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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]

Seaweed is rich in many unique bioactive compounds such as polyphenols and sulfated polysaccharides that are not found in terrestrial plant. The discovery of numerous biological activities from seaweed has made seaweed an attractive functional food source with the potential to be exploited for human health benefits. During food processing and digestion, cell wall polysaccharide and polyphenols commonly interact, and this may influence the nutritional properties of food. Interactions between cell wall polysaccharide and polyphenols in plant-based system has been extensively studied. However, similar interactions in seaweed have received little attention despite the vast disparity between the structural and chemical composition of plant and seaweed cell wall. This poses a challenge in extracting seaweed bioactive compounds with intact biological properties. This review aims to summarize the cell wall polysaccharide and polyphenols present in brown, red and green seaweed, and current knowledge on their potential interactions. Moreover, this review gives an overview of the gut modulation effect of seaweed polysaccharide and polyphenol. Graphical Abtsract: Polysaccharide and polyphenols from algae, the potential interaction between them and their gut modulation effect. [ABSTRACT FROM AUTHOR]

AbstractThe present study aims to investigate the dye decolorization efficiency of the brown seaweed Dictyota bartayresiana against reactive blue 19 (RB19) dye. The process variables namely dye and biosorbent concentration, pH and incubation time were optimized through BBD based RSM for achieving enhanced dye decolorization. The experimental data well fitted into Freundlich isotherm and proving the heterogenous adsorption of RB19. The Temkin and Dubinin – Radushkevich isotherm models showcased the endothermic and chemisorption mediated adsorption of RB19 onto D. bartayresiana. The pseudo second order kinetic model exhibited the chemisorption assisted adsorption and the Weber Morris kinetic model proved that the intra particle diffusion was not the rate limiting step in the adsorption of RB19 onto D. bartayresiana. Thermodynamic studies revealed the spontaneous, feasible and endothermic process of biosorption. Interaction between the dye and the biosorbent was assessed through UV-Vis, FT-IR and SEM which confirmed the process of decolorization. Desorption and regeneration studies revealed that 73% of the dye was desorbed in the first cycle using 0.1 M NaOH as eluent with regeneration efficiency of 68% which reduced in subsequent cycles highlighting the reusability of the biosorbent. Toxicity assessments of untreated and D. bartayresiana treated RB19 dye solution were examined on the microflora, brine shrimp and fenugreek and the results revealed the nontoxic nature of D. bartayresiana treated RB19 solution. Thus, this study provides valuable insights on utilization of D. bartayresiana as an eco-friendly biosorbent for the decolorization of RB19 and affirms its safe use in various biological applications. [ABSTRACT FROM AUTHOR]

AbstractThe exploration of endophytic fungi associated with seaweeds has garnered significant interest due to their crucial ecological functions and potential as sources of valuable bioactive compounds. In this study, we isolated and identified endophytic fungi from the brown seaweed Dictyopteris pacifica, collected from the intertidal zone of Yeongdoek, Gyeongsangbuk-do in Korea. Through morphological examination and molecular phylogenetic analysis using multiple molecular markers, including ITS, LSU, SSU, TEF1, TUB2, and RPB2 sequences, we identified three fungal species not previously recorded in Korea: Emericellopsis fuci, Neoarthrinium lithocarpicola, and Periconia chimonanthi. Detailed descriptions of morphological characteristics and phylogenetic analyses are provided. This study represents the first report of these endophytic fungi isolated from D. pacifica in Korea, thereby enhancing the understanding of the diversity of seaweed-associated endophytic fungi in the region. [ABSTRACT FROM AUTHOR]

Risk is an inherent characteristic of aquaculture production. For a holistic understanding of risk, the risk assessment process must account for both subjective and objective dimensions of risk. This paper empirically studies the role of risk perception and the risk properties of inputs used in aquaculture to explain the low adoption rates of seaweed farming in Chile. We propose a risk production estimation framework with selectivity to explore the role of risk, given that many aquaculture concessions remain totally or partially unexploited. We found that farmers are more likely to produce seaweed when they perceive greater access to financing, but also that this activity is more exposed to theft than other activities. Moreover, results suggest that labor and energy are risk-increasing inputs, while we found that capital and the number of hectares available are risk-decreasing inputs. The latter is important as it suggests that larger seaweed producers and more investment would reduce production variability. [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]

Portieria hornemannii, a marine red alga, has attracted considerable attention due to its possible therapeutic characteristics. NFκB, a crucial transcription factor involved in regulating immune and inflammatory responses, plays a central role in controlling the expression of various genes associated with inflammation, such as MMP 9. This study employed an aqueous extract of Portieria hornemannii (Ph) and subjected it to UV-Visible, FTIR spectroscopy, and GC-MS analysis to identify its phytochemical composition. The presence of Vanillin, tert-butyldimethylsilyl ether, Dodecane, 1-fluoro-, and Pentanoic acid, 5-hydroxy-2,4-di-t-butylphenyl esters in Ph indicates their potential anti-inflammatory properties, suggesting their potential application in inflammation treatment. In summary, Ph exhibited anti-inflammatory properties by modulating the expressions of NFκB-associated MMP 9 in zebrafish embryos, potentially reducing the risk of inflammatory diseases. [ABSTRACT FROM AUTHOR]

The Chinese goal to reach carbon peak by 2030 and achieve carbon neutrality by 2060 (the "30/60" dual carbon goal) will require a swift and dramatic reduction in greenhouse gas emissions. Among various ocean carbon dioxide removal (CDR) technologies, seaweed cultivation has gained more attention due to its potential for CO2 removal. However, the current legal framework in China lacks specific laws and regulations addressing seaweed cultivation for carbon removal. This paper highlights three key points: (1) the existing Chinese legal system needs to be updated to keep up with policy changes and govern the practice of seaweed cultivation for carbon removal; (2) transitioning seaweed cultivation from aquaculture to an ocean CDR approach can promote climate mitigation benefits; and (3) successful implementation requires not only technical and financial support but also the establishment of comprehensive policy and legal frameworks. [ABSTRACT FROM AUTHOR]

Settlement induction potential of two red algae, Sahlingia subintegra and Rhodosorus marinus, and one green macroalgae, Ulvella leptochaete was examined to identify potential alternative algal species to improve reliability and reproducibility of Haliotis tuberculata sp. settlement. CCA was used as a positive control. Settlement rates, post-larval survival and growth of Haliotis tuberculata sp. were evaluated for different algal species tested. Results showed that Sahlingia subintegra induced significantly higher settlement rates (58.17 ± 12.71%) compared to CCA, Ulvella leptochaete and Rhodosorus marinus. In all treatments, post-larvae were weekly fed a mix of diatoms (Amphora sp., and Navicula incerta). At four weeks post settlement, post-larval survival rates were significantly higher on CCA and Sahlingia subintegra substrates compared to the other two algal species tested. However, at four and five weeks post settlement there were no significant differences in post-larval shell length and growth rates between CCA and Sahlingia subintegra substrates. These findings suggest that Sahlingia subintegra could be a promising alternative red macroalgae providing settlement cue for abalone hatchery stages, particularly for Haliotis tuberculata sp. and could contribute to improve abalone breeding techniques through the selection of alternative settlement substrates that could be easily managed in abalone farms environments. [ABSTRACT FROM AUTHOR]

In Australia, cultured greenlip abalone (Haliotis laevigata) are fed formulated diets that lack macroalgae. This has resulted in a pale lip colour in contrast to the vivid green lip colour of wild abalone. We evaluated the effects of supplementing 15% dried macroalgae meal, using either commercially available macroalgae meal (MSM) or harvested Gracilaria cliftonii, on colour change in greenlip abalone. Abalone were fed the respective diets in a three month laboratory trial and an additional four month on-farm trial. The inclusion of MSM into formulated abalone diet did not change lip, foot, or shell colour, whereas the G. cliftonii meal treatment changed lip and shell colour. The laboratory study was extended for another three months. Greenlip abalone either: (1) continued to be fed their experimental diet; or (2) the abalone were fed a diet with no dried algal meal. The colour changes observed in the first study were retained for one month, after which the colour declined. The addition of 15% G. cliftonii meal to formulated diets can be used to manipulate greenlip abalone lip and shell colour. A minimum of three months is recommended and abalone should be harvested within one month to maintain the desirable colour changes. [ABSTRACT FROM AUTHOR]

Caulerpa is a widely distributed genus of chlorophytes (green macroalgae) which are important for their dietary, social and coastal ecosystem value. Ocean acidification (OA) threatens the future of marine ecosystems, favouring macroalgal species that could benefit from increased seawater carbon dioxide (CO2) concentrations. Most macroalgae species possess CO2 concentrating mechanisms (CCMs) that allow active uptake of bicarbonate (HCO3−). Those species without CCMs are restricted to using CO2, which is currently the least abundant species of dissolved inorganic carbon (DIC) in seawater. Thus, macroalgae without CCMs are predicted to be likely benefit from OA. Caulerpa is one of the rare few genera that have species both with and without CCMs. The two most common Caulerpa species in New Zealand are C. geminata (possesses a CCM) and C. brownii (non-CCM). We investigated the responses of growth, photo-physiology and DIC utilisation of C. geminata and C. brownii to four mean seawater pH treatments (8.03, 7.93, 7.83 and 7.63) that correspond to changes in pH driven by increases in pCO2 simulating future OA. There was a tendency for the mean growth rates for C. brownii (non-CCM) to increase under lower pH, and the growth rates of C. geminata (CCM) to decline with lower pH, although this was not statistically significant. However, this is likely because variability in growth rates also increased as seawater pH declined. There were few other differences in physiology of both species with pH, although there was tendency for greater preference for CO2 over HCO3− uptake in the CCM species with declining seawater pH. This study demonstrates that DIC-use alone does not predict macroalgal responses to OA. [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]

Alginates, hydrophilic anionic polysaccharides with notable bioactivity and biocompatibility, have drawn significant attention, particularly due to their extensive use in the pharmaceutical industry and associated health benefits. Brown seaweeds serve as the primary source of alginates. However, extraction methods, especially traditional ones, face efficiency challenges, impacting the yield. Green extraction methods promise an eco-friendly alternative, but their industrial-scale implementation is still unproven. Importantly, these extraction methods could yield alginates of different molecular weights and consequent varied biological effects. Alginates possess antibacterial, antioxidant, anti-diabetic, and immunomodulatory properties, forming the cornerstone of their health benefits and pharmaceutical applications. The hydrogel formation characteristic of alginates is crucial for pharmaceutical applications, including drug delivery, wound dressing, and tissue regeneration. Despite the existence of numerous articles exploring the extraction methods, properties, and applications of alginates, a gap exists in the literature that connects these aspects with health benefits. This review aims to bridge this gap by providing a comprehensive discussion of the extraction methods, properties, health benefits, and pharmaceutical applications of alginates. [ABSTRACT FROM AUTHOR]

Marine algae, a rich source of bioactive substances, have long been utilized in biomedical and veterinary sciences. This study breaks new ground by assessing the antiviral therapeutic potential of water extracts from four algal species – Colaconema formosanum, Caulerpa microphysa, Gelidium amansii and Sarcodia suae – against vesicular stomatitis virus (VSV) infection. The standout among these was Sarcodia suae water extract (SSWE), which not only significantly repressed VSV replication and enhanced cell survival without cytotoxic effects, but also demonstrated its antiviral activity through interference with viral attachment, entry, RNA replication, and egress, and reduced VSV-induced autophagy in Mv1Lu cells during the late stages of infection. The EC50 of SSWE was 0.422 ± 0.14 mg ml‒1. The cytotoxicity assay confirmed the high biocompatibility of SSWE. This study identifies SSWE as a promising natural antiviral agent and elucidates its mechanisms of action, highlighting the need for further research to optimize its use in controlling VSV-related diseases. Highlights: The bioactive water extract of Sarcodia suae was identified as a sustainable antiviral agent for the algal cultivation industry. The antiviral activity of S. suae against vesicular stomatitis virus (VSV) infection was confirmed. The mechanisms of action of the extract from Sarcodia suae on the autophagic pathway were demonstrated. [ABSTRACT FROM AUTHOR]

The Bangiales are one of the most common seaweeds in sub-Antarctic and Southeastern Pacific upper intertidal habitats. Here we report records of an 'olpidioid' marine obligate parasite infecting Bangiales between 39°20′–41°44′S in the Southeastern Pacific for the first time. The disease resembles the 'Olpidiopsis blight disease' reported for farmed Bangiales in Japan and Korea and wild Pyropia from Scotland morphologically and developmentally. The Chilean isolate infects commercial Chilean laver or 'luche' (Porphyra sensu lato) and Bangia sensu lato from wild populations in the Southeastern Pacific. Phylogenetic markers (cox2, 18S) identify it as Olpidiopsis porphyrae. We relate the occurrence of this pathogen to both 'luche' fisheries in Chile and the potential consequences for its emergent aquaculture in the Southeastern Pacific. Highlights: The parasite Olpidiopsis porphyrae (Oomycota) is reported in Chile and the Southeastern Pacific for the first time. O. porphyrae infects Chilean Porphyra and Bangia sensu lato. The prevalence of O. porphyrae is very variable between populations, and highly seasonal in a locality of Southern Chile. [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]

AbstractFucose is abundant in marine organisms, primarily as fucoidan and fucosylated chondroitin sulfate. Our previous study characterized a sulfated and fucosylated glucuronomannan (SFGM) isolated from marine brown algae, exhibiting notable antiviral activity and potential for drug development. Herein, a trisaccharide fragment of this SFGM in the form of [α-L-Fuc(2, 4-diS)]-(1→3)-α-D-Man-(1→4)-α-D-GlcA-OMP was synthesized for the first time. Stereoselective formation of the α-1,2-cis-fucosidic bond was achieved by leveraging solvent effects. The sulfated trisaccharide as the final product, featuring a 2,4-diS-fucose unit and the p-methoxyphenyl group as a pendant at the anomeric position, was successfully accomplished. The synthetic strategy developed in this study offers a foundation for the pharmaceutical development of these SFGM oligosaccharides. [ABSTRACT FROM AUTHOR]

This study focuses on a rare sail-shaped macrofossil, Alienum velamenus gen. & sp. nov. from the Jiangchuan Biota in Yunnan Province, China. The new species presented here possesses an unique bipartite body consisting of a wide unbranched, asymmetrical sail-shaped anterior section and a small narrow tail-like posterior section. The macrofossil of the new species is preserved through carbonaceous compression. Its appearance is different from known macroalgae but similar to Vetulicolia from the early Cambrian Chengjiang Biota. The anterior section of the new species, which is broad and smooth, shows only indistinctly arranged suspected gill slits and a nearly horizontal pharyngeal groove, without significant segmented structures. Owing to lack of samples, the specific biological properties and taxa of the new species are still undefined. The discovery of Alienum velamenus indicates that the Jiangchuan Biota is an exceptional lagerstätte with great potential for the preservation of Precambrian early life through carbonaceous compression. Furthermore, the Jiangchuan Biota shows significant differences in species diversity from the Miaohe Biota of the Doushantuo Formation and the Shibantan Biota of the Dengying Formation in the Three Gorges area of Hubei Province. [ABSTRACT FROM AUTHOR]

This study investigated the diversity of endophytic fungi isolated from the brown seaweed, Sargassum thunbergia, collected from six coastal regions in Korea: Gangneung, Pohang, Buan, Taean, Tongyeong and Yeosu. A total of 154 fungal strains were isolated using ITS rDNA sequence analysis, resulting in 84 species across 43 genera. Species diversity, assessed based on the Shannon index, was highest in Tongyeong (H′=3.273), followed by Pohang (H′=3.209), Buan (H′=2.691), Yeosu (H′=2.649), Gangneung (H′=2.342), and Taean (H′=2.025). Principal Coordinates Analysis (PCoA) revealed that water temperature and dissolved oxygen are the primary environmental factors influencing the regional variation in fungal community structure. This study underscores the significance of environmental conditions in shaping the diversity and community composition of endophytic fungi in S. thunbergii. [ABSTRACT FROM AUTHOR]

The marine algae Ulva spp. are commonly used as model biofouling organisms. As biofouling studies are primarily conducted using field-collected specimens, factors including species identity, seasonal availability, and physiological status can hinder the replicability of the results. To address these limitations, a protocol was developed for the on-demand laboratory culture and release of Ulva zoospores. The biofouling potential of laboratory-cultured and field-collected Ulva blades was compared using a waterjet. No significant differences were found between field and laboratory-cultured samples in either spore adhesion (before waterjet) or the proportion of spores retained after waterjet exposure. However, there was significant variability within each session type in pre- and post-waterjet exposures, indicating that spore adhesion and retention levels vary significantly among trial runs. In addition, all our laboratory cultures were Ulva Clade C (LPP complex). In contrast, our field samples contained a mix of Ulva Clade C, U. compressa clade I, and U. flexuosa Clade D. This protocol for on-demand production of Ulva spores can improve biofouling research approaches, enables comparison of results across laboratories and regions, and accelerate the development of anti-biofouling strategies. [ABSTRACT FROM AUTHOR]

The non-food segment of the Chinese seaweed market, which is crucial for developing the hydrocolloid industry, relies heavily on the seaweed supply from Chile, Peru, and, to a much lesser extent, Indonesia, in addition to domestic production. In this paper we investigate the degree of market integration between seaweed from these countries. We find that the market is highly integrated as the Law of One Price holds, suggesting a global market. Furthermore, the import price from Chile and Indonesia follows the lead of the import price from Peru. As the hydrocolloid industry develops in China, increased demand for seaweed from Chile and Peru is expected, which increases the extraction of seaweed from natural beds. This situation will be unsustainable if Chile and Peru continue to rely primarily on wild extraction. [ABSTRACT FROM AUTHOR]

The marine red alga, Gracilaria eucheumatoides, is economically significant for its agar production and pharmacologically active compounds. This study reveals its complete mitochondrial genome (mitogenome), sequenced using Illumina's next-generation technology. The mitogenome is a 25,909 bp circular molecule with a G + C content of 27.21%, comprising 24 protein-coding genes, two ribosomal RNA genes, 24 transfer RNA genes, and one open reading frame (ORF) with an unidentified function. Both gene structure and composition are highly conserved within Gracilaria. The phylogenetic analyses fully support a close relationship of G. eucheumatoides with other Gracilaria species, as well as its sister relationship with G. urvillei. This mitogenome sequencing effort of G. eucheumatoides provides crucial data for future phylogenetic research on marine red algae. [ABSTRACT FROM AUTHOR]

AbstractThe potential of seaweed as a renewable resource is becoming increasingly recognized by diverse stakeholders in Europe. Currently, several initiatives are working on accelerating the development of the European algae industry. Seaweed cultivation can be an important cornerstone in developing EU aquaculture and achieving the European Green Deal. An expert working group was selected and established in February 2021 by the European knowledge brokering mechanism Eklipse. This group was tasked to explore and map the current state of knowledge regarding ecosystem services (ES) provided by seaweed cultivation, including knowledge gaps, constraints, potential negative impacts and tradeoffs. The study was based on the Delphi process and a Quick Scoping Review (QSR). The results of each method showed differences in constraints, negative impacts and knowledge gaps, revealing the need for better communication and collaboration between the involved stakeholders. Both methods identified the following six ES provided by seaweed cultivation: (i) provisioning food, (ii) provisioning hydrocolloids and feed, (iii) regulating water quality, (iv) provisioning habitats, (v) provisioning of nurseries and (vi) regulating climate. Nevertheless, the specific ES identified differed between seaweed taxa. In addition, both methods highlighted also potential negative environmental impacts (e.g., wider ecosystem effects), technological constraints and knowledge gaps (e.g., production). The identified knowledge gaps and constraints were further discussed and prioritized with stakeholders in a workshop in Brussels. This workshop identified the structural research needs for future investigations, including: improved knowledge of environmental impacts; better management of genetic diversity and clear definitions of legal frameworks to support the development of the EU initiative on seaweed sustainable use. This paper summarizes the findings of the investigations of the expert group and future challenges for seaweed cultivation under current and near-future climatic scenarios. [ABSTRACT FROM AUTHOR]

In recent studies, marine macroalgae (seaweeds) have been highlighted as excellent sources of acquiring many bioactive polymers and metabolites with vast chemical and biological values, which has attracted increasing research interests in seaweeds. Among a diversity of seaweed-derived bioactive constituents, polysaccharides have been affirmed to possess an extensive array of bioactivities, such as antioxidant, antimicrobial, anticarcinogenic, immune-enhancing and anti-inflammatory activities. Due to the exhibition of these bioactivities, seaweed polysaccharides have been promised great application potential in food, feed, pharmaceutical, nutraceutical, and cosmeceutical industries. As discovered, these bioactivities were mainly contributed by the complex polymeric structural features and chemical compositions of seaweed-derived polysaccharides and were highly associated with the extraction methods. This study has comprehensively reviewed the current and prospective applications of seaweeds and their polysaccharides from nutritional and bioactive perspectives, with further shedding light on the insight into the structure-bioactivity relationship of seaweed-derived polysaccharides. [ABSTRACT FROM AUTHOR]

The study was to investigate the influence of the addition of sea vegetable (gim) flakes on physicochemical, nutritional, and antioxidative properties and stability over storage of salt-reduced fried fish cake. The addition of gim flakes at 1%, 2%, and 3% (w/w) in fried fish cake reduced the salt content by 13%, 15%, and 18%, respectively. Fried fish cakes prepared with gim flakes demonstrated lower fat and sodium content and higher protein, phenolic content, and antioxidative properties. The results of these studies demonstrated that the beneficial value and overall quality of fried fish cake can be improved through the addition of gim. [ABSTRACT FROM AUTHOR]

Macroalgae are being intensively explored as a nature-based solution to address climate change. Although there are still some uncertainties about recognizing macroalgae in climate mitigation, the research trend on macroalgae carbon potential continues to increase. We collected secondary data, literature reviews, and expert opinions through focus group discussions to estimate the carbon sequestration potential of macroalgae and examine its feasibility in Indonesian climate mitigation. Our analysis shows that the carbon sequestration potential of macroalgae in Indonesia is significant, estimated to range from 351.246-2.526.332 Mg C yr−1, placing macroalgae as the third largest marine carbon store after mangroves and seagrass. In addition, macroalgae have higher CO2 sequestration rates than other blue carbon habitats. Our assessment of the viability of macroalgae in the blue carbon shows that macroalgae meet the critical elements of blue carbon criteria, including carbon sequestration scale, long-term storage, anthropogenic impact, and social or environmental interventions. However, aligning it with other climate mitigation policies is essential for macroalgae to be fully recognized in blue carbon. This preliminary study suggests that macroalgae could be necessary for Indonesia's climate mitigation action. [ABSTRACT FROM AUTHOR]

Seaweed farming in Maine, USA has grown exponentially over the last 5 years. Our work builds upon a prior Maine aquaculture sector benchmarking study to assess changes between the 2017 and 2022 harvest seasons. We interviewed 16 farmers who collectively harvested over 1 million lbs. (wet weight) of seaweed, ∼22 times the harvest volume from the 2017 season. We observed three notable improvements on kelp farms in Maine between 2017 and 2022: (1) median seaweed yield grew by 28%, from 3.3 to 4.24 lbs./ft.; (2) labor efficiency improved by 1,275%, from a median of 7.55 to 103.8 lbs. harvested per hour of labor and management input; and (3) median net margin per pound harvested increased from −$6.41 to $0.16/lb. These gains can likely be attributed to increased farmer knowledge, "learning by doing," extension support, improved seed production, and increases in scale. When benchmarks were recalculated according to three size groupings, we found that net margins ($/lb.) increased and breakeven price decreased with farm size (total lbs. harvested), indicating economies of scale. We found that fishermen, shellfish farmers, and other members of the working waterfront continue to leverage seaweed farming as a worthwhile source of supplementary income. [ABSTRACT FROM AUTHOR]

Bioremediation using tropical marine algae provides cost effective and eco-friendly alternative mean of removing toxic and harmful substances from the environment. Bioremediation is an important tool in sustainable environmental management and protection. This study examined the productivity and bioremediation potential of Nannochloropsis oculata and Porphyridium cruentum in Water Soluble Fraction (WSF) of petroleum fuels by investigating the growth of Nannochloropsis oculata and Porphyridium cruentum at 0%, 10% 20% 30% 40% 50% 75% 100% of WSF of kerosene, diesel, and gasoline. Growth was monitored optically every two days for fourteen days using 721 Visible Spectrophotometer. Productivity was measured using prescribed procedure. Bioremediation potential of test algae were examined using standard method for the GC analysis of diesel range organics in 100% WSFs. The minimum growth for both species was recorded at 100% in all the fuels. The maximum growth of Porphyridium cruentum was obtained at 10% in all fuels, while the maximum growth of Nannochloropsis oculata was obtained at 30% in both kerosene and gasoline and at 50% in diesel. Whereas Porphyridium cruentum was greatly inhibited by all fuels, Nannochloropsis oculata was stimulated at lower concentration of the fuels. Nannochloropsis oculata proved more efficient for bioremediation of the petroleum fuels with 84.58%, 65.51% and 70.77% removal efficiency for kerosene, diesel and gasoline respectively, while Porphyridium cruentum was 58.94%, 46.64% and 56.67% respectively. Nannochloropsis oculata is a very strong and reliable candidate for bioremediation of petroleum hydrocarbons and should be subjected to further examination for sustainable and eco-friendly remediation of petroleum pollution. In this study, bioremediation of 100% Water Soluble Fraction (very high concentration) of the three most commonly used petroleum fuels (gasoline, diesel, kerosene) were examined. The bioremediation potential of the test algae were examined simultaneously in three petroleum fuels to enhance comparative assessment and to reduce the effect of environmental changes. This study identifies specific tropical marine alga that has high biomass productivity and bioremediation efficiency in tropical marine or coastal waters polluted with very high concentration of WSF of petroleum hydrocarbons. The result of this study is recommended for adoption by the bioremediation industries for the removal of high concentration of WSF of petroleum hydrocarbons in tropical marine waters and industrial waste waters. It may also be subjected to further examination. [ABSTRACT FROM AUTHOR]

The use of mycorrhiza and seaweed are becoming significant and complementary applications in different production systems because organisms increased quality of seedlings and crop yield. This study has been conducted under growth chamber conditions to determine some of the seedling growth parameters (length (cm), stem diameter (mm), fresh weight (g plant −1), dry weight (g plant −1), root fresh weight (g plant −1), root dry weight (g plant −1), leaf area (cm2 plant−1), SPAD, photosynthesis rate (%) and color parameters). As a plant material, Cuma F1 and Mert F1 genotype seeds were sown. Endo Roots Soluble (Mycorrhiza (ERS)) and MC-Extra (Seaweed) were applied in different doses (0, 250 and 500 mg kg−1) to seedling growing vessels at a rate of 10 ml per plant. Treatment effects in tomato were found statistically significant (p ≤.01**) on stem diameter, fresh weight, dry weight. Seedling length, leaf area and SPAD results were also statistically significant (p ≤.01**), and the results of these parameters were higher in ERS. ERS increases the leaf area and SPAD measurements in tomato seedlings. The results of pepper measurements were found to be statistically significant at p ≤.05* on root fresh weight, SPAD and photosynthesis rate. The highest values of root fresh weight, SPAD were obtained from 250 mg kg−1 doses of ERS; the highest value of photosynthesis rate was measured from 500 mg kg−1 doses of ERS on pepper. The effect of 500 mg kg−1 ERS on seedling growth was found statistically significant in pepper. [ABSTRACT FROM AUTHOR]

Nature derived compounds represent a valuable source of bioactive molecules with enormous potential. The sea is one of the richest environments, full of skilled organisms, where algae stand out due to their unique characteristics. Marine macroalgae adapt their phenotypic characteristics, such as chemical composition, depending on the environmental conditions where they live. The compounds produced by these organisms show tremendous potential to be used in the biomedical field, due to their antioxidant, anti-inflammatory, immunomodulatory, and anti-cancer properties. Cancer is one of the deadliest diseases in the world, and the lack of effective treatments highlights the urgent need for the development of new therapeutic strategies. This review provides an overview of the current advances regarding the anti-cancer activity of the three major groups of marine macroalgae, i.e., red algae (Rhodophyta), brown algae (Phaeophyceae), and green algae (Chlorophyta) on pancreatic, lung, breast, cervical, colorectal, liver, and gastric cancers as well as leukemia and melanoma. In addition, future perspectives, and limitations regarding this field of work are also discussed. [ABSTRACT FROM AUTHOR]

In this study, we conducted sea urchin removal (SUR) experiments at two sites along Hokkaido's southwestern and northwestern coasts in the Sea of Japan and one site along the northeast coast in the Sea of Okhotsk, to elucidate the biomass balance between macroalgae and sea urchins at different urchin barren sites. The experiments resulted in the restoration of macroalgal biomass at all sites and an increase in macroalgal diversity, indicating that it was the impact of high grazing pressure reducing the macroalgae, regardless of the particular experimental site. Notably, the recovery of the macroalgal biomass was characterized by increased kelp biomass, including Saccharina japonica var. religiosa and S. japonica var. ochotensis. In addition, negative correlations were observed between macroalgal biomass and sea urchin density. The lowest sea urchin density inducing an increase of macroalgal biomass was approximately the same in the reproductive growth phase (0.1 kg m−2) and in the vegetative growth phase (0.15 kg m−2) of Saccharina spp., the dominant kelps, regardless of the experimental site. These values can be helpful indicators for managing sea urchin density in order to restore macroalgae. In contrast, the maximum sea urchin density inducing the lowest macroalgal biomass varied markedly depending on the study site, indicating that different levels of kelp productivity are influenced by oceanographic conditions. Moreover, a strong positive correlation was observed between macroalgal biomass and sea urchins' gonadosomatic index (GSI). Based on this correlation, macroalgal biomass supporting sea urchins with commercial value (GSI ≥ 15%) was estimated to be 1.6 kg m−2. This sea urchin density value is also a helpful indicator for managing macroalgal biomass and commercially valuable sea urchins. Moreover, this value will depend on the influence of the oceanographic environment of the site, particularly the nutrient conditions, on macroalgal productivity. In addition, we have also discussed how macroalgae and sea urchins can best coexist at the experimental sites. Sea urchin removal (SUR) restored macroalgal biomass and diversity. Recovery of macroalgal biomass by SUR was characterized by kelps. Kelp biomass required to support the commercial sea urchin production was estimated. [ABSTRACT FROM AUTHOR]

Effective monitoring of non-indigenous seaweeds and combatting their effects relies on a solid confirmation of the non-indigenous status of the respective species. We critically analysed the status of presumed non-indigenous seaweed species reported from the Mediterranean Sea, the Northeast Atlantic Ocean and Macaronesia, resulting in a list of 140 species whose non-indigenous nature is undisputed. For an additional 87 species it is unclear if they are native or non-indigenous (cryptogenic species) or their identity requires confirmation (data deficient species). We discuss the factors underlying both taxonomic and biogeographic uncertainties and outline recommendations to reduce uncertainty about the non-indigenous status of seaweeds. Our dataset consisted of over 19,000 distribution records, half of which can be attributed to only five species (Sargassum muticum, Bonnemaisonia hamifera, Asparagopsis armata, Caulerpa cylindracea and Colpomenia peregrina), while 56 species (40%) are recorded no more than once or twice. In addition, our analyses revealed considerable variation in the diversity of non-indigenous species between the geographic regions. The Eastern Mediterranean Sea is home to the largest fraction of non-indigenous seaweed species, the majority of which have a Red Sea or Indo-Pacific origin and have entered the Mediterranean Sea mostly via the Suez Canal. Non-indigenous seaweeds with native ranges situated in the Northwest Pacific make up a large fraction of the total in the Western Mediterranean Sea, Lusitania and Northern Europe, followed by non-indigenous species with a presumed Australasian origin. Uncertainty remains, however, regarding the native range of a substantial fraction of non-indigenous seaweeds in the study area. In so far as analyses of first detections can serve as a proxy for the introduction rate of non-indigenous seaweeds, these do not reveal a decrease in the introduction rate, indicating that the current measures and policies are insufficient to battle the introduction and spread of non-indigenous species in the study area. Non-indigenous seaweed species in the Northeast Atlantic Ocean, the Mediterranean Sea and Macaronesia are critically reanalysed. > 19,000 distribution records revealed considerable variation in diversity of non-indigenous seaweed species in the study area. Taxonomic and biogeographic uncertainties hamper a critical evaluation of the non-indigenous status of many seaweed species. [ABSTRACT FROM AUTHOR]

A wide variety of bioactive secondary metabolites that seaweeds are claimed to generate can be used by the pharmaceutical industry to create novel medications. The primary goal of the current study was to use the HR-LCMS and NMR approach to analyse the phytochemical content of a methanolic extract of Gracilaria edulis. The HR-LCMS and NMR analysis reveals the presence of bioactive compounds (amino acid, fatty acid, triterpenoids, carotenoid, aromatic compounds, flavonoids, secondary alcohols, diterpenes, lipid, phenolic compounds, sesquiterpenoids, quinolizidine alkaloid, and benzoquinone). The present study's findings support the existence of significant phytocompounds in G. edulis and are useful for future in-depth investigation to create medications from marine algae to treat a variety of ailments. The goal of current research is to discover all-natural treatments for a wide variety of illnesses and conditions. [ABSTRACT FROM AUTHOR]

In this study investigation of accumulations of critical raw materials (cobalt (Co), antimony (Sb), vanadium (V), lanthanum (La) and tungsten (W)) from wastewater by using C. fracta were aimed. Besides, assessment of the potential health risks in terms of the use of organic fertilizer obtained from the macroalga to be harvested from the treatment were also aimed. Highest Co, Sb, V, La and W accumulations by algae in reactor were 125±6.2%, 201.25±10%, 318.18±15%, 357.97±18%, and 500±25%, respectively. When compared with control, Co, Sb, V, La and W in algae increased 2.25, 3.01, 4.18, 4.58, and 6 times, respectively. The algae was very high bioaccumulative for Co and La. Highest MPI was calculated as 3.94. Non-carcinogenic risk of CRMs according to different exposure types (ingestion, inhalation, and dermal) were calculated for man, woman and child. There is not any non-carcinogenic risk from the investigated exposure ways of algae as organic fertilizer. [ABSTRACT FROM AUTHOR]

In this article, chemical structure and conformation in an aqueous solution of a new sulfated polysaccharide, PCL, extracted from green seaweed Chaetomorpha linum were elucidated by SEC-MALL, IR, NMR and SAXS. The results indicated that the obtained polysaccharide is a sulfated arabinogalactan with a molecular weight of 223 kDa, and is mainly composed of →3,6)-α-D-Galp4S→ and →2)-α-L-Araf→ connecting together through 1→3 glycoside linkages. It has a broken rod-like conformation in solution with Rgc estimated as 0.43 nm from SAXS measurements. The polysaccharide exhibited a notable anticoagulant activity measured by the assays of activated partial thromboplastintime, thrombintime and prothrombine time as well as a significant cytotoxic activity against hepatocellular, human breast cancer, and cervical cancer cell lines. [ABSTRACT FROM AUTHOR]

Among marine primary producers, macroalgae support complex and productive coastal food webs, but coastal primary production relies on terrigenous inputs and remineralized organic matter which both vary seasonally. An approach combining stable isotope and biochemical analyses enables a better characterization of macroalgae specificities and highlights environmental influences on their chemical signature. This study compared the isotopic signature and biochemical composition of 22 Mediterranean macroalgae belonging to Rhodophyta (red algae), Phaeophyceae (brown algae) and Chlorophyta (green algae) between March and November 2010 to capture the differences in species chemical signatures potentially driven by metabolic traits or environmental drivers. Carbon stable isotope values were evidenced as a good proxy of specific carbon metabolism: low values observed in red algae could be related to the reported absence of carbon concentrating mechanisms (CCMs) in this group while higher values were driven by strong CCM activity in green algae. Biochemical patterns also differed between groups: soluble carbohydrates were a major component for red algae, while lipids and proteins dominated in brown algae, and insoluble carbohydrate concentrations were high in green algae. Variation within species across two collection times could be related to environmental changes and algal metabolism. δ15N values confirm the efficiency of this parameter as a proxy of the impact of human influence in the Bay of Marseille. Isotopic and biochemical content was measured in 22 Mediterranean macroalgae. Carbon descriptors are related to the metabolism of the specific macroalgal group. Seasonal variation of descriptors correlates with environmental variability. [ABSTRACT FROM AUTHOR]

The present study aimed to analyze the application of a seaweed biofertilizer as an attenuator of salt stress on the morphophysiology of scarlet eggplants. The experiment was carried out under protected conditions in Areia, PB, Brazil, using an incomplete factorial arrangement in a randomized block design with four replications and two plants per plot by adopting the Box Central Composite Design with five electrical conductivities of irrigation water – ECiw (0.50 – control, 1.15, 2.75, 4.35 and 5.00 dS m−1) and five concentrations of seaweed biofertilizer (0 – control, 1.45, 5.00, 8.55 and 10 mL L−1). The electrical conductivity of irrigation water at values starting at 0.5 dS m−1 negatively affected the growth of scarlet eggplants. Therefore, the crop is considered sensitive to salt accumulation. The increase in electrical conductivity of irrigation water negatively affected the morphophysiology of scarlet eggplants, with reductions higher than 10% at electrical conductivity values higher than 1.37 dS m−1. Biofertilization at 6.67 mL L−1 mitigates the effects of salt stress on the gas exchange variables and the phytomass accumulation of scarlet eggplants 60 days after sowing. The seaweed biofertilizer can be used to improve the physiological and morphological performance of scarlet eggplants. [ABSTRACT FROM AUTHOR]

The concept of floating algae index (FAI), a measure of the red-edge reflectance of floating vegetation, has been used to map floating macroalgae in global oceans. However, when the algae mats are submerged in water due to winds and other factors, the reduced reflectance (and thus reduced FAI value) is interpreted as being caused by reduced areal density (or biomass density) of algae, leading to underestimated algae amount. Here, a depth invariant FAI is proposed to overcome this difficulty. The depth invariant FAI is formulated using three spectral bands whose selective water attenuations can compensate for the reduced reflectance, resulting in FAI values that are nearly independent of the submerged depth of up to 30 cm with underestimates of the algae amount reduced from >50% to a few percent. In this study, the concept of depth invariant FAI is demonstrated through simulations only. With the new Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission and other hyperspectral satellite missions in the near future, such a concept is expected to be tested and evaluated with satellite data, from which the optimal bands can be selected to reduce uncertainties in mapping floating macroalgae. [ABSTRACT FROM AUTHOR]

The rate of cyanide reduction in the aqueous solutions by adsorption onto the diatomite magnano composite boosted with alginate polymer beads (DMBA) was evaluated. The R software using RSM was used as an experimental technique to design a statistical equation. Based on statistical results obtained, second order model due to insignificant lack of fit (0.12) and the higher value of correlation coefficient (0.92) was selected as a suitable model to design of the adsorption process. Based on the stationary points, the maximum adsorption of cyanide (98.11%) was achieved under selected conditions (initial cyanide concentration, 4.88 mg L−1; contact time, 91.06 min and DMBA dosage, 2.05 g L−1). The Sips nonlinear model indicated the best compatibility with the experimental data. It was found to be a successful model for predicting the heterogeneity of surfaces. The maximum adsorption capacity of cyanide onto DMBA was determined 208.55 mg g−1. The pseudo-first-order model was found to agree well with the adsorption experimental data obtained for cyanide. The thermodynamic data revealed the spontaneous sorption and endothermic for the adsorption of cyanide onto DMBA. [ABSTRACT FROM AUTHOR]

Nigrospora (Xylariales, Apiosporaceae) consists of species of terrestrial plant endophytes and pathogens. Nigrospora has also been reported in marine environments such as mangroves, sea fans, and macroalgae. However, limited research has been conducted on Nigrospora associated with macroalgae. Here, we isolated Nigrospora species from three types of algae (brown, green, and red algae) from Korean islands (Chuja, Jeju, and Ulleung) based on phylogenetic analyses of multigenetic markers: the internal transcribed spacers (ITS), beta-tubulin (BenA), and translation elongation factor 1 (TEF1-α). A total of 17 Nigrospora strains were isolated from macroalgae and identified as nine distinct species. The majority of Nigrospora species (seven) were found on brown algae, followed by red algae (three), and then green algae (two). To our understanding, this study represents the first account of N. cooperae, N. covidalis, N. guilinensis, N. lacticolonia, N. osmanthi, N. pyriformis, and N. rubi occurring in marine environments. Additionally, this study provides the first report of the occurrence of N. cooperae, N. covidalis, N. guilinensis, N. lacticolonia, and N. osmanthi in South Korea. This study will provide valuable insights for future research exploring the functions of fungi in macroalgal communities. [ABSTRACT FROM AUTHOR]

This study explores the role of a biostimulant derived from the seaweed Ascophyllum nodosum (AN) in mitigating salt stress in rice plants. The weekly (S+W) and biweekly (S+B) biostimulant treatments exhibited enhanced shoot and root biomass, maintained ionic balance, and increased pigment content (total chlorophyll increased by 26.35% and 31%, carotenoids by 11.90% and 16.67% in S+W and S+B treatments, respectively) compared to untreated salt-stressed plants (CS). Improved gas exchange parameters and PSII efficiency were observed in S+W and S+B treatments. AN-biostimulant treatments mitigated salt-induced oxidative stress by positively regulating the antioxidant defense system. Notably, a strong negative correlation was observed between antioxidants and oxidative markers. Furthermore, AN-biostimulant treatments induced key metabolites (organic acids, sugars, amino acids, flavonoids), emphasizing the integrated role of multiple pathways in enhancing salt tolerance in rice. These findings highlight the potential of AN biostimulants as eco-friendly tools for crop enhancement in challenging environments. [ABSTRACT FROM AUTHOR]

As fossil fuel is depleted day by day, there is a vast gap in the market and supply of fuel to the different industries that consume oil. In order to improve fuel properties, performance, combustion, and emissions from diesel engines, microalgae oil biodiesels are used as fuel with 20% of diesel on a mass basis by volume and 50 and 100 ppm of CeO2 nanoparticles as additives in combinations of biodiesel/diesel blends. The engine configuration consists of a single-cylinder, four-stroke, 3.5 kW, 1500 rpm diesel engine. Experiments were performed at constant speed on experimental test fuels for various load conditions. The addition of cerium oxide (CeO2) in the added biodiesel diesel blends improved the brake thermal performance (45%) compared to engine output. With CeO2 in the B20 blends, better combustion properties were observed, such as increased length of combustion (36 CA°), ignition delay (16 CA°), and heat release rate (55 J/deg) in the cylinder. The enhanced and improved fuel characteristics and combustion characteristics of CeO2 in the added biodiesel diesel blends minimise HC (0.54 g/kWh) and CO (4.6 g/kWh) emissions and smoke (0.61%) while increasing NOx (10.2 g/kWh) emissions from the engine cylinder. [ABSTRACT FROM AUTHOR]

The Agulhas Marine Province (AMP) extends along most of the south coast of South Africa, from Cape Agulhas to the vicinity of the Mbashe River mouth in the Eastern Cape Province, and has its own distinctive warm-temperate seaweed flora, with high levels of diversity and endemism. Seaweed floras are excellent indicators of seawater temperature regimes and therefore very useful in studies of climate change. We provide new analyses of seawater temperatures for 50-km sections along this coast and discuss them in relation to upwelling mechanisms, with particular focus on Algoa Bay. The biogeography of the South African south coast/AMP seaweed flora is placed in a southern African context, and patterns of endemism are discussed. Commercial harvesting has involved only intertidal collection of Gelidium pristoides, but other species may have commercial potential. Seaweed aquaculture on this coast is currently limited to shore-based cultivation as abalone feed, but the potential for sea-based seaweed cultivation is discussed, with particular reference to Algoa Bay and the declared Algoa Bay Aquaculture Development Zone. [ABSTRACT FROM AUTHOR]

Seaweeds are macroscopic marine algae that are allocated into three categories based on the seaweed color (green, brown and red seaweeds). Seaweeds are known for its nutrition and beneficial non-nutritive compounds. Seaweeds have ample nutrition content including carbohydrates, minerals, proteins, and vitamins. Green seaweeds have a high concentration of carbohydrates and lipids whereas red seaweeds have abundant content of proteins. The mineral content ranges up to 36% of its dry weight. The beneficial non-nutritive compounds are phenolic compounds that are classified into phenolic acids, flavonoids, bromophenols and phlorotannins in seaweeds. The phlorotannin compounds are found mostly in brown seaweeds whereas the bromophenols are observed in red seaweeds. The phenolic compounds identified demonstrated bioactive properties which have been confirmed through in vivo cell culture studies. Due to seaweed's beneficial properties, the seaweed biomass have been consumed as a portion of convenience food in the Asian diet and has expanded to the Western diet. Over the last few decades, the extract or the biomass has been used in making fertilizers, animal feed, pharmaceuticals, and cosmeceuticals. This review helps to understand the nutrition content, especially phenolic compounds with their bioactive properties and recent development in applications. [ABSTRACT FROM AUTHOR]

Seaweeds are rich in phenolic compounds such as phlorotannins and have antioxidant, antibacterial, and anti-inflammatory activities. As exogenous bioactive compounds, seaweed polyphenols exist in the form of aglycone, esters, glycosides, and polymers. Most of them are not directly absorbed in the human digestive tract but undergo extensive modifications by digestive enzymes or bacteria before absorption or excretion. Up-to-date in vitro and in vivo seaweed polyphenol bioaccessibility studies have been reviewed, outlining seaweed polyphenols, especially phlorotannins, have low oral bioaccessibility, bioavailability, and high bioactivity paradox. Moreover, special attention is also given to other factors such as food matrix, food processing methods, and host factors on the absorption of seaweed polyphenols. In digestion tract, proteins can form both covalent and non-covalent bonds with polyphenols and thus hinder the absorption of polyphenols. However, lipids and polysaccharides in food can enhance the bioaccessibility of polyphenols to some extent. It is worth noticing that food processing technologies and host gut flora composition can also alter the absorption and bioactivity of specific seaweed phenolics. [ABSTRACT FROM AUTHOR]

Marine heatwaves (MHWs) are recognized as principal drivers of ocean change. However, interactions with other important local and global drivers such as ocean acidification, eutrophication and sedimentation, and the physiological mechanisms via which MHWs act on species are poorly understood. Additionally, past studies have often focused on ecologically dominant taxa such as kelps, fucoids and coral, potentially leading to a lack of understanding of direct impacts on associated species. To this end, we examined the individual and interactive impacts of MHW duration (14 and 28 days) and intensity (20.5°C and 23°C) as well as irradiance (2.3 and 4.4 mol m–2 d–1) on standardized growth of Caulerpa brownii, Corallina berteroi and Phymatolithopsis complex, three temperate macroalgal taxa that are important spaceholders in their native ecosystem in Te Whanganui a Tara Wellington, Aotearoa New Zealand. All three taxa exhibited no declines in growth in response to the exposure to longer and more intense MHWs. We posit that the simulated MHW scenarios were tolerated due to large thermal safety margins which can be expected from the range centre/leading edge position of the sampled populations, even though some of these scenarios far exceeded the intensities encountered in this region previously. Interactions between intensity, duration and irradiance were limited to an antagonistic irradiance-duration interaction in the non-calcareous green macroalga Ca. brownii only. Together, the displayed tolerance of the study species to the simulated scenarios implies limited impacts of strong MHWs four weeks or shorter in duration on ecosystem functioning in New Zealand kelp forest systems if brown algal canopies remain intact. [ABSTRACT FROM AUTHOR]

Calcified macroalgae are essential components of marine ecosystem, yet much of their physiology remains to be understood. Here, the nutrient (NO3– and PO4–3) uptake physiologies of two branched macroalgae, Actinotrichia fragilis (Nemaliophycidae) and Amphiroa fragilissima (Corallinophycidae), and the non-geniculate rhodolith Sporolithon sp. (Corallinophycidae) were examined. Sporolithon sp. had the lowest uptake rate through time and the three calcified macroalgae had a surge in NO3– and PO4–3 uptake that occurred between 3 and 20 min, with a maximum uptake at 3 min, after which the nutrient uptake rates declined. The NO3– uptake of the three calcified macroalgae followed Michaelis-Menten kinetics. For NO3– uptake, Sporolithon sp. had the lowest Km (2.72 ± 0.97 µM), Vmax (0.08 ± 0.01 µmol gDW–1 h–1), Vmax/Km (0.05 ± 0.03 µmol gDW–1 h–1 µM−1) and α (0.01 ± 0.00 µmol gDW–1 h–1 µM−1), while A. fragilis had the highest Km (12.35 ± 0.71 µM) and Vmax (6.41 ± 0.23 µmol gDW–1 h–1), and A. fragilissima had the highest Vmax/Km (1.52 ± 0.26 µmol gDW–1 h–1 µM−1) and α (0.37 ± 0.01 µmol gDW–1 h–1 µM−1). Moreover, the PO4–3 uptake rate of the three species was faster at higher PO4–3 levels. These differences in species-specific nutrient uptake traits are likely caused by differences in morphology. These traits are important for survival and proliferation of this group of marine organisms, particularly in a nutrient-variable environment. [ABSTRACT FROM AUTHOR]

The aim of the current study was to determine whether daily fucoidan supplementation (Undaria pinnatifida extract containing >85% fucoidan, 1 g/day) for three-weeks in a double blind-placebo controlled cross-over trial (ACTRN12621000872831) could modulate alterations in faecal (calprotectin, lysozyme and IgA) and salivary (lactoferrin, lysozyme and IgA) markers of mucosal immune competence typically observed in response to both acute physical activity, and a period of intensified exercise training, in healthy recreationally active men (n = 12). Participants responded positively to the intensified training with 16–19% improvement in mean power that was not different between supplement groups. Faecal biomarkers and concentrations of lactoferrin, lysozyme and IgA from resting saliva samples were largely stable over the supplementation period. Concentrations of salivary biomarkers varied significantly over time in response to acute exercise, however differences between supplementation groups were modest. For salivary lysozyme, there was a trend for a lower magnitude of increase post-exercise (p = 0.08) and limited return towards pre-exercise in response to fucoidan. For salivary IgA, a greater acute exercise response was noted for IgA in response to fucoidan (~2.7-fold higher; p = 0.02). Different dosage and supplementation protocols and inclusion of additional immune markers should be considered in subsequent assessments of any potential benefits of fucoidan supplementation in healthy active adults. [ABSTRACT FROM AUTHOR]

Global climate change has increased atmospheric transpiration and evaporation and decreased rainfall, and these changes have exacerbated water deficit-induced restrictions on agricultural production in arid and semi-arid areas. To test the influence of seaweed fertilization, a product of Qingdao Bright Moon Seaweed Group Co., Ltd®., on tomato drought response in sandy soils, on tomato drought response in sandy soils, a pot experiment was conducted in a greenhouse to measure biomass and leaf parameters, including chlorophyll concentration, relative water content, and carbohydrate and nitrogen content, under two water-availability scenarios including 85 ± 5% field water content and without irrigating treatment (chemical fertilization under well-watered conditions (WW), chemical fertilization under drought-stressed conditions (WD), seaweed fertilization under well-watered conditions (WW + SF), and seaweed fertilization under drought-stressed conditions (WD + SF)). The results showed that under water deficit stress, seaweed fertilization increased soil urease activity (429%) and soil ammonium nitrogen content, thereby increasing the nitrogen content available to the plants. Seaweed fertilization also enhanced the leaf proline content and water content of the plants, and decreased oxidative damage (low malondialdehyde content, which is lower 43.8% compared with WD). In addition, seaweed fertilization increased the leaf nitrogen content and reduced the nonstructural carbohydrate contentto maintain a relatively low total nonstructural carbohydrate/nitrogen (C/N) ratio. Taken together, seaweed fertilization-induced changes improved drought resistance in tomato seedlings and these results suggested that seaweed fertilization has the potential to improve crop drought resistance in sandy areas. [ABSTRACT FROM AUTHOR]

Marine algae are becoming an important source of valuable candidates of functional food that remain unexplored. Compositional analysis showed that marine algae contain essential nutrients, such as carbohydrates, proteins, fats, and minerals, of which polysaccharides are the main bioactive component. Depending on the source, marine algae polysaccharides are sulfated, which have diverse structures and compositions that influence their biological activities. A growing body of evidence has demonstrated that sulfated polysaccharides derived from marine algae (SPs) exhibit various bioactivities, especially immunomodulation. This review aims at summarizing the structural characteristics of SPs, their immunomodulatory effects, and the structural-immunomodulatory activity relationships between them from articles in recent decade, in order to provide a theoretical basis for the further applications of SPs as promising food or feed additives and possible health products to modulate the immune response. [ABSTRACT FROM AUTHOR]