found at 20 ppt treatment. These results provide valuable data for the development and management of the aquaculture of S. muticum. [ABSTRACT FROM AUTHOR]

Brown macroalgae represent a sustainable and abundant source of lipids with acknowledged functional and health benefits. Nonetheless, macroalgae lipidome has been poorly unraveled due to lipids complex structural and chemical diversity. In this study, a comprehensive lipidomic analysis was performed in four macroalgae: Saccharina latissima , Fucus vesiculosus , Fucus serratus and the invasive Sargassum muticum , using HILIC-C30RP-HRMS. Neutral lipids (tri-, di-glycerides) comprised 72–82% of total lipids (TL) with a highly unsaturation profile (27–49% depending on species). The polar lipidome comprised glycolipids, phospholipids, betaine lipids and sphingolipids with varied content among macroalgae. S. latissima displayed the greatest level of glycolipids (23% of TL), by contrast with the dominance of long-chain polyunsaturated betaine lipids (10–18% of TL) in the other species, particularly in S. muticum. Phospholipids and sphingolipids were detected in low abundance (<1.7% of TL). This study elevated the potential of brown macroalgae as an emerging reservoir of bioactive lipids with nutritional relevance. [Display omitted] • Brown macroalgae lipidome was characterized by untargeted HILIC-C30RP-HRMS. • Lipid content was <10% in all the brown macroalgae species analyzed. • Polar profile encompasses glycolipids, betaine lipids, phospholipids, and sphingolipids. • Neutral lipids, tri- and di-glycerides, accounted for 72–82% of total lipids. • Betaine lipids are a main polar component in Fucales algae with potential biotechnological relevance. [ABSTRACT FROM AUTHOR]

Sargassum muticum , an invasive seaweed, has colonized many parts of the world along the coast. Marine environment invaded by this species is aggravated the complexity by CO 2 -induced ocean acidification (OA) and coastal eutrophication. However, the coupling effects of seawater acidification and eutrophication on this invasive species remain unclear. In this study, we cultured Sargassum muticum at two concentrations of p CO 2 (420 ppmv, LC and 1000 ppmv, HC) and nitrate (10 μM, LN and 200 μM, HN) for 16 days, to investigate the coupling effects of CO 2 -induced seawater acidification and nitrate enrichment on growth and photosynthesis of Sargassum muticum. The results showed that high CO 2 increased the relative growth rate (RGR) of alga by 58.9% under LN condition, while such increment was not found under HN condition. Thus, the highest RGR was emerged in the HCLN treatment. The photosynthetic rate curve under different inorganic carbon concentrations (P C curve) presented that high CO 2 increased the maximum inorganic carbon utilization rate (V max) by 8.1% under HN condition; while inhibited it by 29.8% under LN condition. The affinity to inorganic carbon, reflected by the half-saturation constant (K 0.5), was improved significantly by high CO 2 and/or high nitrate, compared with LCLN treatment. The photosynthetic rate curves under different irradiances (P I curve) suggested that the maximum photosynthetic rate (P max) of alga was enhanced remarkably by high N, and kept unaffected by high CO 2. The lowest value of dark respiration rate (R d) was found in HCLN treatment, and there was no significant difference among the other three treatments. Additionally, an increase chlorophyll a content caused by high N was only found in HC treatment. After 16 d culture, nitrate reductase activity (NRA) of algae in HN treatments decreased significantly, compared with those in LN treatments. Furthermore, high CO 2 enhanced NRA dramatically only in algae grown at LN level. Correspondingly, the lowest nitrate uptake rate (NUR) was found in LCHN treatment, and there was no significant difference among the other three treatments. In conclusion, our results showed that elevated CO 2 enhanced the RGR, and the coupling of high CO 2 and nitrate affected the photosynthesis and NUR, however did not synergistically promote growth of S. muticum. Therefore, we speculate that the future OA may exacerbate the invasiveness of S. muticum ; nevertheless, the eutrophication of seawater would not amplify this effect. • Ocean acidification promotes growth of Sargassum muticum. • Both ocean acidification and enrichment of NO 3 −−N increase photosynthesis of Sargassum muticum. • Ocean acidification and NO 3 −−N enrichment non-synergistically enhance invasiveness of S. muticum. [ABSTRACT FROM AUTHOR]

Macroalgae, or seaweed, has a long history of use in human diets, especially in Eastern nations. However, the present interest in these species is driven by their remarkable bioactive and nutritional qualities and their significant availability and underutilization, making them incredibly alluring to people following alternative dietary patterns like vegetarianism and veganism. Sargassum muticum, also known as Japanese wireweed or Asian seaweed, is considered edible and has been consumed in some cultures, popular as a soup ingredient in Korea. This brown macroalgae found in marine environments has been introduced in various regions outside its native range, including Europe and North America. Moreover, this species could be helpful in feeding animals or as soil fertilizer. In this study, the nutritional properties of this marine macroalga were investigated. Nutritional parameters such as protein, sugar, and fiber content were analyzed using classical techniques. In addition, its proximate composition was also determined in terms of moisture, fixed and volatile carbon, and ash content using thermogravimetry, and their major minerals, including calcium, potassium, and magnesium, was determined using the ICP-OS technique. In terms of its mineral content, it was found to have a high mineral content (21% of ash), which consisted mainly of calcium (9 g/kg dw), potassium (77 g/kg dw), and magnesium (12 g/kg dw). In addition, this study determined the presence of iodine using ICP-MS, and 106 mg/kg dw of this essential element was quantified in these algae. The results of this study highlighted the potential nutritional benefits of the tested marine algae. Their composition revealed significant concentrations of vital elements, making them highly advantageous for human/animal dietary requirements with possible health benefits.

Macroalgae are a potentially novel source of nutrition and biologically active molecules. Proliferative species such as Eucheuma denticulatum, Solieria chordalis (red algae) and Sargassum muticum (brown alga) constitute a huge biomass that can be exploited. In this study, we focus on the extraction of polysaccharides from these three macroalgae species and the characterization of cell wall polysaccharides such as carrageenans, fucoidans and alginates by Fourier Transform Infrared spectroscopy with Attenuated Reflectance Module (FTIR-ATR). The comparison of purified extracts with commercial solutions of fucoidans, alginates or carrageenans shows a strong similarity between the spectra. It demonstrates that the methods of extraction that have been used are also suitable purifying technics. Moreover, it validates infrared spectroscopy as a quick, simple and non-destructive method for the accurate analysis of polysaccharides. The FTIR technique applied to samples collected at different periods of the year allowed us to highlight differences in the composition of fucoidans, alginates and carrageenans. Different classes corresponding to the season can be distinguished by statistical multidimensionnal analysis (Principal Component Analysis) showing that the structure of algal polysaccharides, related to bioactivity, depends on the period of harvest. FTIR results showed that S. chordalis and E. denticulatum possess a dominant type of carrageenan called iota-carrageenan. This type of carrageenan is in the majority when the alga is at maturity in its development cycle. During its growth phase, iota-carrageenan precursors can be detected by FTIR spectra, enabling a better control of the extraction and an application of these compounds in various economic sectors. When the alga E. denticulatum is in its juvenile stage, we found traces of kappa-carrageenan and nu-carrageenan polysaccharides in some extracts.

This work reports the detailed structure of fucoidan from Sargassum miticum (2SmF2) and its ability to potentiate the inhibitory effect of glycolysis inhibitor 2-deoxy-d-glucose (2-DG). 2SmF2 was shown to be sulfated and acetylated galactofucan containing a main chain of alternating residues of 1,3- and 1,4-linked α-l-fucopyranose, fucose fragments with monotonous 1,3- and 1,4-type linkages (DP up to 3), α-d-Gal-(1→3)-α-L-Fuc disaccharides, and 1,3,4- and 1,2,4-linked fucose branching points. The sulfate groups were found at positions 2 and 4 of fucose and galactose residues. 2SmF2 (up to 800 µg/mL) and 2-DG (up to 8 mM) were not cytotoxic against MDA-MB-231 and SK-MEL-28 as determined by MTS assay. In the soft agar-based model of cancer cell colony formation, fucoidan exhibited weak inhibitory activity at the concentration of 400 µg/mL. However, in combination with low non-cytotoxic concentrations of 2-DG (0.5 or 2 mM), 2SmF2 could effectively inhibit the colony formation of SK-MEL-28 and MDA-MB-231 cells and decreased the number of colonies by more than 50% compared to control at the concentration of 200 µg/mL. Our findings reveal the metabolically oriented effect of fucoidan in combination with a glycolysis inhibitor that may be beneficial for a therapy for aggressive cancers.

This study was conducted to investigate the general properties of an enzymatic extract of Sargassum muticum (SM) produced using a crude enzyme from Shewanella oneidensis PKA 1008 and their anti-inflammatory activities. The SM was mixed with crude enzymes from S. oneidensis PKA 1008 (1:1 (v/v)) and incubated at 30 °C for 0, 3, 6, 12, 24, 48, and 60 h. S. oneidensis PKA 1008 crude enzyme showed the highest SM enzymatic extracts degradation ability when reacted with SM for 48 h. These evaluations demonstrated a 134.25% increase in reducing sugar content and a 14.90% reduction in viscosity at 48 h. The pH, lightness (L*) and yellowness (b*) of the SM enzymatic extracts decreased significantly with increasing reaction time. Moreover, the SM enzymatic extracts demonstrated significant anti-inflammatory activity. These results indicate that the crude enzyme from S. oneidensis PKA 1008 can be used to enhance the polysaccharide degradation of SM, and the resultant oligosaccharides may have an anti-inflammatory effect. [ABSTRACT FROM AUTHOR]

The seaweed Sargassum muticum, collected on the southern coast of Galicia, yielded a tetraprenyltoluquinol chromane meroditerpene compound known as 1b, whose structure is revised. The relative configuration of 1b was determined by J-based configurational methodology combined with an iJ/DP4 statistical analysis and further confirmed by measuring two anisotropic properties: carbon residual chemical shift anisotropies (13C-RCSAs) and one-bond 1H-13C residual dipolar couplings (1DCH-RDCs). The absolute configuration of 1b was deduced by ECD/OR/TD-DFT methods and established as 3R,7S,11R. [ABSTRACT FROM AUTHOR]

Vibrio parahaemolyticus can enhance bacterial resistance to disinfectants and antimicrobials by forming biofilms. The development of new natural antimicrobials is essential for the control of biofilm-related contamination and infection. In this paper, we preliminarily explored the inhibitory activity of Sargassum muticum extracts (HA-PTs) against the biofilm of V. parahaemolyticus. HA-PTs exerted anti-biofilm activity by destroying the integrity of the cell membrane, curbing the motility of single and colonial bacteria, hindering the synthesis of polysaccharide intercellular adhesion, inhibiting the secretion of extracellular DNA, and reducing the metabolic activity of biofilms. Furthermore, experiments on four free radicals (DPPH•, •OH, ABTS+•, and O 2 −•) scavenging activity and total antioxidant capacity (FRAP method and phenanthroline method) demonstrated that HA-PTs have strong reducing properties and can capture a variety of free radicals, which in turn prevents them from participating in oxidative reactions. When HA-PTs were applied to Chinese shrimp infected with V. parahaemolyticus , it could prolong their shelf life by controlling the pH rise caused by protein degradation, inhibiting the bacterial proliferation, reducing the content of total volatile basic nitrogen produced by protein degradation, and reducing the accumulation of thiobarbiturates caused by oxidative deterioration of fats. • It is the first report to analyze the anti-biofilm mechanism of HA-PTs against V.P. • HA-PTs can affect the cell membrane integrity and normal physiological activities. • HA-PTs have great free radical scavenging activity and total antioxidant capacity. • HA-PTs can extend the shelf life of infected shrimp from less than 2 days–6 days. [ABSTRACT FROM AUTHOR]

Abstract Plant disease administration is difficult due to the nature of phytopathogens. Biological control is a safe method to avoid the problems related to fungal diseases affecting crop productivity and some human pathogenic bacteria. For that, the antimicrobial activity of the seaweed Sargassum muticum methanol and water extracts were investigated against human bacterial pathogens and fungal plant pathogens. By using 70 percent methanol, the seaweed powder was extracted, feeding additives assay, ultrastructure (TEM). Results revealed significant inhibition of S. muticum methanol extract against Salmonella typhi (25.66 mm), Escherichia coli (24.33 mm), Staphylococcus aureus (22.33 mm) and Bacillus subtilis. (19.66 mm), some fungal phytopathogens significantly inhibited Fusarium moniliforme (30.33mm), Pythium ultimum (26.33 mm), Aspergillus flavus (24.36mm), and Macrophomina phaseolina (22.66mm). Phytochemical investigation of S. muticum extract showed the presence of phenolic and flavonoid compounds. Results suggested that there is an appreciable level of antioxidant potential in S. muticum (79.86%) DPPH scavenging activity. Ultrastructural studies of Fusarium moniliforme hypha grown on a medium containing S. muticum extract at concentration 300mg/ml showed a thickening cell wall, disintegration of cytoplasm, large lipid bodies and vacuoles. In conclusion, our study revealed The antibacterial activity of S. muticum extract significantly against some Gram positive, Gram negative bacteria and antifungal activity against some phytopathogenic and some mycotoxin producer fungi. Flavonoids, phenolic play an important role as antioxidants and antimicrobial properties. Such study revealed that S. muticum methanol extract could be used as ecofriendly biocontrol for phytopathogenic fungi and feeding additives to protect livestock products.

The alien brown seaweed Sargassum muticum (Yendo) Fensholt is currently observed along the coasts of Morocco. The present study aimed to evaluate the impact of physicochemical parameters on the distribution of S. muticum at four sites on the Atlantic coast of Morocco harvested between 2019 and 2020. This study showed that the highest biomass, thalli length, and fertility values were recorded in sampling sites characterized by optimal physicochemical (temperature, pH, and salinity) and nutrient H₃PO₄ during summer. The highest biomass values were recorded in August for Sidi Bouzid and Moulay Abdellah sites, conversely, in Saada and Jorf Lasfar sites the highest values were observed in February and March respectively. The thallus length was slightly larger in Moulay Abdellah site with 77.30 ± 14.09 cm compared with the three other sites during the summer/spring periods. Minimum thalli length was recorded in September for all studied sites. The thalli of S. muticum were fertile earlier in Sidi Bouzid and Saada during spring and peaked during the summer season for all studied sites showing a positive correlation with increasing temperature. Finally, the collected data shows that indeed physicochemical parameters influence bioecological parameters. Thus, contributed to a better understanding of the temporal variation of S. muticum phenology on the Moroccan Atlantic coast, these data provide the necessary information for coastal marine management and biomonitoring program as well as sustainable utilization of this renewable marine resource. • The study examines Sargassum muticum in Morocco's Atlantic coast, focusing on its spread and impact. • It looks at how environmental factors affect S. muticum across four Moroccan coast sites from 2019 to 2020. • Ideal conditions like temperature, pH, salinity, and nutrients boost S. muticum growth in summer. • Biomass peaks in August at Sidi Bouzid and Moulay Abdellah, but in February and March at Saada and Jorf Lasfar, showing growth differences. • Moulay Abdellah has longer thalli in summer/spring, with a slight decrease in September everywhere. • Fertility starts earlier at Sidi Bouzid and Saada in spring, peaking in summer across all sites due to rising temperatures. • The study emphasizes how environmental factors affect S. muticum , urging better coastal management. • It enhances understanding of S. muticum 's cycle along Morocco's Atlantic coast, aiding marine management and resource use. [ABSTRACT FROM AUTHOR]

Once the tide recedes and leaves a significant amount of stranded seaweed on the coast, marine macroalgae pose a serious threat to the surrounding area. Through this work, we considered a large-scale application of stranded macroalgae in building construction. For the first time we studied the impact of incorporating Sargassum mitucum seaweed fiber in replacement of flax fiber used for a standard structural cob. Thus, cob specimens were elaborated and analyzed to evaluate their compressive and hygrothermal performances. It was found that the compressive strength and water vapor resistance factors of cob decreased with the algae content. Additionally, the obtained results showed that a cob made with Sargassum muticum algae presented better thermal (insulation and inertia) and hygroscopic properties than those of a cob made with a flax fiber. Indeed, the replacement of flax straw by algae lead to a reduction in the thermal conductivity by 38% when compared to the standard cob with 2.5% of flax straw fiber. Consequently, numerical simulation showed a reduction in the energy needs in buildings made with an algae-based cob when compared to those made with a flax-based cob. This study can contribute to a global environmental and economic issue, i.e., the valorization of brown algae on a large scale. Indeed, the worldwide knows the largest sea of sargassum algae extent measures over 8850 km2. This huge mass of brownish algae is expanding every year, which now covers an area from Africa to the Caribbean. It weighs more than 20 million tons and extends from the Gulf of Mexico to the west coast of Africa. We show that stranded algae, which are considered as wastes, have the ability to improve the mechanical and hygrothermal performance of cob-based material.

In the present study, alginate yield and composition were investigated during the seasonal life cycle of the alien brown alga Sargassum muticum harvested from the Atlantic coast of Morocco. Alginate yield ranged from 11.14% in winter to 25.62% in spring/early summer, coinciding with maximum vegetative growth. Monthly monitoring of the alginate block structure showed that the highest mannuronate (M)/guluronate (G) ratio was recorded during the maximum development of S. muticum, before sexual maturity and during resumption of vegetative growth, giving maximum flexibility to the alga. The unusually high molar monad fractions (FG) and dyad fractions (FGG) of guluronic acid in late summer/early autumn appeared to be related to stiffness of senescent thalli. Rheological characterisation showed that the alginate of S. muticum exhibited pseudoplastic behaviour, with the highest apparent viscosities measured in late summer/early autumn when the G blocks dominated the alginate structure. This study suggests that S. muticum could be exploited as an alginophyte for commercial applications. The best harvest time is May-June, which corresponds to the highest alginate yield, maximum thallus growth, and largely completed sexual reproduction, ensuring sustainable exploitation of the species. [ABSTRACT FROM AUTHOR]

This study investigated the effects and the anti-inflammatory activity of Sargassum muticum ethanol extract in lipopolysaccharide-induced RAW 264.7 murine macrophage cells and in a croton oil-induced mouse ear edema model. Pretreatment of lipopolysaccharide-induced RAW 264.7 cells with Sargassum muticum ethanol extract (0.1-100 µg/ml) inhibited lipopolysaccharide-induced production of nitric oxide, interleukin-6 and tumour necrosis factor alpha in a dose-dependent manner. The expression of lipopolysaccharide-induced, inducible nitric oxide synthase and cyclooxygenase-2 in the Sargassum muticum ethanol extract-treated group was also suppressed in a dose-dependent manner. Furthermore, we found that Sargassum muticum ethanol extract induced anti-inflammatory effects by inhibiting Mitogenactivated protein kinases (extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38) and nuclear factor kappa B, p65 phosphorylation in lipopolysaccharide-stimulated RAW 264.7 cells. The antiinflammatory activity of Sargassum muticum ethanol extract in vivo was evaluated in the ear edema model of a croton oil-treated mouse. Compared to the untreated control, croton oil-induced ear edema was found to be reduced by about 33 % upon treatment with 250 mg/kg Sargassum muticum ethanol extract. [ABSTRACT FROM AUTHOR]

The present study focused on the dynamics of the phenology and life cycle of the Phaeophyceae invader Sargassum muticum at three sites on the Atlantic coast of Morocco over a period of two years (2013 and 2014). The results showed that S. muticum has two distinct growth phases; one with slower growth in winter followed by one with faster growth in spring-early summer, when the species exhibited high elongation and branching activities with thalli length ranging from 1 to more than 5 m depending on the study site. The site S1, with a rocky substratum covered by submerged sands, promotes thalli elongation, with maximum lengths of 643.33 11.10 cm recorded in July. At the rocky sites (S2 and S3), the maximum length of the seaweed depends on the pools’ depth. Although the elongation of thalli is enhanced by the water body depth, the settlements’ density (5-48 ind. m–2) seems to be mainly related to the nature of the substrate. The maturity index progressively increases from spring to early summer, when it reaches the highest values. S. muticum seems to be more abundant and more easily acclimated in shallow rockpools (sufficiently lighted and semi-exposed to wave action at the mid and lower tidal levels) than in protected sandy bottom sites with low hydrodynamic forces.

Marine algae contain many bioactive constituents. In the current research, the brown seaweed Sargassum muticum was collected from Red Sea and its extract used as a capping agent for the formulation of biocompatible stable silver nanoparticles (AgNPs). The seaweed-fabricated AgNPs were studied through UV–vis, TEM, XRD, EDX, FTIR and Zeta potential analyses. The chemical constituents of S. muticum extract were evaluated by RP-HPLC and 1H NMR. Both seaweed extract and AgNPs had mosquito larvicidal and adulticidal activities. The seaweed-fabricated AgNPs induced high larval mortality against mosquitoes from both Indian and Saudi Arabian strains when compared to the seaweed extract. The LC 50 values of AgNPs against the Indian strains of Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi were 43.9, 35.9 and 27.0 μg/ml, respectively; those against the Saudi Arabian strains of Ae. aegypti and Cx. pipiens were 110.4 and 126.2 μg/ml, respectively. In adulticidal experiments, the LC 50 values of S. muticum -fabricated AgNPs against Indian strains of Cx. quinquefasciatus, Ae. aegypti and An. stephensi were 42.3, 34.3 and 29.7 µg/ml, respectively, whereas those against the Saudi Arabian strains of Ae. aegypti and Cx. pipiens were 86.4 and 120.0 µg/ml, respectively. Minimal doses of seaweed-fabricated AgNPs were highly effective in inhibiting the growth of Bacillus subtilis (11.25 mm inhibition zone), Escherichia coli (13.35 mm) , Klebsiella pneumoniae (14.24 mm) and Salmonella typhi (12.23 mm). Additionally, the seaweed extract was highly efficient to adsorb methylene blue (MB) and methyl orange (MO) dyes. In conclusion, the S. muticum extract revealed to be an effective capping agent to fabricate AgNPs to be industrially used for the control of deadly mosquito vectors and as an antimicrobial and dye adsorbent agent. [Display omitted] • Marine macroalgae, S. muticum was used as a capping agent for the synthesis of biocompatible stable AgNPs. • The phytoconstituents of seaweed extract was examined by RP-HPLC-MS, 1H NMR, and AgNPs were confirmed by UV–vis, FTIR, TEM, XRD, EDX and zeta potential analyses. • Significant larval and adult toxicity was achieved using seaweed extract and AgNPs on key mosquito vectors. • Seaweed extract and AgNPs highly inhibit the growth of all tested bacteria. • Low-cost dye adsorbent ability of seaweed extract at 0.3 g per 10 mL was obtained. [ABSTRACT FROM AUTHOR]

The invasive brown alga Sargassum muticum was first recorded in Norway in 1988 and is presently common in the sublittoral fringe on the sheltered coast in South Norway. Here, results from a study on mesofauna associated with S. muticum in an archipelago on the southwest coast of Norway are presented, with two stations placed in sounds exposed to tidal currents and two in sheltered bays. Sargassum muticum occurred with a patchy distribution and an estimated density of less than 7 individuals m−2 at three of the stations (two in sheltered bays and one in a sound) and 42 individuals m−2 at the fourth station (placed in a sound). A total of 102 distinct faunal taxa were identified, with an average of 31 taxa per sample. Crustacea and Gastropoda constituted around half of the identified taxa. Fauna richness showed no relation to site type but had a curvilinear correlation with habitat size (dry weight of thallus). Total and sessile fauna richness showed a significant negative correlation with branching density. Vagile faunal density showed a curvilinear correlation with weight of epiphytes and was significantly related to site type with higher densities in the bays. The community composition of vagile fauna reflected this and was significantly related to site type, but not to epiphyte weight or branching density. When including sessile taxa in a community analysis the stations became less separated, and the community was significantly influenced by branch density. Thus, both site characteristics and morphology of S. muticum influenced the associated fauna community. [ABSTRACT FROM AUTHOR]

The Sargassum genus is rich in glycoglycerolipids, phytosterols, terpenoids, polyphenols, nitrogenous compounds, and other components, and it exhibits various biological activities. Response surface methodology optimization based on Box-Behnken design was applied to extract polyphenols with antioxidant and anti-biofilm activities from Sargassum muticum. Results indicated that the optimal extraction conditions were an ethanol concentration of 56%, a temperature of 58 °C, a time of 5 h, and a liquid/material ratio of 40 mL/g. Under these conditions, the contents of polyphenols and phlorotannins were 10.76 ± 0.42 mg/g and 1.62 ± 0.04 mg/g, respectively. The EtOH extract of S. muticum was further purified with organic solvents of different polarities, and the ethyl acetate fraction (HA-PTs) exhibited the highest purity of polyphenols and phlorotannins, along with the best antioxidant and anti-biofilm activities. In phytochemical analysis, the main substances identified were polysaccharides, phytosterols, polyphenols, flavonoids, and phlorotannins. According to UHPLC-DAD-ESI-MS/MS analysis, four types of phlorotannins were identified from HA-PTs: dibenzodioxine-1,3,6,8-tetraol, tetraphlorethol, pentaphlorethol, and fucopentaphlorethol. These results indicate that the polyphenols of S. muticum have the potential to become new natural antioxidants and antibacterial agents. • It is the first extraction of TPs with antioxidant and antibiofilm activities from S. muticum. • E2 had the highest polyphenol purity and the best biological activity. • E2 was mainly composed of flavonoids, phytosterols, polyphenols and phlorotannins. • The phlorotannins in the extract are predominantly phlorethol-type. [ABSTRACT FROM AUTHOR]

• Bio-functionality enhancement of nanohydroxyapatite (nHA). • Engineering the morphology of nHA as hexagonal rod using CTAB & SDS (1:1). • S. muticum (SM) extract prepared by sonication gives better antimicrobial activity. • MIC of SM + nHA was determined against S. aureus , E. faecalis , V. cholerae , S. typhi. The bio-functionality enhancement of nanohydroxyapatite (nHA) has currently become a major research field in the Health Care Industry. Researchers attempt to improve the antimicrobial activity by loading the antibiotics directly or doping the antimicrobial-enhancing ions such as Ag, ZnO, and Sr to nHA. There are few reports that Green synthesize also improves the same and not the morphology. Here we report, a two-step method of engineering the morphology of nHA using CTAB & SDS, and consequently, incorporating Sargassum muticum extract (SME), could promote the antimicrobial effect. Moreover, among the four methods of extraction, namely, hydrothermal, constant temperature bath and sonication, the extract obtained through sonication demonstrated potent antimicrobial activity against four pathogens tested, whereas, the extracts obtained through other methods exhibited activity only against two pathogens. The Minimum Inhibitory Concentration (MIC) for the SME-added nHA has successfully been determined against the pathogens S. aureus, E. faecalis, V. cholerae and S. typhi. Further, supportive studies, to confirm the composition, phase, morphology and porosity were also carried out and the results are discussed in detail. [ABSTRACT FROM AUTHOR]

The seaweed Sargassum muticum, collected on the southern coast of Galicia, yielded a tetraprenyltoluquinol chromane meroditerpene compound known as 1b, whose structure is revised. The relative configuration of 1b was determined by J-based configurational methodology combined with an iJ/DP4 statistical analysis and further confirmed by measuring two anisotropic properties: carbon residual chemical shift anisotropies (13C-RCSAs) and one-bond 1H-13C residual dipolar couplings (1DCH-RDCs). The absolute configuration of 1b was deduced by ECD/OR/TD-DFT methods and established as 3R,7S,11R.

The endophytic fungal community in the marine ecosystem has been demonstrated to be relevant source of novel and pharmacologically active secondary metabolites. The current study focused on the evaluation of cytotoxic and apoptosis induction potential in the culture extracts of endophytic fungi associated with Sargassum muticum, a marine brown alga. The cytotoxicity of the four marine endophytes, Aspergillus sp., Nigrospora sphaerica, Talaromyces purpureogenus, and Talaromyces stipitatus, was evaluated by the MTT assay on HeLa cells. Further, several physicochemical parameters, including growth curve, culture media, and organic solvents, were optimized for enhanced cytotoxic activity of the selected extract. The Aspergillus sp. ethyl acetate extract (ASE) showed maximum cytotoxicity on multiple cancer cell lines. Chemical investigation of the metabolites by gas chromatography–mass spectroscopy (GC-MS) showed the presence of several compounds, including quinoline, indole, 2,4-bis(1,1-dimethylethyl) phenol, and hexadecenoic acid, known to be cytotoxic in ASE. The ASE was then tested for cytotoxicity in vitro on a panel of six human cancer cell lines, namely, HeLa (cervical adenocarcinoma), MCF-7 (breast adenocarcinoma), Hep G2 (hepatocellular carcinoma), A-549 (lung carcinoma), A-431 (skin/epidermis carcinoma), and LN-229 (glioblastoma). HeLa cells were most vulnerable to ASE treatment with an IC50 value of 24 ± 2 μg/ml. The mechanism of cytotoxicity exhibited by the ASE was further investigated on Hela cells. The results showed that the ASE was capable of inducing apoptosis in HeLa cells through production of reactive oxygen species, depolarization of mitochondrial membrane, and activation of the caspase-3 pathway, which shows a possible activation of the intrinsic apoptosis pathway. It also arrested the HeLa cells at the G2/M phase of the cell cycle, eventually leading to apoptosis. Through this study, we add to the knowledge about the marine algae associated with fungal endophytes and report its potential for purifying specific compounds responsible for cytotoxicity.

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The brown seaweed Sargassum muticum was processed by non isothermal autohydrolysis under conditions selected to maximize fucoidan solubilization (170 °C). Acetone precipitation was tried for recovery of fucose-containing oligosaccharides present in hydrolyzates. The acetone:hydrolyzate volume ratio influenced both yields and composition of the precipitated fractions. The sugar components were mostly found as oligomers, their content increased with acetone:hydrolyzate volume ratio 2.0 (v/v) exhibited slight. The fractions precipitated with 0.1 and 0.9 acetone volumes showed higher phenolic and sulfate content, which was positively correlated with the antiradical activity, and exhibited slightly cytotoxic activity against human colon adenocarcinoma cells. The highest volumes of acetone used led to a slight increase in the apparent viscosity as well as the elastic and viscous moduli of formulated aqueous dispersions of alginate. Steady-state and oscillatory shear measurements of above representative dispersions indicated that the alginate extracted after acetone precipitation exhibited a slight enhancement of the viscoelastic features. [ABSTRACT FROM AUTHOR]

Marine heatwaves (MHWs) are emerging as forceful agents of ecosystem change and are increasing in frequency, duration, and intensity with climate change. During MHWs, physiological thresholds of native species may be exceeded while the performance of invasive species with warm affinities may be enhanced. As a consequence, MHWs could significantly alter an ecosystem's invasive dynamics, but such interactions are poorly understood. Following a 10‐d acclimation period, we investigated the physiological resistance and resilience of an intertidal rock pool assemblage invaded by the seaweed Sargassum muticum to realistic 14‐d marine heatwave scenarios (+1.5°C, +2.0°C, +3.5°C) followed by a 14‐d recovery period. We conducted mesocosm experiments in both summer and winter to investigate temporal variability of MHWs. MHW treatments had clear negative impacts on native seaweeds (Fucus serratus and Chondrus crispus) while enhancing the performance of S. muticum. This pattern was consistent across season indicating that acclimation to cooler ambient temperatures results in winter MHWs having significant impacts on native species. As climate warming advances, this may ultimately lead to changes in competitive interactions and potentially exclusion of native species, while invasive species may proliferate and become more conspicuous within temperate rocky shore environments. [ABSTRACT FROM AUTHOR]

The present work reports on the antibacterial and antioxidant activity of gold and silver nanoparticles, synthesized by an extract of the brown macroalga Sargassum muticum (SM). These nanoparticles were synthesized and fully characterized by means of UV–Vis spectroscopy and electron microscopy. These techniques confirmed that spherical nanoparticles, with mean diameters of 10.4 ± 1.2 nm for Au@SM and 41.0 ± 5.7 nm for Ag@SM, were formed. To investigate the possible role of these biomolecules in this green synthetic process, Fourier-transformed infrared spectroscopy analysis was performed before and after the synthesis of nanoparticles. Furthermore, the carbohydrate composition was examined along with other variations observed after the synthesis of nanoparticles by size-exclusion chromatography. The study of the changes observed indicated that the polysaccharide fraction of the extract plays a role in the formation of the nanoparticles as well as in their stabilization. The in vitro antioxidant activity was analyzed by the determination of the reducing power, total content of phenolic compounds and the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) scavenging activity. Lastly, the antibacterial activity was tested against three types of bacteria with different cell wall composition. In particular, Ag@SM showed good inhibitory capacity on Gram+, especially on Staphylococcus aureus with a MIC of 3.38 µg/mL. [ABSTRACT FROM AUTHOR]

Herpes simplex virus 1 (HSV-1) remains a prominent health concern widespread all over the world. The increasing genital infections by HSV-1 that might facilitate acquisition and transmission of HIV-1, the cumulative evidence that HSV-1 promotes neurodegenerative disorders, and the emergence of drug resistance signify the need for new antiviral agents. In this study, the in vitro anti-herpetic activity of sulfated polysaccharides (SPs) extracted by enzyme or hot water from seaweeds collected in France and Mexico from stranding events, were evaluated. The anti-herpetic activity evaluation of the semi-refined-polysaccharides (sr-SPs) and different ion exchange purified fractions showed a wide range of antiviral activity. Among them, the sr-SPs from the Rhodophyta Halymenia floresii showed stronger activity EC50 0.68 μg/mL with SI 1470, without cytotoxicity. Further, the antiviral activity of the sr-SPs evaluated at different treatment schemes showed a high EC50 of 0.38 μg/mL during the viral adsorption assays when the polysaccharide and the virus were added simultaneously, whilst the protection on Vero cell during the post-infection assay was effective up to 1 h. The chemical composition, FTIR and 1H NMR spectroscopic, and molecular weights of the sr-SPs from H. floresii were determined and discussed based on the anti-herpetic activity. The potential utilization of seaweed stranding as a source of antiviral compounds is addressed.

Epifaunal assemblages inhabiting the non-indigenous macroalga Sargassum muticum (Yendo) Fensholt were investigated on two physically distinct intertidal rocky (S1) and sandy (S2) sites along the Atlantic coast of Morocco. The objective of this study was to test whether the habitat-forming marine alga S. muticum invasive in these sites supported different epifaunal assemblages under different environmental conditions and through time. The gastropods Steromphala umbilicalis, S. pennanti, and Rissoa parva and the isopod Dynamene bidentata were the most contributive species to the dissimilarity of epifaunal assemblage structure between both sites throughout seasons. SIMPER analysis showed a dissimilarity of 58.3–78.5% in the associated species composition of S. muticum between study sites with respect to sampling season. Species diversity and total abundance were significantly higher at the rocky site compared to the sandy site. PERMANOVA analyses showed significant differences of associated epifaunal assemblage structure for the season and site interaction. Accordingly, site and season were determinant factors conditioning the role of habitat in structuring epifaunal assemblages. [ABSTRACT FROM AUTHOR]

In this examination, the proficiency of alga biomass Sargassum muticum for simultaneous uptake of methylene blue (MB) and lead (II) (Pb2+) ions from aqueous solution is investigated. The brown alga is surveyed by scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption–desorption procedures. Impact of operating variables (brown alga mass, contact time and initial MB and Pb+2-ion concentration) on the simultaneous contaminants uptake is performed by means of central composite design and upgraded through response surface method (RSM). Accuracy of the equation procured by RSM is checked by the variance investigation and computing of determination coefficient (R2) among predicted and the experimental values of simultaneous noxious substances removal. Bon accord among empirical and envisaged values is commented. The optimum conditions are settled at contact time (30 min), 39 mg L−1 for MB and 30 mg L−1 for Pb2+ ions and brown alga mass (0.3 g) to reach maximum retention percentage. Adsorption kinetic depicted three phases intra-particle diffusion mode and coordinated the pseudo-second-order design very well. Batch equilibrium results reveal that MB and Pb2+ ions biosorption onto alga biomass could be all around portrayed by Langmuir isotherm model contrasted with Freundlich approach. In any case, removal percentage elaborated from column studies is inferior to those computed from batch technique. Column can be recouped and reutilized even after 5-adsorption–desorption cycles. X-ray photoelectron spectroscopy and FTIR scrutinies uncovered that hydroxyl, carbonyl and amino functional groups are responsible for the biosorption of both pollutants onto non-living brown alga. Previous tests achieved on paint wastewater demonstrated that the invasive biomass Sargassum muticum could be an effective and promising biosorbent for dye/metal wastewater treatment. [ABSTRACT FROM AUTHOR]

The brown seaweed Sargassum muticum is one of the best-studied invasive marine species, although most studies are short-term and focus on the expansion phase of invasion. Here I report 30 years of observations of the invasion of the north coast of Spain by S. muticum at regional (400 km coastline) and local scales (at the site where the invasion was first detected). At the local scale, this long-term series reveals a 'boom-bust' process where the expansion ('boom') phase lasted 12 years and the decline ('bust') was completed in 8 years. This cycle is supported by evidence at the regional scale. The impact of S. muticum on the recipient assemblages was only moderate during the initial 'boom' phase of the invasion and negligible afterwards. In conclusion, 30 years after its first observation in the region, Sargassum muticum can be considered an addition to the algal flora rather than a threat to the native assemblages. [ABSTRACT FROM AUTHOR]

A novel multistage water-based process was evaluated for the production of sap and other liquid fractions from frozen Sargassum muticum in an attempt to propose an integral and yearly-around utilization of this invasive alga. Three aqueous extracts including (i) the defrosting liquid phase, (ii) the sap liquid obtained by pressing and (iii) the autohydrolysis extract from the solid residue remaining after pressing were characterized for yield, phenolic content, reducing power and antiradical properties. Alginate precipitation and a further liquid–liquid extraction stage using ethyl acetate were assayed to concentrate the phenolic fraction. Alginate exhibited similar viscoelastic features to those commercial available. The aqueous extracts contained 3–12 g phloroglucinol equivalents (PGE)/100 g extract, whereas the ethyl acetate extracts contained up to 55 g PGE/100 g extract and 1 g was as potent ABTS+ radical scavenger as 0.5 g Trolox. The aqueous phase produced by autohydrolysis of the solids were cytotoxic against HCT 116 cells (IC50 < 50 µg mL) without noxious effect on normal cells. [ABSTRACT FROM AUTHOR]

There is now a greater concern in the marine organisms, especially algae, to find active ingredients to be used as therapeutic drugs in the medical applications. Delivery of drugs into the target organs with high specificity is now achieved when these compounds are coated on nanoparticles which improve the therapeutic properties of anti-tumor products. So, the current investigation aimed to assess the hepatoprotective capacity of silver nanoparticles (AgNPs) prepared by using ethanol extraction of Sargassum muticum (SmAgNPs) versus diethylnitrosamine (DEN) promoted liver tumor in male rats. Swiss albino male rats were allocated into several treated groups. Diethylnitrosamine (DEN, 20 mg per kg body weight) was used for 2 months in male rats to induce liver tumor and then treated with several concentrations (25, 50, and 75 mg per kg body weight) of algae extracts and SmAgNPsas well as with a reference drug (30 mg/kg of Silymarin) for 8 weeks. The results revealed that treatment of DEN-rats with SmAgNPsdecreased levels of the liver function enzymes, namely, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), decreased rates of the DNA damage, and increased activity levels of antioxidant enzymes such as catalase (CAT) and glutathione peroxidase (GPx). Additionally, DEN-rats treated with silver nanoparticles of S. muticum elevated the expression levels of tumor suppressor genes (such as ING3 and Akr1b10) and diminished the levels of oncogene (FoxP1) expression explaining that SmAgNPshas antitumor activity through alteration of the liver cancer-related genes. The results concluded that the high competence of S. muticum nanoparticles for protecting the DNA from damage and increase the antioxidant activities as well as enhance the up-regulation of tumor suppressor mRNAs is attributed to its rich active compounds of fucoxanthin (as marine carotenoids) and fucosterol (marine sterol). [ABSTRACT FROM AUTHOR]

The inhibition effect of the invasive brown seaweed Sargassum muticum extract (ESM), harvested from the Atlantic coast of Morocco, against the corrosion of carbon steel (CS) in 1 M HCl medium was studied for the first time using gravimetric, electrochemical and surface techniques. The methanolic crude extract of Sargassum muticum (ESM) is rich in alginate biopolymer. The evaluation corrosion tests showed that this algal extract acts as a good mixed corrosion inhibitor for CS substrate in 1 M HCl since inhibition efficiency of 97% was reached with 1 g/L of ESM at 303 K. AC impedance findings showed that the seaweed extract adding in the corrosive electrolyte increases the polarization resistance and conversely decreases the charge capacitance at the interface. Adsorption of ESM on the substrate surface followed the Langmuir adsorption isotherm. X-ray photoelectron spectroscopy analyses (XPS) demonstrated that the corrosion inhibition mechanism of CS substrate in 1 M HCl environment by the investigated algal extract is typical of the chemisorption process and the protective barrier is mainly formed by the adsorbed biological macromolecules. • The Sargassum muticum extract (ESM) is an effective biological inhibitor for the carbon steel corrosion in 1 M HCl. • The adsorption of ESM biological macromolecules on the steel surface is best described by the Langmuir model. • ESM is chemisorbed on the steel surface. • XPS analysis has provided the composition of adsorbed protective layer on the steel surface. [ABSTRACT FROM AUTHOR]