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Eucheuma denticulatum and Kappaphycus alvarezii are two of the most commercially important, cultivated carrageenophytes in Southeast Asia. Their large-scale farming through repeated vegetative propagation and virtual monocropping has resulted in a variety of phyconomic issues. The efficacy of two European, commercial liquid extracts from the brown seaweeds, i.e., Ascophyllum nodosum (ANE), a fucoid, and Laminaria digitata (LDE), a kelp, on the direct formation of axes and survival of these two eucheumatoids was examined using tissue culture techniques. Seaweed apical sections (2–3 mm long) were cultured for 45 days, with different concentrations of ANE and LDE (i.e., 0.005, 0.05, 0.5, 1.5, and 2.5 mL L−1) and compared with a control (UV-filtered seawater). Lower concentrations (< 1.5 mL L−1) of both liquid extracts promoted morphogenesis and growth of E. denticulatum and K. alvarezii in tissue culture, with the dilution rate of 0.05 mL LDE L−1 resulting in a high percentage survival (i.e., 95.3 ± 0.9%), formation of direct axes (i.e., 95.3 ± 0.9%), and the longest length (i.e., 10.0 ± 0.3 mm) for E. denticulatum after a typical 45-day culture period. A 0.5 mL ANE L−1 concentration was found to be beneficial for the tissue culture of K. alvarezii, given the relatively high final survival and direct axes formation (i.e., 96.2 ± 2.2%) and axes length (i.e., 8.2 ± 0.1 mm). This study supports the application of these temperate, brown seaweed-derived extracts as a phycobiostimulant enrichment in eucheumatoid micropropagation for mass production of plantlets for out-planting purposes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Laminaria japonica polysaccharide, which is an important bioactive substance of Laminaria japonica with anti‐inflammatory and antioxidant effects. In this study, the molecular weight, functional groups and surface morphology were investigated to evaluate the digestive properties of Laminaria japonica polysaccharide before and after steam explosion. RESULTS: The results indicated that the Laminaria japonica polysaccharide entered the large intestine to be utilized by the gut microbiota after passing through the oral, gastric and small intestinal. Meanwhile, Laminaria japonica polysaccharide of steam explosion promoted the growth of beneficial bacteria Phascolarctobacterium and Intestinimonas, and increased the content of acetic, propionic and butyric acids, which was 2.29‐folds, 2.60‐folds and 1.63‐folds higher than the control group after 48 h of fermentation. CONCLUSION: This study reveals that the effect of steam explosion pretreatment on the digestion in vitro and gut microbiota of Laminaria japonica polysaccharide will provide a basic theoretical basis for the potential application of Laminaria japonica polysaccharide as a prebiotic in the food industry. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

TEPCO planned the release of Advanced Liquid Processing System (ALPS)-treated water, which is decontaminated stagnated water by ALPS, to the Pacific Ocean in 2023 after diluting it more than a hundred times in accordance with the policy of the Japan government. Since the low level of I-129 can remain in ALPS-treated water, the background I-129 concentration in seaweed samples around 1F NPS before the release of ALPS-treated water was recorded in this study. The iodine in seaweed samples was extracted via TMAH alkali-dissolution, and the I-129 concentration was measured by 8900 Triple Quadrupole ICP-MS. The resulting I-129 concentration was <5.4 × 10−2 Bq/kg-wet (sargassum) and <2.7 × 10−2 Bq/kg-wet (laminaria), respectively. [ABSTRACT FROM AUTHOR]

The Arctic is projected to warm by 2 to 5 °C by the end of the century. Warming causes melting of glaciers, shrinking of the areas covered by sea ice, and increased terrestrial runoff from snowfields and permafrost thawing. Warming, decreasing coastal underwater irradiance, and lower salinity are potentially threatening polar marine organisms, including kelps, that are key species of hard-bottom shallow communities. The present study investigates the physiological responses of four kelp species (Alaria esculenta, Laminaria digitata, Saccharina latissima, and Hedophyllum nigripes) to these environmental changes through a perturbation experiment in ex situ mesocosms. Kelps were exposed for 6 weeks to four experimental treatments: an unmanipulated control; a warming condition under the CO2 emission scenario SSP5-8.5; and two multifactorial conditions combining warming, low salinity, and low irradiance reproducing the future coastal Arctic exposed to terrestrial runoff under two CO2 emission scenarios (SSP2-4.5 and SSP5-8.5). The physiological effects on A. esculenta, L. digitata, and S. latissima were investigated, and gene expression patterns of S. latissima and H. nigripes were analyzed. Across all species and experimental treatments, growth rates were similar, underlying the acclimation potential of these species to future Arctic conditions. Specimens of A. esculenta increased their chlorophyll a content when exposed to low irradiance conditions, suggesting that they may be resilient to an increase in glacier and river runoff with the potential to become more dominant at greater depths. S. latissima showed a lower carbon : nitrogen (C : N) ratio under the SSP5-8.5 multifactorial conditions' treatment, suggesting tolerance to coastal erosion and permafrost thawing. In contrast, L. digitata showed no response to the conditions tested on any of the investigated physiological parameters. The down-regulation of genes coding for heat-shock proteins in H. nigripes and S. latissima underscores their ability to acclimate to heat stress, which portrays temperature as a key influencing factor. Based on these results, it is expected that kelp communities will undergo changes in species composition that will vary at local scale as a function of the changes in environmental drivers. [ABSTRACT FROM AUTHOR]

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Due to global rises in temperature, recent studies predict marine species shifting toward higher latitudes. We investigated the impact of interacting abiotic drivers on the distribution potential of the temperate kelp Laminaria hyperborea. The ecosystem engineering species is widespread along European coasts but has not yet been observed in the High Arctic, although it can survive several months of low temperatures and darkness. To investigate its ability to extend northward in future, we conducted a long‐term multifactorial experiment with sporophytes from Porsangerfjorden, Norway—close to the species' documented northernmost distribution margin. The samples were exposed to three different photoperiods (PolarDay, LongDay, and PolarNight) at 0°C, 5°C, and 10°C for 3 months. Optimum quantum yield of photosynthesis (Fv/Fm), dry weight, pigments, phlorotannins, and storage carbohydrates were monitored. Both physiological and biochemical parameters revealed that L. hyperborea was strongly influenced by the different photoperiods and their interaction with temperature, while temperature alone exerted only minor effects. The Fv/Fm data were integrated into a species distribution model to project a possible northward expansion of L. hyperborea. The combination of extended day lengths and low temperatures appeared to be the limiting reason for northward spread of L. hyperborea until recently. However, with water temperatures reaching 10°C in summer, this kelp will be able to thrive also in the High Arctic. Moreover, no evidence of stress to Arctic winter warming was observed. Consequently, L. hyperborea has a high potential for spreading northward with further warming which may significantly affect the structure and function of Arctic ecosystems. [ABSTRACT FROM AUTHOR]

The commercial use of kelp continues to gain interest worldwide. While in some East Asian countries kelp farming has a long history, the kelp industry in South Africa is based on harvesting of kelp from natural kelp forests or by beach-cast collection. This study examined the potential for kelp aquaculture on South Africa's west coast, focusing on the three indigenous species of kelp, Ecklonia maxima, Laminaria pallida and Macrocystis pyrifera. Geospatial analysis was used to identify and assess nine potentially suitable areas for kelp farming, based on natural habitat conditions, and examination of potential conflicts with other users and enabling land-use factors. An assessment of the market, technical and financial aspects of a kelp farming opportunity indicated that a 4 ha kelp farm, with longlines producing 750 to 1,000 t of fresh kelp per annum, could be viable as an integrated aquaculture activity adjacent to an existing mussel or oyster farm. We recommend a detailed feasibility study for kelp aquaculture in South Africa, with market and technical research, and financial modelling. Current seaweed industry legislation is mostly concerned with the wild resource, and there is a need for specific policies relating to seaweed aquaculture to facilitate growth of the industry. [ABSTRACT FROM AUTHOR]

The Benguela upwelling region on the west coast of South Africa/Namibia has the only major kelp forests on the African continent. South Africa has four species of laminarian kelps; Ecklonia maxima, Laminaria pallida dominate kelp forests in the west coast Benguela upwelling system, with Macrocystis pyrifera occurring rarely in this region and Ecklonia radiata largely confined to the more nutrient-poor south and east coasts. Growth studies on these species have been limited to laboratory experiments and very few initial, small-scale coastal studies. As in other Atlantic regions, there is growing interest in the potential for kelp aquaculture in Southern Africa, and recent pilot initiatives. A comprehensive summary of available literature on South African kelps, their biology and ecology, distribution and growth parameters, is presented, and the potential for kelp aquaculture discussed in relation to recent developments elsewhere on Atlantic and Eastern Pacific coastlines. Recommendations are made with respect to the choice of potential species and sites. [ABSTRACT FROM AUTHOR]

Kelp forests are facing a global decline due to climate change and human-induced stressors, underlining the urgency for proactive interventions. Among the most used restoration methods, "green gravel" has emerged as a promising solution for the recovery of degraded kelp forests. While initial findings suggest its potential effectiveness, green gravel remains a novel approach that requires fine-tuned protocols and optimisation across all stages of the process. In this study, we assessed the performance of two different seeding densities for kelp growth on green gravel to optimise the use of seeding material. Our results show that, while the juveniles in the high-density treatment grew faster, they also had a higher mortality rate during green gravel production. This was a hypothesised outcome, as growing sporophytes reared under laboratory conditions allows for faster production of a large number of individuals, increasing competition for space, which may drive higher mortality rates. Comprehensive experimentation is essential to unlock the full potential of green gravel and ensure its efficiency in all process steps, to achieve successful kelp forest restoration. Well-defined and optimised protocols are indispensable for minimising production costs, simplifying logistics, and allowing future efforts to scale up. [ABSTRACT FROM AUTHOR]

BACKGROUND: Including seaweed in cattle feed has gained increased interest, but it is important to take into account that the concentration of toxic metals, especially arsenic, is high in seaweed. This study investigated the arsenic species in milk from seaweed‐fed cows. RESULTS: Total arsenic in milk of control diets (9.3 ± 1.0 μg As kg−1, n = 4, dry mass) was significantly higher than seaweed‐based diet (high‐seaweed diet: 7.8 ± 0.4 μg As kg−1, P < 0.05, n = 4, dry mass; low‐seaweed diet: 6.2 ± 1.0 μg As kg−1, P < 0.01, n = 4, dry mass). Arsenic speciation showed that the main species present were arsenobetaine (AB) and arsenate (As(V)) (37% and 24% of the total arsenic, respectively). Trace amounts of dimethylarsinic acid (DMA) and arsenocholine (AC) have also been detected in milk. Apart from arsenate being significantly lower (P < 0.001) in milk from seaweed‐fed cows than in milk from the control group, other arsenic species showed no significant differences between groups. CONCLUSION: The lower total arsenic and arsenate in seaweed diet groups indicates a possible competition of uptake between arsenate and phosphate, and the presence of AC indicates that a reduction of AB occurred in the digestive tract. Feeding a seaweed blend (91% Ascophyllum nodosum and 9% Laminaria digitata) does not raise As‐related safety concerns for milk. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Marine foundation species underpin some of the world's most diverse ecosystems but they are increasingly threatened by intensification of marine heatwaves (MHWs). Where MHWs exceed critical thermal maxima (CTmax), increased mortality and population declines can occur. CTmax is increasingly used to assess MHW population vulnerability but studies estimating CTmax across species, range edges and thermal histories in a comparable manner remain lacking. We determined the impact of MHWs on subsequent CTmax estimates of matched cool/warm affinity pairs of marine foundation species (kelp, seagrass and bivalves) in the Western English Channel. Following a 4‐week MHW simulation, individuals were subjected to a CTmax trial, where temperatures were raised by 2°C day−1 until physiological end points were reached. We found no positive effect of MHWs on CTmax but clear negative impacts were observed for some groups of foundation species. Increased MHW intensity had a stepwise negative impact on the physiology of both warm (Laminaria ochroleuca) and cool water (L. digitata) kelp species that manifested in significant reductions in CTmax. Surprisingly, this was most marked in the warm water species, which runs opposite to the assumed safety of leading‐edge populations. The physiology of warm (Zostera noltii) and cool (Z. marina) seagrasses was negatively impacted by increasing MHW intensity but no significant decrease in CTmax was observed. Both bivalve species (Mytilus edulis and Magallana gigas) showed marked resistance to exposure to MHWs, which was unexpected given the observed vulnerability of these species to stressful summertime conditions. Our results show pre‐exposure to realistic MHWs can influence CTmax values but generalities are difficult to make across groups or based on assumed thermal safety margins. We show CTmax is a labile trait and exposure to MHWs, can erode the resilience of an individual or population to subsequent thermal challenges. This leaves uncertainty within frameworks built to understand where and when MHWs will be most impactful. Further experimentation across a wider range of species and thermal challenges is needed to better understand the dynamic nature of CTmax and field validation is needed to determine the responses of individuals and populations within complex natural systems. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The use of macroalgae for food has been extensive in Asia historically. However, there has been a renewed interest at present in macroalgae due to its recognition as a potential carbon capture agent and a blue carbon donor besides their utility in biofuel production. Bioplastics is an umbrella term for a wide variety of polymers that can be either biobased or biodegradable, or both. Macroalgal polysaccharides and their inherent film‐forming capacity are exploited in the bioplastics industry and macroalgal polysaccharide‐based biofilms are extensively used in food packaging due to their compatibility and ease of production. Commercial macroalgae‐based bioplastics production is ongoing, with research dedicated to the development of biodegradable/compostable biofilms suitable for the food packing and biomedicine sector. This review aims to provide an overview of the polysaccharides of macroalgae that can be used to form biofilms and bioplastics. Different methods for biofilm formation are discussed along with summarizing the effect of plasticizers, the method of film formation, and biodegradability. The major source of marine macroalgal polysaccharaides are agar, alginate, carrageenan, laminarin, fucoidan, and ulvan. Different groups of macroalgae are utilized for the production of polysaccharide derived bioplatics, namely, brown algae (Padina pavonica, Ascophyllum nodosum, Laminaria japonica, Rugulopteryx okamurae, Sargassum natans, Sargassum siliquosum, Jolyna laminarioides, Gracilaria salicornia), green algae (Ulva fasciata, Halimeda opuntia, Codium fragile, Ulva intestinalis, Ulva lactuca, Ulva rigida), and red algae (Eucheuma cottonii, Porphyra sp., Kappaphycus alvarezii, Gracilaria corticata). The outcome of the review reveals that there is a vast scope for macroalgal polysaccharide‐derived bioplastics for a sustainable environment. [ABSTRACT FROM AUTHOR]

Mycosporine-like amino acids (MAAs) are the natural UV-absorbing compounds with antioxidant activity found in microalgae and macroalgae. We collected red algae Asparagopsis taxiformis, Meristotheca japonica , and Polysiphonia senticulosa from Nagasaki, where UV radiation is more intense than in Hokkaido, and investigated the effect of UV radiation on MAA content. It was suggested that A. taxiformis and M. japonica contained shinorine and palythine, while UV-absorbing compound in P. senticulosa could not be identified. The amounts of these MAAs were lower compared to those from Hokkaido. Despite an increase in UV radiation in both regions from February to April, MAA contents of red algae from Nagasaki slightly decreased while those from Hokkaido significantly decreased. This difference was suggested the amount of inorganic nitrogen in the ocean. Antioxidant activity of MAAs increased under alkaline conditions. The extract containing MAAs from P. senticulosa showed the highest antioxidant activity among 4 red algae. [ABSTRACT FROM AUTHOR]

DNA cytosine methylation is an important epigenetic mechanism in genomic DNA. In most land plants, it is absent in the chloroplast DNA. We detected methylation in the chloroplast DNA of the kelp Saccharina latissima, a non‐model macroalgal species of high ecological and economic importance. Since the functional role of the chloroplast methylome is yet largely unknown, this fundamental research assessed the chloroplast DNA cytosine methylation in wild and laboratory raised kelp from different climatic origins (High‐Arctic at 79° N, and temperate at 54° N), and in laboratory samples from these origins raised at different temperatures (5, 10 and 15°C). Results suggest genome‐wide differences in methylated sites and methylation level between the origins, while rearing temperature had only weak effects on the chloroplast methylome. Our findings point at the importance of matching conditions to origin in restoration and cultivation processes to be valid even on plastid level. [ABSTRACT FROM AUTHOR]

Ecological theory predicts that kelp forests structured by trophic cascades should experience recovery and persistence of their foundation species when herbivores become rare. Yet, climate change may be altering the outcomes of top‐down forcing in kelp forests, especially those located in regions that have rapidly warmed in recent decades, such as the Gulf of Maine. Here, using data collected annually from 30+ sites spanning >350 km of coastline, we explored the dynamics of Maine's kelp forests in the ~20 years after a fishery‐induced elimination of sea urchin herbivores. Although forests (Saccharina latissima and Laminaria digitata) had broadly returned to Maine in the late 20th century, we found that forests in northeast Maine have since experienced slow but significant declines in kelp, and forest persistence in the northeast was juxtaposed by a rapid, widespread collapse in the southwest. Forests collapsed in the southwest apparently because ocean warming has—directly and indirectly—made this area inhospitable to kelp. Indeed, when modeling drivers of change using causal techniques from econometrics, we discovered that unusually high summer seawater temperatures the year prior, unusually high spring seawater temperatures, and high sea urchin densities each negatively impacted kelp abundance. Furthermore, the relative power and absolute impact of these drivers varied geographically. Our findings reveal that ocean warming is redefining the outcomes of top‐down forcing in this system, whereby herbivore removal no longer predictably leads to a sustained dominance of foundational kelps but instead has led to a waning dominance (northeast) or the rise of a novel phase state defined by "turf" algae (southwest). Such findings indicate that limiting climate change and managing for low herbivore abundances will be essential for preventing further loss of the vast forests that still exist in northeast Maine. They also more broadly highlight that climate change is "rewriting the rules" of nature, and thus that ecological theory and practice must be revised to account for shifting species and processes. [ABSTRACT FROM AUTHOR]

In this study, we evaluated Electrical Impedance Spectroscopy (EIS) as a monitoring tool of the physiological state of Bryopsis, Cystoseira, Stypopodium, Cladophora, Taonia, Padina, Ulva and Sargassum tissues. We analyzed the electrical response differences in the EIS between species and in the same seaweed tissue before and after electroporation. Electroporation using high voltage pulsed electric field (PEF) treatment was used as a model for cell disruption affecting the tissue physiology without being noticeable to the naked-eye. Significant differences in all the seaweeds were observed before and after electroporation. We found that seaweed species with smaller and rounder cells have a clearer dispersion profile (around a frequency of 10–100 kHz) compared to the dispersion profile of seaweed with larger cells with unround form. Those results suggest that EIS could be used as a fast non-invasive monitoring technique of the changes in the physiology of seaweeds. [ABSTRACT FROM AUTHOR]

Sargassum fusiforme and Sargassum fulvellum are types of brown algae used for their nutritional value and medicinal properties, including anti-inflammatory, antioxidant, and anticancer effects. Despite their importance in various industries, many seaweed byproducts containing dietary fiber and polysaccharides are discarded in landfills. These byproducts can be recycled and repurposed for different applications. In this study, we investigated the impact of S. fusiforme food processing byproducts (MbP-SFF) and S. fulvellum food processing byproducts (MbP-SFV) on improving intestinal motility and reducing inflammation in mice with constipation induced by loperamide. To evaluate this, mice were orally administered 500 mg/kg/day of the byproducts once daily for 8 days. Constipation was induced by 5 mg/kg/day of loperamide for two days after oral administration for 6 days. Each sample contained approximately 70% carbohydrates. MbP-SFF had 52.0% mannuronic acid and 18.8% guluronic acid, while MbP-SFV had 36.9% mannuronic acid and 32.9% guluronic acid. These byproducts enhanced fecal excretion and intestinal motility by modulating inflammatory responses. Furthermore, they restored the balance of the gut microbiota disrupted by loperamide, increasing beneficial Bifidobacterium and reducing harmful Staphylococcus aureus. Overall, MbP-SFF and MbP-SFV improved intestinal motility and inflammation by influencing the gut microbiota and inflammatory responses in a loperamide-induced mouse model. These byproducts show potential as ingredients in functional foods aimed at enhancing gut health, potentially reducing waste disposal costs and addressing environmental concerns associated with their utilization. [ABSTRACT FROM AUTHOR]

It is important to eliminate the fishy odor and improve the aroma quality of seafood. In this study, the Saccharina japonica (S. japonica) seedling, which is a new food material, was investigated for the effects of fermentation with Saccharomyces cerevisiae (S. cerevisiae) through sensory evaluation, GC–MS, and odor activity value (OAV) analysis. GC–MS analysis revealed the presence of 43 volatile compounds in the unfermented S. japonica seedling, with 1-octen-3-ol, hexanal, and trans-2,4-decadienal identified as the main contributors to its fishy odor. After fermentation with S. cerevisiae, 26 volatile compounds were identified in the S. japonica seedling. Notably, the major malodorous fish compounds, including 1-octen-3-ol, hexanal and trans-2,4-decadienal, were no longer present. The results indicate that fermentation with S. cerevisiae is an effective method for removing fishy malodor compounds and enhancing the volatile components with fruity, sweet, green, and floral notes in the Saccharina japonica seedling. This process facilitates the elimination of fishy malodor and enhance the fruity, sweet, green, and floral notes of S. japonica seeding and other seaweeds. [ABSTRACT FROM AUTHOR]

The Arctic archipelago of Svalbard is a hotspot of global warming and many fjords experience a continuous increase in seawater temperature and glacial melt while sea‐ice cover declines. In 1996/1998, 2012–2014, and 2021 macroalgal biomass and species diversity were quantified at the study site Hansneset, Kongsfjorden (W‐Spitsbergen) in order to identify potential changes over time. In 2021, we repeated the earlier studies by stratified random sampling (1 × 1 m2, n = 3) along a sublittoral depth transect (0, 2.5, 5, 10, and 15 m) and investigated the lower depth limits of dominant brown algae between 3 and 19 m. The maximum fresh weight (FW) of all seaweeds was 11.5 kg m−2 at 2.5 m and to 99.9% constituted of kelp. Although biomass distribution along the depth transect in 2021 was not significantly different compared to 2012/2013, the digitate kelp community (Laminaria digitata/Hedophyllum nigripes) had transformed into an Alaria esculenta‐dominated kelp forest. Consequently, a pronounced shift in kelp forest structure occurred over time as we demonstrate that biomass allocation to thallus parts is kelp species‐specific. Over the past decade, kelp demography changed and in 2021 a balanced age structure of kelps (juveniles plus many older kelp individuals) was only apparent at 2.5 m. In addition, the abundances and lower depth limits of all dominant brown algae declined noticeably over the last 25 years while the red algal flora abundance remained unchanged at depth. We propose that the major factor driving the observed changes in the macroalgal community are alterations in underwater light climate, as in situ data showed increasing turbidity and decreasing irradiance since 2012 and 2017, respectively. As a consequence, the interplay between kelp forest retreat to lower depth levels caused by coastal darkening and potential macroalgal biomass gain with increasing temperatures will possibly intensify in the future with unforeseen consequences for melting Arctic coasts and fjord ecosystem services. [ABSTRACT FROM AUTHOR]

Environmental changes associated with rapid climate change in the Arctic, such as the increased rates of sedimentation from climatic or anthropogenic sources, can enhance the impact of abiotic stressors on coastal ecosystems. High sedimentation rates can be detrimental to nearshore kelp abundance and distribution, possibly due to increased mortality at the spore settlement stage. Spore settlement and viability of the Arctic kelp Laminaria solidungula were examined through a series of lab‐based sedimentation experiments. Spores were exposed to increasing sediment loads in three experimental designs simulating different sedimentation scenarios: sediment deposition above settled spores, settlement of spores on sediment‐covered substrate, and simultaneous suspension of spores and sediments during settlement. Spore settlement was recorded upon completion of each experiment, and gametophyte abundance was assessed following a growth period with sediments removed to examine short‐term spore viability via a gametophyte‐to‐settled‐spore ratio. In all three types of sediment exposure, the addition of sediments caused a 30%–40% reduction in spore settlement relative to a no‐sediment control. Spore settlement decreased significantly between the low and high sediment treatments when spores were settled onto sediment‐covered substrates. In all experiments, increasing amounts of sediment had no significant effect on spore viability, indicating that spores that had settled under different short‐term sediment conditions were viable. Our results indicate that depending on spore‐sediment interaction type, higher rates of sedimentation resulting from increased sediment loading could affect L. solidungula spore settlement success with potential impacts on the long‐term persistence of a diverse and productive benthic habitat. [ABSTRACT FROM AUTHOR]

Pyropia nereocystis is an annual northeastern Pacific‐bladed bangialean species whose macroscopic stage epiphytized the annual canopy forming bull kelp Nereocystis luetkeana. I examined three in situ facets of these epiphyte‐host dynamics in the central California region: (1) spatial and temporal variation in the presence of P. nereocystis epiphytes as a function of host density, (2) the relationship between individual host morphology and epiphytic P. nereocystis biomass, and (3) the ecophysiological growth ramifications for subtidal transplants of both life stages of P. nereocystis. Swath canopy surveys and whole host collections were conducted at five sites between November 2017 and February 2019. Additionally, transplants of P. nereocystis gametophytes and sporophytes were conducted across multiple subtidal depths. I observed temporal changes in the proportions of hosts epiphytized by P. nereocystis, with differences in seasonal persistence of P. nereocystis among sites and between years. Biomass of P. nereocystis was positively correlated with individual host stipe length, stipe surface area, and the primary principal component (PC) of stipe morphometrics denoted by principal component analysis (PCA). Gametogenesis in P. nereocystis epiphytes was spatially heterogeneous and limited for the 2018–2019 cohort due to comprehensive removal of hosts by the February 2019 sampling period. Transplants of P. nereocystis gametophytes yielded similar growth responses among depths, and sporophyte (conchocelis) transplant areal growth was positively correlated with transplant depth. These findings detail spatiotemporal complexity and multi‐scale (individual, site, and whole region) phenological nuances for central Californian P. nereocystis epiphytes. [ABSTRACT FROM AUTHOR]

This text provides a summary of the life and work of Klaus Lüning, a prominent researcher in the field of seaweed biology. Lüning's career spanned several decades, during which he made significant contributions to the study of seaweed communities and their environmental requirements. He conducted research on the thermal requirements of seaweeds and investigated the circadian rhythms of growth in kelp species. Lüning also explored the presence of the hormone melatonin in seaweeds. Throughout his career, he supervised numerous students and collaborated with researchers from around the world. After retiring, Lüning established an algal farm and continued his research on Ulva. Unfortunately, he passed away in 2023 after battling cancer. Lüning's pioneering work and dedication to science left a lasting impact on the field of macroalgal research. [Extracted from the article]

Simple Summary: Humanity faced the hottest year in observational history in 2023. If the trend of rising temperatures on Earth continues, irreversible changes in the environment will occur with negative consequences for the lives of us all. In order to limit the further increase in temperatures on Earth, it is necessary to reduce the emissions of greenhouse gases (GHGs) in various sectors. Since ruminant farming is a significant contributor to anthropogenic GHG emissions due to methane emissions, we attempted to reduce methane emissions in dairy cows by using brown seaweed (Ascophyllum nodosum) in cow rations. Indeed, we achieved a reduction in methane emissions, without disturbing the productivity of cows. We also found a more favorable metabolic status and milk composition in supplemented cows. Additional studies are needed to define precisely how brown seaweeds can be included into strategies to reduce methane emissions from the dairy industry. The dairy industry contributes significantly to anthropogenic methane emissions, which have an impact on global warming. This study aimed to investigate the effects of a dietary inclusion of brown seaweed Ascophyllum nodosum on enteric methane emissions (EMEs), hematological and blood biochemical profiles, and milk composition in dairy cows. Eighteen Holstein cows were divided into three groups: CON (non-supplemented cows), BS50 (50 mL of 10% A. nodosum), and BS100 (100 mL of 10% A. nodosum). In each cow, measurements of EME, dry matter intake (DMI), and milk yield (MY), as well as blood and milk sampling with respective analyzes, were performed before supplementation (P1), after 15 (P2) days, and after 30 (P3) days of supplementation. A. nodosum reduced (p < 0.05) methane production, methane yield, and methane intensity in both BS50 and BS100, and raised DMI (p < 0.05) only in BS50. Total bilirubin (p < 0.05) was higher in BS50 compared to CON cows in P2, and triacylglycerols were lower (p < 0.05) in BS50 than in CON cows in P3. Higher milk fat content was found in BS50 than in CON cows in P3. C16:0 proportions were higher (p < 0.05) in BS50 and BS100 than in CON cows, while C18:3n-3 was higher (p < 0.05) in BS100 than in BS50 and CON cows in P3. Dietary treatment with A. nodosum reduced EMEs and showed the potential to increase DMI and to improve energy status as well as milk composition in peak-lactating dairy cows. [ABSTRACT FROM AUTHOR]

Crithidia mellificae and Lotmaria passim are trypanosomatids that infect honeybees, and many studies suggest that both parasites contribute to the decline in the honeybee population. The Japanese honeybee (Apis cerana japonica) is a native honeybee that inhabits various areas of Japan and is one of the most important pollinators. Both parasites have been well studied in the western honeybee (Apis mellifera) but have been poorly investigated in A. c. japonica. The present study investigated the presence of C. mellificae and L. passim in one feral and six managed A. c. japonica colonies at three different institutes. Five out of seven colonies were polymerase chain reaction‐positive for L. passim (71.4%); however, C. mellificae was not detected. Four of the five colonies were positive in both the midgut and hindgut, but one was positive only in the hindgut. A homology search and phylogenetic tree of the glycosomal glyceraldehyde‐3‐phosphate dehydrogenase (gGAPDH) and cytochrome b (Cytb) genes obtained in this study indicated that the sequences belonged to L. passim. The results of this study emphasize concerns regarding the health of this ecologically important pollinator and the importance of further investigation of the prevalence of L. passim in A. c. japonica in a wider area of Japan. [ABSTRACT FROM AUTHOR]

Bread can be a major contributor to sodium intake, but sodium chloride reduction poses difficulties since it influences the functional properties of dough and flavor of bread. This study evaluated dough and bread properties in reduced-sodium systems containing fermented or unfermented macroalgae Saccharina latissima or Alaria esculenta. Recipes contained equal amounts of sodium (4 mg Na+/g flour), where sodium chloride contributed 3 or 3.5 mg Na+/g flour and 8.9–33.3 mg macroalgae/g flour contributed the remaining 0.5 or 1 mg Na+/g flour. A full-salt and three salt-reduced controls (6, 4, 3.5, and 3 mg Na+/g flour) were used for comparison. Empirical dough rheology, stickiness, ratios of polymeric to monomeric proteins, and bread characteristics (specific volume, crumb structure, and firmness) were measured. A trained sensory panel conducted a descriptive sensory analysis. Macroalgae addition increased water absorption and decreased dough development time, dough stability, the polymeric to monomeric protein ratio, and specific volume in a dose-dependent manner. Macroalgae addition increased the perception of saltiness, but also algae flavor and odor. Bread with fermented S. latissima received lower scores for certain undesirable sensory attributes than other bread with algae. [ABSTRACT FROM AUTHOR]

Polyphenols (PP) found in brown algae are known for their wide range of biological activities including noteworthy antitumor properties. This article presents a method for obtaining an active polyphenolic extract from the Arctic alga Fucus vesiculosus with 98% purity and radical scavenging activity equivalent to 862 mg of ascorbic acid per gram of extract. Immunostimulant effects of polyphenols were assessed in vitro using venous blood from two groups of people: healthy people (HP) and people with chronic undifferentiated lymphocytic leukemia (LP). Polyphenols activated the surface properties of immunocompetent cells. Specifically, polyphenols dose-dependently increased the percentage of cells' spreading and adhesion by 2–3 times. Additionally, polyphenols increased the number of activated lymphocytes in the LP blood to levels characteristic of HP. Given their natural origin, high activity, non-toxicity, and straightforward production process, these studied polyphenols exhibit immense potential for use as new pharmaceuticals or as active components with immunostimulatory effects. [ABSTRACT FROM AUTHOR]

Brown algae are multicellular organisms that have evolved independently from plants and animals. Knowledge of the mechanisms involved in their embryogenesis is available only for the Fucus, Dictyota, and Ectocarpus, which are brown algae belonging to three different orders. Here, we address the control of cell growth and cell division orientation in the embryo of Saccharina latissima, a brown alga belonging to the order Laminariales, which grows as a stack of cells through transverse cell divisions until growth is initiated along the perpendicular axis. Using laser ablation, we show that apical and basal cells have different functions in the embryogenesis of this alga, with the apical cell being involved mainly in growth and basal cells controlling the orientation of cell division by inhibiting longitudinal cell division and thereby the widening of the embryo. These functions were observed in the very early development before the embryo reached the 8-cell stage. In addition, the growth of the apical and basal regions appears to be cell-autonomous, because there was no compensation for the loss of a significant part of the embryo upon laser ablation, resulting in smaller and less elongated embryos compared with intact embryos. In contrast, the orientation of cell division in the apical region of the embryo appears to be controlled by the basal cell only, which suggests a polarised, non-cell-autonomous mechanism. Altogether, our results shed light on the early mechanisms of growth rate and growth orientation at the onset of the embryogenesis of Saccharina, in which non-cell-specific cell-autonomous and cell-specific non-cell-autonomous processes are involved. This complex control differs from the mechanisms described in the other brown algal embryos, in which the establishment of embryo polarity depends on environmental cues. [ABSTRACT FROM AUTHOR]

A growing interest in more sustainable and alternative food sources has brought seaweed and macroalgae to the spotlight for the general worldwide cuisine. Algae are often praised for their high nutritional value and are rich in potassium, calcium, and magnesium. Abundant in base precursors, algae are particularly interesting from an acid-base perspective. Their unique biochemical composition suggests a low potential renal acid load (PRAL), which is a commonly used estimate for the amount of acid or base a certain food produces in humans. Here, we analyzed the PRAL value of n = 106 macroalgae. Results suggested a strong alkalizing potential, with a mean PRAL value of −86.76 mEq/100 g. The lowest PRAL values were found for Laminaria ochroleuca (−286.78 mEq/100 g), Gelidium micropterum (−268.46 mEq/100 g), and Palmaria palmata (−259.16 mEq/100 g). We observed a strong inverse relationship of PRAL with algae's potassium content (Spearman's rho = −0.79, p < 0.001) and a moderate relationship with algae's calcium content (Spearmen's rho: −0.34, p < 0.001). Our data point at a potential role for several macroalgae as potent alkalizing marine drugs and suggest that a 10 g edible portion of some algae alone could contribute to a substantial PRAL reduction of up to −28.68 mEq. This might be of particular importance for individuals who benefit from a more alkaline diet and warrants further investigation in future studies. [ABSTRACT FROM AUTHOR]

The drug target protein β-secretase 1 (BACE1) is one of the promising targets in the design of the drugs to control Alzheimer's disease (AD). Patients with neurodegenerative diseases are increasing in number globally due to the increase in the average lifetime. Neuro modulation is the only remedy for overcoming these age related diseases. In recent times, marine bioactive compounds are reported from Phaeophyceae (Brown Algae), Rhodophyta (Red Algae) and Chlorophyta (Green Algae) for neuro-modulation. Hence, an important attempt is made to understand the binding and stability of the identified bioactive compounds from the above marine algae using BACE1 as the molecular target. The docking study shows that the bioactive compound Fucotriphlorethol A (– 17.27 kcal/mol) has good binding affinity and energy compared to other compounds such as Dieckol (– 16.77 kcal/mol), Tetraphlorethol C (– 15.12 kcal/mol), 2-phloroeckol (– 14.98 kcal/mol), Phlorofucofuroeckol (– 13.46 kcal/mol) and the co-crystal (– 8.59 kcal/mol). Further, molecular dynamics simulations studies had been carried out for β-secretase 1 complex with Fucotriphlorethol A and Phlorofucofuroeckol for 100 ns each. Results are compared with that of the co-crystal inhibitor. Molecular dynamics simulations studies also support the stability and flexibility of the two bioactive compounds Fucotriphlorethol A and Phlorofucofuroeckol with BACE1. [ABSTRACT FROM AUTHOR]

Harvested Laminaria hyperborea contributes to approximately 3.3 million tonnes of epiphytes discarded as waste despite containing organisms such as red algae and bryozoa, known to produce a range of high-value and bioactive compounds. Our research aim is to valorize epiphyte biomass by exploring the cytotoxic and antimicrobial potential in various extracts and optimized fractionation by flash chromatography. All extracts and fractions were tested for cytotoxicity towards cell lines derived from Acute Myeloid Leukemia (AML), prostate cancer (PC-3), and breast cancer (MCF-7), as well as non-tumorigenic cell lines from the kidney and heart using metabolic activity as a read-out. Antimicrobial activitywas assessed using microplate based Alamar Blue assay and minimum inhibitory concentration (MIC) to determine the MIC against various human pathogens. Six extracts demonstrated significant cytotoxicity across all five cell lines (EC50 values below 46 μg/mL), while hexane extract selectively targeted AML cells with EC50 of 1.1 μg/mL. The hexane and ethyl acetate extracts displayed antimycobacterial and antifungal activity (MIC 100 μg/mL). Amultistep flash fractionation of themethanolic extract revealed several cytotoxic and antimicrobial activities. The flash fractions displayed a selective activity pattern depending on the elution solvent. Nine fractions were cytotoxic towards all cell lines (EC50 below 72 μg/mL), and four were highly cytotoxic (EC50 below 5.4 μg/mL). Two non-polar fractions were selective for the AML cell line. These results highlight the potential for discovering anticancer and antimicrobial compounds in epiphytes from Laminaria, necessitating further research on their active compounds. Overall, this work underscores the environmental and scientific value of converting marine by-products into a valuable resource, aligning with sustainability and ethical goals. [ABSTRACT FROM AUTHOR]

Brown algae (Phaeophyceae) exhibit a wide diversity of sexual systems, reproductive modes and life histories. The evolution of this diversity has often involved transitions between sexual systems, which may influence genetic diversity and diversification, and phenotypic evolution. This study reports a novel sexual system in kelp. We identified male gametophyte strains of Laminaria pallida that, despite presenting morphological features typical of a male, developed both antheridia and egg-like structures, which suggest an incomplete suppression of femaleness during sexual determination of gametophytes. The sperm released by these variant male gametophytes successfully fertilize eggs produced by female gametophytes, developing into sporophytes with normal morphologies. However, morphologically abnormal sporophytic offspring were formed in isolated variant male gametophytes, indicating that the egg-like structures were not successfully self-fertilized by sperm. The causes of the unsuccessful intragametophytic selfing are unknown, but absence of pheromone production by the egg-like structures is a hypothesis suggested by available evidence. Partial co-sexuality is clearly inherited, as all male gametophyte strains descended from the same sporophyte developed egg-like structures. Further investigation into the genetics and maturation of male partheno-sporophytes will help to estimate the potential effects of this mechanism on natural populations. Morphologically typical male gametophytes in Laminaria pallida developed both antheridia and egg-like structures. Male sexual reproductive ability was retained by partially co-sexual L. pallida gametophytes. Partial co-sexuality appears to be heritable but varies between L. pallida individuals. [ABSTRACT FROM AUTHOR]

Amphiboreal taxa are often composed of vicariant phylogroups and species complexes whose divergence and phylogeographic affinities reflect a shared history of chronic isolation and episodic trans-Arctic dispersal. Ecological filters and shifting selective pressures may also promote selective sweeps, niche shifts and ecological speciation during colonization, but these are seldom considered at biogeographical scales. Here we integrate genetic data and Ecologic Niche Models (ENMs) to investigate the historical biogeography and cohesion of the polymorphic rockweed Fucus distichus throughout its immense amphiboreal range, focusing on trans-Arctic asymmetries, glacial/interglacial dynamics, and integrity of sympatric eco-morphotypes. Populations were sampled throughout the Pacific and the Atlantic, from southern rear-edges to the high-Arctic. They were genotyped for seven microsatellites and an mtDNA spacer, and genetic diversity and structure were assessed from global to local scales. ENMs were used to compare niche divergence and magnitude of post-glacial range shifts in Pacific versus Atlantic sub-ranges. Haplotypic and genotypic data revealed distinct and seemingly isolated Pacific vs Arctic/Atlantic gene-pools, with finer-scale regional sub-structuring pervasive in the Pacific. MtDNA diversity was highly structured and overwhelmingly concentrated in the Pacific. Regionally, Alaska showed the highest intra-population diversity but the lowest levels of endemism. Some sympatric/parapatric ecotypes exhibited distinct genotypic/ haplotypic compositions. Strikingly, niche models revealed higher Pacific tolerance to maximum temperatures and predicted a much more consolidated presence in the N E Atlantic. Glacial and modern ranges overlapped extensively in the Pacific, whereas the modern Atlantic range was largely glaciated or emerged during the Last Glacial Maximum. Higher genetic and ecogeographic diversity supports a primary Pacific diversification and secondary Atlantic colonization, also likely reflecting the much larger and more stable climatic refugia in the Pacific. The relic distribution and reduced ecological/morphological plasticity in the NE Atlantic are hypothesized to reflect functional trans-Arctic bottlenecks, recent colonization or competition with congeners. Within the Pacific, Alaska showed signatures of a post-glacial melting pot of eastern and southern populations. Genetic/ecotypic variation was generally not sufficiently discontinuous or consistent to justify recognizing multiple taxonomic entities, but support a separate species in the eastern Pacific, at the southern rear-edge. We predict that layered patterns of phylogeographic structure, incipient speciation and niche differences might be common among widespread low-dispersal amphiboreal taxa. [ABSTRACT FROM AUTHOR]

Cyclotides are a type of defense peptide most commonly found in the Violaceae family of plants, exhibiting various biological activities. In this study, we focused on the Viola japonica as our research subject and conducted transcriptome sequencing and analysis using high-throughput transcriptomics techniques. During this process, we identified 61 cyclotides, among which 25 were previously documented, while the remaining 36 were designated as vija 1 to vija 36. Mass spectrometry detection showed that 21 putative cyclotides were found in the extract of V. japonica. Through isolation, purification and tandem mass spectrometry, we characterized and investigated the activities of five cyclotides. Our results demonstrated inhibitory effects of these cyclotides on the growth of Acinetobacter baumannii and Bacillus subtilis, with minimum inhibitory concentrations (MICs) of 4.2 μM and 2.1 μM, respectively. Furthermore, time killing kinetic assays revealed that cyclotides at concentration of 4 MICs achieved completely bactericidal effects within 2 h. Additionally, fluorescence staining experiments confirmed that cyclotides disrupt microbial membranes. Moreover, cytotoxicity studies showed that cyclotides possess cytotoxic effects, with IC50 values ranging from 0.1 to 3.5 μM. In summary, the discovery of new cyclotide sequences enhances our understanding of peptide diversity and the exploration of their activity lays the foundation for a deeper investigation into the mechanisms of action of cyclotides. [ABSTRACT FROM AUTHOR]

Background: In addition to the other uses for macroalgae, since the 1970s, there has been interest in using macroalgae as a source of biofuels, due to the high rates of productivity and intrinsic advantages over other biofuel crops such as not requiring land use or significant freshwater input. A wide range of conversion processes exist but anaerobic digestion was one of the first demonstrated and is still a widely proposed conversion pathway. To be economically viable and scalable within Europe, the industry will need to be based on a small number of fast growing, high-yielding European macroalgae species. There is a wide body of scientific work on the conversion of seaweeds to biofuel via anaerobic digestion. Main text: These studies demonstrate that the efficiency of this conversion pathway is highly variable between species, processing techniques, composition and digestor conditions. In this paper, we review this body of work specifically linking it to candidate species for European macroalgae bio-energy cultivation with the aim to promote the future development of the European macroalgal cultivation sector and allow for a better alignment with the requirements for biofuel production from macroalgae. Conclusions: Overall, anaerobic digestion of seaweed offers opportunities for large-scale energy production which avoids some of the issues that have faced previous generations of biofuels, but there are a number of key challenges to overcome to ensure wider adoption and economic viability. (1) Optimising the biomass production to ensure an economic and uniform feedstock with the composition optimised to increase desirable characteristics such as sugar content and the carbon and nitrogen ratio and to reduce inhibitory factors such as halogenated secondary metabolites, sulphur and heavy metals. (2) Improving conversion rates through co-digestion, pre-treatments and tailored microbial communities, using scalable and economically feasible technology. (3) Developing tailored microbial communities capable of utilising the diverse polysaccharides in seaweed feedstock and being tolerant of the saline conditions associated with them. Addressing these issues will deliver significant benefits towards the development of a bio-energy industry based on the anaerobic digestion of cultured seaweeds. [ABSTRACT FROM AUTHOR]

The edible brown seaweed, Ecklonia cava, is highly valued for its bioactive compounds, and is widely used in food supplements and functional foods. The increasing demand for this seaweed in the food industry emphasizes the necessity for sustainable cultivation practices. This study focused on inducing callus in the meristem and stipe of E. cava using different culture media: Provasoli's enriched seawater medium (PESI), enriched artificial seawater medium (ESAW), artificial enriched seawater medium (ASP2), or Von Stosch's enriched seawater medium (VS). Various abiotic stress factors (photoperiod, agar concentration, and temperature), growth regulators, carbon sources, polyamines, and plasma treatments were explored for their impact on callus induction. Both stipe and meristem explants developed callus within three to six weeks across all media except ASP2. Callus development was favored at temperatures between 8 to 13 °C and in the absence of light. Stipe explants showed a higher callus induction rate (up to 65.59 ± 6.24%) compared to meristem (up to 57.53 ± 8.32%). Meristem explants showed optimal callus induction in PESI medium with a low concentration of indole-3-acetic acid (IAA; 40.93 ± 8.65%). However, higher concentrations of IAA and 1-naphthaleneacetic acid (NAA) reduced meristem callus induction. Stipe showed high induced-callus (up to 50.37 ± 5.17%) in PESI medium with low concentrations of IAA, NAA, and 6-benzylaminopurine (BAP). Both stipe and meristem explants induced largest callus at 2% sucrose, but higher carbon source concentrations reduced callus induction. Spermine (Spm) at 1 µM resulted in high induced calluses; however, increasing Spm concentrations decreased callus induction. This tissue culture technique not only supports mass cultivation of E. cava, but also holds potential for extending to other seaweed species, contributing to the sustainability of seaweed stocks for the food industry. [ABSTRACT FROM AUTHOR]

Background: Baobab fruit is valued for its nutritional and medicinal benefits. Although it is acknowledged that baobab pulp is beneficial for health, studies that link its nutraceutical properties to the ability to eliminate reactive species (ROS and RNS) are scarce. Methods: The nutritional profile and the antioxidant properties of baobab pulp extracts from Angola were evaluated. Thus, for the first time, the evaluation of in vitro scavenging capacity against the most physiologically relevant reactive oxygen species (ROS) and reactive nitrogen species (RNS) were the focus of investigation. Results: Angolan fruit pulp presented high contents of ash (8.0%) and total dietary fiber (52%). Vitamin E content was reported for the first time in fruit pulp. Green solvents were used to quantify bioactive compounds and antioxidant activity. Hydroalcoholic extracts exhibited the highest contents of phenolics (1573.0 mg/100 g) and flavonoids (768.7 mg/100 g). Thus, hydroalcoholic extracts showed higher antioxidant activity, and higher scavenging capacity for ROS (O2•−, H2O2, HOCl, ROO•) and RNS (•NO, ONOO−), being most active for •NO and ONOO−. Conclusion: For the first time, Angolan baobab fruit was described in respect to its nutritional contribution as well as its positive antioxidant effects, both as a functional food and as a nutraceutical ingredient. [ABSTRACT FROM AUTHOR]

Species interactions can influence key ecological processes that support community assembly and composition. For example, coralline algae encompass extensive diversity and may play a major role in regime shifts from kelp forests to urchin‐dominated barrens through their role in inducing invertebrate larval metamorphosis and influencing kelp spore settlement. In a series of laboratory experiments, we tested the hypothesis that different coralline communities facilitate the maintenance of either ecosystem state by either promoting or inhibiting early recruitment of kelps or urchins. Coralline algae significantly increased red urchin metamorphosis compared with a control, while they had varying effects on kelp settlement. Urchin metamorphosis and density of juvenile canopy kelps did not differ significantly across coralline species abundant in both kelp forests and urchin barrens, suggesting that recruitment of urchin and canopy kelps does not depend on specific corallines. Non‐calcified fleshy red algal crusts promoted the highest mean urchin metamorphosis percentage and showed some of the lowest canopy kelp settlement. In contrast, settlement of one subcanopy kelp species was reduced on crustose corallines, but elevated on articulated corallines, suggesting that articulated corallines, typically absent in urchin barrens, may need to recover before this subcanopy kelp could return. Coralline species differed in surface bacterial microbiome composition; however, urchin metamorphosis was not significantly different when microbiomes were removed with antibiotics. Our results clarify the role played by coralline algal species in kelp forest community assembly and could have important implications for kelp forest recovery. [ABSTRACT FROM AUTHOR]

In the Azores Archipelago, Cryptomeria japonica is, currently, the most cultivated forestry tree for timber production, landscaping, and gardening, generating large amounts of foliage waste that is used for local essential oils (EOs) production. However, the existing literature on the biological potential of EOs from different C. japonica foliage parts, such as female cones (FC), remains limited. Thus, in the present study, EOs extracted by hydrodistillation from Azorean C. japonica immature and mature FC (IFC and MFC), as well as some major EO components, were screened for their: (i) antioxidant capacity, evaluated by DPPH free-radical-scavenging activity (FRSA) and β-carotene-linoleic acid bleaching activity (BCBA), (ii) antimicrobial activities, assessed by the disc diffusion method against eight bacteria and one fungus, and (iii) toxicity against Artemia salina. Among both FC EO samples, the IFC EO exhibited the best DPPH–FRSA, BCBA, and growth inhibitory activity against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, and Penicillium italicum, as well as a slightly increased toxic potential, due to their differential compositions, as assessed by GC–MS analysis. Thus, the FC's maturation process decreased their EOs' bioactivities. In conclusion, this finding could help in determining the optimal developmental stage for enhancing the antioxidant and antimicrobial compounds content in FC EOs. In turn, this contributes to increasing the commercial potential of C. japonica's EO industry. [ABSTRACT FROM AUTHOR]

Background: Snakebite envenomation (SBE) causes diverse toxic effects in humans, including disability and death. Current antivenom therapies effectively prevent death but fail to block local tissue damage, leading to an increase in the severity of envenomation; thus, seeking alternative treatments is crucial. Methods: This study analyzed the potential of two fucoidan sulfated polysaccharides extracted from brown seaweeds Fucus vesiculosus (FVF) and Undaria pinnatifida (UPF) against the fibrinogen or plasma coagulation, proteolytic, and phospholipase A2 (PLA2) activities of Bothrops jararaca, B. jararacussu, and B. neuwiedi venom. The toxicity of FVF and UPF was assessed by the hemocompatibility test. Results: FVF and UPF did not lyse human red blood cells. FVF and UPF inhibited the proteolytic activity of Bothrops jararaca, B. jararacussu, and B. neuwiedi venom by approximately 25%, 50%, and 75%, respectively, while all venoms led to a 20% inhibition of PLA2 activity. UPF and FVF delayed plasma coagulation caused by the venoms of B. jararaca and B. neuwiedi but did not affect the activity of B. jararacussu venom. FVF and UPF blocked the coagulation of fibrinogen induced by all these Bothropic venoms. Conclusion: FVF and UPF may be of importance as adjuvants for SBE caused by species of Bothrops, which are the most medically relevant snakebite incidents in South America, especially Brazil. [ABSTRACT FROM AUTHOR]

Salinity is an environmental stress that severely impacts rice grain yield and quality. However, limited information is available on the molecular mechanism by which salinity reduces grain quality. In this study, we investigated the milling, appearance, eating and cooking, and nutritional quality among three japonica rice cultivars grown either under moderate salinity with an electrical conductivity of 4 dS/m or under non-saline conditions in a paddy field in Dongying, Shandong, China. Moderate salinity affected rice appearance quality predominantly by increasing chalkiness rate and chalkiness degree and affected rice eating and cooking and nutritional quality predominantly by decreasing amylose content and increasing protein content. We compared the expression levels of genes determining grain chalkiness, amylose content, and protein content in developing seeds (0, 5, 10, 15, and 20 days after flowering) of plants grown under saline or non-saline conditions. The chalkiness-related gene Chalk5 was up-regulated and WHITE-CORE RATE 1 was repressed. The genes Nuclear factor Y and Wx, which determine amylose content, were downregulated, while protein-content-associated genes OsAAP6 and OsGluA2 were upregulated by salinity in the developing seeds. These findings suggest some target genes that may be utilized to improve the grain quality under salinity stress conditions via gene-pyramiding breeding approaches. [ABSTRACT FROM AUTHOR]

Foundation species are spatially dominant species that increase habitat complexity and provide substrate and shelter for many smaller species. Through a mensurative field experiment, we tested the hypothesis that functional aspects of the associated communities are related to structural and functional properties of the foundation species. Specifically, we contrasted invertebrate communities living in mussel (Mytilus) and seaweed (Chondrus) stands from the same rocky intertidal environments in Atlantic Canada. Both stands reach similar heights above the substrate, but they differ structurally (rigid mussel shells vs. flexible seaweed fronds) and functionally (mussels generate biowaste while seaweeds offer food for herbivores). Our data supported the hypothesis in various ways. Detritivory (mostly by oligochaetes) was more prevalent in mussel stands, while herbivory was more prevalent in seaweed stands. Predators were mostly mites and, consequently, they were more prevalent in mussel stands, as mites eat oligochaetes. Functional traits related to body and mobility types were also related to properties of the foundation species. Overall, we conclude that structural and functional properties of foundation species can predict functional aspects of the associated communities. This concept may help to develop effective restoration strategies after the loss of foundation species due to anthropogenic factors. [ABSTRACT FROM AUTHOR]

The range‐expansion of tropical herbivores due to ocean warming can profoundly alter temperate reef communities by overgrazing the seaweed forests that underpin them. Such ecological interactions may be mediated by changes to seaweed‐associated microbiota in response to warming, but empirical evidence demonstrating this is rare. We experimentally simulated ocean warming and marine heatwaves (MHWs) to quantify effects on two dominant temperate seaweed species and their microbiota, as well as grazing by a tropical herbivore. The kelp Ecklonia radiata's microbiota in sustained warming and MHW treatments was enriched with microorganisms associated with seaweed disease and tissue degradation. In contrast, the fucoid Sargassum linearifolium's microbiota was unaffected by temperature. Consumption by the tropical sea‐urchin Tripneustes gratilla was greater on Ecklonia where the microbiota had been altered by higher temperatures, while Sargassum's consumption was unaffected. Elemental traits (carbon, nitrogen), chemical defences (phenolics) and tissue bleaching of both seaweeds were generally unaffected by temperature. Effects of warming and MHWs on seaweed holobionts (host plus its microbiota) are likely species‐specific. The effect of increased temperature on Ecklonia's microbiota and subsequent increased consumption suggest that changes to kelp microbiota may underpin kelp‐herbivore interactions, providing novel insights into potential mechanisms driving change in species' interactions in warming oceans. [ABSTRACT FROM AUTHOR]

Simple Summary: The intestinal epithelium is the layer of cells that line the digestive tract, and it acts both as a selective filter to facilitate the absorption of nutrients and a protective barrier to toxins and infection. The functional integrity of this constantly renewing cell layer depends on so-called tight junction proteins, a class that includes two regulatory proteins called occludin and zonula occludens-1 (ZO-1). We studied the effect of two different prebiotic seaweed supplements for 41 weeks on occludin and ZO-1 expression in two genetic lines of laying hen. Differences between genetic lines in the level of occludin in a highly absorptive section of the small intestine called the jejunum were found. There also were differences due to seaweed supplementation in the ZO-1 protein, and red seaweed supplementation appeared to have more impact in the brown laying hen strain than in the white strain. Overall, our results are consistent with previous studies showing genetic differences in diet response. It is proposed that prebiotic diet supplements improve intestinal function, in part by improving the barrier function of the intestinal epithelium with an associated increase in the expression of tight junction proteins, including occludin and zonula occludens-1 (ZO-1). We examined the expression of these proteins in two strains of laying hens (Lohman LSL-lite (White) and Lohman Brown-lite (Brown)) who were supplemented or not with 3% Chondrus crispus or 0.5% Ascophyllum nodosum seaweeds from 31 to 72 weeks of age. Occludin was localized to the lateral surfaces and across the intestinal epithelium in all animals. Reactivity for ZO-1 was concentrated at the apicolateral epithelial cell membrane border. Mood's median test indicated that White hens may express more occludin in villus epithelium (median intensity 3.5 vs. 2.5 in Brown hens, p = 0.06) but less ZO-1 in the deep cryptal epithelium (median intensity 1.5 vs. 2.5 in Brown hens, p = 0.06). Western blotting also showed higher levels of occludin in White than Brown hens (p < 0.05). A decrease in ZO-1 Western blot expression was associated with Chondrus crispus supplementation in comparison to controls (p < 0.05), but not with Ascophyllum nodosum supplementation (p > 0.05). In conclusion, genetic strain and dietary seaweed supplements affect tight junction regulatory protein expression levels but do not impact the anatomical distribution, as seen in cryosections. [ABSTRACT FROM AUTHOR]

Rugulopteryx okamurae (RO) is an invasive brown seaweed that causes severe environmental problems in the Mediterranean Sea. This work proposed an extraction method that enables their use as a raw material for producing sodium alginate. Alginate was successfully extracted from this invasive seaweed, with its gelling performance in the presence of Ca2+ ions comparable to existing commercial alginates. The mannuronic acid (M)-to-guluronic (G) acid ratio in the 1H-NMR profile indicated a higher percentage of G in the RO-extracted alginate, which implies a greater formation of so-called egg box structures. These differences resulted in their different rheological behaviour, as sodium alginate aqueous solutions exhibited a greater viscosity ( η at 1 s−1 = 3.8 ± 0.052 Pa·s) than commercial alginate (2.8 ± 0.024 Pa·s), which is related to the egg box structure developed. When gelled in the presence of calcium, an increase in the value of the elastic modulus was observed. However, the value of the tan δ for the extracted alginate was lower than that of commercial alginate gels, confirming a structure more densely packed, which implies a different restructuring of the alginate chain when gelling. These results confirm the suitability of using invasive Rugulopteryx okamurae as a source of calcium alginate gels. In this way, sustainable bio-based materials may be produced from undesired biomass that currently poses a threat to the ecosystem. [ABSTRACT FROM AUTHOR]

Adansonia digitata L. is a royal tree that is highly valued in Africa for its medicinal and nutritional properties. The objective of this study was to use its fruit shell extract to develop new, powerful mono and bimetallic nanoparticles (NPs) and biochar (BC) using an eco-friendly approach. Silver (Ag), iron oxide (FeO), the bimetallic Ag-FeO NPs, as well as (BC) were fabricated by A. digitata fruit shell extract through a reduction process and biomass pyrolysis, respectively, and their activity against tomato pathogenic fungi Alternaria sp., Sclerotinia sclerotiorum, Fusarium equiseti, and Fusarium venenatum were detected by agar dilution method. The Ag, FeO, Ag-FeONPs, and BC were characterized using a range of powerful analytical techniques such as ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier Transform-Infra Red (FT-IR), dynamic light scatter (DLS), and zeta potential analysis. The fabricated Ag, FeO and Ag-FeO NPs have demonstrated a remarkable level of effectiveness in combating fungal strains. UV-Vis spectra of Ag, FeO, Ag-FeONPs, and BC show broad exhibits peaks at 338, 352, 418, and 480 nm, respectively. The monometallic, bimetallic NPs, and biochar have indicated the presence in various forms mostly in Spherical-shaped. Their size varied from 102.3 to 183.5 nm and the corresponding FTIR spectra suggested that the specific organic functional groups from the plant extract played a significant role in the bio-reduction process. Ag and Ag-FeO NPs exhibited excellent antifungal activity against pathogenic fungi Alternaria sp., S. sclerotiorum, F. equiseti, and F. venenatum. The current study could be a significant achievement in the field of antifungal agents since has the potential to develop new approaches for treating fungal infections. [ABSTRACT FROM AUTHOR]

This study focuses on optimizing the thermal pyrolysis process to maximize pyrolysis oil yield using marine biomass or seaweed. The process, conducted in a batch reactor, was optimized using response surface methodology and Box–Behnken design. Variables like temperature, residence time, and stirring speed were adjusted to maximize bio-oil yield. The optimal conditions yielded 42.94% bio-oil at 463.13 °C, with a residence time of 65.75 min and stirring speed of 9.74 rpm. The analysis showed that temperature is the most critical factor for maximizing yield. The bio-oil produced contains 11 functional groups, primarily phenol, aromatics, and alcohol. Its high viscosity and water content make it unsuitable for engines but suitable for other applications like boilers and chemical additives. It is recommended to explore the potential of refining the bio-oil to reduce its viscosity and water content, making it more suitable for broader applications, including in engine fuels. Further research could also investigate the environmental impact and economic feasibility of scaling up this process. [ABSTRACT FROM AUTHOR]

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide, and hyperlipidemia is one major inducing factor of CVD. It is worthy to note that fucoidans are reported to have hypolipidemic activity with species specificity; however, the underlying mechanisms of action are far from clarification. This study is aimed at investigating the plasma lipid-lowering mechanisms of the fucoidan from L. japonica Aresch by detecting the levels of hepatic genes that are involved in lipid metabolism. Our results demonstrated that the fucoidan F3 significantly lowered total cholesterol and triglyceride in C57BL/6J mice fed a high-fat diet. In the mouse liver, fucoidan F3 intervention significantly increased the gene expression of peroxisome proliferator-activated receptor (PPAR) α, liver X receptor (LXR) α and β, and ATP-binding cassette transporter (ABC) G1 and G8 and decreased the expression of proprotein convertase subtilisin/kexin type 9 (PCSK9), low-density lipoprotein receptor, cholesterol 7 alpha-hydroxylase A1, and sterol regulatory element-binding protein (SREBP) 1c and SREBP-2. These results demonstrated that the antihyperlipidemic effects of fucoidan F3 are related to its activation of PPARα and LXR/ABC signaling pathways and inactivation of SREBPs. In conclusion, fucoidan F3 may be explored as a potential compound for prevention or treatment of lipid disorders. [ABSTRACT FROM AUTHOR]

The increasing demand for healthy aquatic products has contributed to the rapid growth of aquaculture. Despite the many progresses, over the years, in aquaculture production, animal welfare and reduction of the stress induced by captivity remain a challenge in this sector, and overcoming it is fundamental to improve animal growth performance and resilience to environmental threats (e.g., disease outbreaks and/or climate change impacts). To address this challenge, aquafeeds biofortified with natural ingredients with functional properties, such as macroalgae, have emerged as a promising strategy to enhance fish immunity. The present study aimed at evaluating the potential of Laminaria digitata to improve juvenile gilthead seabream (Sparus aurata) physiological status and resilience, through the modulation of immunomodulatory and antioxidant responses. To explore this hypothesis, four independent treatments were carried out in which fish were fed with different experimental aquafeeds: control feed and biofortified feeds with 1.5%, 3% and 6% of whole L. digitata (incorporated as a dried and powdered ingredient). Fish (n=9) were collected from each treatment upon 30 and 60 days of biofortification in order to assess animal growth and condition indexes, haematological parameters, innate humoral parameters (antiprotease (AP) activity, peroxidase (POD) activity and immunoglobulin M (IgM)) and oxidative stress biomarkers (lipid peroxidation (LPO), catalase (CAT) activity, glutathione S-transferase (GST) activity, superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC)). Significant differences (α = 0.05) between treatments in biomarker responses were tested through a nested-design ANOVA, followed by Tukey HSD multiple comparisons. Pearson correlations between the different endpoints were also explored. Results indicate that a dietary inclusion of 1.5% L. digitata is the most effective biofortification dose, significantly improving antioxidant responses of S. aurata, by increasing levels of CAT, GST and T-AOC, along with the reduction in LPO levels. Additionally, the inclusion of 1.5% L. digitata enhances immunity by increasing the levels of IgM and POD, while maintaining the growth performance and condition indices of the fish. These findings underscore the potential utilization of L. digitata as a functional feed ingredient in aquaculture with relevant immune and antioxidant attributes. [ABSTRACT FROM AUTHOR]

Culturing kelps for commercial, conservation, and scientific purposes is becoming increasingly widespread. However, kelp aquaculture methods are typically designed for ocean‐based farms, and these methods may not be applicable for smaller scale cultivation efforts common in research and restoration. Growing kelps in closed, recirculating culture systems may address many of these constraints, yet closed system approaches have remained largely undescribed. Extensive declines of the bull kelp (Nereocystis luetkeana), an ecologically important canopy species in the Northeast Pacific, have received widespread attention and prompted numerous research and conservation initiatives. Here, we detail two approaches for cultivating N. luetkeana sporophytes in closed recirculating systems. Nereocystis luetkeana were reared as attached thalli in custom seaweed growth flumes and also free‐floating in tumble culture tanks. Careful control of stocking density, water motion, aeration, and nutrient levels allowed for rapid growth and normal morphogenesis of laboratory‐grown kelp. Culture systems reached up to 3 kg · m−3, and individual thalli attained lengths of up to 6 m before the trials were terminated. Our results demonstrate the potential of recirculating, closed culture systems to overcome limitations associated with traditional culture methods. Recirculating systems enable the precise control of culture conditions, improving biosecurity and facilitating cultivar development and other research. Kelps can be grown away from the ocean or outside their native ranges, and seasonal or annual species can be produced year‐round without seasonal constraints. [ABSTRACT FROM AUTHOR]