Year-Round Quantification, Structure and Dynamics of Epibacterial Communities From Diverse Macroalgae Reveal a Persistent Core Microbiota and Strong Host Specificities.

Volatile organic compounds (VOCs) are produced by macroalgae in response to environmental stresses.A novel approach using Solid Phase Microextraction (SPME) was used to quantify the production of several VOCs from eight common intertidal algal species from the UK (Ascophyllum nodosum (Linnaeus) Le Jolis, Fucus vesiculosus (Linnaeus), Fucus serratus (Linnaeus), Laminaria digitata (Hudson) Lamouroux, Ulva lactuca (Linnaeus), Ulva intestinalis (Linnaeus), formerly known as Enteromorpha, Palmaria palmata (Linnaeus) Kuntze and Griffithsia flosculosa (J.Ellis) Batters).The volatile compounds included halogenated, sulphur containing, aldehydes, non-methane hydrocarbons (NMHC) and oxygenated species.Overall, the production of VOCs by these algae was not considerably different under illumination or in darkness; this suggests that the VOC production occurs during both algae photosynthesis and in other metabolic processes such as respiration or osmoregulation.Desiccation played an important role in the production of VOCs with greater production by macroalgae after desiccation.This production was related to the alga's normal position within the intertidal zone; there was a lower production of VOCs for species growing near the high water mark and a greater production for algae taken from the low tide position.There were also species differences in the VOC profiles and quantities released.For example, chlorinated and oxygenated compounds were principally released by the brown alga Ascophyllum nodosum, while green algae such as Ulva lactuca and Ulva intestinalis released greater amounts of brominated, sulphur containing compounds, aldehydes and non-methane hydrocarbons than the other algae tested.The kelps (e.g.Laminaria digitata) had the greatest release of iodinated compounds such as diiodomethane.These processes make significant contributions to the VOCs in seawater and, by transfer to the atmosphere, in the coastal atmosphere.

Intraspecific variation in seaweeds: The application of new tools and approaches

IN view of the fact that a study of the literature on the red and brown algae revealed considerable uncertainty as to whether true cellulose occurs in these plants, the following seaweeds were examined for cellulose by the usually accepted methods:—among the red algae, Corallina officinalis, Bostrychia scorpioides, Chondrus crispus, Rhodymenia palmata ; among the brown algae, Laminaria saccharina, L. digitata, Fucus serratus, F. vesiculosus, Ascophyllum nodosum, Pelvetia canaliculata and P. canaliculata, forma libera.

Zinc concentrations in marine macroalgae and a lichen from western Ireland in relation to phylogenetic grouping, habitat and morphology

Acclimation potential and biochemical response of four temperate macroalgae to light and future seasonal temperature scenarios

Members of various algal lineages are known to be strong producers of atmospherically relevant halogen emissions, that is a consequence of their capability to store and metabolize halogens. This study uses a noninvasive, synchrotron-based technique, X-ray absorption spectroscopy, for addressing in vivo bromine speciation in the brown algae Ectocarpus siliculosus, Ascophyllum nodosum, and Fucus serratus, the red algae Gracilaria dura, G.gracilis, Chondrus crispus, Osmundea pinnatifida, Asparagopsis armata, Polysiphonia elongata, and Corallina officinalis, the diatom Thalassiosira rotula, the dinoflagellate Lingulodinium polyedrum and a natural phytoplankton sample. The results highlight a diversity of fundamentally different bromine storage modes: while most of the stramenopile representatives and the dinoflagellate store mostly bromide, there is evidence for Br incorporated in nonaromatic hydrocarbons in Thalassiosira. Red algae operate various organic bromine stores - including a possible precursor (by the haloform reaction) for bromoform in Asparagopsis and aromatically bound Br in Polysiphonia and Corallina. Large fractions of the bromine in the red algae G.dura and C.crispus and the brown alga F.serratus are present as Br(-) defects in solid KCl, similar to what was reported earlier for Laminaria parts. These results are discussed according to different defensive strategies that are used within algal taxa to cope with biotic or abiotic stresses.

Detection of Some Conserved Domains in Phytochrome-like Proteins from Algae

Among seaweed groups, brown algae had characteristically high concentrations of mannitol, and green algae were characterised by fructose. In red algae, metabolite profiles of individual species should be evaluated. Seaweeds are metabolically different from terrestrial plants. However, general metabolite profiles of the three major seaweed groups, the brown, red, and green algae, and the effect of various extraction methods on metabolite profiling results have not been comprehensively explored. In this study, we evaluated the water-soluble metabolites in four brown, five red, and two green algae species collected from two sites in northern Japan, located in the Sea of Japan and the Pacific Ocean. Freeze-dried seaweed samples were processed by methanol-water extraction with or without chloroform and analysed by capillary electrophoresis- and liquid chromatography-mass spectrometry for metabolite characterisation. The metabolite concentration profiles showed distinctive characteristic depends on species and taxonomic groups, whereas the extraction methods did not have a significant effect. Taxonomic differences between the various seaweed metabolite profiles were well defined using only sugar metabolites but no other major compound types. Mannitol was the main sugar metabolites in brown algae, whereas fructose, sucrose, and glucose were found at high concentrations in green algae. In red algae, individual species had some characteristic metabolites, such as sorbitol in Pyropia pseudolinearis and panose in Dasya sessilis. The metabolite profiles generated in this study will be a resource and provide guidance for nutraceutical research studies because the information about metabolites in seaweeds is still very limited compared to that of terrestrial plants.

Occurrence of steryl glycosides and acylated steryl glycosides in some marine algae

Seaweed habitats are characterised by constantly fluctuating environmental conditions which can influence the biochemical composition of species. To quantify the natural variability in concentrations and composition of pigments and fatty acids, a seasonal and spatial analysis of ecologically and economically important seaweed species (Fucus serratus, Ascophyllum nodosum, Himanthalia elongata, Laminaria digitata and Palmaria palmata) from Ireland was undertaken. Results revealed both common and species-specific patterns in seasonal and spatial algal composition. Generally, pigment concentrations decreased during summer months and were associated with a higher ratio of xanthophylls to chlorophylls. A similar response was observed regarding the proportions of polyunsaturated fatty acids (PUFA) which also decreased during summer. Concentrations in total fatty acids (TFA) revealed two distinct patterns in the five species investigated. In the two fucoid species, an increase in TFA during summer months was positively correlated with high proportions of monounsaturated fatty acids, implying an accumulation of storage lipids; in the remaining three species, proportions of PUFA were highest during winter and generally followed the seasonal trends of TFA. On a larger, geographical, scale, results demonstrated an influence of sampling location on pigments and fatty acids. Results highlight the complexity of interacting seasonal, spatial and species-specific drivers determining the biochemical composition of seaweeds which influences their value as food source and should be considered when natural stocks are harvested for high-value commercial applications.

To explore the polysaccharides from selected seaweeds of Atlantic Canada and to evaluate their potential anti-influenza virus activities, polysaccharides were isolated from several Atlantic Canadian seaweeds, including three red algae (Polysiphonia lanosa, Furcellaria lumbricalis, and Palmaria palmata), two brown algae (Ascophyllum nodosum and Fucus vesiculosus), and one green alga (Ulva lactuca) by sequential extraction with cold water, hot water, and alkali solutions. These polysaccharides were analyzed for monosaccharide composition and other general chemical properties, and they were evaluated for anti-influenza virus activities. Total sugar contents in these polysaccharides ranged from 15.4% (in U. lactuca) to 91.4% (in F. lumbricalis); sulfation level was as high as 17.6% in a polysaccharide from U. lactuca, whereas it could not be detected in an alikali-extract from P. palmaria. For polysaccharides from red seaweeds, the main sugar units were sulfated galactans (agar or carrageenan) for P. lanosa, F. lumbricalis, and xylans for P. palmata. In brown seaweeds, the polysaccharides largely contained sulfated fucans, whereas the polysaccharides in green seaweed were mainly composed of heteroglycuronans. Screening for antiviral activity against influenza A/PR/8/34 (H1N1) virus revealed that brown algal polysaccharides were particularly effective. Seaweeds from Atlantic Canada are a good source of marine polysaccharides with potential antiviral properties.

The component acids of the fats of the following marine algae have been investigated by gas-liquid chromatography:Rhodymenia palmata, Laurencia pinnatifida, Laminaria digitata, L. saccharina, Fucus vesiculosus, F. serratus, Pelvetia canaliculata, Ascophyllum nodosum. The principal saturated acids are palmitic and myristic acids, some contain ca. 2–5% of stearic acid; traces of C8 and C10 saturated acids are present, but C12 (and in all but one) C 20saturated acids are absent. The major unsaturated acids are octadecenoic and octadecadienoic acids (probably oleic and linoleic acids), but some species also contain appreciable amounts (up to 12%) of hexadecenoic acid. All the oils contain significant amounts of an eicosatetraenoic acid (probably arachidonic acid) and in some eicosatrienoic and/or eicosapentaenoic acids are also present in small quantities. Two acids of unknown constitution (possibly branched chain acids) are also present in minor amounts. No C22 unsaturated acids could be detected.INTRODUCTIONVery little is known about the component fatty acids of marine algae. Lovern (1936) examined the fatty acids from the fats of Fucus vesiculosus, Laminaria digitata and Rhodymenia palmata using lead salt crystallization and fractional distillation techniques (Table 2). With these methods, however, it was not possible to separate individual unsaturated acids having the same number of carbon atoms from one another. The mean unsaturation values of these fractions were therefore evaluated from their iodine values and expressed as the number of hydrogen atoms necessary to convert the fraction to the corresponding fully saturated state; thus ( — 4–0H) indicates an average unsaturation corresponding with two double bonds.

Marine algae have been utilized by man since prehistoric times as food, drugs or raw materials for chemicals; however, their more concentrated exploitation dates back only to the past 50 years or so. The discovery, isolation and purification of polysaccharides in the brown and red algae with characteristics favorable for different industrial applications created such a demand for these plants that worldwide shortage resulted, causing a keen competition among nations for the control of natural growing beds. Calculations are presented on the total potential world supply of harvestable algae and alternative solutions for satisfying the growing demands of the phycocolloid industries are discussed, including the current efforts to grow algae under controlled conditions for predictable harvests. The feasibility of such aquaculture ventures is evaluated and the pros and cons of creating algae factories are pointed out. TEXT Marine algae are lower plants restricted to the salt water environment. They range in size from the microscopic unicellular organisms to the largest plants on the earth. Certain groups of them reach considerable dimensions and are called kelps in general. According to their pigmentation, one Distinguishes among green, brown and red algae. All three groups are quite distinct and were already recognized by the Romans. Different uses date back to early historic times, both as food and medicaments. The brown algae were found to accumulate large quantities of iodine in their bodies, and dried weeds were already used in ancient China for the treatment of goiter. Some green algae are still cooked especially by Oriental people - into soups or made into salads) while red algae are smoked and sold as a delicacy in many of the Nordic countries. These uses of algae, however, did not warrant their large-scale exploitation. Only the discovery in this century that both the brown and red algae contain substances which are relatively easy to extract and have characteristics useful in different applications, lead to the foundation of what might be termed seaweed industry. Most of the marine algae have a highly slippery consistency, which is due to mucous substances which they manufacture in their cells and secrete toward the environment. These substances serve the protection of the plants and all have one common characteristic -- they are made up of long polymers of different sugars. Since they will produce a colloidal system in water, they fall into the category of hydrocolloids and since. They are obtained from algae) the Greek name of which is Phykos, they are termed phycocolloids. In modern industry there are basically three such colloids which are Widely utilized: [1] algin, or alginic acid) and its different salts obtained exclusively from brown algae; [2] agar-agar, produced by certain red algae and [3] carrageen in, extracted from other red algae. Alginates are widely utilized in different foods for the high viscosity solutions they produce where such requirement is present, as in creams, to which they impart a better whipping ability.

Comparative studies on the nutrition of two species of abalone, Haliotis tuberculata L. and Haliotis discus hannai Ino. V. The role of polyunsaturated fatty acids of macroalgae in abalone nutrition

A revitalized view of feeding by herbivorous marine fishes is sought through two questions. First, What characteristics of major taxa of algae identify them as predictably high or low quality foods? Second, are marine algae valuable foods for fishes which do not mechanically disrupt cell walls and do not harbor specialized enzymes or microbes capable of lysing cell walls? Energy, ash and nutrient content of 16 species of marine algae were employed to assess food quality of fleshy red, green, brown and calcareous red algae. On the basis of ash, calories, total protein and total lipid content, fleshy algae should be superior to calcareous algae as foods for fishes; in addition, green algae should be superior to brown algae and brown algae superior to red algae. When the probable digestibility of storage and extracellular carbohydrates is considered, green and red algae are predicted superior to brown algae as food. Two species of damselfishes (Pomacentridae) from the Gulf of California,Eupomacentrus rectifraenum andMicrospathodon dorsalis, eat red and green algae and ignore brown and calcareous algae. They feed, therefore, in a fashion consistent with predictions based only on algal chemistry. These fishes absorb at least 20–24% of the biomass, 57–67% of the protein, 46–56% of the lipid and 37–44% of the carbohydrate contained in algae eaten in the wild. Since these damselfishes do not masticate their food, it appears that herbivorous fishes can digest major fractions of algal nutrients without mechanical destruction of algal cells.