Grateloupia Turuturu Research Articles

Reinboldiella koreana sp. nov. (Ceramiales, Rhodophyta) is the correct name for the specimens previously known as Reinboldiella schmitziana in Korea

Epiphytic algae are important components of marine ecosystems. Despite the importance of epiphytic algae in marine ecosystems, our knowledge of these taxa is still limited. The marine red algal genus <i>Reinboldiella</i>, which is distributed mainly in the northwestern Pacific region, is characterized by tiny thalli that are epiphytic on various other red algae. Six species of the genus have been reported in Japan, Taiwan, and Korea. In this study, 50 Korean Reinboldiella specimens, previously known as <i>Reinboldiella schmitziana</i>, were collected from 11 localities and reexamined to verify their taxonomic status. We describe a new species, <i>Reinboldiella koreana</i> sp. nov., based on <i>rbc</i>L phylogeny and morphological observations. A total of four grateloupiacean species (<i>Pachymeniopsis lanceolata</i>, <i>P. elliptica</i>, <i>Grateloupia turuturu</i>, and <i>G. asiatica</i>) were identified as host species of <i>R. koreana</i> sp. nov. Due to the restricted host range of <i>R. koreana</i> sp. nov., a phylogenetic tree was reconstructed using the <i>cox</i>1 marker to confirm the co-phylogenetic relationships between the epiphytic algae and their grateloupiacean hosts. Two of the four cox1 haplotypes of <i>R. koreana</i> were found in different host species, regardless of which haplotype they were. It indicates that there are no co-phylogenetic relationships between <i>R. koreana</i> and host species.

Chemical composition and nutrient profiles of nine red macroalgae species

Nine red macroalgae (Amphiroa rigida, Gracilaria bursa-pastoris, Gracilaria gracilis, Grateloupia torture, Jania rubens, Laurencia obtusa, Laurencia pyramidalis, Liagora viscida, and Pterocladiella capillaries) were collected from coastal waters of Türkiye, and their proximate, fatty acid, soluble carbohydrate, and mineral profiles were investigated in the present study. According to the results, the crude protein content of the samples was between 4% and 23.8%, and four of the samples (G. turuturu, L. obtusa, L. pyramidalis, and P. capillacea) contained more than 10% protein. The crude lipid content of all the samples was below 1.6%, and the total carbohydrate content was between 38.3% and 76.9%. The macroalgae samples were generally richer in saturated fatty acids, palmitic acid being the most abundant, whereas G. gracilis had the highest content of unsaturated fatty acids (55.8%). All samples exhibited high contents of myo-inositol or glucose. Also, the samples generally had a good composition of minerals. Still, the heavy metal (i.e., Pb and Cd) content of Gracilaria gracilis was higher (59.6 µg/kg, P < 0.05) than those of the other algae samples. This study provides valuable insight into the chemical composition and fatty acid, mineral, and soluble carbohydrate profiles of Amphiroa rigida, Gracilaria bursa-pastoris, Gracilaria gracilis, Grateloupia turuturu, Jania rubens, Laurencia obtusa, Laurencia pyramidalis, Liagora viscida, and Pterocladiella capillacea from Türkiye.Graphical

A novel seaweed-based biodegradable and active food film to reduce freezer burn in frozen salmon

The imperative to replace conventional plastic food packaging has led to the development of edible and biodegradable alternatives. This study has formulated an effective packaging solution for the preservation of frozen salmon. Alginate films were prepared by integrating ethanolic extracts from two edible seaweeds, Sargassum muticum and Grateloupia turuturu. The optical and mechanical properties of the films, as well as their effectiveness in preserving frozen salmon over a 6-month period at −18 °C, were assessed and compared to other alginate and synthetic plastic films. The quality parameters of the final product were also assessed. Films incorporating Grateloupia extract exhibited a 34% reduction in thickness and 51% lower moisture content when compared to alginate. Meanwhile, those containing Sargassum extract demonstrated improved water resistance, with a 11% decrease in solubility. The seaweed-incorporated films demonstrated gradual biodegradation over time. Samples packaged with these films displayed a substantial decrease in colour changes, ranging from 58% to 64%, compared to commercial plastic film packaging. This enhanced protection against freezer burn is likely due to the presence of lipid-derivate compounds in the Grateloupia extract. The findings of this study suggest the potential use of alginate-based films incorporated with Grateloupia and Sargassum extracts as edible and biodegradable packaging for frozen fish, offering a sustainable and improved alternative to synthetic plastic films.

Complete Mitogenome Sequencing, Annotation, and Phylogeny of Grateloupia turuturu, a Red Alga with Intronic cox1 Gene.

The mitochondrial genome (mitogenome) is essential for identifying species and tracing genetic variation, gene patterns, and evolutionary studies. Here, the mitogenome of Grateloupia turuturu was sequenced on the Illumina sequencing platform. This circular mitogenome (28,265 bp) contains 49 genes, including three rRNAs, twenty transfer RNAs (tRNAs), and twenty-six protein-coding genes (PCGs). Nucleotide composition indicates biased AT (68.8%) content. A Group II intronic sequence was identified between two exons of the cox1 gene, and this sequence comprises an open reading frame (ORF) that encodes a hypothetical protein. The gene content, annotation, and genetic makeup are identical to those of Halymeniaceae members. The complete mitogenome sequences of the Grateloupia and Polyopes species were used in a phylogenetic analysis, which revealed that these two genera are monophyletic and that G. turuturu and G. elliptica are closely related. This newly constructed mitogenome will help us better understand the general trends in the development of cox1 introns in Halymeniaceae, as well as the evolution of red algal mitogenomes within the Rhodophyta and among diverse algal species.

Recent changes on the abundance and distribution of non-indigenous macroalgae along the southwest coast of the Bay of Biscay

Twenty-three rocky shores along approximately 225 km on the southwest coast of the Bay of Biscay were sampled during the springs of 2014 and 2021, to explore changes in the distribution and abundance of four non-indigenous species (NIS) macroalgae (i.e., Asparagopsis armata, Grateloupia turuturu, Sargassum muticum, and Undaria pinnatifida) by using a semi-quantitative scale. Results showed relevant changes in the distribution and abundance of NIS. The kelp U. pinnatifida was recorded in 2021 for the first time on two shores. The distribution of G. turuturu showed an extension in its range of distribution of 200 km to the east. The other two target species S. muticum and A. armata were widely distributed along the whole 225 km of the studied area in 2014 and 2021, with higher abundance in 2021. Therefore, we strongly advise the necessity of future monitoring programs for these four NIS species. These monitoring programs will explore the progress of invasion and resilience of native species.

Effects of salinity and irradiance on early developmental stages of &lt;italic&gt;Grateloupia turuturu&lt;/italic&gt; (Halymeniaceae, Rhodophyta) tetrasporophytes

&lt;i&gt;Grateloupia turuturu&lt;/i&gt; is a red alga with a flat but firm slippery thallus. Throughout its lifetime, this alga experiences a wide range of environmental stresses in the intertidal rocky shores. The aim of this study is to investigate the effect of salinity and irradiance on the early developmental stages of &lt;i&gt;G. turuturu &lt;/i&gt;tetrasporophytes. The released carpospores were cultivated at different salinities (S = 15, 25, and 35) and irradiances (50, 100, and 200 μmol photons m&lt;sup&gt;-2&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;). Germination of carpospores and development of juvenile tetrasporophytes were observed every 5 days and recorded by a digital camera. Discoid crusts were formed at all conditions within 5 days. The discoid crusts at 200 μmol photons m&lt;sup&gt;-2&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt; died within 20 days regardless the salinity. The discoid crusts at S = 35 also died at all irradiance conditions within 25 days. Except for those at S = 35 and 200 μmol photons m&lt;sup&gt;-2&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;, the discoid crusts reached about 8,000–9,000 μm&lt;sup&gt;2&lt;/sup&gt; by day 20. Regardless of irradiance, the upright thalli formation rate from discoid crusts was 85 and 10% at S = 15 and S = 25, respectively. These results suggest that salinity and irradiance are important factors influencing early developmental stages of &lt;i&gt;G. turuturu&lt;/i&gt;.

Physiological effects of micro-plastics on the red algae, Grateloupia turuturu and Chondrus sp.

Plastics are the most abundant marine litter in the world's oceans and can be degraded into micro-plastics. These emerging pollutants negatively affect marine organisms, but little is known on the effects on macroalgae. In this study, we investigated the effects of micro-plastics on two species of red algae: Grateloupia turuturu and Chondrus sp. Grateloupia turuturu has a slippery surface while Chondrus sp. has a rough surface. Different surface characteristics of these macroalgae may affect adherence of micro-plastics. Both species were exposed to 5 different concentrations (0, 20, 200, 2000 and 20,000 ng/L) of polystyrene microspheres. Adherence capacity, accumulating micro-plastics on the surface was higher for Chondrus sp. than G. turuturu. Chondrus sp. at 20,000 ng/L only showed a decrease in growth rate and photosynthesis activity, and an increase of reactive oxygen species (ROS). However, G. turuturu was not significantly affected by micro-plastics at all tested concentrations. Shaded light and inhibition of gas flow by adhered micro-plastics may be a reason for the reduction of growth and photosynthesis and production of ROS. Based on this result, the toxic effects of micro-plastics appear to be species specific, dependent on the adherence capacity of macroalgae.

Differentiation of the Organoleptic Volatile Organic Compound Profile of Three Edible Seaweeds.

The inclusion of seaweeds in daily-consumption food is a worthy-of-attention challenge due to their high nutritional value and potential health benefits. In this way, their composition, organoleptic profile, and toxicity must be assessed. This work focuses on studying the volatile organic compounds (VOCs) emitted by three edible seaweeds, Grateloupia turuturu, Codium tomentosum, and Bifurcaria bifurcata, with the aim of deepening the knowledge regarding their organoleptic profiles. Nine samples of each seaweed were prepared in glass vials, and the emitted headspace was analyzed, for the first time, with a gas chromatography-ion mobility spectrometry device, a highly sensitive technology. By statistically processing the collected data through PCA, it was possible to accurately differentiate the characteristic patterns of the three seaweeds with a total explained variance of 98%. If the data were pre-processed through PLS Regression, the total explained variance increased to 99.36%. The identification of 13 VOCs was accomplished through a developed database of compounds. These outstanding values in addition to the identification of the main emissions of VOCs and the utilization of a never-before-used technology prove the capacity of GC-IMS to differentiate edible seaweeds based solely on their volatile emissions, increase the knowledge regarding their organoleptic profiles, and provide an important step forward in the inclusion of these highly nutritional ingredients in the human diet.

Cultivable seaweeds eliminate the lethal effects of the harmful alga, Margalefidinium polykrikoides, on early life stage fish

Margalefidinium polykrikoides (aka Cochlodinium polykrikoides) is a harmful algal bloom (HAB)-forming dinoflagellate that is well-known for its ichthyotoxic properties, causing economically significant fish kills globally during bloom events. In this study, we evaluate the ability of seaweeds, including Ulva spp., Gracilaria sp., Chondrus crispus, and Grateloupia turuturu to mitigate the ichthyotoxicity of cultured and bloom populations of M. polykrikoides towards early life stage forage fish (Menidia menidia, Menidia beryllina, and Cyprinodon variegatus). In assays with both cultured and wild M. polykrikoides, live seaweed thalli – particularly Ulva spp. – significantly extended fish survival in all cases, with higher concentrations of seaweed resulting in a greater protective effect. In some cases, seaweeds completely mitigated fish mortality, resulting in survival not statistically different from the control. DMSP, an antioxidant compound produced by seaweeds, significantly reduced the ichthyotoxic effects of M. polykrikoides (p < 0.005) with no Ulva present, suggesting that the antioxidant properties of seaweeds and seaweed metabolites may be partly responsible for the protective effects. Partition chamber survival assays demonstrated that close physical proximity between the fish and Ulva was necessary for a protective effect to occur. Finally, we show that over longer timescales, very low concentrations of Ulva (0.2 g L-1) can significantly reduce (68–92% reduction) bloom populations of wild M. polykrikoides compared to control (p < 0.05). Collectively, the results of this study demonstrate that (1) aquaculture of Ulva spp. may be a viable strategy to protect caged fish farms from M. polykrikoides blooms, (2) existing beds of Ulva and other seaweeds may provide a refuge for vulnerable fish populations during M. polykrikoides blooms, and (3) the protective effects of seaweeds from M. polykrikoides ichthyotoxicity is due to a localized antioxidant-rich microenvironment around the surface of the seaweed, neutralizing short-lived reactive oxygen species produced by M. polykrikoides.

Physiological Impacts of Nitrogen Starvation and Subsequent Recovery on the Red Seaweed Grateloupia turuturu (Halymeniaceae, Rhodophyta)

Grateloupia turuturu is a potential aquaculture species as it has a significant number of high-valued compounds. The purpose of this study was to evaluate the physiobiochemical performances of G. turuturu under nitrogen deficiency and resupply. In this study, G. turuturu was exposed to different lengths of nitrogen starvation (from 0 to 28 days) and subsequently subjected to a 21-day nitrogen-recovery period. The nitrate and ammonium uptake rates, growth rates, and nitrogenous compounds of G. turuturu were periodically measured. The results showed that the nitrogen-starved G. turururu absorbed ammonium much faster than nitrate after nitrogen recovery. Furthermore, an overcompensatory uptake of ammonium was induced via nitrogen deficiency in a short phase after nitrogen resupply. The time and rates of depletion of different compositions varied during nitrogen starvation. Specifically, pigment contents decreased faster than protein and total nitrogen contents, and the reduction rate of protein was the lowest. After nitrogen resupply, though G. turuturu gradually recovered, growth rates and pigments from long-term nitrogen starvations could not recover enough to reach their original values. Our study reveals the physiological changing processes of G. turuturu during nitrogen starvation and recovery and provides baseline information aiding in the development of strategies for G. turuturu cultivation.

The Brown Alga Bifurcaria bifurcata Presents an Anthelmintic Activity on All Developmental Stages of the Parasitic Nematode Heligmosomoides polygyrus bakeri.

The current control of gastrointestinal (GI) parasitic nematodes mainly relies on the widespread use of anthelmintics, which has inevitably led to resistance. Therefore, there is an urgent need to find new sources of antiparasitic compounds. Macroalgae represent a rich source of active molecules and are widely described as having medicinal properties. In the present study, we investigated the potential anthelmintic activity of aqueous extracts from three species of algae (Bifurcaria bifurcata, Grateloupia turuturu and Osmundea pinnatifida) on the murine parasite Heligmosomoides polygyrus bakeri. Using a set of complementary in vitro tests, including larval development assays, egg hatching tests and nematicidal activity assays on larvae and adults, we report the nematicidal activity of aqueous extracts of B. bifurcata. In addition, aqueous extract fractionation using liquid/liquid partitioning with a solvent of increasing polarity was performed in order to identify the groups of active molecules underlying the anthelmintic activity. Non-polar extracts (heptane, ethyl acetate) demonstrated high anthelmintic potential, highlighting the role of non-polar metabolites such as terpenes. Here, we highlight the strong anthelmintic potential of the brown alga B. bifurcata on a mouse model of GI parasites, thus confirming the strong interest in algae as natural alternatives for the control of parasitic nematodes.

Optimization of R-Phycoerythrin Extraction by Ultrasound-Assisted Enzymatic Hydrolysis: A Comprehensive Study on the Wet Seaweed Grateloupia turuturu

Enzyme-assisted extraction (EAE) and ultrasound-assisted extraction (UAE) are both recognized as sustainable processes, but little has been done on the combined process known as ultrasound-assisted enzymatic hydrolysis (UAEH), and even less on seaweed. The present study aimed to optimize the UAEH of the red seaweed Grateloupia turuturu for the extraction of R-phycoerythrin (R-PE) directly from the wet biomass by applying a response surface methodology based on a central composite design. Three parameters were studied: the power of ultrasound, the temperature and the flow rate in the experimental system. Data analysis demonstrated that only the temperature had a significant and negative effect on the R-PE extraction yield. Under the optimized conditions, the R-PE kinetic yield reached a plateau between 90 and 210 min, with a yield of 4.28 ± 0.09 mg·g-1 dry weight (dw) at 180 min, corresponding to a yield 2.3 times higher than with the conventional phosphate buffer extraction on freeze-dried G. turuturu. Furthermore, the increased release of R-PE, carbohydrates, carbon and nitrogen can be associated with the degradation of G. turuturu constitutive polysaccharides, as their average molecular weights had been divided by 2.2 in 210 min. Our results thus demonstrated that an optimized UAEH is an efficient method to extract R-PE from wet G. turuturu without the need for expensive pre-treatment steps found in the conventional extraction. UAEH represents a promising and sustainable approach that should be investigated on biomasses where the recovery of added-value compounds needs to be improved.

New records and observations of marine algae from Morocco (Eastern Atlantic Ocean)

ABSTRACT In the present paper, three algal species are recorded for the first time from Morocco: the two red algae Antithamnion villosum and Antithamnionella ternifolia and the green alga Lychaete rhodolithicola. Furthermore, two other red algae species are recorded for the first time from the Moroccan Atlantic coast and this part of the eastern Atlantic Ocean: Antithamnion amphigeneum and Antithamnionella boergesenii. Descriptions of these newly reported species are provided accompanied by photographs for each species. In addition, new observations and taxonomic remarks for some species are also provided. The green alga Lychaete rhodolithicola has a limited distribution in the North-eastern Atlantic Ocean of Europe, and the report of this species from Morocco extends the distribution of this species, because it is the first record of this species in Africa and outside Europe. This is one of the rare documentations with description and illustrations of L. rhodolithicola. The foliose species Grateloupia turuturu is studied in detail; it has been widely misidentified as G. doryphora. An examination of all specimens going under the name G. doryphora in the Moroccan herbaria has determined these specimens to be Grateloupia turuturu. An identification key for all Moroccan species of Antithamnion, Antithamnionella and Lychaete is presented.

Effects of Nitrogen Source and Concentration on the Growth and Biochemical Composition of the Red Seaweed Grateloupia turuturu (Halymeniaceae, Rhodophyta)

Seaweeds, as biofilters that remediate seawater eutrophication, have been widely applied in integrated cultivations for both ecological and economic benefits. Although Grateloupia turuturu (Rhodophyta) is considered as a qualified species in integrated maricultivation, its growth and biochemical performance under different nitrogen conditions are still unknown. Here, we cultured G. turuturu under two nitrogen sources (nitrate and ammonium) at six concentrations (0, 25, 50, 100, 200, and 400 µM) to investigate its growth and nitrogenous compounds (total and inorganic nitrogen, soluble protein, amino acids, and pigments) as well as the allocation pattern of nitrogen storage pools. Our results showed that G. turuturu was well acclimated to high concentrations of both nitrogen sources, and algal age played an important role in the preference of nitrogen sources. Most of the biochemical compositions in G. turuturu increased significantly with the increased concentrations of nitrogen, except for the protein and nitrate contents. Protein and residual organic nitrogen (RON, mainly amino acids) were found to be the two main nitrogen storage pools in G. turuturu. Our study revealed that G. turuturu can produce more profitable compositions at high nitrogen concentrations, making it a profitably promising biofilter to remediate eutrophication.

Characterization of dissolved organic matter in biochar derived from various macroalgae (Phaeophyta, Rhodophyta, and Chlorophyta): Effects of pyrolysis temperature and extraction solution pH

Characterization of biochar-derived dissolved organic matter (DOM) can provide deep insight into potential applications of biochar. Herein, biochar from six macroalgae (Phaeophyta—Sargassum fusiforme, Sargassum thunbergii, and Sargassum vachellianum; Rhodophyta—Grateloupia turuturu and Chondria crassicaulis; and Chlorophyta—Ulva pertusa) were subjected to pyrolysis at different temperatures (200 °C–500 °C). The effects of pyrolysis temperature and extraction solution pH on the characteristics of the macroalgal biochar-derived DOM (MBDOM) were investigated via fluorescence excitation–emission matrix spectroscopy with parallel factor (PARAFAC) analysis. Five humic-like substances and one protein-like substance were identified. The distributions of the six PARAFAC components depended on the macroalgae species, pyrolysis temperature, and extraction solution pH. The proportion of the protein-like substance (0 %–46.77 %) was less than that of the humic-like substances (100 %–53.23 %) in a given MBDOM regardless of the extraction solution pH values. Fluorescence spectral indicators show that DOM from macroalgal biochar is more autochthonous and humified than that from the corresponding biomass. Hierarchical cluster analysis and redundancy analysis results further show that the macroalgae species, pyrolysis temperature, and extraction solution pH jointly affect DOM characteristics with varying contribution levels.

The Red Seaweed Grateloupia turuturu Prevents Epidermal Dysplasia in HPV16-Transgenic Mice.

The role of dietary profiles in promoting or reducing the risk of multiple types of cancer is increasingly clear, driving the search for balanced foods and nutraceuticals. The red seaweed Grateloupia turuturu has been used as human food showing a balanced nutritional profile. This study aims to test in vivo chemopreventive effects of G. turuturu against cutaneous pre-malignant lesions in transgenic mice for the human papillomavirus type 16 (HPV16). Forty-four female HPV+/− or HPV−/− mice received a standard diet or were supplemented with 10% G. turuturu for 22 consecutive days. Cutaneous lesions (ear and chest skin) were identified histologically. Complementarily, the weights and histology of internal organs as well as blood biochemical and DNA integrity parameters were also assessed. G. turuturu consistently reduced the incidence of epidermal dysplasia induced by HPV16 on both cutaneous sites. Moreover, biochemical, DNA integrity and histological analyses confirmed G. turuturu edibility as no signs of toxicity were found. Dietary supplementation with G. turuturu is an effective and safe chemopreventive strategy in this model.

Polar Lipids Composition, Antioxidant and Anti-Inflammatory Activities of the Atlantic Red Seaweed Grateloupia turuturu.

Grateloupia turuturu Yamada, 1941, is a red seaweed widely used for food in Japan and Korea which was recorded on the Atlantic Coast of Europe about twenty years ago. This seaweed presents eicosapentaenoic acid (EPA) and other polyunsaturated fatty acids (PUFAs) in its lipid fraction, a feature that sparked the interest on its potential applications. In seaweeds, PUFAs are mostly esterified to polar lipids, emerging as healthy phytochemicals. However, to date, these biomolecules are still unknown for G. turuturu. The present work aimed to identify the polar lipid profile of G. turuturu, using modern lipidomics approaches based on high performance liquid chromatography coupled to high resolution mass spectrometry (LC–MS) and gas chromatography coupled to mass spectrometry (GC–MS). The health benefits of polar lipids were identified by health lipid indices and the assessment of antioxidant and anti-inflammatory activities. The polar lipids profile identified from G. turuturu included 205 lipid species distributed over glycolipids, phospholipids, betaine lipids and phosphosphingolipids, which featured a high number of lipid species with EPA and PUFAs. The nutritional value of G. turuturu has been shown by its protein content, fatty acyl composition and health lipid indices, thus confirming G. turuturu as an alternative source of protein and lipids. Some of the lipid species assigned were associated to biological activity, as polar lipid extracts showed antioxidant activity evidenced by free radical scavenging potential for the 2,2′-azino-bis-3-ethyl benzothiazoline-6-sulfonic acid (ABTS●+) radical (IC50 ca. 130.4 μg mL−1) and for the 2,2-diphenyl-1-picrylhydrazyl (DPPH●) radical (IC25 ca. 129.1 μg mL−1) and anti-inflammatory activity by inhibition of the COX-2 enzyme (IC50 ca. 33 µg mL−1). Both antioxidant and anti-inflammatory activities were detected using a low concentration of extracts. This integrative approach contributes to increase the knowledge of G. turuturu as a species capable of providing nutrients and bioactive molecules with potential applications in the nutraceutical, pharmaceutical and cosmeceutical industries.

Red seaweeds strengthening the nexus between nutrition and health: phytochemical characterization and bioactive properties of Grateloupia turuturu and Porphyra umbilicalis extracts

Red seaweeds strengthening the nexus between nutrition and health: phytochemical characterization and bioactive properties of Grateloupia turuturu and Porphyra umbilicalis extracts

Seaweeds’ carbohydrate polymers as plant growth promoters

Currently, the high food demand led to a mass agriculture practices, whereas crop productivity is one of the major concerns for the producers. However, the intensification of the use of synthetic fertilizers has led to serious harmful impacts for human health and for the environment. The quest for novel and natural agricultural products is a current trend, hence seaweed polysaccharide bioactivity can contribute for this pursuit. The seaweed principal carbohydrates (agar, carrageenan and alginate) were extracted and chemically characterized from five red seaweeds, namely Gracilaria gracilis (Slender wart weed), Asparagospis armata (Harpoon weed), Calliblepharis jubata (False eyelash weed), Chondracanthus teedei var. lusitanicus and Grateloupia turuturu (Devil's tongue weed); and three brown seaweeds Colpomenia peregrina (Oyster thief), Sargassum muticum (Wireweed) and Undaria pinnatifida (Wakame). Afterwards, it was evaluated the impact of these sulphated polysaccharides on kale (Brassica oleracea) growth. Among the polymers tested, iota-carrageenan (from Calliblepharis jubata), kappa/ iota-carrageenan (from the female gametophyte of Chondracanthus teedei var. lusitanicus) and agar (from Gracilaria gracilis) showed a positive effect on kale growth. Through the quantification of polysaccharides and uronic acids, it appears that the polymer chemical structure is the decisive factor that affects the plant biostimulant activity.

Seaweeds as Valuable Sources of Essential Fatty Acids for Human Nutrition.

The overexploitation of terrestrial habitats, combined with the ever-growing demand for food, has led to the search for alternative food sources. The importance of seaweeds as food sources has been growing, and their potential as sources of fatty acids (FA) make seaweeds an interesting feedstock for the food and nutraceutical industries. The aim of this study is to assess the potential of five red seaweeds (Asparagospis armata, Calliblepharis jubata, Chondracanthus teedei var. lusitanicus, Gracilaria gracilis, and Grateloupia turuturu) and three brown seaweeds (Colpomenia peregrina, Sargassum muticum and Undaria pinnatifida), harvested in central Portugal, as effective sources of essential FA for food or as dietary supplements. FA were extracted from the biomass, transmethylated to methyl esters, and analyzed through gas chromatography-mass spectrometry. G. gracilis presented the highest content of saturated fatty acids (SFA) (41.49 mg·g−1), whereas C. jubata exhibited the highest content of highly unsaturated fatty acids (HUFA) (28.56 mg·g−1); the three G. turuturu life cycle stages presented prominent SFA and HUFA contents. Omega-6/omega-3 ratios were assessed and, in combination with PUFA+HUFA/SFA ratios, it is suggested that C. jubata and U. pinnatifida may be the algae with highest nutraceutical potential, promoting health benefits and contributing to a balanced dietary intake of fatty acids.