Search Results (155)

Seaweeds, classified as non-vascular plants, have definite advantages over terrestrial plants as they grow rapidly, can be cultivated in coastal environments, and are dependable and non-endangered sources of biomass. Algal bioproducts, which include a wide range of bioactive compounds, have drawn much interest because of their applications in nutraceuticals, pharmaceuticals, agriculture, and cosmetics. Particularly in the pharmaceutical and nutraceutical fields, algal bioproducts have shown tremendous activity in regulating enzymes involved in human diseases. However, the drawbacks of conventional extraction methods impede the complete exploitation of seaweed biomass. These include low efficiency, high cost, and potential harm to the environment. Enzyme technology developments in recent years present a viable way to overcome these challenges. Enzymatic processes improve product yields and reduce the environmental impact of processing, while facilitating the more effective extraction of valuable bioactive compounds as part of an integrated biorefinery approach. Enzyme-assisted biorefinery techniques can greatly advance the creation of a circular bioeconomy and increase the yield of extracted seaweed bioproducts, thus improving their value. With the potential to scale up to industrial levels, these biotechnological developments in enzymatic extraction are developing rapidly and can advance the sustainable exploitation of seaweed resources. This review emphasises the increasing importance of enzyme technologies in the seaweed biorefinery and their contribution to developing more environmentally friendly, economically feasible, and sustainable methods for valorising products derived from seaweed. In the biorefinery industry, enzyme-assisted methods have enormous potential for large-scale industrial applications with further development, opening the door to a more sustainable, circular bioeconomy. Full article

As the global demand for eco-friendly food ingredients grows, marine macroalgae emerge as a valuable resource for multiple applications using a circular bioeconomy approach. In this study, green macroalgae Ulva flexuosa, naturally accumulated in aquaculture ponds as a residual biomass (by-product) of shrimp and oyster farming, were investigated regarding their bioactivity, chemical composition, and antioxidant properties. The use of aquaculture by-products as raw materials not only reduces waste accumulation but also makes better use of natural resources and adds value to underutilized biomass, contributing to sustainable production systems. For this, a comprehensive approach including the evaluation of its composition and environmentally friendly extraction of bioactive compounds was conducted and discussed. Green macroalgae exhibited high fiber (37.63% dry weight, DW) and mineral (30.45% DW) contents. Among the identified compounds, palmitic acid and linoleic acid (ω-6) were identified in the highest concentrations. Pigment analysis revealed a high concentration of chlorophylls (73.95 mg/g) and carotenoids (17.75 mg/g). To evaluate the bioactivity of Ulva flexuosa, ultrasound-assisted solid–liquid extraction was performed using water, ethanol, and methanol. Methanolic extracts showed the highest flavonoid content (59.33 mg QE/100 g), while aqueous extracts had the highest total phenolic content (41.50 mg GAE/100 g). Ethanolic and methanolic extracts had the most potent DPPH scavenging activity, whereas aqueous and ethanolic extracts performed best at the ABTS assay. Overall, we show the upcycling of Ulva flexuosa, an underexplored aquaculture by-product, as a sustainable and sensible strategy for multiple value-added applications. Full article

Seaweeds represent a vital yet often understudied component of the diet and cultural heritage of many coastal communities globally. This study investigated seaweed consumption practices in coastal communities of Tawi-Tawi, Philippines, through one-to-one interviews (n = 280) and focus group discussions (n = 7). The study revealed that nearly all (99%) of the population consumes seaweeds, with women comprising the majority of consumers who have done so since childhood (68% female vs. 32% male). These consumers were predominantly married (79%), within the 21–40 age group (53%), with families of 5–7 members (43%), practicing Islam (97%), and belonging to the Sama tribe (71%). A significant portion (48%) had resided in the area for 21–30 years, attained elementary to high school education (66%), and had a monthly income ranging from 1000 to 10,000 Philippine pesos (72%). Seaweed consumption was a family-wide practice (88%), including children, who typically started around 4–8 years old (61%), driven by perceived nutritional benefits (43%), preferred flavor (80%), affordability (19%), ease of preparation (33%), and cultural integration (23%). The primary edible seaweeds identified were Kappaphycus alvarezii (63%), K. striatus (58%), Kappaphycus spp. (47%), Eucheuma denticulatum (57%), Caulerpa lentillifera (64%), Caulerpa spp. (51%), C. cf. macrodisca ecad corynephora (45%), C. racemosa (30%), and Solieria robusta (49%), with less frequent consumption of K. malesianus (8%), Chaetomorpha crassa (3%), Gracilaria spp. (0.72%), and Hydroclathrus clathratus (0.36%). Specific plant parts were preferred for certain species, and preparation predominantly involved raw (75%) or cooked (77%) salads with spices, primarily prepared by mothers (72%). Consumers generally avoided seaweeds showing signs of ice-ice disease (95%), pale coloration (91%), or epiphyte infestation (84%). Consumption frequency was typically 1–3 times per week (45%), with knowledge largely passed down through generations (95%). Seaweed salads were primarily consumed as a viand (92%) at home (97%), with locals perceiving seaweed consumption as contributing to a healthy diet (40%) and overall well-being [e.g., aiding hunger (76%), improving digestion (20%), preventing obesity (14%), and aiding brain development (3%)]. The study’s findings emphasize the significant yet often overlooked role of seaweeds in the food systems and cultural heritage of Tawi-Tawi’s coastal communities. Future efforts should prioritize the sustainable management of wild resources, explore the cultivation of diverse edible species, and enhance nutritional awareness. Further research into traditional seaweed knowledge holds broader value. Full article

The exploitation of underutilised resources is critical for achieving a sustainable society, and non-edible seaweeds are promising candidates. This study focused on the red alga Portieria hornemannii from Okinawa, Japan, a seaweed with a distinctive aroma, and determined its volatile organic compounds (VOCs) and halogenated secondary metabolites using headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS) at various extraction temperatures. HS-SPME-GC-MS analysis revealed 52 VOCs in Okinawan P. hornemannii, including predominant compounds α-pinenyl bromide (IUPAC name: 2-bromomethyl-6,6-dimethylbicyclo [3.1.1]hept-2-ene; halogenated monoterpene), myrcene disulfide (3-(6-methyl-2-methylidenehept-5-enylidene)dithiirane), and 5,6-dimethyl-1H-benzimidazole, the content of which in the extract increased with increasing extraction temperature from 30 to 60 °C. On the other hand, the β-myrcene (7-methyl-3-methyleneocta-1,6-diene) content, which likely contributes majorly to the distinct fresh odour of the algae, declined as the temperature increased. Furthermore, the proportion of β-myrcene obtained using SPME was significantly higher than that extracted using solvent liquid extraction (SLE) (7.20% in SPME at 30 °C vs. 0.09%, respectively). However, SLE-GC-MS provided a different P. hornemannii volatile profile, allowing for the acquisition of more furan-, alcohol-, ester-, and carboxylic acid-containing compounds. These data provide valuable information, such as a systematic analytical framework for volatiles profiling in the marine macroalgae P. hornemannii, with potential applicability in the development of food and fragrance products. Full article

The aquaculture sector is essential for meeting seafood demand while ensuring sustainability. It involves farming fish, mollusks, crustaceans, other invertebrates, and algae in controlled environments, helping to conserve marine resources and reduce ecological pressures. Sustainable practices, such as an integrated multitrophic recirculating aquaculture system (IMTA-RAS) with fish and seaweed, can minimize the environmental impact of fish aquaculture. However, the impact of the introduction of macroalgae on the fish muscle metabolism has not been studied. This research examines the impact of growing Senegalese sole (Solea senegalensis) together with sea lettuce (Ulva ohnoi) on fish metabolism using high-resolution ¹H-NMR-based metabolomics. Three farming systems were compared. These were E₁, a recirculating aquaculture system (RAS); E₂, an IMTA-RAS integrating U. ohnoi for biofiltration; and E₃, an IMTA-RAS with U. ohnoi and Phaeobacter sp. strain 4UAC3, a probiotic bacterium isolated from wild U. australis known to counteract fish pathogens. A metabolomic analysis revealed that energy metabolism was enhanced in IMTA-RAS and even more in IMTA-RAS-Phaeobacter–grown fish, increasing overall metabolic activity. These results indicate that the presence of the algae with the probiotic had a clear impact on the physiological state of the fish, and this deserves further investigation. This study contributes to the understanding of the physiological responses of fish to innovative aquaculture practices, supporting the development of more sustainable and efficient management that reduces the environmental impact and increases fish health and welfare. Full article

Utilizing biomass resources to develop carbon-based microwave-absorbing materials adheres to the principles of sustainable development. Nevertheless, the single loss mechanism of pure carbon materials is limited. Additionally, the carbonization of artificially synthesized polymers has poor environmental performance and involves complex processes. These issues restrict their performance and broader applicability. In this study, cobalt-doped seaweed sludge porous carbon (Co/SSPC) with different cobalt contents was synthesized via a simple grinding–carbonization treatment. The addition of cobalt can regulate the graphitization degree of porous carbon, achieving a suitable amorphous-to-crystalline carbon ratio of 2.05. This not only enhances magnetic loss but also modifies dielectric loss and optimizes impedance matching. The construction of synergistic magnetic and dielectric loss mechanisms enables Co/SSPC to exhibit excellent microwave absorption performance. Specifically, Co/SSPC achieved a minimum reflection loss (RL_min) of −66.91 dB at a thickness of 4.79 mm and an effective absorption bandwidth (EAB) of 5.09 GHz at a thickness of 1.6 mm. This study provides a practical approach for the functional application of natural polymer waste algal sludge and highlights its potential in the low-cost production of microwave absorbing materials. Full article

Consumers’ growing concern about sustainability and health affects their food choices as long as there is acceptance in terms of sensory aspects. The challenge of finding new sustainable food sources with a smaller ecological footprint makes seaweed a candidate for human consumption, considering that they are poorly exploited marine food resources in European countries. Therefore, this study aimed to evaluate the effect of the inclusion of different seaweeds (wakame and sea spaghetti) in three traditional Portuguese recipes, namely octopus salad (SP and SPW), monkfish rice with prawns (AT and ATW) and stewed cuttlefish with white beans and clams (FC and FCE), regarding their acceptance and nutritional aspects. Sensory and physicochemical analyses were carried out using reference methods. The results showed that the modified recipes with seaweeds (SPW, ATW, and FCE) were well accepted by a nontrained sensory panel and did not change nutritional aspects in terms of macronutrient content, ash, and sodium. However, the inclusion of wakame contributed to an increase in the potassium content in octopus salad (SPW) and monkfish rice (ATW). In short, sensory results highlighted the potential for seaweed inclusion in Portuguese traditional recipes without compromising its identity. Future work should evaluate the partial substitution of fish/mollusks with seaweed in traditional recipes to improve the sustainability and nutritional contribution of these recipes. Full article

The red seaweed Asparagopsis taxiformis (Bonnemaisoniaceae, Rhodophyta) produces a bioactive natural product, bromoform, which, when fed to ruminant livestock, can eradicate methane emissions. However, to cultivate enough A. taxiformis to produce a yield that would have a meaningful impact on global greenhouse gas emissions, we need to advance our current understanding of the biology of this seaweed species. Here, we used both a domesticated diploid tetrasporophyte (>1.5 years in culture) and wild samples to establish a high-quality draft nuclear genome for A. taxiformis (lineage 6 based upon phylogenetic analyses using the cox2-3 spacer). The constructed nuclear genome is 142 Mb in size (including 70.67% repeat regions) and was determined to encode for approximately 10,474 protein-coding genes, including those associated with secondary metabolism, photosynthesis, and defence. To obtain information regarding molecular differences between cultured and wild tetrasporophytes, we further explored differential gene expression relating to their different growth environments. Cultured tetrasporophytes, which contained a relatively higher level of bromoform compared to wild tetrasporophytes, demonstrated an enrichment of regulatory factors, such as protein kinases and transcription factors, whereas wild tetrasporophytes were enriched for the expression of defence and stress-related genes. Wild tetrasporophytes also expressed a relatively high level of novel secretory genes encoding proteins with von Willebrand factor A protein domains (named rhodophyte VWAs). Gene expression was further confirmed by proteomic investigation of cultured tetrasporophytes, resulting in the identification of over 400 proteins, including rhodophyte VWAs, and numerous enzymes and phycobiliproteins, which will facilitate future functional characterisation of this species. In summary, as the most comprehensive genomic resource for any Asparagopsis species, this resource for lineage 6 provides a novel avenue for seaweed researchers to interrogate genomic information, which will greatly assist in expediating production of Asparagopsis to meet demand by both aquaculture and agriculture, and to do so with economic and environmental sustainability. Full article

The possible regulatory effects of C2H2 zinc finger proteins, which are important transcription factors, on intertidal seaweed responses to abiotic stress are unclear. This study was conducted to comprehensively analyze the C2H2 gene family of a representative intertidal seaweed species (Pyropia haitanensis) and clarify its genomic characteristics and biological functions. A total of 107 PhC2H2 zinc finger protein-encoding genes distributed on five P. haitanensis chromosomes were identified and divided into three subgroups. The expression levels of 85, 61, 58, 45, and 41 PhC2H2 genes responded in the maturation of filaments, high-temperature, salt, low-irradiance, and dehydration stress, respectively. The PhC2H2 gene family was conserved during Porphyra evolution, with no indications of large-scale genome-wide replication events. On average, PhC2H2 genes had more transposable element (TE) insertions than Pyropia yezoensis and Porphyra umbilicalisC2H2 genes, suggesting that TE insertions may have been the main driver of PhC2H2 gene family expansion. A key gene (PhC2H2.94) screened following a quantitative trait locus analysis was significantly responsive to high-temperature stress and was associated with photosynthesis, peroxisomes, the ubiquitin proteasome pathway, and the endoplasmic reticulum-related protein processing pathway, which contribute to the stress tolerance of P. haitanensis. Additionally, PhC2H2.94 transgenic Chlamydomonas reinhardtii exhibited increased tolerance to heat stress. This study provides new insights and genetic resources for characterizing the molecular mechanism underlying intertidal seaweed responses to abiotic stresses and breeding stress-resistant macroalgae. Full article

Sargassum hemiphyllum var. chinense is a common brown seaweed along the southeastern coast of China, playing a significant ecological role and possessing considerable resource utilization value. However, its genetic diversity and phylogeographic patterns remain poorly understood. In this study, we employed multiple molecular markers, including the nuclear ITS sequence (ribosomal internal transcribed spacer), the plastid rbcL gene (encoding the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase), and the mitochondrial cox3 and cox1 genes (encoding cytochrome c oxidase subunits III and I, respectively), to elucidate the genetic and phylogeographic structure of S. hemiphyllum var. chinense. Our findings demonstrate that the combined use of plastid and mitochondrial gene sequences is suitable for phylogeographic studies of this species. Genetic structure difference was observed among 15 populations which localities covering most of its distribution range, likely resulting from colonization by ancestors of different origins and limited gene flow among populations. The study revealed two distinct lineages of S. hemiphyllum var. chinense, exhibiting a north–south geographical distribution with a mixed zone in the southern Fujian–eastern Guangdong coastal region. These lineages are inferred to have diverged during the Middle to Late Pleistocene due to the isolation of the East China Sea and South China Sea during glacial periods. Sub-lineage differentiation was also detected within the northern lineage. The southern lineage experienced demographic expansion following the end of the Last Glacial Maximum, while the northern lineage remained stable. The southern Fujian–eastern Guangdong region, characterized by high genetic diversity, may have served as a glacial refugium or a contact zone for the post-glacial recolonization of the two lineages. Global warming may lead to range contraction and reduced genetic diversity in this species. The high genetic diversity area should be prioritized for conservation efforts. Overall, these findings provide insights into the genetic structure status and causes of S. hemiphyllum var. chinense and offer a scientific basis for proposing reasonable measures for its resource management. Full article

Parasitic diseases pose a serious threat to the health of humans and the steady development of livestock husbandry. Although there are certain drug-based treatment methods, with the widespread application of drugs, various parasites are gradually developing drug resistance. Natural products are highly favored by researchers due to their characteristics such as low toxicity, multi-target effects, and low risk of drug resistance. The ocean, as the largest treasure trove of biological resources on Earth, has a special ecosystem (high pressure, high salt, and low oxygen). This enables marine organisms to develop a large number of unique structures during their survival competition. So far, a variety of compounds, such as terpenoids, have been isolated from the algae. As potential drugs, these compounds have certain curative effects on various diseases, including tumors, parasitic diseases, Alzheimer’s disease, and tuberculosis. This paper systematically reviews and analyzes the current advances in research on the antiparasite effects of seaweed extracts. The primary objective of this research is to formulate a conceptual foundation for marine pharmaceutical exploration, focusing on the creation of innovative marine-based medicinal compounds to overcome the emerging problem of parasite resistance to conventional treatments. Full article

The Anthropocene has ushered in unprecedented environmental challenges, with invasive seaweed blooms emerging as a critical yet understudied facet of climate change. These blooms, driven by nutrient runoff and oceanic alterations, disrupt ecosystems, threaten biodiversity, and impose economic and public health burdens on coastal communities. However, invasive seaweeds also present an opportunity as a sustainable resource. This study explores the valorization of Sargassum spp. for agricultural applications, focusing on the development of biodegradable bioplastics and biostimulants. Field trials demonstrated the effectiveness of Marine Symbiotic^® Sargassum-derived biostimulant in distinct agricultural contexts. In the Dominican Republic, trials on pepper crops showed significant improvements, including a 33.26% increase in fruit weight, a 21.94% rise in fruit set percentage, a 45% higher yield under high-stress conditions, and a 48.42% reduction in fruit rejection compared to control. In Colombia, trials across four leafy green varieties revealed biomass increases of up to 360%, a 50% reduction in synthetic input dependency, and enhanced crop coloration, improving marketability. Additionally, Sargassum-based biofilms exhibited favorable mechanical properties and biodegradability, offering a sustainable alternative to conventional agricultural plastics. Carbon credit quantification revealed that valorizing Sargassum could prevent up to 89,670 tons of CO₂-equivalent emissions annually using just one Littoral Collection Module^® harvesting system, while biostimulant application enhanced carbon sequestration in crops. These findings underscore the potential of invasive seaweed valorization to address multiple climate challenges, from reducing plastic pollution and GHG emissions to enhancing agricultural resilience, thereby contributing to a sustainable Blue Economy and aligning with global sustainability goals. Full article

Surf zones are important nursery grounds for fish larvae and juveniles. However, little is known about fish larvae and juveniles in the surf zone along the coast of Jiangsu Province. To describe the species composition of fish larvae and juveniles, monthly collections were conducted at eight stations during the spring tide from February 2024 to January 2025. The fish larvae and juveniles were sampled using a seine net (1m × 4m; 1 mm mesh aperture), with sampling repeated three times at each station per month. A total of 1435 fish larvae and juveniles were collected, belonging to 42 species and 37 genera in 21 families. Almost half of them were postflexion larvae. Gobiidae, with 14 species, was the most diverse family. Based on the index of relative importance (IRI) result, the dominant species was Amoya pflaumi, accounting for 35.33% of the total number of individuals collected. Common species were Mugil cephalus, Amblychaeturichthys hexanema, Tridentiger trigonocephalus, Acanthogobius ommaturus, Mugilogobius abei, Thryssa mystax, Periophthalmus modestus, Sillago sihama, and Mugilogobius myxodermus. All other species were classified as rare. No fish larvae or juveniles were collected in February 2024 and January 2025. The species number, catch per unit effort (CPUE), Margalef’s richness index, Pielou’s evenness index, and Shannon–Wiener diversity index showed similar trends, and significant differences could be found for each parameter among sampling months. The cluster analysis from the ten months (excluding February 2024 and January 2025) indicated a significant seasonal change in the community structure of fish larvae and juveniles. Fish larvae and juveniles were abundant and diverse at one station near an aquaculture tidal flat for seaweed. This study provides essential basic data to support the management and conservation of fishery resources in the surf zone along the coast of Jiangsu Province. Full article

Currently, marine algae are still an under-exploited natural bioresource of bioactive compounds. Seaweeds represent a sustainable source for obtaining bioactive compounds that can be useful for the fabrication of new active products with biomedical benefits and applications as biomedicinals and nutraceuticals. The objective of this review is to highlight scientific papers that identify biocompounds from marine macroalgae and emphasize their benefits. The method used was data analysis to systematize information to identify biocompounds and their various benefits in pharmaceuticals, cosmetics, and nutraceuticals. The research results demonstrate the multiple uses of seaweeds. As pharmaceuticals, seaweeds are rich sources of bioactive compounds like polysaccharides, protein compounds, pigments, and polyphenols, which have demonstrated various pharmacological activities such as antioxidant, antibacterial, anti-inflammatory, antiviral, anticoagulant, and potentially anticarcinogenic effects. Seaweed has gained recognition as a functional food and offers a unique set of compounds that promote body health, including vitamins, minerals, and antioxidants. In conclusion, the importance of this review is to expand the possibilities for utilizing natural resources by broadening the areas of research for human health and marine nutraceuticals. Full article

The brown seaweed Rugulopteryx okamurae is a major invasive species in Europe, menacing local ecosystems. The challenge lies in assessing application routes for this biomass, testing different extraction technologies (overnight agitation, mechanical homogenization, pH-shift, ionic liquid-, and ultrasound-assisted extractions) and parameters. There was a higher yield in the extracts homogenized with 70% ethanol, especially with 1:20, w/v, biomass–solvent ratio, than in aqueous extracts. As to overnight agitation, 70% ethanol produced results (24.5–28.3%) similar to those found in the homogenized extracts. However, in the former, the best biomass–solvent proportion was 1:10, w/v. Mineral matter yield presented specific patterns, reaching 59.6 ± 1.1% (70% ethanol) and 82.3 ± 0.1% (water). The highest total polyphenol level was attained in the 70% ethanol, 1:20, w/v, extract, 310.7 ± 22.1 mg GAE/100 g dw seaweed. This extract had a higher FRAP/ABTS. The extract attained with overnight agitation, 70% ethanol, 1:10, w/v, had 48% COX-2 inhibition as anti-inflammatory activity. Besides showing the potential of R. okamurae for pharmacological purposes, especially in the antioxidant and anti-inflammatory area, this study enabled us to rank technologies and conditions for the utilization of this abundant biomass resource by the industry. Full article