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Sargassum polycystum is among the seaweed species in the Philippines that are considered coastal waste after drifting on the shorelines. Although there has been a report on the potential of S. polycystum as a biostimulant for certain crops, its utilization as a hydroponic nutrient solution is not yet thoroughly analyzed. Thus, a study utilizes various ratios of S. polycystum seaweed extract (SE) mixed with commercial hydroponic nutrient solution (CHNS) to the growth and yield of green leaf lettuce grown under the Kratky method of hydroponic system. Treatments are 100% CHNS and percentage replacements of CHNS with SE (25%, 50%, and 75%, respectively). The result shows a 10.53% increase in lettuce plant height grown under 25% and 50% SE compared to 100% CHNS. A similar result is also observed in the lettuce leaf width (14.29%), leaf length (7.14%), and plant weight (22.41%). Regarding root length, replacing 50% SE resulted in longer root length (44.83%) and more leaves (10%) compared to lettuce plants grown under 100% CHNS. However, replacement of SE beyond 50% is detrimental to leaf length and comparable to all growth and yield parameters with 100% CHNS. Regarding the return on investment, 50% SE replacement has the highest return of 98.62% compared to 100% CHNS, with 49.87% only for a projected six cropping cycles. Hence, a 50% replacement of CHNS with SE from its recommended rate can be suggested for more profitable production of green leaf lettuce under a hydroponic system. [ABSTRACT FROM AUTHOR]

This work aims at exploring the green synthesis of ZnO NPs from Sargassum cinctum; a brown marine macro algae. In the green synthesis of ZnO NPs, the bioactives present in Sargassum cinctum extract are capable of reducing and stabilising agents in the development of the said particles. In contrast to normal approaches, which usually involve the use of harmful chemicals to make nanoparticles, this technique is considered ecologically beneficial. X-ray diffraction, scanning electron microscopy, and fourier transform infrared spectroscopy studies were employed to characterise the synthesised Sc-ZnO NPs. The crystalline structure, size distribution, and functional groups revealed in the seaweed extract were all supported by these studies and may be the reason for the nanoparticles stability and biological activity. In order to determine the anticancer property of the Sc-ZnO NPs, the particles were tested on breast cancer cell lines. The findings shown in the outcomes showed that Sc-ZnO NPs had the ability to suppress the growth of breast cancer cells. In general, this research indicates that Sc-ZnO NPs prepared with the help of green techniques based on Sargassum cinctum might be considered as a rather effective and environmentally friendly anticancer agent for breast cancer. The observations made allow for the possibility of the further use of these nanoparticles for the creation of new, environmentally-friendly anticancer agents that have less adverse effects on the environment and high selectivity towards cancer cells. [ABSTRACT FROM AUTHOR]

Sargassum thunbergii is an economically significant algal species in China. During its cultivation, the decomposition of dead thalli releases nutrients into the surrounding water, a process influenced by environmental factors such as dissolved oxygen and sediment. To understand the decomposition process of S. thunbergii under the influence of dissolved oxygen and sediments, a laboratory simulation was conducted to study its decomposition under various environmental conditions. The changes in biomass, as well as the carbon, nitrogen, phosphorus, lignin, cellulose, and hemicellulose content of S. thunbergii, were analyzed. Additionally, the microbial composition of the sediment was examined. The results indicated that both high oxygen levels and the presence of sediments accelerated the decomposition of S. thunbergii, leading to reductions in the content of carbon, nitrogen, phosphorus, lignin, cellulose, and hemicellulose. Compared to the low oxygen group, the high oxygen group experienced the fastest mass loss of S. thunbergii. However, the differences in nitrogen and phosphorus content changes between high and low oxygen conditions were not significant (p > 0.05). Furthermore, the sediment microorganisms were primarily composed of the phyla Proteobacteria, Firmicutes, and Desulfobacterota, which were closely associated with the life cycle of seaweed. These findings demonstrate that the decomposition of S. thunbergii is a complex process influenced by multiple factors. High oxygen, low oxygen, and sediments all promoted the decomposition of S. thunbergii, releasing substantial nutrients. Therefore, it is recommended that in the decay period of S. thunbergii, the decayed thalli should be promptly removed from aquaculture areas to prevent secondary pollution. [ABSTRACT FROM AUTHOR]

Skin cancer is one of the most common types of cancer worldwide, with exposure to UVB radiation being a significant risk factor for its development. To prevent skin cancer, continuous research efforts have focused on finding suitable photoprotective ingredients from natural sources that are also environmentally friendly. This study aimed to develop oil-in-water photoprotective nanoemulsions containing marine macroalgae extract. A Box–Behnken experimental design was used to identify the most promising formulation composition, resulting in optimal physical properties. These properties, including droplet size, polydispersity index (PDI), and zeta potential, were evaluated using dynamic light scattering (DLS). To assess the photoprotection capacity of the formulations, electrical impedance spectroscopy (EIS) was employed to evaluate alterations in the electrical characteristics of excised pig skin membranes placed in Franz cells equipped with a 4-electrode set-up. The final composition of the nanoemulsion was caprylic/capric triglycerides 4%, Macrogolglycerol ricinoleate 30%, and algae extract 1%. The nanoemulsions had an average droplet size of 128.5 ± 8.6 nm, a PDI of 0.25 ± 0.06, and a zeta potential of 45.14 ± 0.02 mV. Compared to the control group, the photoprotective capacity of the oil-in-water nanoemulsions was statistically significant. Specifically, only a 15% reduction in the skin membrane electrical resistance following UVB exposure was observed when the formulation containing algae extract was used, whereas a 50% reduction was observed for the vehicle. In conclusion, this work demonstrates that the developed nanoemulsions based on natural ingredients show promising protective capacity against UVB exposure of the skin. [ABSTRACT FROM AUTHOR]

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Sargassum is the most abundant and diverse macroalgae in Gunungkidul Coast, Indonesia. The use of Sargassum as a cosmetic ingredient in Gunungkidul is limited, despite its antioxidant and antibacterial properties. This study aimed to identify Sargassum based on DNA barcoding and to explore its antioxidant and antimicrobial properties. Three types of Sargassum were collected from the Gunungkidul coast and were identified through DNA barcoding targeting the nuclear ribosomal Internal Transcribed Spacer 2 (ITS2) sequences. Triphasic method of n-heptane/ EtOAc/acetonitrile/butane-1-ol/water solvents was employed for extraction. The extract bioactivity was evaluated by testing it against the minimum inhibitory concentration (MIC) of four bacterial species and its IC50 capacity. DNA barcoding identified three confirmed species: S. oligocystum, closely related to S. aquifolium; S. ilicifolium, closely related to S. yinggehaiense; and S. aquifolium, closely related to both S. oligocystum and S. megalocystum. The three phases of triphasic extract were separated into phases: 1 (top), 2 (middle), and 3 (bottom). MIC test against four microbes showed a range of activity from no inhibition to minimal activity. The antioxidant capacity examination of S. ilicifolium and S. aquifolium extracts using IC50 yielded values ranging from strong to very strong. These findings were further supported by the LC-MS dereplication, which revealed the presence of sargachromanols A and cystodione I molecules. [ABSTRACT FROM AUTHOR]

The nutrient composition and biostimulant properties of seaweed were determined as solid biofertilizer for cultivating tomato seedlings in a greenhouse. Seaweeds (Sargassum wightii, Sargassum longifolium, Laminaria digitata, and Gelidiella acerosa) were collected from rocky areas and turned into a powder, and their nutrient compositions were analyzed. The brown seaweed showed indoleacetic acid (IAA), gibberellic acid (GA3), indole butyric acid (IBA), and abscisic acid (ABA). The amount of IAA ranged from 0.52 to 21.5 μg/mL. Compared with the other brown algae, the G. acerosa extract presented the maximum amount of GA3 (149 μg/mL). The amount of IBA ranged from 1.5 to 15.3 μg/mL, and the ABA level was high in S. wightii (2.5 μg/mL). All algae powders were subjected to biofertilizer preparation and their biostimulant properties were studied. The algal biostimulant improved flower cluster number, fruit number, shoot dry weight, and root dry weight in tomato plants in a greenhouse. Macroalgae fertilizer improved urease, phosphatase, invertase, and catalase activities (p<0.05) and the microbial population in the soil. The results showed positive effects of biostimulants on soil physicochemical and biological properties. [ABSTRACT FROM AUTHOR]

Recent Sargassum horneri blooms, altering marine ecosystems, highlight an urgent need to understand their impact on phytoplankton and the regulation of organic matter export from the euphotic zone. To this end, we examined the effects of floating Sargassum on the phytoplankton size composition and their rates of sinking and lysis in the area of floating Sargassum horneri near the Zhoushan archipelago. We found that the presence of floating Sargassum horneri significantly influences the marine ecosystem by increasing the proportion of pico-sized phytoplankton, indicating community miniaturization. This shift suggests a novel mechanism by which floating macroalgae may alter the structure and function of phytoplankton communities. Our findings also indicate that these macroalgae enhance the sinking and lysis rates of phytoplankton, which could have profound effects on the vertical transport of organic matter and biogeochemical cycling in the ocean. The potential aggregation of pico-sized phytoplankton may facilitate their sinking in the surface layer, possibly leading to a reduction of lysis rates because of competition with floating seaweed. Conversely, in deeper layers, the decomposition of phytoplankton could result in the formation of aggregates of pico-sized phytoplankton, accelerating their sedimentation. These results highlight the complex interactions between phytoplankton size, lysis and sinking rates, and underscore the importance of considering these dynamics in understanding carbon export and sequestration in marine environments. [ABSTRACT FROM AUTHOR]

A series of in vitro studies were conducted to explore the anti-methanogenic potential of five seaweeds collected from the Indian sea and to optimize the level(s) of incorporation of the most promising seaweed(s) into a straw and concentrate diet to achieve a significant reduction in methane (CH4) production without disturbing rumen fermentation characteristics. A chemical composition analysis revealed a notable ash content varying between 55 and 70% in seaweeds. The crude protein content was highly variable and ranged between 3.25 and 15.3% of dry matter. Seaweeds contained appreciable concentrations of tannins and saponins. Among the seaweeds, Spyridia filamentosa exhibited significantly higher CH4 production, whereas the percentage of CH4 in total gas was significantly lower in the cases of Kappaphycus alvarezii and Sargassum wightii. The ranking of seaweeds in terms of CH4 production (mL/g OM) is as follows: Sargassum wightii < Kappaphycus alvarezii < Acanthophora specifera < Padina gymnospora < Spyridia filamentosa. A remarkable decrease of 31–42% in CH4 production was recorded with the incremental inclusion of Kappaphycus alvarezii at levels of 3–5% of the dry matter in the diet. The addition of Sargassum wightii led to a significant decrease of 36–48% in CH4 emissions when incorporated at levels of 4–5% of dry matter, respectively. The findings of this study revealed a significant decrease in the numbers of total protozoa and Entodinomorphs, coupled with increasing abundances of sulfate-reducing microbes and minor methanogens. Metagenome data revealed that irrespective of the seaweed and treatment, the predominant microbial phyla included Bacteroidota, Bacillota, Pseudomonadota, Actinomycetota, Fibrobacterota, and Euryarchaeota. The prevalence of Methanobrevibacter was similar across treatments, constituting the majority (~79%) of the archaeal community. The results also demonstrated that the supplementation of Kappaphycus alvarezii and Sargassum wightii did not alter the feed fermentation pattern, and therefore, the reduction in CH4 production in the present study could not be attributed to it. Animal studies are warranted to validate the extent of reduction in CH4 production and the key processes involved by supplementation with Kappaphycus alvarezii and Sargassum wightii at the recommended levels. [ABSTRACT FROM AUTHOR]

Massive blooms of pelagic Sargassum in Caribbean shores cause several economic and environmental affectations. Their industrial exploitation could help to mitigate the negative impacts associate with their accumulation; however, their utilization had been limited due the presence of a recalcitrant polyphenolic net (lignin). So, this study was focused on the development of a treatment with mild operation conditions which reduce the lignin content facilitating the production of value-added compounds under a zero-waste scheme. The treatment was carried out with hydrogen peroxide (H2O2) as oxidant reagent; it is cheaper than other reagents and during their reaction, the only products are oxygen and water; their concentration and retention time were evaluated achieving delignification yields from 30.72 to 75.43%. The best conditions for Sargassum delignification were 3 h and 10% (v/v) of H2O2. Infrared specters and thermogravimetrical analysis confirmed the remotion of the recalcitrant material. As well, micrographs obtained by the scanning electronic micrograph prove that the treatment removes the layer which covers the carbohydrates matrix. The industrial applications of the oxidative process could help to turn the Sargassum crisis into an opportunity, contributing to the mitigation of the environmental and socioeconomic impacts. [ABSTRACT FROM AUTHOR]

Influenza is a contagious viral infection of the respiratory tract, affecting nearly 10% of the world's population, each year. The aim of this study was to extract and identify antiviral compounds against the influenza-A virus (H1N1) from different species of Egyptian marine algae. Three samples of marine macroalgae species were extracted and the antiviral activity of the extracts were tested on Madin Darby Canine Kidney cells. The bioactive compounds present in the most active fractions were identified using gas chromatography-mass spectrometry (GC-MS), then the binding potentials of the identified compounds were examined towards neuraminidase (NA) of the influenza-A virus using molecular docking. The methanolic extract of Sargassum aquifolium showed promising in-vitro antiviral activity with a selectivity index (SI) value of 101. The GC-MS analysis showed twelve compounds and the molecular docking analysis found that tetradecanoic acid showed the strongest binding affinities towards the NA enzyme. [ABSTRACT FROM AUTHOR]

The cosmetics industry is experiencing continuous growth and the search for dermoactive metabolites continues to increase, positioning natural marine products as an essential element in this market. The genus Sargassum , a cosmopolitan brown alga, stands out for its diversified arsenal of metabolites with biological properties of great interest for the cosmetic sector. This study presents an updated review of the dermocosmetic properties of 17 Sargassum species published between 2020 and 2024, emphasizing increasing interest in its antioxidant and photoprotective properties. Furthermore, the review highlights the crucial role of green extraction methodologies, such as ultrassom-assisted extraction (EAU), enzyme-assisted extraction (EAE) and microwave-assisted extraction (MAE). It is also provided a conceptual outline of the spectrometric analytical techniques used for characterization of extracts and identification of active composts, such as polysaccharides (alginate and fucoidane), phenolic composts (phlorotannins and phenylpropanóids) and terpenoids (diterpenoids, saponins and norisoprenóids). In addition to addressing bioprospecting and the potential of the biorefinery in the cosmetics sector, this review analyzes challenges related to quality control of raw materials, seasonal fluctuations of seaweed and regulations governing the collection and use of seaweed. To provide a detailed update on the dermocosmetic potential of these algae, the review aims to support future research and encourage bioprospection of this biomass as a sustainable and promising source for the development of new bioproducts. [ABSTRACT FROM AUTHOR]

Developing bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) through simple, economical, and innovative methods is vital for sustainable energy conversion. Here, we showcase a green and sustainable approach for synthesizing CuCo₂O₄ - Sargassum Tenerrimum derived carbon composites (CCST) directly from fresh seaweed and a deep eutectic solvent (DES), marking its initial application in HER/OER. The successful transformation of seaweed and metal precursors into CCST was accomplished using a direct pyrolysis method at 900 °C in an inert atmosphere. Here, Seaweed granules acted as the carbon source, with DES employed for its multifunctional properties, including serving as a solvent, a structural template, and a catalyst for fostering material development. When these materials were assessed as electrocatalysts for OER in 1 M KOH media, the optimal catalyst (CCST-9 (1:2)) exhibited a low overpotential of 381 mV at 10 mA cm−2 with a Tafel slope of 44 mV dec−1. In addition, the same material achieved low overpotential of 383 mV at 10 mA cm−2 with a Tafel slope of 100 mV dec−1 when tested as an electrocatalyst for HER in 0.5 M H 2 SO 4 media. Interestingly, CCST-9 (1:2) demonstrated excellent long-term stability in OER in 1 M KOH during a 24-h chronoamperometry test, with only a minor reduction in current density. The present study contributes new perspectives to the development of scalable and high-performance bifunctional catalysts, achieved through an environmentally friendly and cost-effective synthetic strategy. • This study uses abundant, sustainable marine biomass as an eco-friendly carbon source for synthesizing efficient electrocatalysts. • A green solvent, DES, was utilized as both a structural template and catalyst for material development. • The synthesis approach is sustainable, cost-effective, and amenable to scalability, enhancing its practical applicability. • The synthesized electrocatalysts demonstrated exceptional electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Benthic metabolism and net carbon accumulation in mangroves sediments strongly depend on the quantity and quality of organic matter (OM) supplied, including material brought by coastal waters such as the macroalgae Sargassum spp. Mesocosms were used to assess the effect of eutrophication by Sargassum on mangrove sediments. The concentration of fatty acids (FAs), organic carbon and its carbon isotopic signature, and the sediments–air CO2 fluxes were used to follow the evolution of sedimentary OM in surface and subsurface sediments for 60 d. Sargassum beaching shifted microbial and crab metabolism, leading to a preferential degradation of the labile fraction of OM from both Sargassum (δ13C = −17.7‰ and high concentration of essential FAs) and mangrove leaves (δ13C: −28.9‰ and high concentrations of 18:2ω6 and 18:3ω3). Fatty acids composition of crabs hepatopancreas revealed they preferentially fed on Sargassum and these invertebrates also increased the particulate OM tidal export. In addition, microbial activity at the sediment surface was enhanced, as revealed by strong production of branched FAs and higher CO2 fluxes in mesocosms containing Sargassum. However, Sargassum beaching also increased the transfer and preservation of more refractory OM from mangrove leaves found in higher quantity in subsurface sediments (6–8 cm) after 60 d. Inputs of macroalgae induced a negative priming effect and enhanced the preservation of blue carbon in the sediments. This negative priming effect was enhanced by crab activities. These biotic interactions that include microbial communities apparently make mangrove efficient in storing carbon in a context of growing eutrophication of the tropical ocean. [ABSTRACT FROM AUTHOR]

The use of industrial drugs to treat inflammatory diseases, cancer, and diabetes has become controversial because compared with natural products, these drugs have been found to cause adverse side effects. However, an alternative to synthetic medications has been uncovered from natural sources such as kelp, a term used for large brown seaweed, which is a class of seaweed. Although brown algae are one of the most common and largest subgroups used for food, they have been reported to have increased health benefits owing to the high biological activities of the compounds that are extracted from these brown seaweeds. Fucoidan, a major component obtained from various species of brown algae, is a rather varied group of sulfated polysaccharides (SPs) with complex and heterogeneous structures that lack uniformity and have high nutritional value, and health benefits when consumed. This review discusses some of the key areas in which Fucoidan plays a crucial role in promoting human health and its practical applications. As a result, the analytical literature pertaining to the bioactive characteristics of SPs isolated from the Fucaceae, Laminariaceae, Sargassum, and other groups is emphasized, along with information about their prospective biomedical applications as valuable natural resources in the near future for use in human health. Stability studies, Fucoidan structure, Fucoidan and nanoparticles, the biological activity of Fucoidan, the safety of Fucoidan in humans and animals, Fucoidan patents and commercial applications, and the nutraceutical benefits of Fucoidan extract were performed. [ABSTRACT FROM AUTHOR]

The current study investigated the effect of hot water extracts from Sargassum sp. and Padina sp. macroalgae in preventing the oxidation of oil extracted from rainbow trout waste over 42 days at 30 °C. The treatments were fish oil without preservatives (control: C), fish oil containing 100 ppm butylated hydroxytoluene (BHT), fish oil with 1000 ppm Sargassum sp. extract, and fish oil with 1000 ppm Padina sp. extract. The extraction yields, DPPH radical scavenging activity, and total phenolic content of Sargassum extract were higher than those of Padina extract by 10.4%, 86%, and 28%, respectively. On the 35th day, the peroxide values (PV) of the fish oil treated with Sargassum and Padina extracts were similar to the control group, with values of 33.7 and 34.3 meq O2/kg, respectively. However, p-anisidine values in the control samples increased significantly (P < 0.05) over the 42 days compared to the other groups. Total oxidation (TOTOX) and free fatty acid (FFA, expressed as oleic acid) values of the fish oils treated with Sargassum and Padina extracts were significantly lower than those of the control samples (P < 0.05). Additionally, UV232 absorbance values were higher in the control group compared to the samples treated with macroalgae extracts. Color difference (ΔE) and whiteness index (WI) values remained within acceptable ranges for all samples. These findings, particularly the promising effects of Sargassum extract, suggest its potential as a natural preservative in fish oil, offering valuable insights for future studies. [ABSTRACT FROM AUTHOR]

Sargassum species play a key role in habitat formation in tropical and subtropical regions; however, species identification has been hampered by the phenological plasticity exhibited in response to environmental conditions and life history. Molecular phylogenetics has challenged taxa circumscriptions and proven critical in delimiting species in this genus. Yet, the Atlantic species of Sargassum remain poorly understood, and recent studies have shown low molecular diversity between the species in the NW Atlantic. Here, we expand the taxon sampling to the NE Atlantic to assess the diversity of Sargassum in the Atlantic basin, based on a comprehensive morphological and multigene approach. We selected genes commonly used in delineating species in this genus (ITS2, rbcLS, cox3, mtsp) and explored additional markers (cox2, nad6, psbC, clpC, atpB) to infer the phylogenetic relationships between the morphospecies observed in the NE Atlantic. Phylogenetic analyses using single‐gene and multigene alignments including 185 new sequences confirmed the low molecular diversity and supported the distinction of a single clade in Sargassum section Sargassum of N Atlantic benthic species. In contrast, morphological analysis resulted in the identification of 10 species and three new morphospecies that we described here but opt not to equate to species until further molecular evidence is available. Our results were congruent with previous findings from the NW Atlantic and highlight the morphological and ecological diversity of Sargassum in the Atlantic. These results suggest a recent colonization and incipient speciation of Sargassum in the Atlantic basin and showcase the need of further high‐throughput analyses. [ABSTRACT FROM AUTHOR]

Brown algae are one of the most abundant biomasses on Earth. To recycle them as blue carbon sources, an effective decomposition system is necessary. This study focused on microorganisms present in seawater that decompose brown algae which contain laminarin and alginate. Where Undaria and Sargassum spp. were present, genera Psychromonas, Psychrobacter , and Pseudoalteromonas were predominant in seawater, while genera Arcobacter and Fusobacterium increased in abundance during the process of decomposition. The inoculation of Undaria samples into laminarin-minimal media led to a predominance of Pseudoalteromonas species. A Pseudoalteromonas isolate, identified as Pseudoalteromonas distincta , possesses genes encoding a putative laminarinase, polysaccharide lyase family 6 (PL6) alginate lyases, and a PL7 alginate lyase. The culture media of P. distincta contained no monosaccharides, suggesting the rapid conversion of polysaccharides to metabolites. These findings indicated that Pseudoalteromonas species play a major role in the decomposition of brown algae and affect the microbiota associated with them. [ABSTRACT FROM AUTHOR]

This experiment was conducted to investigate the effects of dietary sargassum powder, sargassum powder extract, and sargassum residue on serum biochemical indexes, antioxidant capacity, and production performance of sows under heat stress. Eighty sows (Landrace x Yorkshire) with gestation age of about 107 days were randomly divided into four groups, with four replicates in each group, and five sows in each replicate. Sows were divided into group SP, group SPE-1, group SPE-2 and heat stress control group (group C). The experiment lasted for 28 days. The results showed as follows: Compared with group C, the concentrations of malondialdehyde (MDA), interleukin-1β (IL-1β), and interleukin- 6 (IL-6) in groups SP and SPE-1 were significantly decreased on days 14 and 28 (P<0.05). The activities of catalase (CAT) and superoxide dismutase (SOD) were significantly increased (P<0.05). On day 14, the activities of cyclooxygenase-1 (COX-1) and cyclooxygenase-1 (COX-2) in groups SP and SPE-1 were significantly decreased (P<0.05). On day 28, the content of tumor necrosis factor-α (TNF-α) was significantly decreased ( P<0.05). In addition, on days 14 and 28 of the trial, the concentrations of total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL), total protein (TP), albumin (ALB), and globulin (GLB) and the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) in groups SP and SPE-1 were significantly decreased ( P<0.05). On day 28, the concentrations of urea nitrogen (BUN), creatinine (CREA), and uric acid (UA) were also significantly decreased ( P<0.05). The average daily feed intake of sows and average weight of weaned piglets in groups SP and SPE-1 were significantly increased (P<0.05), and the number of healthy piglets produced was two more than that in group C. The results show that sargassum powder and sargassum powder extract can increase serum antioxidant capacity, improve serum biochemical indices, improve production performance and relieve heat stress of sows. [ABSTRACT FROM AUTHOR]

Sargassum sp., a brown seaweed abundant in Semau Island, East Nusa Tenggara, Indonesia, has potential as an alternative feed source in animal nutrition due to its rich chemical composition. This study aimed to determine Sargassum sp.'s chemical and carbohydrate composition using different drying methods to evaluate its suitability as livestock feed. A Completely Randomized Design (CRD) with three treatments--sun drying, oven drying at 60°C, and air drying--and five replications were employed. Using standard proximate analysis, fresh seaweed samples were dried according to the treatments and analyzed for dry matter, organic matter, crude protein, crude fat, crude fiber, and carbohydrate content. The results showed that the drying method significantly affected (P < 0.05) the dry matter, moisture content, ash content, organic matter, crude protein, and crude fat of Sargassum sp. but had no significant effect (P > 0.05) on crude fiber and carbohydrate content. Air-dried samples exhibited the highest crude protein content (6.38%) compared to sun-dried (4.71%) and oven-dried (4.94%) samples, indicating better preservation of protein at lower temperatures. Crude fat content was highest in sun-dried samples (0.56%) and lowest in air-dried samples (0.24%). Carbohydrate content ranged from 52.83% to 54.00% across all treatments without significant differences. These findings suggest that air drying is the most effective method for retaining the nutritional components of Sargassum sp., enhancing its potential as a valuable ingredient in animal feed formulations. The drying method significantly influences Sargassum sp. seaweed's chemical composition. Air drying preserves key nutritional components, making it the recommended method for processing Sargassum sp. for use in animal nutrition. [ABSTRACT FROM AUTHOR]

Sargassum algae, being able to proliferate without the need to be attached to a substrate, travel through the ocean generating massive stagnations on the Caribbean coasts of the continent, becoming an environmental problem. Because its composition mainly includes polysaccharides, such as cellulose and hemicellulose, these algae were used to produce nanocellulose and create hydrogels to apply to germination. This article aims to develop of nanocellulose hydrogels from Sargassum and study the effect of it adding nanocellulose hydrogels from Sargassum algae loaded with Ca-PO4- and NO3 as nutrients in the germination process. The Sargassum algae used underwent two hydrolysis processes, one basic and one acid, with which it was possible to increase the cellulose content from 25.7 ± 0.42% to 34.05 ± 0.39 after the first hydrolysis and after 90.15 ± 0.44% after the second. Size reduction to nanocellulose was performed employing an ultrasonic homogenizer sonicator. The obtained nanocellulose was characterized using infrared spectroscopy, X-ray diffraction, and transmission electron microscopy, showing that by the alkaline method, the sizes were between 135-190 nm while by the acid method, the fiber sizes were between 108-163 nm with a difference of 1.04 in the crystallinity index between the two hydrolyses. With the nanocellulose, hydrogels were formed using 5%, 10%, and 15% borax as crosslinking agents. Drying curves and scanning electron microscopy were performed on the hydrogels. Nutrients Ca-PO4-NO3 were added to the hydrogel and their release in water was studied through Ultraviolet-Visible spectrophotometry, with which it was decided to use the hydrogel containing 10% borax in the germination study. The effect of the hydrogel loaded with nutrients on the germination of bean and linseed seeds employing a complete factorial design 23. Obtaining results that the nutrient with the greatest influence on germination was nitrogen while the nutrient with the least favorable results was the match. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the potential application of activated Sargassum aquifolium macroalgae (ASAM) as a biosorbent for uranium(VI) and thorium(IV) ions, employing controlled experimental conditions. The parameters examined included pH, biosorbent mass, initial concentration, contact time, and temperature. To enhance sorption characteristics, the raw Sargassum aquifolium macroalgae (SAM) biomass underwent separate pre-treatments using phosphoric acid (H3PO4) and potassium hydroxide (KOH). Various models were employed to analyze the kinetic and sorption isotherm data, and thermodynamic parameters were determined to assess the sorption mechanism. The KOH-treated SAM demonstrated a higher capacity for biosorbing U(VI) and Th(IV) compared to the acid-treated biomass. The sorption mechanism was investigated through characterization techniques such as FTIR, SEM/EDS, XRD, Zeta-potential, and BET analysis. The desorption-sorption cycle efficiency of both sorbents was evaluated, indicating that 0.1 mol L-1 HNO3 exhibited the most efficient desorption reagent for both metal cations over five consecutive cycles. These findings suggest the potential of ASAM as a biosorbent for removing U(VI) and Th(IV) from aqueous solutions. Furthermore, the study demonstrated the remarkable effectiveness of the two activated sorbents in eliminating U(VI) and Th(IV) ions from real wastewater samples. [ABSTRACT FROM AUTHOR]

Background: The present study was conducted to investigate the northern coast of the Persian Gulf (Bushehr province), which is exposed to industrial, agricultural, shipping, and oil pollution. This study aimed to determine the contamination of the northern coast of the Gulf using macroalgae and predict these elements in sediments. Methods: Two items of sediment sampling and macroalgae were investigated. Linear regression was used to predict the amount of trace elements in sediments by macroalgae. In this study, aluminium (Al), calcium (Ca), cadmium (Cd), cerium (Ce), copper (Cu), lanthanum (La), lithium (Li), niobium (Nb), nickel (Ni), phosphorus (P), scandium (Sc), samarium (Sm), thorium (Th), and vanadium (V) were measured. Results: The results showed that the highest amounts of Cd, La, Nb, Sc, and Th in sediment were recorded in Emam Hassan port. The highest mean amounts of Al, Li, and Sm in sediment were reported in Bushehr port. The mean of the highest amount of trace elements absorption was reported in Sargassum glaucescens, Gracilaria corticate, and Rhizoclonium riparium, respectively. The results of linear regression analysis showed that S. glaucescens had the highest efficiency in predicting the amounts of elements in sediments. Conclusion: Predicting the amount of trace elements in sediments by macroalgae can be a great help in this field. In addition, by using the algal index, the amount of this pollution in sediments can be determined with the lowest cost.

Abstract Influxes of sargassos are responsible for economic and environmental disasters in areas where they bloom, especially in regions whose main income relies on tourism and with limited capacity for sanitation and public health response. A promising way of valorization would be to convert this incredible biomass into tools to fight the deadly vector mosquito Aedes aegypti. In the present study, we generated hydrolates and aqueous extracts from three main Sargassum morphotypes identified in Guadeloupe (French West Indies): Sargassum natans VIII, Sargassum natans I and Sargassum fluitans. We conducted a chemical characterization and a holistic evaluation of their potential to induce toxic and behavioral effects in Ae. aegypti. Despite the low insecticidal potential observed for all the extracts, we found that S. natans VIII and S. fluitans hydrolates deterred oviposition, induced contact irritancy and stimulated blood feeding behavior in host seeking Ae. aegypti females, while aqueous extracts from S. natans I and S. fluitans deterred both blood feeding behavior and oviposition. Chemical characterization evidenced the presence of phenylpropanoid, polyphenols, amino acids and esters. Thus, Sargassum spp. aqueous extracts and hydrolates could be used to manipulate Ae. aegypti behavior and be valorized as control tools against this mosquito.

This research project aimed to address the growing concern about methane emissions from seaweed by developing a Convolutional Neural Network (CNN) model capable of accurately predicting these emissions. The study used PANDAS to read and analyze the dataset, incorporating statistical measures like mean, median, and standard deviation to understand the dataset. The CNN model was trained using the ReLU activation function and mean absolute error as the loss function. The model performance was evaluated through MAPE graphs, comparing the mean absolute percentage error (MAPE) between training and validation sets and between true and predicted emissions, and analyzing trends in yearly greenhouse gas emissions. The results demonstrated that the CNN model achieved a high level of accuracy in predicting methane emissions, with a low MAPE between the expected and actual values. This approach should enhance our understanding of methane emissions from Sargassum, contributing to more accurate environmental impact assessments and effective mitigation strategies.

This study investigates the temporal trends and correlations between Saharan dust mass concentration densities (DMCD) and Sargassum concentrations (SCT) in the tropical North Atlantic. Average DMCD data for June, July, and August from 1980 to 2022, alongside SCT data for the same months from 2012 to 2022, were analyzed using Mann–Kendall tests for trends and lagged regression models to assess whether higher Saharan dust levels correlate with Sargassum outbreaks in the region. A comprehensive analysis reveals a significant upward trend in Saharan dust quantities over the study period, with the summer months of June, July, and August exhibiting consistent increases. Notably, 2018 and 2020 recorded the highest mean DMCD levels, with June showing the most significant increasing trend, peaking in 2019. These findings are consistent with previous studies indicating a continuous elevation in Saharan dust concentrations in the tropical atmosphere of the North Atlantic. Simultaneously, Sargassum concentrations also show a notable increasing trend, particularly in 2018, which experienced both peak SCT and elevated DMCD levels. Mann–Kendall tests confirm statistically significant upward trends in both Saharan dust and Sargassum concentrations. Simple linear regression and lagged regression analyses reveal positive correlations between DMCD and SCT, highlighting a temporal component with stronger associations observed in July and the overall June–July–August (JJA) period. These results underscore the potential contribution of elevated Saharan dust concentrations to the recent surge in Sargassum outbreaks in the tropical North Atlantic. Furthermore, the results from forward stepwise regression (FSR) models indicate that DMCD and chlorophyll (CHLO) are the most critical predictors of SCT for the summer months, while sea surface temperature (SST) was not a significant predictor. These findings emphasize the importance of monitoring Saharan dust and chlorophyll trends in the Eastern Caribbean, as both factors are essential for improving Sargassum modeling and prediction in the region. This study provides valuable insights into the climatic factors influencing marine ecosystems and highlights the need for integrated environmental monitoring to manage the impacts on coastal economies.

AbstractAlginate lyase, which catalyzes the cleavage of alginate, has potential biocatalytic applications in agriculture, food, fodder, nutraceutical, pharmaceuticals, medical diagnostic and bioenergy industries. In this study, a novel alginate lyase-producing Streptomyces sp. LB55 (GenBank Accession No. MT176164) was isolated from Sargassum seaweed waste, and its extracted alginate lyase was immobilized onto glutaraldehyde cross-linked silicon dioxide nanoparticles. Fourier-transform infrared (FTIR) spectroscopic analysis suggests the binding of extracted alginate lyase with silicon dioxide nanoparticles via covalent bonds. FTIR analysis also revealed the retention of the secondary structure of immobilized alginate lyase by exhibiting amide I and amide II bands. The glutaraldehyde cross-linked silicon dioxide nanoparticles retained 71.9 ± 2.63% of alginate lyase activity. The optimal pH and temperature for maximal alginate lyase activity were recorded at pH 7.5 and temperatures of 40 and 45 °C, for free and immobilized forms, respectively. In comparison to free alginate lyase, the immobilized enzyme was thermodynamically efficient by displaying higher values of activation energy (52.3 kJ/mol), enthalpy (49.8 kJ/mol) and entropy (–69.7 J/mol/K) of catalysis. The immobilized alginate lyase had a strong affinity for alginate by exhibiting low Km (1.75 ± 0.12 mg/mL) and high Vmax (30.4 ± 2.66 U/mg-protein) values. The immobilized alginate lyase activity was unaffected at 2% NaCl concentration and could be successively reused six times without considerable loss of activity. The overall results demonstrate for the first time the potential of silicon dioxide nanoparticles as an effective matrix to immobilize alginate lyase for sustainable and cost-effective depolymerization of alginate. [ABSTRACT FROM AUTHOR]

Biocrude production using the hydrothermal liquefaction (HTL) process is a promising alternative energy source to conventional fossil fuels. Using algal feedstock types in this process has many advantages, such as not needing to dry a high moisture content, which consumes much energy. In this study, the feedstock types of Sargassum angustifolium macroalgae, Chlorella vulgaris, and Spirulina sp. microalgae affected the yield and property of the biocrude products were obtained at 350 °C, 18 MPa, 35 min residence time, and 8.7 wt% feedstock concentration. The biocrude yields from Sargassum angustifolium, Chlorella vulgaris, and Spirulina sp. were 26.15 wt%, 55.8 wt%, and 56.32 wt%, respectively. These values revealed that feedstock's carbon and nitrogen contents have the most effect on the biocrude yield, and increasing these elements increases the biocrude yields. Moreover, the properties of the produced biocrudes revealed that the main components were esters, organic acids, ketones, aldehydes, aromatic rings, amides, amines, alcohol, and phenol. The thermal gravimetric analysis (TGA) results of biocrudes showed the decomposition of more organic components at the 175-600 °C temperature range. Also, the simulated distillation of biocrudes showed that most biocrude components from Sargassum angustifolium and Chlorella vulgaris are the same as heavy naphtha, and the biocrude from Spirulina sp. is similar to kerosene. These results showed that the produced biocrude from Chlorella vulgaris has a higher yield and quality than other resources. The quality of the biocrude produced from Sargassum angustifolium is comparable to other biocrudes. Besides, the higher solid-phase yield produced from Sargassum angustifolium was used as a heavy metal biosorbent. The effect of adsorbent concentration and adsorption time on adsorption efficiency was investigated. Results showed that the maximum adsorption efficiency of Fe2+, Zn2+, and Mn2+ was 47.07 wt%, 48.93 wt%, and 42.47 wt%, respectively, at 2 g/L adsorbent concentration and 60 min adsorption time, and the structure destruction of the solid phase was carried out under the biosorption process. [ABSTRACT FROM AUTHOR]

Long used in East Asian cuisine and traditional medicine, the brown seaweed Hizikia fusiformis (also known as Sargassum fusiforme or Hizikia fusiforme) is also referred to as "Hijiki." Given its abundant environmental and bioactive characteristics, it has received considerable attention. This systematic review aimed to present comprehensive data from the existing literature on the environmental and bioactive characteristics of H. fusiformis. Using three databases to search for published studies on related fields between 2002 and 2023, 1344 papers were screened and narrowed down to a set of 49 papers by the predetermined criteria. Evidence shows that H. fusiformis is a promising resource in the environmental protection and bioactive domains. Overall, more research and methods are needed to organically combine the development of H. fusiformis in the environmental and bioactive fields to gain greater economic benefits and environmental protection capabilities. [ABSTRACT FROM AUTHOR]

Strawberries are susceptible to decay and destruction while being harvested and stored. This study had the following objectives: (1) the documentation of fungi and mycotoxin production associated with infected strawberry fruits; (2) the evaluation of the primary phytochemicals of Sargassum cinereum and Padina boergesenii by gas chromatography–mass spectrometry (GC–MS) and Fourier transform infrared (FT-IR) analysis to identify the active chemical composition of the seaweed extracts; and (3) the assessment of the antifungal activity of five extracts from brown seaweeds both in vitro and in vivo against fungal infections on fresh fruit under post-harvest conditions. The most common fungi were Aspergillus niger 14.36%, Botrytis cinerea 38.29%, and Mucor irregularis 16.88%. Padina boergesenii acetone extract had the highest in vitro antifungal activity. The methanol extracts of both S. cinereum and P. boergesenii were effective against the pathogenicity and aggressiveness (in vivo) on post-harvest strawberry fruits. B. cinerea could produce botrydial and dihydrobotrydial toxins with concentrations of 8.14 µg/mL and 4.26 µg/mL, respectively. A. niger could produce ochratoxin A with a concentration of 10.05 µg/mL. The present study demonstrates that the extracts of macroalgae S. cinereum and P. boergesenii contain secondary metabolites and antioxidants, indicating their potential utilization in antifungal applications. [ABSTRACT FROM AUTHOR]

Sargassum (brown seaweed) is free-floating brown algae found on ocean shores in large quantities littering shorelines and causing visual and olfactory nuisances affecting the tourism and fishery industries. In this study, Sargassum is valorized to ultraporous carbon material via hydrothermal carbonization (HTC) at temperatures 180, 220, and 260 °C followed by KOH activation. The synthesized ultraporous superactivated hydrochar (SAH) is then analyzed by physical (thermogravimetric analysis and ultimate analysis), morphological (Brunauer-Emmet-Teller surface area and scanning electron microscopy), and chemical characterizations (Fourier Transform Infrared Spectroscopy and Boehm titration). It was found that the SAH proved to be thermally stable, carbon-dense with very high BET surface area ranging from 1216.92 to 1404.09 m2/g, total pore volume ranging from 0.69 to 0.77 cm3/g and micropore volume ranging between 0.32 to 0.36 cm3/g. Substantial surface oxygen-containing acidic functional groups were present on the SAH extending from 356.04 to 452.82 μmol/g. These physical and morphological alterations made SAH an excellent adsorption material with Methylene blue adsorption where as high as 641.03 mg/g at room temperature and 714.29 mg/g at 37 °C. Influential adsorption parameters were investigated, showing high maximum adsorption at solution pH 12, 24 h contact time, and under 37 °C respectively. Additionally, SAH showed selective adsorption behavior towards methylene blue in the presence of methyl orange. The possible adsorption mechanisms associated with the uptake of methylene blue are pore filling and electrostatic attraction being the dominant adsorption mechanisms. From adsorption isotherm modeling, the Langmuir model has proven to be the best fit with R2 at 0.99. A thermodynamic study was conducted confirming spontaneous adsorption (negative ΔG) favoring higher adsorption temperatures with an entropy-driven process (ΔH = 11.57 kJ/mol, ΔS = 169.94 J/mol). From kinetic modeling, Elovich model showed the best fit describing chemisorption characteristics. [ABSTRACT FROM AUTHOR]

Since 2011, holopelagic Sargassum have been massively stranding in the coastal environments of the Caribbean Islands inducing damages to coastal ecosystems, public health and the economy. To limit the risks associated with Sargassum stranding, floating barriers with nets can be placed in front of sensitive areas, to divert Sargassum away from the coast. To evaluate the potential transfer of metallic trace element (MTE) from Sargassum to adjacent marine life, seagrasses (Halophila stipulacea, Thalassia testidinum) and urchin (Lytechinus variegatus) were sampled, both close (0 m) and far (200 m) from barriers installed during 4 years in two bays: Baie Cayol (BC) and Cap Est (CE) in Martinique (FWI). A bay without barriers Baie-Tresor (BT) was also sampled in order to compare the effects of Sargassum accumulated in a natural environment versus an environment with floating barriers. The short-term effects of barriers were evaluated by measuring the evolution of MTE after four days, in the algae (Dictyota spp.), located close to Sargassum accumulations. All sampling was realized during two periods of active (July 2021) and reduced (January 2022) Sargassum stranding. The measured concentrations of 19 metal(loid)s trace elements revealed that the proximity of Sargassum to the barriers did not increase MTE concentration. The absence of increase in MTE was observed all sites (BT, BC and CE) and during periods of limited and important Sargassum stranding. Similarly, translocations of Dictyota close to Sargassum accumulations did not reveal any increase in MTE concentrations in the algae after 4 days. The present study suggests that the use of barriers to manage Sargassum stranding would not constitute an important threat of MTE contamination of marine environments. [ABSTRACT FROM AUTHOR]

Sargassum is a brown alga in the coasts of warm waters of the world. In Iran this alga found in the coasts of Persian Gulf and Oman Sea. A little information is available from molecular variation of this genus because the genetic variability of this alga. In this study, sixteen populations of five species of Sargassum were analyzed with ISSR bands. These populations were collected from five localities of the Persian Gulf coasts in two seasons (autumn and winter) from 2018 to 2022. We performed clustering and ordination methods for molecular analysis. Also, genetic diversity parameters were measured for all populations. In UPGMA and PCA analyses, the populations of different species separated into distinct clusters. Also, these analyses confirmed the classification of genus to sections. Coefficients of diversity were high for the most populations. The highest amount of diversity was seen in S. swatzii. Furthermore, specific bands were seen in this species.Significant genetic differences and some degree of gene exchange were seen among the studied populations. According to the Mantel test, the genetic diversity of the studied populations is related to geographical distance. In Analysis of molecular variance, 85% of total variation is attributed to among population differences. While 15% of total variation is related to within population variation. [ABSTRACT FROM AUTHOR]

In Caribbean islands, the washing ashore of tons of pelagic Sargassum spp., consisting of two species Sargassum fluitans and Sargassum natans, has been regularly occurring since 2011. As green lubrication is a growing trend in the tribology industry, biochar is a promising alternative. Sargassum biochars, produced from Sargassum pelagic algae, are therefore being studied as solid lubricants. This study aims to explore their potential applications. Biochars from brown algae were pyrolyzed at 400 °C and then annealed at different temperatures (from 600 °C to 1500 °C). The Raman spectra collected on the different biochars showed that there was a structural organization of the biochars as the temperature increased. The tribologic properties of the biochars were studied and compared to a solid lubricant reference (exfoliated graphite). Raman spectroscopy analysis revealed a progressive structural reorganization with increasing temperature, leading to a 58% reduction in the coefficient of friction. The morphology and the structure of the tribofilm are investigated by profilometry, scanning electron microscopy, and Raman microspectrometry. Overall, these results can be considered as a first step for utilizing the biochar derived from brown algae Sargassum sp. as an additive in the lubricant industry, for the purpose of emission reduction. [ABSTRACT FROM AUTHOR]

Governance generally, and appropriate operational institutions specifically, are said to be crucial to increasing human adaptive capacity amidst environmental change. But existing conceptualizations tend to assume a universal model of governance will work for states of all sizes. This article questions this orthodoxy which disregards the lack of clarity on size-relevant institutional design and functioning. We do so by focusing on the role of governance in the adaptive capacity of small island developing states (SIDS) facing a new marine social-ecological threat. We draw on a unique dataset of capacity self-assessments undertaken by thirty-eight key agencies involved in the management of sargassum seaweed influx events in the Eastern Caribbean. We found support for the findings of public administration scholars who show that country size is a contextual factor affecting adaptive capacity beyond the control of managers. The implication is that the ability of SIDS to adapt to new or emergent environmental change is crucially inhibited by size-related governance constraints while solutions that mitigate these effects – informal networks and regional organizations – are not well captured by existing metrics. To ensure assessments of adaptive capacity are contextually appropriate we need a more nuanced appreciation of the impacts of state size on governance outcomes. [ABSTRACT FROM AUTHOR]

The threat of declining seaweed beds has been a concern around the world. Seagrass and seaweed (brown algae) beds are essential habitats supporting fisheries. However, approximately 22% of these habitats have been lost in Japan due to increased coastal landfill sites and ports. This study aims to rehabilitate the depletion of these habitats by constructing an artificial reef in Wakasa Bay, Japan, and monitoring Sargassaceae succession in the second and fourth years after the construction was completed. In this study, we set up four sites on the artificial reef. Then we identified the seaweed species composition and coverage of the Sargassaceae using underwater visual observation by scuba divers. The seaweed coverage was already over approximately 80% in the second year after construction. The Sargassum horneri and S. confusum dominated during the first and second sampling in the second year after construction, and Myagropsis myagroides and S. patens during the third and fourth sampling in the fourth year after construction. Thus, the recovery of species composition takes longer than that of coverage. Therefore, observing species composition recovery is essential when constructing the artificial reef. [ABSTRACT FROM AUTHOR]