Red Alga Palmaria Palmata Research Articles

A critical review of the edible seaweed Palmaria palmata (L.) Weber & Mohr and its bioactive compounds in the “omics” era

The red alga Palmaria palmata (“dulse”; Palmariaceae, Rhodophyta) has been used as food since the fifth century, especially in the North Atlantic region. Dulse is a good alternative to cereals due to its high nutritional profile. A critical review based on scientific and grey literature of dulse bioactive compounds and their activity identified key knowledge gaps. The review synthesis emphasizes the importance of species delimitation, microbial community characterization and multi-omics in the research of P. palmata. Recent advances and uncertainty in delimitating P. palmata are introduced in a phylogenetic context, and recommendations are given for future phytochemical studies. We refer to the concept of “seaweed holobiont” as the functional entity encompassing the seaweed and its associated microbiota, and call for action to characterize the microbial communities, since their interactions with the environment and seaweeds are important in seaweed well-being and postharvest quality changes (e.g. microbial spoilage and degradation of algal matrices). Finally, we discuss the status and trends of using multi-omics to address important research questions of P. palmata, and to help us understand the source, biosynthesis and function of its bioactive compounds.

The use of seaweed as sustainable feed ingredient for the house cricket (Acheta domesticus): investigating cricket performance and nutritional composition

Abstract The house cricket (Acheta domesticus) is considered one of the most promising farmed insect to be used as novel food, thanks to its attractive nutritional profile and its great taste. To the best of our knowledge, crickets in Europe are reared on soybean meal-rich feed which won’t be sustainable in the long run. Insect producers have shown interest in using more environmentally friendly substrates for cricket’s rearing. Among these, seaweed has been investigated as feed ingredients for insect rearing. However, no studies on crickets are available. We aimed to evaluate the potential use of the alga Palmaria palmata in the diet of house crickets (5%, 10% and 20% of the diet), in terms of insect performances and nutritional composition (protein, lipid, amino acids and fatty acids). Crickets fed seaweed-enriched diets showed good performance parameters (individual weight, cricket yield and survival) compared to crickets fed the control diet without presenting statistically significant differences (), while their nutritional composition changed significantly for some components. Protein content of the crickets increased when more seaweed was added to their diets (), while the fat content decreased (). Also, the amino acid composition of the crickets remained stable between dietary groups, except for histidine, methionine and lysine which increased in crickets fed more seaweed in the diet (, , , respectively). Finally, the presence of seaweed in the diet led to a transfer of the omega-3 eicosapentaenoic acid from the seaweed to the crickets (), which are naturally lacking this fatty acid. Based on this study, we conclude that the red alga Palmaria Palmata is a suitable substrate for cricket mass rearing up to 20 g/100 g of the diet. However, higher seaweed inclusion and longer dietary administration time could affect the nutritional composition of the house cricket differently, therefore they should be investigated.

Red Algae Palmaria Palmata: Biological and Chemical-Technological Characteristics, Recommendations for Its Use as a Source of Nutrients in Human Nutrition

One of the ways to develop micronutrient balanced products may be to include P. palmata red algae in its formulation. The aim is to study the biochemical parameters of P. palmata growing in the White Sea, and to assess the prospects of its use in human nutrition. The thesis presents the biological and chemical-technological characteristics, as well as the results of the drying process of P. palmata growing in the coastal zone of the White Sea, Solovetsky Islands. Analysis of the chemical composition of P. palmata showed that the main components were carbohydrates (45.6–75%) including fiber – 3.6–7.7%, proteins – 7.04–22.62%, ash –18.03–31.74%. The research presents the macro- and microelement composition of P. palmata collected in 2022 in the White Sea. 1 gram of dry algae for iodine, chromium by 12–16% corresponds to the norms of physiological need. The amino acid score value for all essential amino acids is less than 100%, while the limiting amino acids are lysine and threonine. The difference coefficient of amino acid score is 7.6%, the biological value of P. palmata protein is 92%. The dried P. palmata yield from raw algae is 18–20%. Under favorable weather conditions, Palmaria layers are dried to 10–15% water content within 23–26 hours. Based on the results of studies on the safety indicators and chemical composition of P. palmata, the authors demonstrated its applicability in food formulations development as a source of biologically active substances, such as amino acids. Alcohol extracts obtained from P. palmata have antimicrobial activity against Proteus vulgaris and Pseudomonas aeruginosa. In this regard, alcohol extracts from P. palmata can probably be used as an antimicrobial agent in the process of food production.

Spectroscopic insight on impact of environment on natural photoprotectants.

Biomimicry has become a key player in researching new materials for a whole range of applications. In this study, we have taken a crude extract from the red algae Palmaria palmata containing mycosporine-like amino acids - a photoprotective family of molecules. We have applied the crude extract onto a surface to assess if photoprotection, and more broadly, light-to-heat conversion, is retained; we found it is. Considering sunscreens as a specific application, we have performed transmission and reflection terahertz spectroscopy of the extract and glycerol to demonstrate how one can monitor stability in real-world applications.

Differential acclimation responses to irradiance and temperature in two co-occurring seaweed species in Arctic fjords

Arctic fjord systems experience large amplitudes of change in temperature and radiation regime due to climate warming and the related decrease in sea ice. The resultant increase in irradiance entering the water column influences photosynthetic activity of benthic and pelagic primary producers. The subtidal brown alga Desmarestia aculeata and the intertidal red alga Palmaria palmata populate the cold-temperate coasts of the North Atlantic, reaching the polar zone. To evaluate their acclimation potential, we collected both species in Kongsfjorden, Svalbard (78.9°N, 11.9°E), during the Arctic summer and exposed specimens to two different PAR levels (50 and 500 μmol photons m−2 s−1) and temperatures (0, 4 and 8 °C) for 21 days. Photosynthetic parameters and biochemical features (pigment concentration and antioxidants) were assessed. In general, high irradiance was the factor that generated a negative effect for D. aculeata and P. palmata in the photosynthetic parameters of the photosynthesis–irradiance curve and Fv/Fm. The pigment concentration in both species tended to decrease with increasing irradiance. Antioxidant level showed different trends for both species: in D. aculeata, antioxidant potential increased with high irradiance and temperature, while in P. palmata, it only increased with high irradiance. Both species showed responses to the interaction of irradiance and temperature, although D. aculeata was more sensitive to high irradiance than P. palmata. Our study shows how these species, which have similar geographical distribution in the North Atlantic and the Arctic but belong to different taxonomic lineages, have similar strategies of acclimation, although they respond differently to ecophysiological parameters.

The B-group vitamins in the red alga Palmaria palmatа (Barents Sea): Composition, seasonal changes and influence of abiotic factors

An amount, composition and seasonal changes of group B vitamins in the red alga Palmaria palmata growing on the Murmansk coast of the Barents Sea were analyzed, as well as the influence of environmental factors on their concentration. By the method of capillary electrophoresis, it was shown that P. palmata contain only three of six main B vitamins: riboflavin, pyridoxine, and niacin. Significant seasonal variations were observed for these vitamins: two main concentration peaks were distinguished, spring/summer and autumn, which may be associated with the spring activation of growth processes and the preparation of algae for the winter months, respectively. An apparent and high-level positive dependence of the riboflavin content upon the light level and environmental temperature was established, as well as a negative dependence on salinity. As to contents of niacin and pyridoxine, significant linear correlations with intensity of photosynthetically active radiation only were observed. Possible role of those vitamins in P. palmata seasonal acclimation is discussed.

Absorption and Conversion of Diesel Fuel by the Red Alga Palmaria palmata (Linnaeus) F. Weber et D. Mohr, 1805 (Rhodophyta): The Potential Role of Alga in Bioremediation of Sea Water

It was shown for the first time that the red alga Palmaria palmata (Linnaeus) F. Weber et D. Mohr, 1805 not only retained its physiological activity under the conditions of moderate pollution of the seawater with diesel fuel, but also exhibited a pronounced ability for sorption and destruction of petroleum products. The content of diesel fuel components in seawater decreased simultaneously with their accumulation in the algae. Apparently, the entire thallus of P. palmata participated in the destruction of diesel fuel: this process began on the algal surface via the activity of epiphytic hydrocarbon-oxidizing bacteria that provide the conversion of petroleum products into a plant-accessible form available for macrophytes. Subsequently, the petroleum products were neutralized by algal cells. The resilience of P. palmata under the influence of diesel fuel was confirmed by the consistently high metabolic activity of P. palmata cells throughout the 21-day experiment. It is assumed that the ability of macroalgae to form symbiotic associations with hydrocarbon-oxidizing microorganisms is the main factor in their bioremediation.

Effect of Light Quality and Nitrogen Availability on the Biomass Production and Pigment Content of Palmaria palmata (Rhodophyta)

Macroalgae constitute a huge underexploited resource for compounds of interest to the health industry. External factors strongly influence the concentration of these compounds in the algal tissue. This implies a potential for optimizing the growth conditions for cultivated macro algae in order to promote production of valuable compounds. The objective of this study was to determine the influence of light spectral composition (red, blue, and white) and nutrient treatment (30 and 440 µM NO3 - ) on chlorophyll a and carotenoid concentration as well as growth rate of the red algae Palmaria palmata. The results show that the nitrogen load has a larger effect on the pigment concentration and growth rate in the algae, than the light treatments. Experiments with different light spectral composition showed the highest pigment content with white and blue light while red light was less effective. In addition, samples cultivated under white light had higher growth rates compared to red and blue light. Therefore, to increase the concentration of nutritionally valuable pigments cultivation strategies in marine production should be to use blue or white light and use high NO3 concentrations.

Variations in polyphenol and heavy metal contents of wild-harvested and cultivated seaweed bulk biomass: Health risk assessment and implication for food applications

Seaweeds are increasingly used in European cuisines due to their nutritional value. Many algal constituents, such as polyphenols, are important antioxidants and thus considered beneficial to humans. However, many seaweed species can accumulate heavy metals and exhibit potential health risks upon ingestion. We investigated temporal and spatial variations in polyphenol and heavy metal (As, Cd, Hg, Pb) concentrations of three edible seaweed species. The brown algae Saccharina latissima and Alaria esculenta, and the red alga Palmaria palmata were sourced from natural populations and aquaculture in the NE Atlantic and processed as bulk biomass mimicking industrial scales. The mean polyphenol content was species-specific (Alaria > Saccharina > Palmaria), and highest in winter (for Alaria and Saccharina) and spring (for Palmaria); inter-annual and spatial variations were marginal. Heavy metal concentrations varied between species and depended on collection site, but seasonal variations were minimal. Our data suggest that all three species are good sources of antioxidants, and the heavy metal concentrations are below the upper limits set by the French recommendation and the EU Commission Regulation on contaminants in foodstuffs. A health risk assessment indicated that consumption of these seaweed species poses a low risk for humans with regard to heavy metals. However, an EU-wide regulation on maximal concentration of heavy metals in seaweeds should be established.

Iodine content in bulk biomass of wild-harvested and cultivated edible seaweeds: Inherent variations determine species-specific daily allowable consumption

This study represents a large-scale investigation into iodine contents in three commercially important and edible seaweed species from the North Atlantic: the brown algae Saccharina latissima and Alaria esculenta, and the red alga Palmaria palmata. Variability among and within species were explored in terms of temporal and spatial variations in addition to biomass source. Mean iodine concentration in bulk seaweed biomass was species-specific: Saccharina > Alaria > Palmaria. Iodine contents of Saccharina biomass were similar between years and seasons, but varied significantly between sampling locations and biomass sources. In Alaria and Palmaria, none of the independent variables examined contributed significantly to the small variations observed. Our data suggest that all three species are rich sources of iodine, and only 32, 283, or 2149 mg dry weight of unprocessed dry biomass of Saccharina, Alaria, or Palmaria, respectively, meets the recommended daily intake levels for most healthy humans.

Two intertidal, non-calcifying macroalgae (Palmaria palmata and Saccharina latissima) show complex and variable responses to short-term CO2 acidification

Abstract Ocean acidification, the result of increased dissolution of carbon dioxide (CO2) in seawater, is a leading subject of current research. The effects of acidification on non-calcifying macroalgae are, however, still unclear. The current study reports two 1-month studies using two different macroalgae, the red alga Palmaria palmata (Rhodophyta) and the kelp Saccharina latissima (Phaeophyta), exposed to control (pHNBS = ∼8.04) and increased (pHNBS = ∼7.82) levels of CO2-induced seawater acidification. The impacts of both increased acidification and time of exposure on net primary production (NPP), respiration (R), dimethylsulphoniopropionate (DMSP) concentrations, and algal growth have been assessed. In P. palmata, although NPP significantly increased during the testing period, it significantly decreased with acidification, whereas R showed a significant decrease with acidification only. S. latissima significantly increased NPP with acidification but not with time, and significantly increased R with both acidification and time, suggesting a concomitant increase in gross primary production. The DMSP concentrations of both species remained unchanged by either acidification or through time during the experimental period. In contrast, algal growth differed markedly between the two experiments, in that P. palmata showed very little growth throughout the experiment, while S. latissima showed substantial growth during the course of the study, with the latter showing a significant difference between the acidified and control treatments. These two experiments suggest that the study species used here were resistant to a short-term exposure to ocean acidification, with some of the differences seen between species possibly linked to different nutrient concentrations between the experiments.

Enzyme-enhanced extraction of antioxidant ingredients from red algae Palmaria palmata

The effect of various protease and carbohydrase treatments on the extraction of polyphenols and other antioxidant ingredients from the red algae Palmaria palmata (dulse) was investigated. In addition, the relative contribution of different fractions to the overall antioxidant capacity of the hydrolysate was evaluated. Considerable differences were observed both in total phenolic content (TPC) and antioxidant activities of the hydrolysates evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, oxygen radical absorbance capacity (ORAC) and ferrous ion-chelating ability assays. All the proteases tested had significant enhancing effect on the extraction of polyphenols and other active components compared to carbohydrases and cold water extraction (control). The Umamizyme extract had the highest TPC and consequently exhibited the strongest scavenging capacity against DPPH and peroxyl radicals. Further fractionation of the Umamizyme extract revealed that the crude polyphenol fraction possessed the highest peroxyl radical scavenging activity, whereas the crude polysaccharide fraction was more effective for chelating ferrous ions. The data from this study suggest the potential of protease treatment to improve value-added utilization of dulse extracts as antioxidants in functional foods and nutraceuticals.

X-ray structure of a sodium salt of digeneaside isolated from red alga Ceramium botryocarpum

X-ray diffraction analysis has been recently used to determine the crystal structure of the floridoside (2- O-α- d-galactopyranosylglycerol) isolated from red alga Palmaria palmata and Dilsea carnosa, respectively [Simon-Colin, C.; Michaud, F.; Léger, J.-M.; Deslandes, E. Carbohydr. Res. 2003, 338, 2413–2416; Vonthron-Senechau, C.; Sopkova-de Oliveira Santos. J.; Mussio, I.; Rusig, A. M. Carbohydr. Res. 2008, 343, 2697–2698]. In this present study, a similar analysis was performed on another compound belonging to the glycopyranosyl–glycerols family present in red algae, digeneaside. The crystal structure of a hydrated sodium salt of digeneaside (sodium 2- O-α- d-mannopyranosyl- d-glycerate monohydrate) was determined by single-crystal X-ray diffraction analysis at 110 ± 3 K. The space group is C2 with Z = 4, a = 17.9315(12), b = 6.2693(4), c = 10.7805(7) Å, beta = 90.746(7)°.

Influence of dietary protein on essential fatty acids in the gonadal tissue of the sea urchins Psammechinus miliaris and Paracentrotus lividus (Echinodermata)

The elevated accumulation of certain essential long-chain polyunsaturated fatty acids (PUFA) during reproductive maturation can place a significant demand on lipid metabolism. As lipid metabolism is closely linked with protein metabolism, protein intake during maturation may significantly influence transport proteins and enzyme activity which is responsible for supplying the essential fatty acids for gamete development. The present study investigated the influence of increased protein intake on the accumulation of certain long-chain PUFA in two species of commercially valuable sea urchin, Paracentrotus lividus and Psammechinus miliaris during maturation. Sea urchins were fed three macroalgal diets over a 90-day period. These diets included the red alga Palmaria palmata, which had been grown in seawater enriched with two levels of ammonia-N, which produced a high protein content (41%) or low protein content (32%). The third diet (or reference diet) used the brown macroalga Laminaria saccharina with a 23% protein content. The fatty acid composition of the gonads was determined by GC. Feeding the high protein diet had no effect on the maturation and total lipid in the gonad compared with the low protein diet, however, it did significantly increase the levels of docosahexaenoic acid DHA 22:6n-3 in the mature gonad tissue in P. miliaris and P. lividus. In contrast, only P. miliaris exhibited higher levels of arachidonic acid ARA 20:4n-6 when fed the high protein diet. The present study suggests that elevated protein levels can promote the accumulation of DHA and ARA in gonadal tissue during maturation, although the extent of the influence is species-specific and highlights the importance of understanding the complexities and inter-connectivity between protein and lipid metabolism when producing commercially valuable species.

Effect of variation in the protein value of the red macroalga Palmaria palmata on the feeding, growth and gonad composition of the sea urchins Psammechinus miliaris and Paracentrotus lividus (Echinodermata)

The sea urchins Psammechinus miliaris and Paracentrotus lividus were fed three macroalgal diets with varying protein content over a 90-day period. These diets were the red alga Palmaria palmata, which had been grown in seawater enriched with two levels of ammonia-N and contained a protein content of either 41% (High-N) or 32% (Low-N) and the brown alga Laminaria saccharina (23% protein). A significantly different response to the macroalgal diets by the two sea urchin species was found in terms of food consumption rate, food conversion efficiency, gonadal growth and gonad nutritional composition. P. miliaris was able to efficiently utilise the High-N P. palmata, whereas P. lividus exhibited a higher food conversion efficiency (FCE) and specific growth rate (SGR) when fed the Low-N compared with the High-N P. palmata. P. miliaris had a significantly higher food consumption rate and higher gonad index (GI) compared with P. lividus, irrespective of diet type. The lowest FCE, SGR and GI were shown by both species fed L. saccharina. No interspecific difference in gonadal nitrogen content was observed, although a positive relationship was shown between dietary and gonadal nitrogen content for both species. All three macroalgal diets produced bright orange or yellow orange gonad colour in P. lividus. High-N and Low-N P. palmata improved gonad colouration in P. miliaris compared with L. saccharina. The results suggest that P. miliaris can efficiently assimilate high protein plant-based diet, whereas P. lividus is less capable of benefiting from high dietary protein levels and this should be taken into consideration when culturing this species either in land-based or sea-based polyculture systems.

Meristem clusters in cortical layer of thallus cells of the cultured red alga Palmaria palmata

For the first time somatic spotlike formations of 1.5 mm in diameter and height up to 0.5 mm were revealed in thalli of the red alga Palmaria palmata reared in an aerated stirred culture. It was determined that some cortical cells of the thallus are able to divide in the periclinal and anticlinal directions forming spots. Deep freezing and subsequent thawing of thalli showed that the cortical cells of spots were meristematic cells. In certain conditions they enabled the formation of prolifications, which germinated plantlets. These clusters of meristem tissue in the cortical layer of cells of the thallus of P. palmata, which were formed in the culture as in nature, function as growth cells facilitating growth of thalli in thick and natural “planting material” formed upon thalli fragmenting after their freezing in the winter season.

New methods of obtaining plantlets and tetraspores from fragments and cell aggregates of meristematic and submeristematic tissue of the red alga Palmaria palmata

Isolation of meristematic tissue of the red alga Palmaria palmata by a freezing–thawing method and further maintenance of the tissue in culture showed the existence of groups of meristematic cells in superficial cortical layers of thallus forming wart-like outgrowths. For the first time, proliferations (plantlets) were obtained from meristematic tissue of sporophytic and male gametophytic fronds and tetraspores from submeristematic tissue of sporophytic fronds within a short period (6 weeks). Tissue fragments (1 × 1 mm 2) from upper margins of fresh thalli and cell aggregates (10−100,000 cells) from marginal meristem and meristematic warts of fresh thalli and thalli after the freezing–thawing procedure were cultured for getting plantlets. Tissue fragments (TF) and cell aggregates (CA) from submeristematic tissue of fresh thalli were cultured for obtaining tetraspores. For mass getting proliferations (plantlets) and tetraspores we recommend to use CA from marginal tissue of fresh fronds because of fast growth, high numbers of proliferations and simple techniques of the method. The freezing–thawing method allows also to identify meristematic tissue and to obtain plantlets of red algae with apical meristem (e.g., Gelidium spp.).

Initial observations on glycoside deposition in cell walls of Palmaria palmata (L.) Kuntze (Rhodophyta) during spore germination

The cell wall fine structure of the red alga Palmaria palmata has been analysed extensively in recent years, but cell wall biosynthesis has not. The glycosidic composition of the cell walls of gametophytic and sporophytic fronds revealed no differences between the two stages. Spores were isolated from mature sporophytes and cultivated in vitro. Spore settlement, germination and first stages of germling development were described in terms of glycoside composition. Isolated spores were surrounded by a cell wall composed of xylose, galactose and glucose. During germination and germling development, the xylose content increased to the level of glycosides found in erect fronds, concurrently with starch degradation. Spores isolated from Palmaria palmata appeared to be good candidates for studying cell wall biosynthesis.

Intra- and interspecific differences in palatability of Arctic macroalgae from Kongsfjorden (Spitsbergen) for two benthic sympatric invertebrates

Information on herbivore–macroalgae interactions is extremely scarce for Arctic habitats. In this study, the potential of 19 macroalgae as food source for herbivores was investigated for the first time in Arctic waters (Kongsfjorden, Spitsbergen) with emphasis on algal defense against grazing. Only two of the 19 tested macroalgae-associated invertebrates consumed macroalgae in measurable amounts, the locally abundant green sea urchin Strongylocentrotus droebachiensis (OF Müller) and the amphipod Gammarellus homari (JC Fabricius). In the inner basin of the fjord, the dense macroalgal stock represents a potential food source. However, in this area, herbivory plays only a minor role. In contrast, in the outer basin of Kongsfjorden S. droebachiensis exerts a strong top-down control on macroalgal assemblages. Laboratory feeding assays in the with the two herbivores showed grazer-specific feeding preferences. The amphipod G. homari exhibits a preference for delicate red algal species like Devaleraea ramentacea, whereas the sea urchin S. droebachiensis significantly preferred more leathery seaweeds like Laminaria and Alaria. The red alga Palmaria palmata is a very attractive food for both herbivores, while the brown alga Desmarestia viridis and the red alga Ptilota gunneri are among the least preferred algae. To distinguish between physical and tissue-specific plant properties, which have a deterring or stimulating effect on the grazing behaviour, both grazers were offered intact algal tissue and artificial food in separate feeding assays. While physical and tissue-specific plant properties–especially in the Laminariales–deterred G. homari, these properties did not deter S. droebachiensis. This study provides insights into herbivore consumption in the benthic food web of Kongsfjorden. As a general potential top-down factor controlling primary production, herbivory needs to be quantified further in Kongsfjorden to develop adequate carbon flow models for this important reference site for the study of climate change on high latitude marine ecosystems.

Extracts from dulse ( Palmaria palmata) are effective antioxidants and inhibitors of cell proliferation in vitro

Previously, we reported that a 1-butanol soluble extract of the edible red alga Palmaria palmata, known as dulse, exhibited hydroxyl and stable free radical scavenging activity as well as inhibition of lipid peroxidation, attributed to the reducing activity and polyphenol content of the dulse extract. In the present study, we evaluated the antioxidant and antiproliferative activities of two grades of dulse harvested from Canadian Maritime locations differing in UV radiation exposure (i.e. west versus east coasts of Grand Manan Island, New Brunswick). The 1-butanol soluble extract from Grade 1 dulse (reduced UV-exposure) exhibited lower reducing activity versus Grade 2 dulse (greater UV exposure) reflecting a lower requirement for endogenous antioxidant protection. Grade 1 and 2 dulse extracts both inhibited ( p ⩽ 0.03) AAPH-induced lipid peroxidation, but had no effect on AMVN-induced lipid peroxidation, demonstrating the aqueous nature of the antioxidants involved. The Grade 1 and 2 dulse extract inhibition ( p < 0.05) of HeLa cell proliferation was dose-dependent over 0.5–5.0 mg/mL and maximal at 48 and 72 h incubation. The antiproliferative effects of the Grade 1 and 2 dulse extracts in the present study likely reflect the bioactivity of the polyphenol content of these extracts.