Search

Rapid ocean warming is affecting kelp forests globally. While the sporophyte life stage has been well studied for many species, the microscopic life stages of laminarian kelps have been understudied, particularly regarding spatial and temporal variations in thermal tolerance and their interaction. We investigated the thermal tolerance of growth, survival, development, and fertilization of Ecklonia radiata gametophytes, derived from zoospores sampled from two sites in Tasmania, Australia, throughout a year, over a temperature gradient (3–30°C). For growth we found a relatively stable thermal optimum at ~20.5°C and stable thermal maxima (25.3–27.7°C). The magnitude of growth was highly variable and depended on season and site, with no consistent spatial pattern for growth and gametophyte size. Survival also had a relatively stable thermal optimum of ~17°C, 3°C below the optimum for growth. Gametophytes grew to single cells between 5 and 25°C, but sporophytes were only observed between 10 and 20°C, indicating reproductive failure outside this range. The results reveal complex effects of source population and season of collection on gametophyte performance in E. radiata, with implications when comparing results from material collected at different localities and times. In Tasmania, gametophytes grow considerably below the estimated thermal maxima and thermal optima that are currently only reached during summer heatwaves, whereas optima for survival (~17°C) are frequently reached and surpassed during heatwaves, which may affect the persistence and recruitment of E. radiata in a warmer climate. [ABSTRACT FROM AUTHOR]

Since 2010, huge quantities of Sargassum spp. algae have been proliferating in the Atlantic Ocean and stranding on Caribbean beaches, causing major economic, environmental, and health problems. In this study, an innovative high-density binderless particleboard was developed using uniaxial thermo-compression coupled with a cooling system. The raw material consisted of ground Sargassum seaweeds pre-treated by twin-screw extrusion with water to remove sea salt. The raw material and the particleboards were produced by using various analytical techniques such as Dynamic Vapor Sorption (DVS), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), or Thermogravimetric Analysis (TGA). The experimental conditions for thermo-compression (temperature, pressure, time) were evaluated. The best thermo-compression conditions tested were 200 °C, 40 MPa pressure for 7.5 min. This resulted in a particleboard with high density (up to 1.63 ± 0.02 g/cm3) and high flexural strength/modulus (up to 32.3 ± 1.8 MPa/6.8 ± 0.2 GPa, respectively), but a low water contact angle of 38.9° ± 3.5°. Thermal analyses revealed the effect of alginates on the mechanical properties of particleboards. This work opens the door to a new way of adding value to Sargassum seaweed, using the whole algae with minimal pre-treatment. [ABSTRACT FROM AUTHOR]

Whether more species are required to maintain ecosystem functioning as spatial scale increases or across environmental gradients has frequently been studied by examining whether different species drive ecosystem functioning in different sites. However, this approach does rule out the counterfactual scenario where a few species could potentially maintain ecosystem functioning across sites as this requires examining which species can (or cannot) compensate for the loss of others.Here, I used an observational study and a field‐based transplant experiment to examine the effects of species loss on biomass productivity in an intertidal marine macroalgal system. I calculated the number of species required to maintain biomass productivity across four depth zones reflecting a water emersion gradient using two commonly used observational approaches. Then, I combined hypothetical simulated extinction scenarios with field‐based transplant data of relative growth rates of all species across the four depth zones to explore how the number of species required to maintain biomass productivity across depth zones changed under counterfactual scenarios where species compensated for species loss.The observational analyses suggested that between three and four species were required to maintain productivity across the depth zones. The simulated extinction scenarios did not. Rather, decreases in biomass productivity due to the loss of some species (e.g. Fucus spiralis, Ascophyllum nodosum) were easily compensated by other species (e.g. Fucus vesiculosus). However, for some species like F. vesiculosus, the extinction simulations suggested that compensation would be unlikely.Commonly used observational approaches may overestimate the number of species required to maintain ecosystem functioning across environmental gradients and spatial scales. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Marine bacteria play important roles in the degradation and cycling of algal polysaccharides. However, the dynamics of epiphytic bacterial communities and their roles in algal polysaccharide degradation during kelp decay are still unclear. Here, we performed metagenomic analyses to investigate the identities and predicted metabolic abilities of epiphytic bacterial communities during the early and late decay stages of the kelp Saccharina japonica. During kelp decay, the dominant epiphytic bacterial communities shifted from Gammaproteobacteria to Verrucomicrobia and Bacteroidetes. In the early decay stage of S. japonica, epiphytic bacteria primarily targeted kelp-derived labile alginate for degradation, among which the gammaproteobacterial Vibrionaceae (particularly Vibrio) and Psychromonadaceae (particularly Psychromonas), abundant in alginate lyases belonging to the polysaccharide lyase (PL) families PL6, PL7, and PL17, were key alginate degraders. More complex fucoidan was preferred to be degraded in the late decay stage of S. japonica by epiphytic bacteria, predominantly from Verrucomicrobia (particularly Lentimonas), Pirellulaceae of Planctomycetes (particularly Rhodopirellula), Pontiellaceae of Kiritimatiellota, and Flavobacteriaceae of Bacteroidetes, which depended on using glycoside hydrolases (GHs) from the GH29, GH95, and GH141 families and sulfatases from the S1_15, S1_16, S1_17, and S1_25 families to depolymerize fucoidan. The pathways for algal polysaccharide degradation in dominant epiphytic bacterial groups were reconstructed based on analyses of metagenome-assembled genomes. This study sheds light on the roles of different epiphytic bacteria in the degradation of brown algal polysaccharides. [ABSTRACT FROM AUTHOR]

Currently, new agri-tech has been developed and adapted for the cultivation of crops using smart farming technologies, e.g., plant factories and hydroponics. Kelp (Laminaria japonica), which has a high industrial value, was considered as an alternative to chemicals for its eco-friendly and sustainably wide use in crop cultivation. In this study, a fermented kelp (FK) was developed for use in hydroponics. The FK contained various free and protein-bound amino acid compositions produced by fermenting the kelp with Saccharomyces cerevisiae. Supplementing FK as an aeroponic medium when cultivating ginseng sprouts (GSs) elevated the total phenolic and flavonoid contents. Additionally, seven ginsenosides (Rg1, Re, Rb1, Rc, Rg2, Rb2, and Rd) in GSs cultivated with FK in a smart-farm system were identified and quantified by a high-performance liquid chromatography-evaporative light scattering detector/mass spectrometry analysis. Administering FK significantly increased the ginsenosides in the GSs compared to the control group, which was cultivated with tap water. These results indicate the FK administration contributed to the increased accumulation of ginsenosides in the GSs. Overall, this study suggests that FK, which contains abundant nutrients for plant growth, can be used as a novel nutrient solution to enhance the ginsenoside content in GSs during hydroponic cultivation. [ABSTRACT FROM AUTHOR]

Purpose. The crystal adhesion caused by the damage of renal tubular epithelial cells (HK-2) is the key to the formation of kidney stones. However, no effective preventive drug has been found. This study aims to explore the recovery effects of four Laminaria polysaccharides (SLPs) with different sulfate (–OSO3–) contents on damaged HK-2 cells and the difference in the adhesion of damaged cells to nanometer calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) before and after recovery. Methods. Sodium oxalate (2.6 mmol/L) was used to damage HK-2 cells to establish a damaged model. SLPs (LP0, SLP1, SLP2, and SLP3) with –OSO3– contents of 0.73%, 15.1%, 22.8%, and 31.3%, respectively, were used to restore the damaged cells, and the effects of SLPs on the adhesion of COM and COD, with a size of about 100 nm before and after recovery, were measured. Results. The following results were observed after SLPs recovered the damaged HK-2 cells: increased cell viability, restored cell morphology, decreased reactive oxygen levels, increased mitochondrial membrane potential, decreased phosphatidylserine eversion ratio, increased cell migration ability, reduced expression of annexin A1, transmembrane protein, and heat shock protein 90 on the cell surface, and reduced adhesion amount of cells to COM and COD. Under the same conditions, the adhesion ability of cells to COD crystals was weaker than that to COM crystals. Conclusions. As the sulfate content in SLPs increases, the ability of SLPs to recover damaged HK-2 cells and inhibit crystal adhesion increases. SLP3 with high –OSO3– content may be a potential drug to prevent kidney stones. [ABSTRACT FROM AUTHOR]

Post-weaning diarrhea is one of the most common diseases in piglets, which will seriously affect the growth performance of weaned piglets and may even cause their death. LJP has been proven to improve the growth performance of weaned piglets. Protein metabolism is very important for growth, but there is little research on protein metabolism in weaned piglets by LJP. The aim of this study was to evaluate the effect of supplementing different levels of LJP (0, 100, 200 and 400 mg/kg) in the diet on protein metabolism in weaned piglets. A total of 120 piglets with similar initial body wight (6.13±0.21 kg) and age (21±1 day) were randomly assigned into 4 groups, each group had 5 replicates of 6 piglets. Four different levels of LJP (0, 100, 200 and 400 mg/kg) were added to the feed of four groups of piglets and kept for 21 days. The results showed that the content of total serum proteins was significantly increased in piglets supplemented with 200 and 400 mg/kg LJP and the content of albumin was significantly increased in piglets supplemented with 400 mg/kg LJP (p<0.05), compared with the control group. In conclusion, the addition of 200 and 400 mg/kg of LJP to the ration increased protein content in the serum and contributed to the growth and health of weaned piglets. [ABSTRACT FROM AUTHOR]

Background and Aims Marine heatwaves (MHWs) are widely recognized as pervasive drivers of ecosystem change, yet our understanding of how different MHW properties mediate ecological responses remains largely unexplored. Understanding MHW impacts on foundation species is particularly important, given their structural role in communities and ecosystems. Methods We simulated a series of realistic MHWs with different levels of intensity (Control: 14 °C, Moderate: 18 °C, Extreme: 22 °C) and duration (14 or 28 d) and examined responses of two habitat-forming kelp species in the southwest UK. Here, Laminaria digitata reaches its trailing edge and is undergoing a range contraction, whereas Laminaria ochroleuca reaches its leading edge and is undergoing a range expansion. Key Results For both species, sub-lethal stress responses induced by moderate-intensity MHWs were exacerbated by longer duration. Extreme-intensity MHWs caused dramatic declines in growth and photosynthetic performance, and elevated bleaching, which were again exacerbated by longer MHW duration. Stress responses were most pronounced in L. ochroleuca , where almost complete tissue necrosis was observed by the end of the long-duration MHW. This was unexpected given the greater thermal safety margins assumed with leading edge populations. It is likely that prolonged exposure to sub-lethal thermal stress exceeded a physiological tipping point for L. ochroleuca , presumably due to depletion of internal reserves. Conclusions Overall, our study showed that exposure to MHW profiles projected to occur in the region in the coming decades can have significant deleterious effects on foundation kelp species, regardless of their thermal affinities and location within respective latitudinal ranges, which would probably have consequences for entire communities and ecosystems. [ABSTRACT FROM AUTHOR]

Background and Aims Changes in kelp abundances on regional scales have been highly variable over the past half-century owing to strong effects of local and regional drivers. Here, we assess patterns and dominant environmental variables causing spatial and interspecific variability in kelp persistence and resilience to change in Nova Scotia over the past 40 years. Methods We conducted a survey of macrophyte abundance at 251 sites spanning the Atlantic coast of Nova Scotia from 2019 to 2022. We use this dataset to describe spatial variability in kelp species abundances, compare species occurrences to surveys conducted in 1982 and assess changes in kelp abundance over the past 22 years. We then relate spatial and temporal patterns in abundance and resilience to environmental metrics. Key Results Our results show losses of sea urchins and the cold-tolerant kelp species Alaria esculenta , Saccorhiza dermatodea and Agarum clathratum in Nova Scotia since 1982 in favour of the more warm-tolerant kelps Saccharina latissima and Laminaria digitata. Kelp abundances have increased slightly since 2000, and Saccharina latissima and L. digitata are widely abundant in the region today. The highest kelp cover occurs on wave-exposed shores and at sites where temperatures have remained below thresholds for growth (21 °C) and mortality (23 °C). Moreover, kelp has recovered from turf dominance following losses at some sites during a warm period from 2010 to 2012. Conclusions Our results indicate that dramatic changes in kelp community composition and a loss of sea urchin herbivory as a dominant driver of change in the system have occurred in Nova Scotia over the past 40 years. However, a broad-scale shift to turf-dominance has not occurred, as predicted, and our results suggest that resilience and persistence are still a feature of kelp forests in the region despite rapid warming over the past several decades. [ABSTRACT FROM AUTHOR]

Background The sugar kelp Saccharina latissima is a Laminariales species widely distributed in the Northern Hemisphere. Its physiology and ecology have been studied since the 1960s, given its ecological relevance on western temperate coasts. However, research interest has been rising recently, driven mainly by reports of negative impacts of anthropogenically induced environmental change and by the increased commercial interest in cultivating the species, with several industrial applications for the resulting biomass. Scope We used a variety of sources published between 2009 to May 2023 (but including some earlier literature where required), to provide a comprehensive review of the ecology, physiology, biochemical and molecular biology of S. latissima. In so doing we aimed to better understand the species' response to stressors in natural communities, but also inform the sustainable cultivation of the species. Conclusion Due to its wide distribution, S. latissima has developed a variety of physiological and biochemical mechanisms to adjust to environmental changes, including adjustments in photosynthetic parameters, modulation of osmolytes and antioxidants, reprogramming of gene expression and epigenetic modifications, among others summarized in this review. This is particularly important because massive changes in the abundance and distribution of S. latissima have already been observed. Namely, presence and abundance of S. latissima has significantly decreased at the rear edges on both sides of the Atlantic, and increased in abundance at the polar regions. These changes were mainly caused by climate change and will therefore be increasingly evident in the future. Recent developments in genomics, transcriptomics and epigenomics have clarified the existence of genetic differentiation along its distributional range with implications in the fitness at some locations. The complex biotic and abiotic interactions unraveled here demonstrated the cascading effects the disappearance of a kelp forest can have in a marine ecosystem. We show how S. latissima is an excellent model to study acclimation and adaptation to environmental variability and how to predict future distribution and persistence under climate change. [ABSTRACT FROM AUTHOR]

Background and Aims Kelps are the primary foundation species in temperate subtidal rocky shores worldwide. However, global change is causing their decline with consequences for the organisms that rely on them. An accurate assessment of these consequences may depend on which attributes of the associated community are considered. This study shows that conventional α-diversity approaches may overlook some of these consequences compared to spatially explicit approaches such as with β-diversity. Methods A 1-year seasonal study was conducted to compare the macroalgal understorey between healthy reefs with a Laminaria ochroleuca canopy and degraded reefs where the canopy collapsed years ago due to excessive fish herbivory. At each reef, the understorey seaweed assemblage was recorded in five replicate quadrats to estimate α-diversity (total richness, species density, Shannon index) and β-diversity (intra- and inter-reef scale). Key Results The understorey assemblage exhibited a distinct seasonal dynamic in both healthy and degraded reefs. α-Diversity attributes increased in spring and summer; turf-forming algae were particularly dominant in degraded reefs during summer. β-Diversity also showed seasonal variability, but mostly due to the changes in degraded reefs. None of the α-diversity estimates differed significantly between healthy and degraded reefs. In contrast, spatial β-diversity was significantly lower in degraded reefs. Conclusions Although the loss of the kelp canopy affected the composition of the macroalgal understorey, none of the conventional indicators of α-diversity detected significant differences between healthy and degraded reefs. In contrast, small-scale spatial β-diversity decreased significantly as a result of deforestation, suggesting that the loss of kelp canopy may not significantly affect the number of species but still have an effect on their spatial arrangement. Our results suggest that small-scale β-diversity may be a good proxy for a more comprehensive assessment of the consequences of kelp forest decline. [ABSTRACT FROM AUTHOR]

Inverted nozzle-pressurized gyration was used as a processing methodology for regenerating cellulose extracted from Laminaria hyperborea for the first time. The viscoelasticity of cellulose/1-ethyl-3-methylimidazolium acetate (EMIM OAc) solutions exhibited high concentration dependence, leading to the production of cellulose products with diverse structures. The regenerated cellulose transitioned from thin films to fibers (≈ 5 μm diameter) as the concentration was increased. The impact of collection distance and working pressure on the morphology and yield of fibers was investigated. This work provides a new sustainable route for processing biopolymers, offering significant potential for applications in biomedicine and healthcare. [ABSTRACT FROM AUTHOR]

Simple Summary: Weaning is a critical stage in a piglet's life, and the transition from milk to solid feed after weaning is a challenge to the digestive and metabolic capacity of piglets, resulting in lower feed intake and growth rate as well as a higher incidence of post-weaning diarrhoea. Thus, many functional additives have been used as alternatives to antibiotics to improve the health and welfare of piglets since the ban on the use of antibiotic growth promoters in livestock. Plant-derived natural polysaccharides have great potential to replace antibiotic additives. In the field of natural substances, polysaccharides from seaweed species such as kelp are some of the bioactive molecules that have been investigated as feed supplements with positive effects on animal health parameters, which are important for animal nutrition. Bioactive compounds are recognized as attractive dietary interventions for pigs to improve their intestinal health and reduce the incidence of intestinal diseases. Laminaria japonica polysaccharides, as one of them, have prebiotic, anti-microbial, antioxidant, anti-inflammatory and immunomodulatory effects. The aim of this study was to test the hypothesis that the addition of appropriate levels of LJP to the diets of weaned piglets would positively modulate their growth performance, faecal digestive enzyme activity, and serum amino acid content. In this study, we observed that Laminaria japonica polysaccharides could improve growth performance and faecal digestive enzyme activities in weaned piglets. The aim of this experiment was to investigate the effect of Laminaria japonica polysaccharide (LJP) supplementation at levels of 100, 200, or 400 mg/kg on the growth performance, faecal digestive enzyme activity, and serum biochemistry and amino acids of weaned piglets. One hundred and twenty weaned piglets (Barkshire × Licha Black, 21 days old, 6.13 ± 0.16 kg) were randomly divided into four groups with five replicates of six piglets in each group based on body weight. Piglets were fed with different levels (0, 100, 200, and 400 mg/kg) of LJP for a 21-day trial. On day 21, faecal and blood samples were collected from one piglet per pen. The results showed that the supplementation of the 200 and 400 mg/kg LJP significantly increased average daily gain (ADG) and average daily feed intake (ADFI) compared to the control group (p = 0.007; p = 0.002), and dietary LJP linearly increased ADG and ADFI (p = 0.002; p < 0.001). In addition, the supplementation of the 200 and 400 mg/kg LJP significantly increased faecal amylase activity (p < 0.001) compared to the control group, and dietary LJP linearly increased faecal amylase and lipase activities (p = 0.001; p = 0.037). Moreover, dietary LJP at 400 mg/kg increased serum histidine content compared to the other groups (p = 0.002), and dietary LJP linearly increased the contents of serum histidine and asparagine in piglets (p < 0.001; p = 0.046). In conclusion, supplementation of 200 and 400 mg/kg LJP could enhance growth performance and faecal digestive enzyme activity and modulate the serum amino acid content of weaned piglets, potentially contributing to the health of weaned piglets. [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 activity was 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). A multistep flash fractionation of the methanolic 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.

Enzymatic hydrolysis of seaweed and seagrass (anfeltia Ahnfeltia tobuchiensis, laminaria Saccharina japonica, and eelgrass Zostera marina) is investigated. The enzyme preparation Viskoferm was the most effective for the mixture of these macrophytes, with high content of laminaria and eelgrass, under conditions of temperature 65 оC and pH 6.0. The hydrolysis in 16 hours reduced content of high-molecular polysaccharides and increased the portion of easily hydrolysable carbohydrates. Feeding of the sea cucumber juveniles by compound feeds with this fermented mixture of macrophytes had a positive effect on their physiological state; the food was easily digested by the animals and provided good gains. The average daily weight gain of juvenile sea cucumber in hatchery conditions had increased by 1.2 times in case of using the starter compound feed and by 1.5 times — for breeding with the productional compound feed.

The kelp forest and bed of Laminaria ochroleuca were found in October 2023 in Porticello (Scylla -Reggio Calabria, Italy) between 48 and 55 m depth. Samples were collected for future genetic and sedimentological analyses and identification of associated fauna and flora. The aim of the upcoming research campaigns is to update the current knowledge of Laminaria forests in the Messina Strait, estimating the action and consequences of climate change at the local level. The project will involve the community of technical divers in long term monitoring (3–5 years), in order to measure ecosystem services. The information will be used to draft a policy document for the proposal of protected areas of the most extensive forests. [ABSTRACT FROM AUTHOR]

SUMMARY: In the marine environment, distance signaling based on water‐borne cues occurs during interactions between macroalgae and herbivores. In the brown alga Laminaria digitata from North‐Atlantic Brittany, oligoalginates elicitation or grazing was shown to induce chemical and transcriptomic regulations, as well as emission of a wide range of volatile aldehydes, but their biological roles as potential defense or warning signals in response to herbivores remain unknown. In this context, bioassays using the limpet Patella pellucida and L. digitata were carried out for determining the effects of algal transient incubation with 4‐hydroxyhexenal (4‐HHE), 4‐hydroxynonenal (4‐HNE) and dodecadienal on algal consumption by grazers. Simultaneously, we have developed metabolomic and transcriptomic approaches to study algal molecular responses after treatments of L. digitata with these chemical compounds. The results indicated that, unlike the treatment of the plantlets with 4‐HNE or dodecadienal, treatment with 4‐HHE decreases algal consumption by herbivores at 100 ng.ml−1. Moreover, we showed that algal metabolome was significantly modified according to the type of aldehydes, and more specifically the metabolite pathways linked to fatty acid degradation. RNAseq analysis further showed that 4‐HHE at 100 ng.ml−1 can activate the regulation of genes related to oxylipin signaling pathways and specific responses, compared to oligoalginates elicitation. As kelp beds constitute complex ecosystems consisting of habitat and food source for marine herbivores, the algal perception of specific aldehydes leading to targeted molecular regulations could have an important biological role on kelps/grazers interactions. Significance Statement: Similarly to land plants, we showed that some aldehydes may be perceived by a marine brown alga and act as bioactive signals, inducing specific transcriptomic and metabolic regulations. More interestingly, the algal pre‐incubation with 4‐hydroxyhexenal decreased the algal consumption by a specialist grazer after few days, suggesting the establishment of efficient defense responses. [ABSTRACT FROM AUTHOR]

The healthy "superfood" sector is currently quickly developing in Europe, and grocery stores are increasingly stocking macroalgae food supplements. Due to its high amount of protein, fiber, and minerals, numerous studies have demonstrated that seaweed has a significant potential for usage as a functional ingredient in the food sector. The aim of the current study was to evaluate the rheological (ICC 173 standard method) and chemical potentials of using Saccharina latissima flour in the bread sector. The calcium level of S. latissima flour was found to be 8236 mg/kg, the magnesium level was 6041 mg/kg, the K concentration was 62,088 mg/kg, the iron content was 35.23 mg/kg, the P content was 2263 mg/kg, and the I content was 12,530 mg/kg, significantly higher values than those of wheat flour. The antioxidant properties of the algae powder used were highlighted by the analysis of the total polyphenol content and its antioxidant activity (DPPH method). Four bread samples, which were compared with the control sample entirely made of wheat flour in order to evaluate their potential, were made, using a replacement degree from 1.5% to 6% of S. latissima. Rheological analyses were completed using the ICC 173 standard method, as well as sensorial analysis, where a panel of assessors' evaluations compared the sensory properties of samples with 1.5–6% of S. latissima flour to a control sample manufactured with flour type 650. It was concluded that sample A1 (1.5% algae flour) has sensorial properties similar to those of the control sample, and, for the other samples, the properties began to degrade with the increase in the amount of algae flour. Textural analyses performed during 96 h of storage show that the firmness and gumminess increase with the addition of algae flour and over time. The conclusions indicated that samples comprising 4.5% and 6% of S. latissima are unsatisfactory from a rheological and sensory perspective, while samples having 1.5% and 3% of S. latissima can be viewed as sources of fiber and minerals. [ABSTRACT FROM AUTHOR]

Brown seaweeds are a rich source of carotenoids, particularly fucoxanthin, which has a wide range of potential health applications. Fucoxanthin fluctuates within and among seaweeds over time, frustrating efforts to utilise this resource. Thus, we require comprehensive analyses of long- and short-term concentrations across species in field conditions. Here, we used High Performance Liquid Chromatography to compare fucoxanthin content in four brown macroalgae, Ascophyllum nodosum, Fucus serratus, Fucus vesiculosus and Saccharina latissima, monthly for 1 year. F. serratus and F. vesiculosus had significantly higher fucoxanthin content (mg/g), which was highest in Spring (0.39 ± 0.04) and Autumn (0.45 ± 0.04) [mean (± SE)]. Two species, A. nodosum and F. serratus, were collected monthly at the same location for a further two non-consecutive years. For both A. nodosum and F. serratus, a significant interaction effect of seasons and years was identified, highlighting that there is variation in fucoxanthin content among and within species over time. We also show that fucoxanthin content differs significantly among months even within seasons. Therefore, it is not sufficient to assess fucoxanthin in single months to represent seasonality. We discuss how weather, nutrients and reproduction may have driven the seasonal variation, and reveal patterns of fucoxanthin concentration that can provide information concerning its availability for many important medical functions. [ABSTRACT FROM AUTHOR]

Sap from the fresh seaweed Kappaphycus alvarezii (KA) has been reported to improve crop growth, quality, and stress alleviation. However, limited studies are reported for the minimally processed aqueous homogenates (MPHs) derived from dry seaweeds. The present investigation was envisaged to characterize the MPHs from the red seaweed KA and a brown seaweed (SW) and also assess the effect of foliar application on maize ( )crop performance when applied alone or in proportions ranging from 0% to 100%. Two doses (0.35% and 0.7%) were compared with control. Both the MPHs contained several compounds like retronecine, tyrosyl-glycine, hexyl 2- furoate, 1-phosphatidyl-1D-myo-inositol, 12-(2,3-dihydroxycyclopentyl)-2- dodecanone, and trihomomethionine and many others that have known bioactivity for enhancing plant growth and providing stress tolerance. Both doses of MPHs enhanced crop growth and yield; however, the best response was in general observed at a lower dose. The MPH of SW at 100% gave the highest seed yield at a lower dose, which was also on par with that obtained under a lower dose of 100% KA. Other combinations, 80:20 and 40:60 KA : SW, were also found to give comparable yields. The highest dose of 100% MPH of SW was found on par with control, a phenomenon that was investigated in detail with respect to metabolites and antioxidant profile in leaves as well as membrane modeling. Higher ROS and certain sugar and organic acids were observed in 100% MPH of SW at a higher dose, although none of the antioxidant enzymes were significantly affected, nor was there any change in membrane characteristics of the leaf with respect to control as well as lower dose. Improvements in the seed yield were attributed to improved photosynthate production on account of higher dry matter accumulation in the MPH-treated plants, which may also be attributed to the presence of bioactive compounds in the biostimulants. In the future, it is imperative to direct scientific investigations towards the quantification and identification of themost effective concentrations of these compounds within MPHs to optimize plant responses. The study indicated the beneficial use of the MPHs towards increasing crop production by employing optimum dose as foliar spray to crops. [ABSTRACT FROM AUTHOR]

Population dynamics can be influenced by physical and biological factors, particularly in stressful environments. Introduced species usually have great physiological plasticity, resulting in populations with different traits. Undaria pinnatifida, a macroalga originally described from northeast Asia, was introduced in Northern Patagonia, Argentina (San Matías Gulf) around 2010. To describe the spatio‐temporal variability in population structure and morphometry of U. pinnatifida, we conducted monthly field samplings for 2 years at the intertidal area of two contrasting sites in the San Matías Gulf. Individuals of U. pinnatifida were classified by developmental stage, and their morpho‐gravimetric variables were measured. In both intertidal sites juveniles were found in higher proportion during austral autumn and grew and matured during the autumn‐winter months (from May onwards), and individuals senesced during early austral summer (December and January). Conversely, density and biomass were largely different between sites, and individuals showed slight morphological variability between sites. Environmental (e.g., nutrient concentration, available substrate) and biological factors (e.g., facilitation, competition) may explain the observed differences. Since there is not a macroalga with U. pinnatifida morphometrical characteristics in the intertidal environments of San Matías Gulf, studying this recent introduction gives us a better understanding of its potential ecological effects. [ABSTRACT FROM AUTHOR]

Phaeoviruses (Phycodnaviridae) are large icosahedral viruses in the phylum Nucleocytoviricota with dsDNA genomes ranging from 160 to 560 kb, infecting multicellular brown algae (Phaeophyceae). The phaeoviral host range is broader than expected, not only infecting algae from the Ectocarpales but also from the Laminariales order. However, despite phaeoviral infections being reported globally, Norwegian kelp species have not been screened. A molecular analysis of cultured and wild samples of two economically important kelp species in Norway (Saccharina latissima and Laminaria hyperborea) revealed that phaeoviruses are recurrently present along the Norwegian coast. We found the viral prevalence in S. latissima to be significantly higher at the present time compared to four years ago. We also observed regional differences within older samples, in which infections were significantly lower in northern areas than in the south or the fjords. Moreover, up to three different viral sequences were found in the same algal individual, one of which does not belong to the Phaeovirus genus and has never been reported before. This master variant therefore represents a putative new member of an unclassified phycodnavirus genus. [ABSTRACT FROM AUTHOR]

Seaweeds are currently being extensively researched for the presence of a variety of valuable bioactive metabolites. This study examines the phytochemical components, quantification of flavonoid compounds, antioxidant, and anticancer effects of the methanol extract of marine brown alga Sargassum myriocystum from the Rameswaram coastal region of Tamilnadu, India. The seaweed was extracted using 80% methanol, and then a preliminary qualitative analysis was conducted. The total polyphenol and flavonoid content of the extract was calculated. Using column chromatography, a class of phenolic compounds known as flavonoids was separated from the crude methanol extract. Mass spectrometry, FTIR—Fourier transform infrared, GC–MS-gas chromatography-mass spectrometry, and UV–Vis (ultra violet-visible) spectroscopy were used to confirm the bioactive compound fractionated from the extract. Since antioxidants are essential in preventing many diseases, particularly cancer, the free radical scavenging activity of the isolated flavonoid compound, flavone was assessed using antioxidant assays. Anti-proliferation was evaluated using MTT-bromide test in breast cancer cell lines (MCF-7) and morphological assessment of apoptosis was evaluated. The findings of the current investigation demonstrated that seaweed extracts effectively inhibited free radicals and cell proliferation. Hence, the flavonoid extracted from Sargassum myriocystum is a capable antioxidant and anticancer agent with applications in pharmacological sectors. [ABSTRACT FROM AUTHOR]

Seaweed is increasingly considered a promising resource to produce high‐value products such as bioplastics due to potential environmental benefits such as carbon uptake and no land‐use change. However, the environmental assessment of emerging technologies for producing bioplastic from seaweed remains challenging due to the difficulties in modeling future seaweed supply and demand. Within the consequential approach to life cycle assessment, an increase in demand for seaweed is met by the marginal suppliers in the market: those that are not constrained in their capacity to increase supply in response to an increase in demand. Current methods to identify marginal suppliers are however based on quantitative information and do not consider qualitative aspects and uncertainties inherent in the study of emerging technologies. This study, therefore, proposes and tests the use of quantitative storytelling to identify marginal suppliers. The results show that there are two main groups of countries that are expected to be the marginal suppliers of brown seaweed for different reasons. Asian countries are currently the main brown seaweed suppliers and are expected to keep increasing and be marginal suppliers in the future. However, these countries have well‐established brown seaweed aquaculture and their growth is expected to be steady. On the other hand, brown seaweed suppliers in Northern Europe and North America are still emerging but are expected to grow faster in the future due to their production capacity and technological development. [ABSTRACT FROM AUTHOR]

The phenology of the alga-dwelling amphipod Ceinina japonica Stephensen, 1933 (Amphipoda: Eophliantidae) was studied at Rishiri Island, Hokkaido, Japan, from May 2016 to March 2017. Seasonal shifting between the host algal species was confirmed through observations at a coastal field site and a nearby aquaculture facility for kelp. Amphipods mainly occurred in the farmed biennial kelp Saccharina japonica var. ochotensis and wild algae Undaria pinnatifida, with Agarum clathratum, Costaria costata, Saccharina cichorioides, and Sargassum boreale as new host algal records. Amphipods occurred in sporophytes of U. pinnatifida at the field site from February to March and from May to July, but they were found in the kelp of S. j. var. ochotensis during the rest of the year, from August to the following January. Individuals of C. japonica infected sporophytes of the large brown alga Undaria pinnatifida from February to July, and C. japonica reproduced from July to September, a period during which the amphipods switch to a different host in July, the sporophytes of the saccharinan kelp S. j. var. ochotensis, where they stay until January. The amphipods then switched back to U. pinnatifida in January or February. Experimental evidence from a kelp-culturing facility also confirmed the timing of this host shift. The removal of U. pinnatifida from algal culture ropes in such facilities is suggested as a method to prevent amphipod damage, which is important for commercially farmed S. j. var. ochotensis. [ABSTRACT FROM AUTHOR]

The use of aquatic biomass as potential sources for bioenergy production has attracted significant attention worldwide. Production of biogas and bioethanol from both marine and freshwater plants using same pre-treatment methods were evaluated and the results indicate that both processes can be potentially enhanced appropriate methods of pre-treatment. In this study, the effects of thermochemical and enzymatic pre-treatment of selected seaweeds and freshwater macrophytes for biogas and bioethanol production were investigated. It was found that methane biogas yield from the anaerobic digestion of selected aquatic plants was highly dependent on the plant species. For example, biomethane yields of 189, 195, 221, 234 mL/g volatile solids were obtained following anaerobic digestion of acid and enzymatic pre-treatment of Laminaria digitata, Sargassum fluitans, Eichhornia crassipies and Pistia stratiotes, respectively. Additionally, alcoholic fermentation by the yeast Saccharomyces cerevisiae (distiller's strain) was carried out on aquatic plant hydrolysates and the highest ethanol yields (of over 4 g/L) were obtained from Eichhornia crassipies and Pistia stratiotes. Poor fermentation yields from Laminaria digitata, and Sargassum fluitans hydrolysates were attributed to the predominance of un-fermented rhamnose sugars in these plants. The findings demonstrate the importance of reliance on empirical data for each substrate when designing and operating anaerobic digestion and alcohol fermentation systems. The results show that the same pre-treatment methods can be used for both types of bioenergy production, i.e., biogas and bioethanol, from marine and freshwater plants, thereby enhancing the economic viability of both processes in industry-scale applications. [ABSTRACT FROM AUTHOR]

Using low trophic marine resources such as sugar kelp (Saccharina latissimi) is of great interest to increase the circular food production in the ocean. Sugar kelp does, however, contain high levels of carbohydrates and iodine and does not have considerable levels of protein and lipids, which may make it less suitable as a feeding ingredient. A 10-week feeding trial was done to investigate the effect of graded dietary inclusion levels of fermented sugar kelp (FSK), on growth performance, digestibility, retention of nutrients, and mineral composition in postsmolt Atlantic salmon (Salmo salar L.). The experimental diets were made to simulate a standard grower feed for salmon postsmolts in SW with ∼63% plant-based ingredients vs ∼34% marine ingredients and increasing concentrations of FSK between 0% (control feed) and 4% of the diet. During the feeding trial, the weight gain and specific growth rate (SGR) decreased linearly with increasing dietary FSK levels, where the SGR was slightly reduced from 1.2% for the fish given the control feed to 1.1% in the fish given feeds containing 3% and 4% FSK. This resulted in a lower weight gain of up to 9% in the fish given 4% FSK compared to the control. Feed intake and feed conversion ratio were, however, similar in all diet groups, and FSK inclusion did not influence the digestibility of macronutrients or minerals, except for lipid. The reduced growth is likely related to a lower digestible energy level in the diets, and the retention of both lipids and energy was affected by FSK inclusion. Inclusion of FSK also influenced iodine availability and retention, as well as increasing iodine status in whole body and muscle in a dose-dependent manner until reaching a plateau, which corresponds to 124 mg I kg−1 WW (135 mg I kg−1 DW), at 3% FSK inclusion. [ABSTRACT FROM AUTHOR]

Arctic macroalgae species have developed different growth strategies to survive extreme seasonal changes in irradiance in polar regions. We compared photophysiological parameters such as the light saturation parameter (Ek) and pigment composition of green, red, and brown macroalgae collected in January (Polar Night) and October 2020 (end of the light season). Macroalgae in January appeared healthier (morphologically) and had longer lamina (new growth) than those in October. EK values for red, and brown algae were higher with lower maximum quantum yield of PS II fluorescence (Fv/Fm) in January versus October. Furthermore, in January, new tissues in kelp species had higher EK than the older tissue. Higher EK and lower Fv/Fm during the Polar Night indicates that the photosynthetic apparatus is active but slow. Furthermore, we discuss Chlorophyll (Chl) a emission spectra under blue and green excitation light to determine the ratio of Chl a in photosystem II (PS II) vs photosystem I (PS I). Absorbance spectra of P. palmata was used to interpret the emission spectra. The observed spectral shifts in the absorbance and reflectance spectra of different macroalgae is discussed. Photophysiological methods provide health information complementary to future mapping and monitoring of macroalgae. These results reveal that macroalgae grow new tissue in darkness. [ABSTRACT FROM AUTHOR]

Marine seaweeds are rich source of polysaccharides present in their cell wall and are cultivated and consumed in China, Japan, Korea, and South Asian countries. Brown seaweeds (Phaeophyta) are rich source of polysaccharides such as Laminarin and Fucoidan. In present study, both the laminarin and fucoidan were isolated was yielded higher in PP (Padina pavonica) (4.36%) and STM (Stoechospermum marginatum) (2.32%), respectively. The carbohydrate content in laminarin and fucoidan was 86.91% and 87.36%, whereas the sulphate content in fucoidan was 20.68%. Glucose and mannose were the major monosaccharide units in laminarin (PP), however, fucose, galactose, and xylose in fucoidan (STM). FT-IR down peaks represent the carbohydrate of laminarin and fucoidan except, for 1219 cm−1, and 843 cm−1, illustrating the sulphate groups of fucoidan. The molecular weight of laminarin was 3–5 kDa, and the same for fucoidan was 2–6 kDa, respectively. Both the Fucoidan and Laminarin showed null cytotoxicity on Vero cells. Contrastingly, the fucoidan possess cytotoxic activity on human liver cancer cells (HepG2) (IC50—24.4 ± 1.5 µg/mL). Simultaneously, laminarin also shown cytotoxicity on human colon cancer cells (HT-29) (IC50—57 ± 1.2 µg/mL). The AO/EB (Acriding Orange/Ethidium Bromide) assay significantly resulted in apoptosis and necrosis upon laminarin and fucoidan treatments, respectively. The DNA fragmentation results support necrotic cancer cell death. Therefore, laminarin and fucoidan from PP and STM were potential bioactive compounds for anticancer therapy. [ABSTRACT FROM AUTHOR]

Detritus is widely considered to be dead organic matter. However, recent studies have shown that kelp detritus can be functionally equivalent to the attached plant. This is significant, because detritus makes up ~ 42% of all plant biomass. In the Northeast Atlantic, studies on detrital photobiology have been restricted to the genus Laminaria. Here, we present data from a 46 d in situ experiment investigating the effect of decomposition on detrital photosynthetic pigment concentrations and stoichiometry in four Northeast Atlantic kelp species from three genera. We corroborate the lack of a decomposition effect on pigments of cold temperate Laminaria species as identified by previous studies but show that the photophysiology of other kelp genera responds differently. While Saccharina latissima displays an idiosyncratic parabolic response, the annual and thermally plastic kelp Saccorhiza polyschides seems to become less pigmented with increasing detrital age. If S. polyschides becomes increasingly dominant in future parts of a warmer Northeast Atlantic, this may translate to lower detrital photosynthetic potential at the forest scale. However, given our somewhat ambiguous data on this species, this conjecture requires further investigation into detrital photosynthesis. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the impact of brown seaweed extract (Ecklonia maxima) on the morphology and physiology of three different plant species. We conducted experiments using two types of fertilizers: an artificial fertilizer (0.1 g/L) and a biological extract of brown seaweed (Ecklonia maxima) at two concentrations (C1 at 1 mL/L and C2 at 2.5 mL/L). For melon, the application of C1 resulted in significant improvements in photosynthesis parameters, total chlorophyll content, and overall plant growth. When C2 was applied, it further enhanced these parameters, leading to a notable increase in shoot phytomass. In the case of cucumber, C1 led to increased resource allocation towards stems and leaves. Conversely, C2 increased the number of green leaves and contributed to higher shoot phytomass. For tomato plants, the application of C1 resulted in a slight increase in photosynthesis, but it did not significantly impact leaf growth. On the other hand, C2 induced a modest increase in photosynthesis, chlorophyll content, and root growth. In summary, our findings indicate that brown seaweed extract has a discernible influence on the physiology of the studied plants. However, the specific effects on resource allocation largely depend on the plant species and the concentration of the extract applied. [ABSTRACT FROM AUTHOR]

Avrainvillea is a green macroalgal genus of the family Dichotomosiphonaceae (order Bryopsidales). Many species have been morphologically described, but few studies have addressed the genetic diversity of this genus. Based on a rich collection of specimens from the tropical Western Atlantic, Indian and Pacific Oceans, we aimed to (1) reassess Avrainvillea species diversity through species delimitation analyses, (2) update their distribution ranges, (3) reconstruct the species phylogenetic relationships, based on a concatenated multilocus matrix (tufA, rbcL and 18S rDNA) and (4) revise their taxonomy and describe new species where necessary. Our species delimitation approach highlighted 23 secondary species hypotheses in our collection, including nine known and currently accepted species, four species complexes (A. amadelpha, A. lacerata, A. erecta-obscura and A. mazei-nigricans), and eight new species for which we provide descriptions: A. laciniata (Papua New Guinea), A. minima and A. pyrochroma (Madagascar), A. mollis and A. kanakiensis (New Caledonia), A. pavonina (Fiji), A. spongiosa (Pacific) and A. corticata (Indo-Pacific). We also propose the resurrection of A. gracillima Børgesen, the reinstatement of Avrainvillea lacerata var. robustior A.Gepp & E.S.Gepp, and the synonymy of A. rotumensis A.D.R.N'Yeurt, D.S.Littler & Littler with A. pacifica A.Gepp & E.S.Gepp. We complemented the taxonomic work by providing a contemporary dichotomous key for morphological identification of all extant species. Our multilocus phylogeny included 25 species of Dichotomosiphonaceae and recovered Avrainvillea as a polyphyletic group, divided into three distinct clades, with Cladocephalus luteofuscus positioned within the group. The species determined using the species delimitation approach were all monophyletic and 19 of them were highly supported. For the first time, this study also provided genetic sequences for A. asarifolia, A. clavatiramea, A. digitata, A. elliottii, A. fulva, A. gracillima, A. geppiorum, A. pacifica and A. obscura. • Avrainvillea is not monophyletic. • Reassessment of Avrainvillea species diversity delimited 23 secondary species hypotheses. • Eight new species of Avrainvillea were discovered in the Indo-Pacific. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The lipidic extract of Undaria pinnatifida, one of the worst invasive species, was investigated for its potential exploitation in biotechnological applications. The antimicrobial activity of the lipidic extract in three different portions (blade, sporophyll, and holdfast) was assessed by using the Kirby–Bauer method, while the antioxidant activity was evaluated by the TEAC, ORAC, and Folin–Ciocalteu assays. NMR spectroscopy and thin-layer chromatography were employed for the chemical characterization. The extracts showed antibacterial activity against several of the tested Vibrio species: V. aestuarinus, V. fischeri, V. furnisii, V. inusitatus, V. litoralis, and V. mediterranei, including some pathogens for farmed fish. Intriguing antioxidant activity was recorded, with the highest value in the blade (126.907 ± 28.993 mmol Trolox equivalent/g TEAC). Free, saturated, unsaturated, and polyunsaturated fatty acids were highlighted by 1D and 2D NMR spectroscopy. The presence of ω-3 and ω-6 PUFAs indicates the importance of this algal species in the food industry. We suggest the employment of U. pinnatifida as source of new and safer therapeutic agents to control fish and shellfish diseases due to vibriosis, as well as a source of natural antioxidants that are useful for human health, considering the growing interest in the development of strategies for invasive seaweed control. [ABSTRACT FROM AUTHOR]

In this study, the nutritional and phytochemical components of red seaweed, Gracilariopsis longissima, were assessed in relation to the effects of various drying methods (freeze, oven, and sun). Gracilariopsis longissima's proximate composition differed significantly (P < 0.05) among the three drying techniques, with freeze-dried samples having significantly greater protein (30.63 ± 0.90% dry weight) and lipids (1.49 ± 0.05% dry weight) contents. Except for phosphorus and sulfur, the mineral concentrations were likewise considerably greater in the freeze-dried samples. The total amino acids (30.48 ± 0.06% dry weight) and fatty acids contents were substantially greater (P < 0.05) in the freeze-dried samples. In freeze-dried samples, the levels of essential amino acids (18.92 ± 0.02% dry weight) and unsaturated fatty acids (54.08 ± 0.07%) were substantially greater (P < 0.05). When compared to oven- and sun-dried samples, the total phenolic content (88.70 ± 2.19 mg GAE/g dry weight) and the flavonoid content (71.46 ± 2.17 mg QE/g dry weight) of freeze-dried samples was also substantially higher. Among the three distinct drying techniques used, the freeze-drying technique kept G. longissima's higher nutritional and phytochemical components. [ABSTRACT FROM AUTHOR]

Baobab (Adansonia digitata L) is a large tree species growing in semiarid and arid lowlands of Ethiopia and other places. The plant is valued by natives for its contributions as a cash crop and livelihood tree. Previous studies using samples from different countries have documented their phytochemical profiles and nutritional and health benefits. This study explored the phytochemical constituents and biological activities of fruit pulp extracts of baobab collected from Tekeze Valley, Tigrai, Ethiopia. To this end, qualitative phytochemical screening tests, quantitative phytochemical analyses, and gas chromatography-mass spectrometry (GC-MS) analysis were carried out using aqueous extract. Analyses of antioxidant activities were also conducted with aqueous- and methanol-extracts using of 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), and hydroxyl (OH) radical scavenging activity assays. The qualitative screening tests showed the presence of flavonoids, phenols, saponins, tannins, and terpenoids. Quantitative analyses of these phytochemicals at 25, 50, and 100 g/mL aqueous extract resulted in 0.0252 to 0.1000% yields. Yields of flavonoids, phenols, and saponins were higher at 50 g/mL extract, while that of tannins and terpenoids were higher at 100 g/mL. GC-MS analysis resulted in 15 predominant compounds including (1,2bis(trimethylsilyl)benzene (13.17%), 2-methyl-7-phenylindole (11.75%), 2-ethylacridine (10.11%), and benz[b]-1,4-oxazepine-4(5H)-thione,2,3-dihydro-2,8-dimethyl (10.11%). Aqueous and methanol extracts showed concentration-dependent antioxidant activities. In all the assays and concentrations, the antioxidant activities of both extracts were lower than that of the ascorbic acid standard. At equal extract concentrations (e.g., 100 and 250 μg/mL), methanol extract had higher antioxidant activities than aqueous extract. The findings can encourage future initiatives towards large-scale research for compiling a complete phytochemical profile of the fruit pulp of the Ethiopian baobab. [ABSTRACT FROM AUTHOR]

Adansonia digitata L (Baobab) is a large plant species which thrives in many semiarid regions of the world with remarkable economic and nutritional importance. In Ethiopia, it grows in deserts and hot lowlands. Industrially, baobab fruit pulp (powder) is used for producing good quality jams. This study was carried out to (a) develop a formulation protocol for producing high-quality baobab jam, (b) characterize the jam using standard physicochemical, microbiological, and sensory evaluation methods, and (c) examine the effects of time and temperature of storage on the quality as well as shelf life of the jam. Out of the seven formulations tested, a formulation enriched with 55 g table sugar, 45 g baobab fruit powder, 0.50 g ascorbic acid, and 0.40 to 0.60 g citrus pectin jelling (formulation no. 6) and another one enriched with 60 g table sugar, 40 g baobab fruit powder, 0.50 g ascorbic acid, and 0.40 to 0.60 g citrus pectin jelling (formulation no. 7) resulted in the best jam products. The jam product of formulation no. 7 enriched with 0.50 g ascorbic acid and 0.60 g citrus pectin jelling was better in terms of storage stability and sensory acceptability. Increasing storage time (up to 45 to 90 days) and temperature (from 10–12°C to 25–27°C) lowered the products' nutritional quality and sensory acceptability. High-microbial growths were observed in the products stored at higher temperature longer, but all the microbial loads were far below the acceptable limit. In the absence of measures that improve their shelf lives, household and small-scale jam products have to be consumed fresh or within weeks after their preparation. [ABSTRACT FROM AUTHOR]

This study aimed to assess the hypoglycemic efficacy of low molecular weight polysaccharides fractions obtained from Laminaria japonica (LJOO) in a model of type 2 diabetes mellitus (T2DM) constructed using mice. Biochemical parameters were measured after 4 weeks of continuous gavage, and fasting blood glucose (FBG) concentrations were analyzed. Pathological changes in tissues were assessed. The intestinal contents were obtained for 16S rDNA high-throughput sequencing analysis and detection of short-chain fatty acids (SCFAs). LJOO lowered FBG and insulin concentrations. It altered the gut microbiota composition, as evidenced by enriched probiotic bacteria, along with an increase in the Bacteroidetes/Firmicutes ratio and a decrease in the population of harmful bacteria. LJOO stimulated the growth of SCFA—producing bacteria, thereby increasing cecal SCFAs levels. LJOO can potentially aid in alleviating T2DM and related gut microbiota dysbiosis. LJOO may be used as a food supplement for patients with T2DM. [ABSTRACT FROM AUTHOR]

Warming ocean temperatures have been linked to kelp forest declines worldwide, and elevated temperatures can act synergistically with other local stressors to exacerbate kelp loss. The bull kelp Nereocystis luetkeana is the primary canopy‐forming kelp species in the Salish Sea, where it is declining in areas with elevated summer water temperatures and low nutrient concentrations. To determine the interactive effects of these two stressors on microscopic stages of N. luetkeana, we cultured gametophytes and microscopic sporophytes from seven different Salish Sea populations across seven different temperatures (10–22°C) and two nitrogen concentrations. The thermal tolerance of microscopic gametophytes and sporophytes was similar across populations, and high temperatures were more stressful than low nitrogen levels. Additional nitrogen did not improve gametophyte or sporophyte survival at high temperatures. Gametophyte densities were highest between 10 and 16°C and declined sharply at 18°C, and temperatures of 20 and 22°C were lethal. The window for successful sporophyte production was narrower, peaking at 10–14°C. Across all populations, the warmest temperature at which sporophytes were produced was 16 or 18°C, but sporophyte densities were 78% lower at 16°C and 95% lower at 18°C compared to cooler temperatures. In the field, bottom temperatures revealed that the thermal limits of gametophyte growth (18°C) and sporophyte production (16–18°C) were reached during the summer at multiple sites. Prolonged exposure of bull kelp gametophytes to temperatures of 16°C and above could limit reproduction, and therefore recruitment, of adult kelp sporophytes. [ABSTRACT FROM AUTHOR]

Algal carbon‐to‐nitrogen (C:N) and carbon‐to‐phosphorus (C:P) ratios are fundamental for understanding many oceanic biogeochemical processes, such as nutrient flux and climate regulation. We synthesized literature data (444 species, >400 locations) and collected original samples from Tasmania, Australia (51 species, 10 locations) to update the global ratios of seaweed carbon‐to‐nitrogen (C:N) and carbon‐to‐phosphorus (C:P). The updated global mean molar ratio for seaweed C:N is 20 (ranging from 6 to 123) and for C:P is 801 (ranging from 76 to 4102). The C:N and C:P ratios were significantly influenced by seawater inorganic nutrient concentrations and seasonality. Additionally, C:N ratios varied by phyla. Brown seaweeds (Ochrophyta, Phaeophyceae) had the highest mean C:N of 27.5 (range: 7.6–122.5), followed by green seaweeds (Chlorophyta) of 17.8 (6.2–54.3) and red seaweeds (Rhodophyta) of 14.8 (5.6–77.6). We used the updated C:N and C:P values to compare seaweed tissue stoichiometry with the most recently reported values for plankton community stoichiometry. Our results show that seaweeds have on average 2.8 and 4.0 times higher C:N and C:P than phytoplankton, indicating seaweeds can assimilate more carbon in their biomass for a given amount of nutrient resource. The stoichiometric comparison presented herein is central to the discourse on ocean afforestation (the deliberate replacement of phytoplankton with seaweeds to enhance the ocean biological carbon sink) by contributing to the understanding of the impact of nutrient reallocation from phytoplankton to seaweeds under large‐scale seaweed cultivation. [ABSTRACT FROM AUTHOR]

Kelp restoration practices have renewed urgency given worldwide kelp declines (e.g., Eger, Layton, et al., [5]; Eger, Marzinelli, et al., [6]). Abbreviations MCP major capsid protein ONT Oxford Nanopore Technologies NGS Next Generation Sequencing OPC Ocean Protection Council PCR polymerase chain reaction Kelp forests are ecologically and economically valuable marine ecosystems located worldwide. Indeed, we lack information on the role viruses might have in shaping kelp ecology and evolution, including on short timescales during kelp population loss and recovery. [Extracted from the article]

Laminarans are of interest because they have been shown to induce various immune responses in animals and plants. These β-D-glucans differ from each other by their branching rate, which is possibly responsible for their biological activities. In the present study, we characterized a laminaran fraction extracted from Laminaria hyperborea and named LAM2 using sugar composition and structural analyses (NMR). Then, we evaluated its activity as a potential plant elicitor in vitro on tomato seedlings using gene expression analysis and cell wall immunofluorescence labeling. Our study showed that LAM2 isolated from L. hyperborea is a succinylated laminaran which significantly enhanced the plant defense of tomato seedlings and induced cell wall modifications, suggesting a higher elicitor activity than the laminaran standard extracted from Laminaria digitata. [ABSTRACT FROM AUTHOR]

Brine discharged from seawater desalination plants impacts marine life by exposure to increased salinity and, in some cases, temperature. However, the responses of individual species to such stress remains poorly known yet their understanding is essential for assessing and predicting the impacts of seawater desalination plants. In this study, unialgal cultures obtained by the germling emergence method of 34 taxa representative of the Rhodophyta, Chlorophyta and Phaeophyceae seaweeds in the Arabian Gulf, and isolated from the vicinity of two large desalination plants in Kuwait, were subjected to increased temperature and salinity under experimental conditions in the laboratory. The dataset is complemented by measurements of seawater temperature and salinity obtained at increasing distances from the outfalls of desalination plants and along the Kuwaiti coastline including from two pristine areas, Boubiyan and Fintas. Chlorophyta, especially Ulva spp., and Phaeophyceae displayed remarkable tolerance against hypersaline and thermal stress, suggesting that this group can cope better with adverse environmental conditions. Members of the Rhodophyta were considerably more sensitive to temperature increases. [ABSTRACT FROM AUTHOR]

Macroalgae are receiving increased attention as antimethanogenic feed additives for cattle, but most in vivo studies are limited to investigating effects of the red macroalgae Asparagopsis spp. Hence, this study aimed to investigate the CH 4 mitigating potential of 3 brown macroalgae from the Northern Hemisphere when fed to dairy cows, and to study the effects on feed intake, milk production, feed digestibility, and animal health indicators. The experiment was conducted as a 4 × 4 Latin square design using 4 lactating rumen, duodenal, and ileal cannulated Danish Holstein dairy cows. The cows were fed a total mixed ration (TMR) without any macroalgae or the same TMR diluted with, on a dry matter basis, either 4% ensiled Saccharina latissima , 4% Ascophyllum nodosum (NOD), or 2% Sargassum muticum (MUT). Each period consisted of 14 d of adaptation, 3 d of digesta and blood sampling, and 4 d of gas exchange measurements using respiration chambers. Milk yield and dry matter intake (DMI) were recorded daily. Blood was sampled on d 13 and 16 and analyzed for health status indicators. None of the 3 species affected the CH 4 emission. Moreover, milk yield and DMI were also unaffected. Total-tract digestibility of crude protein was significantly lower for NOD compared with other diets, and additionally, the NOD diet also tended to reduce total-tract digestibility of neutral detergent fiber compared with MUT. Blood biomarkers did not indicate negative effects of the dietary inclusion of macroalgae on cow health. In conclusion, none of the 3 brown macroalgae reduced CH 4 emission and did not affect DMI and milk production of dairy cows, whereas negative effects on the digestibility of nutrients were observed when A. nodosum was added. None of the diets would be allowed to be fed in commercial dairy herds due to high contents of iodine, cadmium, and arsenic. [ABSTRACT FROM AUTHOR]

Iodide is accumulated by the brown alga Saccharina japonica at a high concentration and has been proven to be an inorganic antioxidant that plays an important role in oxidative metabolism. Vanadium-dependent bromoperoxidases (vBPOs) and iodoperoxidases (vIPOs), which catalyze the oxidation of iodide, are essential for iodine accumulation and metabolism. Heavy metal pollutant cadmium (Cd) from anthropogenic activities can cause damage to algae mainly by producing oxidative stress. Here, the effects of iodine pretreatment on the stress of S. japonica caused by cadmium were analyzed. The growth experiment showed that iodine pretreatment could reduce the damage of low concentration cadmium on S. japonica young thalli. At the transcriptomic level, gene ontology (GO) enrichment analysis confirmed that cadmium stress could cause a peroxidation reaction in S. japonica. However, the most significant GO term was "photosystem I" in the series with iodine pretreatment. Weighted gene co-expression network analysis (WGCNA) indicated that iodine pretreatment alleviated cadmium stress responses of S. japonica by affecting the photosynthesis process. Analysis of the differentially expressed genes (DEGs) showed that five enzymes from the vBPO family and 13 enzymes from the vIPO family might play crucial roles in this process. [ABSTRACT FROM AUTHOR]

The results of a Adansonia digitata provenance and clone trials situated in Sadore (Niger) and Samanko (Mali) indicate genetic variation at both provenance level and among clones. There were significant differences among provenances at Sadore in both survival and height by age 10. Differences in survival were very marked, and suggest that provenances ranged from very poorly- to well-adapted to the Samanko site. However, height was weakly and negatively correlated to survival; possibly the trees may have grown slightly taller because of less competition. West African provenances have a tendency towards faster growth than those of East African origin, and the provenances from drier locations tend to be better adapted. While early variation among 4 year-old clones of leaf development, an important production trait, was indicated, future observations at later ages on fruit traits will be required to make valid selection decisions. The reported 10 year-old provenance variation in tree survival and growth suggest valuable gains could be made by selection of the best provenances. Further trials across a wider range of sites, representative of target planting sites are recommended. Both genebanks contain valuable genetic plant materials worth maintaining for further research and development. [ABSTRACT FROM AUTHOR]

The IUCN Red List of Threatened Species is an authoritative tool in biodiversity conservation. Whilst IUCN criteria have been applied successfully to groups such as birds and mammals, a Red List assessment of British seaweeds in 2021 revealed that the categories to which seaweed species were assigned were dependent on how the criteria were applied. Here, this seaweed assessment is used as a case study with which to evaluate the IUCN methodology for use with 'non-standard' groups of organisms. A data-driven assessment of red (Rhodophyta), green (Chlorophyta) and brown (Phaeophyceae) seaweeds, which applied three (A, B and D) of the five IUCN criteria (A–E), categorized 13% of 617 British species as threatened. Following peer review, only 7% of species were categorized as threatened (1% Critically Endangered—CR, 3% Endangered—EN, 3% Vulnerable—VU), and 55% as Data Deficient. This reduction in species categorized as threatened suggests that strict application of the IUCN criteria may, at least for the seaweeds, over-estimate threat. As a result of this assessment, recommendations include the need for a more unified monitoring system and a review of the suitability for/application of the IUCN assessment criteria to some types of organisms. For example, in clonal populations, it is not possible to count individuals, and complex life histories cause additional complications. IUCN criteria must be applicable to a wide range of organisms, including seaweeds. [ABSTRACT FROM AUTHOR]

Cervical preparation with laminaria reduces complications with 2nd trimester dilation and evacuation. During a surgical abortion at 22 weeks, we could not remove laminaria manually or with ring forceps due to laminaria "dumbbelling" [1]. Without pushing laminaria into the uterus, we mechanically dilated the cervix and removed the incarcerated laminaria.

Brown seaweeds (Laminariaceae) vary considerably in the content of toxic and essential elements; these variations depend on the taxonomic group and geographical factors. Seaweeds are extensively used in the food industry and widely applied in medicine for both humans and animals. Therefore, it is relevant to examine the correlation between the elemental composition and the geographical origin of kelp thalli obtained from different sources.The aim of the study was to collect, collate, and analyse primary and secondary data on the accumulation of essential, toxic and potentially carcinogenic elements, including iodine, in the thalli of brown seaweeds (Laminariaceae).Materials and methods. This study investigated the concentrations of 17 elements in Laminaria spp. (Al, As, Cd, Cr, Co, Cu, Fe, Hg, Mn, Mo, Ni, Se, Pb, Sr, V, Zn, and I). Experiments were conducted on an Agilent 7900 inductively coupled plasma mass spectrometer. The authors studied publications on the elemental composition of brown seaweeds (Laminariaceae) using literature search and data analysis methods.Results. This article reflects the updated classification of brown seaweeds (Laminariaceae) and summarises information about the mechanisms by which iodine and other elements accumulate in the thallus. The authors established species-specific variations in the order of element uptake and in the accumulation of elemental toxicants. The mutual influence of elements on their accumulation in brown seaweeds (Laminariaceae) was evaluated using Spearman’s rank correlation coefficients.Conclusions. The study results can inform the implementation of a risk-based quality control strategy for herbal medicinal products aimed at reducing human exposure to toxic elements. The authors suggest that the upper limit of iodine content in kelp-based food products should be standardised.