Search

At different parts of the world, Red Seaweeds are one component of human diets especially at Southeast Asia. Red Seaweeds structurally contain bioactive molecules so; we studied the effect of Chondrus crispus on increasing the male albino rat fertility. Twelve male albino rats are used in this study as two group pre-treated group and post- treated one each with 6 animals. The pretreated group was dissected before the post-treated group injection. Each post treated rat injected intramuscular with 1 mg of Chondrus crispus with dose 0.1 ml/ twice per week for 48 day (Mukhtar et al., 2013). The results showed that increasing on the total testosterone levels insignificantly, sperm motility significantly, and decreasing in both FSH and DPPH levels insignificantly and significantly for the MDA levels in the post-treated group. The morphological appearance and histological examination for the sperm, testis and liver were normal as the pretreated group. The molecular studies showed absence of any DNA fragmentation for the testis of both group. The Red Seaweed has an enhanced effect in the testicular function of the animal which might increase their fertility and sexual activities.

Caffeine is present in coastal environments worldwide and there is a need to assess its impact on marine organisms. Here, we exposed two species of ecologically important marine macroalgae (Chondrus crispus and Codium fragile subsp. fragile) to a suite of caffeine concentrations and measured their response. Caffeine concentrations of 10–100 ng L−1 had no significant effect on the growth rate or photosynthetic efficiency of either algae. Extremely high concentrations (100–200 mg L−1), which may occur acutely, produced sublethal effects for both species and mortality in C. fragile subsp. fragile. Our results highlight the need to understand how caffeine impacts marine species.

Snakebites are a serious occupational problem affecting rural populations of tropical and sub-tropical, developing countries. Envenomation caused by the snakes Bothrops jararaca and B. jararacussu is characterized by local pain, edema, hemorrhage, tissue necrosis, and death. Despite the fact that antivenom may prevent the death of bite victims, treatment does not prevent tissue necrosis, often leading to amputation or deformity of the victim’s affected limb.Therefore, more efficient therapies need to be investigated. In this work, we tested the ability of a carrageenan galactan polysaccharide, isolated from a clonal strain of the red alga, Chondrus crispus (commonly known as Irish moss) to inhibit toxic, in vitro (coagulation, hemolytic and proteolytic) or in vivo (hemorrhagic, edematogenic, myotoxic and lethal) activities of B. jararaca or B. jararacussu venom. When the polysaccharide was mixed together with the venoms, inhibition of their toxic activities was achieved, but with different potencies. Moreover, inhibition of hemorrhage, edema, lethality, or myotoxicity was observed, even if the polysaccharide was injected before or after the injection of venoms, regardless of the route of administration (i.e., intravenous, subcutaneous, and intraperitoneal). A gel formulation containing the polysaccharide of C. crispus also protected mice from hemorrhage after administration of the venoms. Thus, the lambda carrageenan polysaccharide, as produced by a strain of C. crispus, may aid antivenom to block the toxic activities of B. jararaca and B. jararacussu venom, as well as to aid in the development of a more efficient therapy for envenomation by these venomous snakes.

To better understand the migration properties of hybrid carrageenan from the seaweed tissue during carrageenan extraction, the effect of increasing the seaweed surface area by the mechanical disintegration of gametophyte Chondrus crispus chips was studied under various temperature and time extraction conditions. Dried Chondrus crispus seaweed chips were milled by a rotor beater mill and classified into eight different size fractions by sieving with varying mesh sizes from 50 to 2000 μm. During extraction at 22 °C, the red color of the filtrate increased significantly with the decreasing particle size of the fraction, correlating with the increasing phycoerythrin concentration (from 0.26 mg PE/g dry seaweed in the >2000 μm size fraction to 2.30 mg PE/g dry seaweed in the 2000 μm size fraction to 2.1 ± 0.1 g/kg filtrate in the

The main four seaweed species for carrageenan production used in industry are Eucheuma denticulatum, Kappaphycus alvarezii, Chondrus crispus, and Sarcothalia crispata. In addition, a fifth ...

THE BIOSORPTION is an effective technique for the removal of uranium and thorium from some types of phosphate rocks of red sea area. In this study Cystoseira osmundacea, Palmaria elegans and Chondrus crispus, were used for the biosorption of uranium (U), and thorium (Th), from phosphates rocks in Egypt in Qusser and Safaga areas west red sea which characterized of shallow-water marine origin and mainly associated with sequences of white hard limestone, white chalk, yellow marls and hard cherts rocks. The obtained results showed that Cystoseira osmundacea, Palmaria elegans and Chondrus crispus have biosorption capacities of (81%, 89% and 90%), for U and (77%, 88% and 91%) for Th, respectively from phosphate of Safaga .and biosorption capacities of (81%, 84% and 89% ), for U and (79%, 81% and 88% ) for Th, respectively from phosphate of Qusser area. it is preferable to use Chondrus crispus on biosorption due to its high sorption capacity than the other two algae.

10 Pág. Departamento de Tecnología de Alimentos​​, Edible seaweeds Chondrus crispus, Codium fragile, Himanthalia elongata, Ulva lactuca and Undaria pinnatifida, without any treatment (control seaweeds), were stored at 4 °C for 15, 30, 60, 15 and 30 days, respectively, until microbial counts exceeded 7 log cfu/g. High pressure processed (HPP) seaweeds, treated at 400 or 600 MPa for 5 min on day 2 after collection, were held at 4 °C until day 180. At the start of storage, 133 volatile compounds were detected in control seaweeds, with 89, 31, 45, 79 and 69 compounds found in C. crispus, C. fragile, H. elongata, U. lactuca and U. pinnatifida, respectively. Chemical groups including the highest number of compounds were aldehydes (24), alcohols (23), ketones (18), hydrocarbons (17) and benzene compounds (14). At the end of storage, 131 compounds were detected in control seaweeds, including 18 aldehydes, 28 alcohols, 23 ketones, 14 hydrocarbons and 13 benzene compounds, and 164 compounds in HPP-treated seaweeds, including 23 aldehydes, 31 alcohols, 19 ketones, 23 hydrocarbons and 15 benzene compounds. Increases in the levels of alcohols, benzene compounds and S-compounds and decreases in hydrocarbons, aldehydes and acids were recorded during storage of some control seaweeds, and increases in the levels of alcohols, acids and N-compounds and decreases in aldehydes, ketones and furans during storage of some HPP-treated seaweeds. Odour acceptance fell below rejection threshold as early as on day 15 for control U. lactuca while it remained acceptable until day 60 for control H. elongata and until day 180 for all the HPP-treated seaweeds. HPP treatment at 400 to 600 MPa for 5 min, in combination with refrigerated storage, is a useful tool for seaweed preservation, given its beneficial effects on microbial quality and sensory characteristics., This research was supported by project AGL2013-42911-R (Ministerio de Economía y Competitividad, Spain). The courageousness and camaraderie from Ana del Olmo during the performance of this study is acknowledged by the rest of authors

Alexandrium catenella is a harmful algal bloom (HAB)-forming dinoflagellate that causes significant damage to the cultivation and harvest of shellfish due to its synthesis of paralytic shellfish toxins. To evaluate the potential for macroalgae aquaculture to mitigate A. catenella blooms, we determined the effects of three cultivable macroalgae - Saccharina latissima (sugar kelp), Chondrus crispus (Irish moss), and Ulva spp. - on A. catenella in culture- and field-based experiments. Co-culture growth assays of A. catenella exposed to environmentally realistic concentrations of each macroalgae showed that all species except low levels of C. crispus caused cell lysis and significant reductions in A. catenella densities relative to control treatments of 17–74% in 2–3 days and 42–96% in ~one week (p Ulva spp. > C. crispus. Seaweeds’ primary anti-A. catenella activity were allelopathic, while nutrient competition, pH elevation, and macroalgae-attached bacteria may have played a contributory role in some experiments. Collectively, these results suggest that the integration of macroalgae with shellfish-centric aquaculture establishments should be considered as a non-invasive, environmentally friendly, and potentially profit-generating measure to mitigate A. catenella-caused damage to the shellfish aquaculture industry.

WOS:000614643900001; Dimethylsulfoniopropionate (DMSP) plays many important physiological and ecological roles in macroalgae. The most common method to measure DMSP is by gas chromatography analysis of the dimethylsulfide (DMS) produced after NaOH hydrolysis (pH \textgreater 12). Storage of DMS, however, is not recommended for more than a week. We investigated if acidification can be a suitable method to preserve DMSP in macroalgal samples over three months of storage, compared to widely used protocols such as drying and freezing at -20 degrees C. The DMSP content of green (Ulva sp. and Ulva compressa), red (Chondrus crispus), and brown (Bifurcaria bifurcata) macroalgae were analyzed: 24 h after NaOH addition (control values); and after acidification (0.2 mol center dot L HCl-1) for 24 h of fresh material, followed by NaOH addition for 24 h. These values were compared to measurements after 3-month storage of samples that had been either dried in a heater (60 degrees C for a night, and storage at room temperature), or frozen at -20 degrees C, or kept in 0.2 mol center dot L HCl-1. There was no significant difference between DMSP measurements on freshly collected material and after acidification of the samples, whether 24 h later or after 3 months of storage. This was in contrast to 3-month storage protocols involving overnight drying at 60 degrees C (75-98% DMSP loss), and to a lesser degree freezing at -20 degrees C (37-80% DMSP loss). We thus advise to acidify macroalgal samples for preservation over long periods of time rather than drying or freezing, when assaying DMSP content.

The Red Sea coast is rich in different types of seaweeds, which are suggested to possess medicinal properties. In this study, methanolic extract of Chondrus crispus (MEC), a species of red algae collected from the southeast coast of Jeddah, Saudi Arabia was prepared and analysed for its chemical composition, antioxidant, anti-inflammatory and cytotoxic properties. HPLC analysis revealed that flavonoids were found to be predominant constituents of MEC followed by phenols and tannins. Among phenols, catechin, gallic and p-coumaric acids were found to be major components of MEC. The MEC at 200 µg/mL concentration significantly decreased the levels of free radicals including 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and displayed significant total antioxidant capacity (TAC). The MEC also significantly inhibited the denaturation of bovine serum albumin (BSA), indicating its anti-inflammatory potential. Furthermore, hepatocellular carcinoma (HepG2) and adenocarcinoma human alveolar (A549) cells treated with MEC exhibited 81.9% and 71.8% cytotoxic cell death respectively as compared to 69% cell death found in cells treated with reference drug sorafinib. Collectively, the data revealed that flavonoids, phenols and tannins are the major chemical constituents of chondrus crispus species of red algae. Further, the methanolic extract of this species was found to exhibit significant antioxidant, anti-inflammatory and cytotoxic properties in several human cancer cell lines. Thus, red algae commonly found along the shore of Red Sea can be utilized for its medicinal value.

Summary Inferring genome-scale metabolic networks in emerging model organisms is challenged by incomplete biochemical knowledge and partial conservation of biochemical pathways during evolution. Therefore, specific bioinformatic tools are necessary to infer biochemical reactions and metabolic structures that can be checked experimentally. Using an integrative approach combining genomic and metabolomic data in the red algal model Chondrus crispus, we show that, even metabolic pathways considered as conserved, like sterols or mycosporine-like amino acid synthesis pathways, undergo substantial turnover. This phenomenon, here formally defined as “metabolic pathway drift,” is consistent with findings from other areas of evolutionary biology, indicating that a given phenotype can be conserved even if the underlying molecular mechanisms are changing. We present a proof of concept with a methodological approach to formalize the logical reasoning necessary to infer reactions and molecular structures, abstracting molecular transformations based on previous biochemical knowledge., Graphical Abstract, Highlights • Combination of metabolite profiling and genome-scale metabolic networks analysis • New method to infer biochemical reactions and metabolites in promiscuous pathways • Red algal model for sterol and mycosporine-like amino acid biosynthesis pathways • Metabolic drift if pathway variation despite conserved initial and final metabolites, Bioinformatics; Genomics; Metabolomics

Molecular resources and transgenic studies in red algae are lagging behind those for green algae. The Agrobacterium-mediated gene-transfer method routinely used in plant transformation has not been fully utilised in the red algae, which, as an important source of phycocolloids, warrant more studies. In this regard, a stepwise methodology was developed for Agrobacterium-mediated transformation of the carrageenophyte Chondrus crispus using pCAMBIA 1301 and a construct featuring a codon-optimized beta-glucuronidase (GUS) reporter gene driven by the endogenous Chondrus actin promoter. The effects of several factors on transformation efficiency were investigated. An intimate association of Chondrus and bacterial cells was observed using scanning electron microscopy. GUS transient expression within Chondrus cortical and medullary cells with both expression cassettes testified to the amenability of Chondrus to Agrobacterium-mediated transformation. Darker staining, indicative of higher GUS activity, was observed with the Chondrus-specific construct, suggesting its superiority over the pCAMBIA 1301. Presence of acetosyringone, the wounding method and the type of co-cultivation medium significantly affected the transformation outcome and efficiency. The Agrobacterium-mediated transient expression presented here constitutes a first step towards tailoring a transformation strategy for Chondrus, which can serve to facilitate further transgenic studies in this important red alga.

The content of photosynthetic pigments (chlorophyll a and phycobiliproteins) and UV-absorbing mycosporine-like amino acids (MAAs) was investigated in three commercially important red macroalgae, Palmaria palmata, Chondrus crispus, and Porphyra dioica, with respect to seasonal changes at three locations in Galway Bay (western Ireland). Several parameters, including light, temperature, salinity, and nutrients, were measured over a 12-month sampling period, in an attempt to correlate changes in the content of compounds with variations in environmental factors. Pigments followed a distinct seasonal pattern, similar for the three species, which correlated in most cases with changes of seasonal environmental factors. As irradiance and temperature decreased in autumn, chlorophyll a and phycobiliprotein concentrations increased and remained high throughout winter, typically reaching maximum levels by late winter, early spring. By contrast, an increase in total MAA contents in all species was induced by increasing daily light doses and irradiance levels, from winter to spring, but without clear significant correlations with light and/or temperature. This could be explained by the low nutrient concentrations observed in summer months, limiting the synthesis and accumulation of MAAs, even when exposed to high irradiance levels. Nutrient availability, in particular nitrate, appears to be a limiting factor for the red algal species under investigation to synthetize MAA compounds when exposed to extreme light/irradiance stress. This study provides therefore the first available account of the seasonal variability of pigments and MAAs in these three commercially and ecologically important edible red seaweeds from Ireland.

The goal of this paper is the valorisation of the Chondrus crispus (Rhodophyta) wastes generated during the industrial extraction of hybrid carrageenan using microwave technology of a temperature range from 140 to 200 °C, using water as a solvent. Mineral and phenolic content, antioxidant capacity and thermorheological features of the recovered hybrid carrageenans were determined. Results indicated the suitability for the recovery of high valuable compounds from these algae residues, after the optimization of the extraction conditions. At microwave processing conditions (160 °C, 5 min), it is still possible to recover around 10% of semi-refined hybrid carrageenan from the industrial raw material as well as to achieve the maximum value of total phenolic compounds of 12.8 mg GAE/g extract and antioxidant capacity of 51.70 mg Trolox/g extract. Extracted biopolymers exhibited thermomechanical features, in terms of viscoelastic moduli or gelling and melting temperatures, comparable to their commercial counterparts.

Ultrasound-assisted extraction was used to recover gelling biopolymers and antioxidant compounds from Chondrus crispus with improved biological potential. The optimal processing conditions were evaluated using a Box-Behnken design, and the impact on the biological and thermo-rheological properties of the carrageenan fraction and on the bioactive features of the soluble extracts were studied. The optimum extraction parameters were defined by extraction time of ~34.7 min; solid liquid ratio of ~2.1 g/100 g and ultrasound amplitude of ~79.0% with a maximum power of 1130 W. The dependent variables exhibited maximum carrageenan yields (44.3%) and viscoelastic modulus (925.9 Pa) with the lowest gelling temperatures (38.7 °C) as well as maximum content of the extract in protein (22.4 mg/g), gallic acid (13.4 mg/g) and Trolox equivalents antioxidant capacity (182.4 mg TEAC/g). Tested hybrid carrageenans exhibited promising biological activities (% of growth inhibition around 91% for four human cancer cellular lines: A549; A2780; HeLa 229; HT-29).

Galdieria sulphuraria and Cyanidioschyzon merolae are thermo-acidophilic unicellular red algal cousins capable of living in volcanic environments, although the former can additionally thrive in the presence of toxic heavy metals. Bioinformatic analyses of transport systems were carried out on their genomes, as well as that of the mesophilic multicellular red alga Chondrus crispus (Irish moss). We identified transport proteins related to the metabolic capabilities, physiological properties, and environmental adaptations of these organisms. Of note is the vast array of transporters encoded in G. sulphuraria capable of importing a variety of carbon sources, particularly sugars and amino acids, while C. merolae and C. crispus have relatively few such proteins. Chondrus crispus may prefer short chain acids to sugars and amino acids. In addition, the number of encoded proteins pertaining to heavy metal ion transport is highest in G. sulphuraria and lowest in C. crispus. All three organisms preferentially utilize secondary carriers over primary active transporters, suggesting that their primary source of energy derives from electron flow rather than substrate-level phosphorylation. Surprisingly, the percentage of inorganic ion transporters encoded in C. merolae more closely resembles that of C. crispus than G. sulphuraria, but only C. crispus appears to signal via voltage-gated cation channels and possess a Na+ /K+ -ATPase and a Na+ exporting pyrophosphatase. The results presented in this report further our understanding of the metabolic potential and toxic compound resistances of these three organisms.

The Nme gene/protein family of nucleoside diphosphate kinases (NDPK) was originally named after its member Nm23-H1/Nme1, the first identified metastasis suppressor. Human Nme proteins are divided in two groups. They all possess nucleoside diphosphate kinase domain (NDK). Group I (Nme1-Nme4) display a single type NDK domain, whereas Group II (Nme5-Nme9) display a single or several different NDK domains, associated or not associated with extra-domains. Data strongly suggest that, unlike Group I, none of the members of Group II display measurable NDPK activity, although some of them autophosphorylate. The multimeric form is required for the NDPK activity. Group I proteins are known to multimerize, while there are no data on the multimerization of Group II proteins. The Group II ancestral type protein was shown to be conserved in several species from three eukaryotic supergroups. Here, we analysed the Nme protein from an early branching eukaryotic lineage, the red alga Chondrus crispus. We show that the ancestral type protein, unlike its human homologue, was fully functional multimeric NDPK with high affinity to various types of DNA and dispersed localization throughout the eukaryotic cell. Its overexpression inhibits both cell proliferation and the anchorage-independent growth of cells in soft agar but fails to deregulate cell apoptosis. We conclude that the ancestral gene has changed during eukaryotic evolution, possibly in correlation with the protein function.

Sol-gel diagrams and the corresponding rheological properties of kappa/iota-hybrid carrageenan hydrogels prepared with calcium counterions at different ionic strengths (

Nutrient composition, total phenolic content (TPC) and in vitro protein digestibility (IVPD) of wild and cultivated seaweeds were determined. Seaweeds had a high range of protein (7–31 % of dry weight (DW)), lipid (3–13 % DW), carbohydrate (32–60 % DW), ash (9–45 % DW) and energy (10–18 MJ kg−1 DW). Seaweeds had favourable amino acid (AA) profiles with moderate (0.77–0.86) to high (0.93–1.07) essential AA indices. Major minerals and trace elements included calcium (0.1–1.1 % DW), magnesium (0.2–0.8 % DW), phosphorous (0.1–0.6 % DW), potassium (2.1–4.6 % DW), sodium (1.1–3.9 % DW), sulphur (0.4–6.5 % DW), copper (1–21 mg kg−1 DW), iron (26–945 mg kg−1 DW), manganese (3–191 mg kg−1 DW) and zinc (28–74 mg kg−1 DW). Red seaweeds contained low TPC (4–5 mg gallic acid equivalents (GAE) g−1 DW) whereas most brown seaweeds contained moderate (11–18 mg GAE g−1 DW) to high levels (47–59 mg GAE g−1 DW). IVPD was mid-range (82–87 %) for Saccharina latissima, Palmaria palmata (W), Palmaria palmata (M-S), Chondrus crispus, Meristotheca papulosa and Sarcodiotheca gaudichaudii and lower (79 %) for Ascophyllum nodosum, Fucus vesiculosus and Alaria esculenta. Despite relatively good AA profiles, estimated digestible protein (DP) levels for seaweeds were generally low (

Seaweeds contain a number of health enhancing and antimicrobial bioactive compounds including sulfated polysaccharides (SP). In the present study, SP extracted from a European red seaweed Irish moss Chondrus crispus was chemically analyzed, SP content extracted and the immune-response effect on wild Irish mussels Mytilus spp. investigated for the first time. A high percent yield of SP was extracted from C. crispus and the immune-stimulant activity of SP was assessed in a laboratory trial with mussels exposed to three different treatments of low (10 μg mL−1), medium (20 μg mL−1) and high (50 μg mL−1) SP dose concentrations and a control mussel group with no exposure to SP. An initial mussel sample was processed prior to the trial commencing and mussels were subsequently sampled on Days 1, 2, 3, 4, 7, and 10 post SP exposure. Both cell, humoral and immune related gene responses including haemocyte cell viability, haemocyte counts, lysozyme activity and expression of immune related genes (defensin, mytimycin and lysozyme mRNA) were assessed. No mussel mortalities were observed in either the treated or non-treated groups. Mussels exposed with SP showed an increase in haemocyte cell viability and the total number of haemocytes compared to control mussels. Lysozyme activity was also higher in treated mussels. Additionally, up-regulated expression of defensin, mytimycin and lysozyme mRNA was observed in SP treated mussels shortly after exposure (on Days 1, 2, and 3) to SP. These results indicate that a high quality yield of SP can be readily extracted from C. crispus and more importantly based on the animal model used in this study, SP extracted from C. crispus can rapidly induce health enhancing activities in Mytilus spp. at a cellular, humoral and molecular level and with a prolonged effect up to ten days post treatment.

NaCl and KCl phase diagrams of two kappa/iota-hybrid carrageenans (KI) are established, and the rhe-ological properties of obtained solutions and gels are reported. KI were extracted from Ahnfeltiopsisdevoniensis and Chondrus crispus seaweeds and showed different chemical composition, 48 mol% of kappacarrageenan (K) and 52 mol% of iota carrageenan (I), and 78 mol% of K and 22 mol% of I, respectively. Phasediagrams are systematically compared those of blends of commercial K and I (K + I) showing equivalentchemical compositions. Results confirm that KI clearly differ from mixtures of K and I. K + I form gels atlower polysaccharide concentration and ionic strength, and exhibit gel separation from a liquid phasewhen large amount (>0.1 mol/L) of KCl is used. In contrast, no syneresis was found in KI gels formed undersimilar conditions. Both KI and K + I gels are strain hardening, and show a concentration scaling of theelasticity with exponents ranging from 1.1 to 3.2 depending on the type of salt and ionic strength. Thestrain at break of KI gels does not show salt specificity and is similar to the strain at break of K + I gels inKCl under similar salt and polysaccharide concentrations. K + I gels in NaCl are more fragile than in KCl,thus showing salt specificity., (POS-A/2012/116) from Xunta de Galicia’sConsellería de Cultura, Educación e Ordenación Universitaria ofSpain and the European Union’s European Social Fund, UK Engi-neering and Physical Sciences Research Council (Grant NumbersEP/H024336/1 and EP/E05899X/1, “Matepro –Optimizing Materials and Processes”, with reference NORTE-07-0124-FEDER-000037 FEDER COMPETE

Parkinson’s disease (PD) is the second most common neurodegenerative disorder in the elderly people, currently with no cure. Its mechanisms are not well understood, thus studies targeting cause-directed therapy or prevention are needed. This study uses the transgenic Caenorhabditis elegans PD model. We demonstrated that dietary supplementation of the worms with an extract from the cultivated red seaweed Chondrus crispus decreased the accumulation of α-synulein and protected the worms from the neuronal toxin-, 6-OHDA, induced dopaminergic neurodegeneration. These effects were associated with a corrected slowness of movement. We also showed that the enhancement of oxidative stress tolerance and an up-regulation of the stress response genes, sod-3 and skn-1, may have served as the molecular mechanism for the C. crispus-extract-mediated protection against PD pathology. Altogether, apart from its potential as a functional food, the tested red seaweed, C. crispus, might find promising pharmaceutical applications for the development of potential novel anti-neurodegenerative drugs for humans.

Polysaccharides have been gaining interesting and valuable applications in the food and pharmaceutical fields. As they are derived from the natural source, they are easily available, non-toxic, cheap, biodegradable and biocompatible. Carrageenan is one among them, which fulfills the criteria of polysaccharide; it is a natural carbohydrate (polysaccharide) obtained from edible red seaweeds. The name Carrageenan is derived from the Chondrus crispus species of seaweed (Rhodophyceace) known as Carrageen Moss or Irish Moss, and Carraigin. A demand based on its application has been widely increasing in food and pharmaceutical sectors. Carrageenan has gained wide applications in experimental medicine, pharmaceutical formulations, cosmetics, and food industries. Through keen references of the reported literature on carrageenan, in this review, we have described about carrageenan, its properties, extraction and refining, and its food and pharmaceutical applications.

In this study, phycobiliproteins, carotenoids (β-carotene and lutein), volatile compounds and antioxidant activity were determined in dried, hydrated, boiled and steamed Chondrus crispus seaweed. Significant changes in phycoerythrin, phycocyanin, β-carotene, lutein, volatile compounds and antioxidant activity have been observed after different culinary treatments (hydration, boiling and steaming). The results show a significantly higher level of β-carotene in seaweed after the culinary treatments. The dried and hydrated samples did not show significant differences in the content of the most abundant phycobiliprotein (phycoerythrin), whereas boiled and steamed samples have significantly lower values. The three principal classes of volatile compounds identified are aldehydes, hydrocarbons and alcohols. Aldehydes have a similar distribution in all sample types. A greater number of compounds were identified in the dried and steamed samples.

Seaweeds are rich sources of bioactive compounds with potential health benefits. Anti-stress effects of the cultivated red alga, Chondrus crispus, were investigated in the Caenorhabditis elegans model. Methanolic extracts of C. crispus (CCME) enhanced C. elegans tolerance to juglone-induced oxidative stress and increased life span; however water extracts did not show such effects. CCME treatment reduced reactive oxygen species (ROS) in the worms and increased the transcription of stress response genes; sod3 , hsp16.2, daf16 and skn1 . The chemical profile of CCME revealed the presence of unsaturated fatty acids, pigments, galactolipids, floridoside, isothionic acid, taurine, phenylalanine and l -citruline. Bioassay guided fractionation revealed that fatty acids, lipids and pigments imparted stress tolerance. Taken together, our results suggest that organic fractions of cultivated C. crispus impart oxidative stress tolerance in C. elegans, possibly by altering the stress response pathways.

Chondrus crispus is a species of red algae that grows on rocks from the middle intertidal into the subtidal zones of the North Atlantic coasts. As such, it has to cope with strongly variable abiotic conditions. Here we studied the response of the photosynthetic apparatus of this red alga to illumination. We found that, as previously described in the case of the unicellular alga Rhodella violacea (E. Delphin et al., Plant Physiol. 118 (1998) 103–113), a single multi-turnover saturating pulse of light is sufficient to induce a strong quenching of fluorescence. To elucidate the mechanisms underlying this fluorescence quenching, we combined room temperature and 77 K fluorescence measurements with absorption spectroscopy to monitor the redox state of the different electron carriers in the chain. In addition, we studied the dependence of these various observables upon the excitation wavelength. This led us to identify energy spill-over from Photosystem II to Photosystem I rather than a qE-type non-photochemical quenching as the major source of fluorescence quenching that develops upon a series of 200 ms pulses of saturating light results, in line with the conclusion of Ley and Butler (Biochim. Biophys. Acta 592 (1980) 349–363) from their studies of the unicellular red alga Porphyridium cruentum . In addition, we show that the onset of this spill-over is triggered by the reduction of the plastoquinone pool.

Carrageenan is a natural carbohydrate (polysaccharide) obtained from edible red seaweeds. The name Carrageenan is derived from the Chondrus crispus species of seaweed known as Carrageen Moss or Irish Moss in England, and Carraigin in Ireland. Carraigin has been used in Ireland since 400 AD as a gelatin and as a home remedy to cure coughs and colds. It grows along the coasts of North America and Europe. Carrageenans are used in a variety of commercial applications as gelling, thickening, and stabilising agents, especially in food products and sauces. Aside from these functions, carrageenans are used in experimental medicine, pharmaceutical formulations, cosmetics, and industrial applications.

Palmaria palmata and Chondrus crispus were grown for 4 weeks in 1-L flasks at 10 °C to evaluate nutrient uptake and their potential application as nutrient biofilters in effluent from finfish culture. For greatest bioremediation benefit within an integrated system, we conclude that a seaweed biofilter using these species should be placed prior to bacterial biofiltration for exposure to greater proportions of ammonium than nitrate, though it is apparent that the productivity of both species is not influenced by the nitrogen source. Five combinations of ammonium– and nitrate–nitrogen were compared, each with a total N concentration of 300 μM (300:0, 270:30, 150:150, 30:270, 0:300). Molar nitrogen/phosphorus ratio was 10:1. The maximum growth rates were 8.9 and 6.0 % per day for P. palmata and C. crispus, respectively. For both species, the total nitrogen uptake was highest at 300 μM ammonium, 4.46 mgN gDW−1 day−1 for P. palmata and 3.40 mg N g DW−1 day−1 for C. crispus. Over a 24-h period, 23–37 % of the available nitrate and 91–100 % of the available ammonium were taken up by P. palmata. In the same period, C. crispus took up 55–87 % of available nitrate and 89–100 % of ammonium. Tissue N in P. palmata was highest (4.1 %) at 270 and 300 μM ammonium, while the nitrogen source did not have a significant effect on the tissue N of C. crispus (mean of 4.6 %).

To evaluate the nutrient removal capabilities of two red macroalgae, apical blades were cultured in the lab for 4 weeks at either 6, 10, or 17°C and nitrate at either 30 or 300 μM, typical of the seasonal range of conditions at a land-based Atlantic halibut farm. Stocking density was 2.0 g L−1, irradiance 125 μmol photons m−2 s−1, photoperiod 16:8 (L:D), and nitrogen to phosphorus ratio 10:1. For both species, the highest growth rate was at 300 μM NO 3 − with Palmaria palmata growing fastest at 6°C, 5.8% day−1, and Chondrus crispus growing best at 17°C, 5.5% day−1. Nitrogen and carbon removal by P. palmata was inversely related to temperature, the highest rate at 6°C and 300 μM NO 3 − of 0.47 mg N and 6.3 mg C per gram dry weight per day. In contrast, C. crispus removal of N was independent of temperature, with mean removal of 0.49 mgN gDW−1 day−1 at 300 μM NO 3 − . The highest carbon removal by C. crispus was 4.4 mgC gDW−1 day−1 at 10°C and 300 μM nitrate, though not significantly different from either 6 or 17°C and 300 μM nitrate. Tissue carbon:nitrogen ratios were >20 in both species at 30 μM nitrate, and all temperatures indicating nitrogen limitation in these treatments. Phycoerythrin content of P. palmata was independent of temperature, with means of 23.6 mg gFW−1 at 300 μM nitrate. In C. crispus, phycoerythrin was different only between 6°C and 17°C at 300 μM nitrate, with the highest phycoerythrin content of 12.6 mg gFW−1 at 17°C. Morphological changes were observed in P. palmata at high NO 3 − concentration as curling of the fronds, whilst C. crispus exhibited the formation of bladelets as an effect of high temperature.

Qualitative and quantitative differences in carrageenan composition of gametophytes and tetrasporophytes of Chondrus crispus were observed in this study. Carrageenans in gametophytes belong to the kappa family (κ-, ι-, ν- and μ-carrageenan). The dominant fractions were κ- and ι-carrageenan (more than 50% of the total carrageenans). In tetrasporophytes, the presence of λ-carrageenan was confirmed. Carrageenan content in gametophytes (37.4 ± 1.68% DW) was higher than in tetrasporophytes (29.13 ± 0.76% DW). Spatial and temporal variation in carrageenan content in both life cycle phases appears to be related mainly to seawater and air temperatures, insolation, water movement and desiccation. The highest values of carrageenan content were recorded in those localities where higher values of precipitation, wind speed or water movement occurred. A bimodal temporal pattern on carrageenan content was observed. Fronds showed a high carrageenan content in spring and autumn. During these seasons, the content was over 40% in gametophytes and 30% in the tetrasporophytes. In summer and winter, these values down in both life cycle phases below 30%. In general the highest carrageenan contents were related to highest seawater temperatures. On the contrary, high air temperature and high insolation appeared to be unfavourable for carrageenan production. GLM models were obtained to predict carrageenan production from natural C. crispus populations, along Galician coast.

Seaweed is more than the wrap that keeps rice together in sushi. Seaweed biomass is already used for a wide range of other products in food, including stabilising agents. Biorefineries with seaweed as feedstock are attracting worldwide interest and include low-volume, high value-added products and vice versa. Scientific research on bioactive compounds in seaweed usually takes place on just a few species and compounds. This paper reviews worldwide research on bioactive compounds, mainly of nine genera or species of seaweed, which are also available in European temperate Atlantic waters, i.e. Laminaria sp., Fucus sp., Ascophyllum nodosum, Chondrus crispus, Porphyra sp., Ulva sp., Sargassum sp., Gracilaria sp. and Palmaria palmata. In addition, Undaria pinnatifida is included in this review as this is globally one of the most commonly produced, investigated and available species. Fewer examples of other species abundant worldwide have also been included. This review will supply fundamental information for biorefineries in Atlantic Europe using seaweed as feedstock. Preliminary selection of one or several candidate seaweed species will be possible based on the summary tables and previous research described in this review. This applies either to the choice of high value-added bioactive products to be exploited in an available species or to the choice of seaweed species when a bioactive compound is desired. Data are presented in tables with species, effect and test organism (if present) with examples of uses to enhance comparisons. In addition, scientific experiments performed on seaweed used as animal feed are presented, and EU, US and Japanese legislation on functional foods is reviewed.

Carrageenan (E-407) and semi-refined carrageenan (E-407a) are some of the main additives used by the food industry for their gelling, emulsifying, thickening, and stabilizing properties. These are natural ingredients, which have been used for decades in food applications and are generally regarded as safe. Internationally, sub-tropical carrageenophytes (e.g., Kappaphycus alvarezii) are cultivated extensively as a source of raw materials for industrial extraction, and their use as potential candidates in integrated multitrophic aquaculture is tentative. We analyzed carrageenan yield (as a percentage of dry weight) and chemical composition (by Fourier transform infrared attenuated total reflection and Fourier transform-Raman) of extracts produced by several carrageenophytes (Gigartinales, Rhodophyta), from different origins, e.g., K. alvarezii (Tanzania, Indonesia, the Philippines, Panama, and Mexico), Kappaphycus striatum (Madagascar), Eucheuma denticulatum (Tanzania, the Philippines, and Madagascar), Betaphycus gelatinum (the Philippines), Chondracanthus chamissoi, and Sarcothalia crispata (Chile). For comparison, some underutilized carrageenophytes were also analyzed, e.g., Chondrus crispus, Mastocarpus stellatus, Gigartina pistillata, Chondracanthus teedei var. lusitanicus, Chondracanthus acicularis, Calliblepharis jubata, Gymnogongrus crenulatus, and Ahnfeltiopsis devoniensis (Portuguese carrageenophytes). The main findings were that the highest carrageenan yield was obtained from K. striatum (Madagascar) with 75.6 (percent dry weight (% DW)); B. gelatinum and K. alvarezii (both from the Philippines) had yields of 71.0% and 68.0% (% DW), respectively; and G. pistillata (Portugal) 65.4% (% DW). Spectroscopic analysis of the phycocolloids allowed determination of a wide range of carrageenan types, e.g., pure iota carrageenan, several kappa–iota hybrid carrageenans with different iota/kappa ratios, and kappa–beta, xi–theta, and xi–lambda hybrid carrageenans.

In this study, hot water extracts of 22 red algal species were evaluated for their potential anticoagulant activities. The extracts from eight species (Grateloupia elliptica, Sinkoraena lancifolia, Halymenia dilatata, Grateloupia lanceolata, Lomentaria catenata, Martensia denticulata, Schizymenia dubyi, Chondrus crispus) showed potent activated partial thromboplastin time (APTT). Of these eight algae, the crude polysaccharide fraction (CpoF) from the hot water extracts of L. catenata and S. dubyi showed the highest APTT activity. Lomentaria catenata and S. dubyi were selected and an enzymatic digestion process which could effectively separate a crude polysaccharide fraction with higher yields from raw algae materials was applied. The 10 enzymes tested included five carbohydrases and five proteases. The Ultraflo and Celluclast digests of L. catenata and the AMG digest of S. dubyi exhibited the most potent anticoagulant activity. Furthermore, in both species, the active compounds were mainly concentrated in the >30 kDa fraction through ultrafiltration and showed strong APTT (>1000) and thrombin time (TT) >1000 activity. The active compounds were shown to be sulfated galactans with a greater than 80% galactose content and an 0.22 ∼ 0.31 sulfate to total sugar ratio.

Methyl jasmonate (MeJA) is a plant hormone important for the mediation of signals for developmental processes and defence reactions in higher plants. The effects of MeJA and the signalling pathways on other photosynthetic organism groups are largely unknown, even though MeJA may have very important roles. Therefore the effects of MeJA in a red alga were studied. A medium-scale expression profiling approach to identify genes regulated by MeJA in the red seaweed Chondrus crispus is described here. The expression profiles were studied 0, 2, 4, 6, 12, and 24 h after the addition of MeJA to the seawater surrounding the algae. The changes in the transcriptome were monitored using cDNA microarrays with 1920 different cDNA representing 1295 unique genes. The responses of selected genes were verified with real-time PCR and the correlation between the two methods was generally satisfying. The study showed that 6% of genes studied showed a response to the addition of MeJA and the most dynamic response was seen after 6 h. Genes that showed up-regulation included several glutathione S-transferases, heat shock protein 20, a xenobiotic reductase, and phycocyanin lyase. Down-regulated transcripts included glucose kinase, phosphoglucose isomerase, and a ribosomal protein. A comparison between different functional groups showed an up-regulation of stress-related genes and a down-regulation of genes involved in energy conversion and general metabolism. It is concluded that MeJA, or a related compound, has a physiological role as a stress hormone in red algae. This study represents to our knowledge the first analysis of gene expression using cDNA microarrays in a red macroalga.

Low light–adapted laboratory-grown thalli of Chondrus crispus were transferred into shallow water and exposed to the natural irradiance prevailing in May–June at Helgoland (German Bight). A set of cut-off filters was used to study the wavelength-dependent response of photosynthesis as well as pigment and mycosporine-like amino acid (MAA) formation. Due to the higher natural irradiance and in some cases additional ultraviolet (UV) radiation, a depression of maximal quantum yield coinciding with a decline in maximal electron transport rate could be observed during the first days of the experiment. Faster recovery of maximal quantum yield and maximal electron transport rate might be related to the increase in lutein and α- and β-carotene concentration. In addition, higher rates of electron transport might be supported by increased chlorophyll a concentration. In parallel, MAA concentration increased resulting in an effective UV sunscreen. Our data suggest that lutein and α- and β-carotene are involv...

Chondrus crispus, a member of the economically important family Gigartinaceae, alternates between two free-living isomorphic life history phases. The carrageenan composition of the gametophyte and tetrasporophyte phases has been used to identify non-reproductive material, and thus provide a better understanding of the ecology of the species. The aim of this study was to compare three methods for identifying the isomorphic phases. The results obtained by the widely used resorcinol test and an iridescence method are compared with those obtained by a technique that involves the acquisition of mid-infrared absorbance spectra from dried samples by Fourier transform infrared spectroscopy (FT-IR). Both the resorcinol test and FT-IR produced similar results with a calculated gametophyte to tetrasporophyte ratio of 2.1 and 2.3:1, respectively. In contrast the iridescence method was less reliable, with a calculated gametophyte to tetrasporophyte ratio of 1.3:1 and a low predictive value (0.70) for selecting tetrasporophytes. The FT-IR technique provides a rapid assessment, does not involve the use of hazardous chemicals, has the potential to be applied to members of the Gigartinaceae for which the resorcinol and iridescence tests are less applicable and it has greater flexibility in that it can identify additional carrageenan fractions.

The effects that ultraviolet radiation (UVR, 280 to 400 nm) and photosynthetically active radiation (PAR, 400 to 700 nm) had on early life stages of Mastocarpus stellatus and Chondrus crispus were studied to determine if differences in UVR tolerance could influence their recruitment success on the upper eulittoral shores of Helgoland (North Sea). Photosynthesis, germination capacity, DNA damage and carpospore repair were measured after exposures to different time lengths and intensi- ties of PAR+UV-A+ UV-B, PAR + UV-A or PAR alone, and also after recovery in low white light. Ger- mination and photosynthesis of the low light adapted carpospores of both species were inhibited as PAR was increased. Supplemental UV-A and UV-B had a small additional effect on the Fv/Fm of M. stellatus but this effect was more pronounced in C. crispus. However, photosynthesis of both species significantly recovered after 48 h. Carpospore viability in C. crispus was more sensitive than in M. stellatus to UVR, while a higher dose was needed to achieve 50% germination inhibition in M. stel- latus. Furthermore, UV-B-induced DNA damage, measured as cyclobutane-pyrimidine dimers (CPDs), was less in M. stellatus spores, which also exhibited an efficient DNA repair mechanism com- pared with C. crispus. In contrast, growth and chlorophyll a contents in young gametophytes of both species were not affected by repeated UV exposures. Higher total carotenoid was measured in plants exposed to UVR, indicating a photoprotection role, because photosynthesis completely acclimated to UVR after 3 d. Furthermore, DNA damage was not detected on mature fronds of both species when exposed to the full solar spectrum. Therefore, the susceptibility of carpospores to UVR could influ- ence species recruitment to the upper eulittoral zone.

Non-methane hydrocarbons (NMHCs) are produced naturally in the ocean and by terrestrial vegetation. Owing to its high reactivity and flux, isoprene (2-methyl-1,3-butadiene) is important in controlling the balance of atmospheric oxidants, and altering air quality on both local and global scales. Here we show, for the first time, that macroalgae (seaweeds) emit isoprene and a number of other non-methane hydrocarbons (NMHCs). We observed NMHC concentrations in rockpools containing macroalgae and estimated fluxes to the atmosphere over a full diurnal cycle. Emissions at our temperate coastal site (Mace Head, Ireland) in autumn are intermediate in magnitude between terrestrial and ocean fluxes (on a unit area basis), and may contribute significant concentrations to the local atmosphere. We also carried out a series of controlled laboratory experiments focusing on isoprene, in natural and artificial light, and under different temperature conditions involving red (Chondrus crispus, Asparagopsis armata), green (Ulva intestinalis, formerly known as Enteromorpha intestinalis) and brown (Laminaria digitata, Ascophyllum nodosum, Pelvetia canaliculata, Fucus vesiculosus, Fucus serratus, Halidrys siliquosa and Laminaria saccharina) macroalgae commonly found on the west coast of Ireland. We observed NMHC emissions from all the algae investigated and emissions were dominated by alkenes. Production is species-dependent, temperature-dependent and related to light availability. We discuss our observations in the context of what is known about the production of isoprene and ethene in higher plants.

The oxygenated derivatives of fatty acids, known as oxylipins, are pivotal signaling molecules in animals and terrestrial plants. In animal systems, eicosanoids regulate cell differentiation, immune responses, and homeostasis. In contrast, terrestrial plants use derivatives of C18 and C16 fatty acids as developmental or defense hormones. Marine algae have emerged early in the evolution of eukaryotes as several distinct phyla, independent from the animal and green-plant lineages. The occurrence of oxylipins of the eicosanoid family is well documented in marine red algae, but their biological roles remain an enigma. Here we address the hypothesis that they are involved with the defense mechanisms of the red alga Chondrus crispus. By investigating its association with a green algal endophyte Acrochaete operculata, which becomes invasive in the diploid generation of this red alga, we showed that (1) when challenged by pathogen extracts, the resistant haploid phase of C. crispus produced both C20 and C18 oxylipins, (2) elicitation with pathogen extracts or methyl jasmonate activated the metabolism of C20 and C18 polyunsaturated fatty acids to generate hydroperoxides and cyclopentenones such as prostaglandins and jasmonates, and (3) C20 and C18 hydroperoxides as well as methyl jasmonate did induce shikimate dehydrogenase and Phe ammonialyase activities in C. crispus and conferred an induced resistance to the diploid phase, while inhibitors of fatty acid oxidation reduced the natural resistance of the haploid generation. The dual nature of oxylipin metabolism in this alga suggests that early eukaryotes featured both animal- (eicosanoids) and plant-like (octadecanoids) oxylipins as essential components of innate immunity mechanisms.

Extracts of a New Zealand carrageenophyte red seaweed, Gigartina atropurpurea, were prepared under conditions simulating those used in two industrial processes: a mild alkaline extraction with aqueous sodium hydroxide and a more vigorous aqueous alkaline extraction with lime. The resulting extracts, recovered by precipitation with isopropyl alcohol, were separated into gelling and non-gelling fractions by leaching with 2.5% KCl. These extraction processes were also applied to separated gametophyte and sporophyte samples of the same seaweed. The carrageenan compositions of these extracts and fractions were determined using modern chemical and spectroscopic techniques. The gametophyte extracts contained mixtures/hybrids of κ and ι carrageenans (and also μ and ν carrageenans, depending on the extraction conditions used). The tetrasporophyte extracts contained a complex λ-type carrageenan (including θ carrageenan, depending on the extraction conditions used). Fractionation of extracts from mixed life phase samples using 2.5% KCl yielded gelling carrageenans quite similar to those from a gametophyte extract of the same species, but the non-gelling fractions were not the same as the corresponding sporophyte extracts. The performance of the extracts and fractions was evaluated in two commercial dairy applications: cold- and hot-processed chocolate milks. The structures of the carrageenans in the various extracts from G. atropurpurea and their performance in cold- and hot-processed chocolate milks were compared with those equivalent extracts analysed previously from Chondrus crispus, Sarcothalia crispata and Gigartina skottsbergii.

A detailed study of the lipophilic composition of Codium tomentosum, Ulva lactuca, Gracilaria vermiculophylla and Chondrus crispus macroalgae cultivated in the Portuguese coast was carried out by gas chromatography-mass spectrometry before and after alkaline hydrolysis. Their long-chain aliphatic alcohols and monoglycerides compositions are reported for the first time. Additionally, other new compounds were also identified: phytol and neophytadiene in C. tomentosum, U. lactuca and G. vermiculophylla and stigmasterol, alpha-tocopherol and 24-methylenecholesterol in C tomentosum. The lipophilic fraction of the studied macroalgae are mainly constituted by fatty acids (110.1-1030.5 mg kg(-1) of dry material) and sterols (14.8-1309.1 mg kg(-1) of dry material). C. tomentosum showed to be a valuable source of stigmasterol (1229.0 mg kg(-1) of dry material) and alpha-tocopherol (21.8 mg kg(-1) of dry material). These results are a relevant contribution for the valorisation of these macroalgae species as sources of valuable phytochemicals. (C) 2015 Elsevier Ltd. All rights reserved.

Background Gastrointestinal microbial communities are diverse and are composed of both beneficial and pathogenic groups. Prebiotics, such as digestion-resistant fibers, influence the composition of gut microbiota, and can contribute to the improvement of host health. The red seaweed Chondrus crispus is rich in dietary fiber and oligosaccharides, however its prebiotic potential has not been studied to date. Methods Prebiotic effects were investigated with weaning rats fed a cultivated C. crispus-supplemented diet. Comparison standards included a fructo-oligo-saccharide (FOS) diet and a basal diet. The colonic microbiome was profiled with a 16S rRNA sequencing-based Phylochip array. Concentrations of short chain fatty acids (SCFAs) in the feacal samples were determined by gas chromatography with a flame ionization detector (GC-FID) analysis. Immunoglobulin levels in the blood plasma were analyzed with an enzyme-linked immunosorbent assay (ELISA). Histo-morphological parameters of the proximal colon tissue were characterized by hematoxylin and eosin (H&E) staining. Results Phylochip array analysis indicated differing microbiome composition among the diet-supplemented and the control groups, with the C. crispus group (2.5 % supplementation) showing larger separation from the control than other treatment groups. In the 2.5 % C. crispus group, the population of beneficial bacteria such as Bifidobacterium breve increased (4.9-fold, p = 0.001), and the abundance of pathogenic species such as Clostridium septicum and Streptococcus pneumonia decreased. Higher concentrations of short chain fatty acids (i.e., gut microbial metabolites), including acetic, propionic and butyric acids, were found in faecal samples of the C. crispus-fed rats. Furthermore, both C. crispus and FOS supplemented rats showed significant improvements in proximal colon histo-morphology . Higher faecal moisture was noted in the 2.5 % C. crispus group, and elevated plasma immunoglobulin (IgA and IgG) levels were observed in the 0.5 % C. crispus group, as compared to the basal feed group. Conclusions The results suggest multiple prebiotic effects, such as influencing the composition of gut microbial communities, improvement of gut health and immune modulation in rats supplemented with cultivated C. crispus. Electronic supplementary material The online version of this article (doi:10.1186/s12906-015-0802-5) contains supplementary material, which is available to authorized users.

A backfiring weapon: The release of H2O2 by an amino acid oxidase is the early defensive reaction of the red alga Chondrus crispus against the endophytic green algal pathogen Acrochaete operculata (see scheme). This reaction can be induced by L-asparagine, which is released by the attacker when it recognises host cell-wall κ-carrageenan oligosaccharides. The induced signal of the attacker thus serves directly as the substrate for the production of the defensive metabolite.

In the present study, the chemical structure and chemoprotective activity of Pyropia yezoensis protein (PYP) were investigated using sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, automated protein sequencing, matrix-assisted laser desorption/ionization-quadrupole ion trap-time-of-flight mass spectrometry and a chemoprotective assay using a synthetic peptide. The PYP fraction was demonstrated to contain two proteins: PYP1 (10 kDa, SDS-resistant dimer) and PYP2 (10 kDa). PYP1 is a novel protein showing sequence homology with the hypothetical function-unknown proteins of Chondrus crispus (Rhodophyta) and Emiliania huxleyi (Haptophyceae). PYP2 is a paralog of an extrinsic protein of photosystem II found in other Rhodophyta. The synthetic peptide PYP1 (1-20), corresponding to the N-terminal 20 residues of PYP1 (ALEGGKSSGGGEATRDPEPT), exhibits chemoprotective activity against acetaminophen-induced cell death in Chang liver cells, indicating that PYP1 is a chemoprotectant of the PYP fraction. A possible association between the structure of PYP and its chemoprotective activity is discussed.

Stress and the mechanisms of protection under excessive photosynthetically active (PAR) and ultraviolet radiation (UVR) were examined in the red alga Chondrus crispus Stackh. collected from the subtidal zone (6 m depth) at Helgoland, North Sea, Germany. Three PAR (400–700 nm) treatments without UVR and three UVR-A/B (290–400 nm) treatments supplemented with 30 μmol m −2 s −1 PAR were given twice. All three stages of plant stress, irritation, damage and acclimation, were observed under high light conditions. In the earlier stages of photoinhibitory PAR and UVR treatment, an induction phase occurred. It was characterized by a significant increase in chlorophyll a and carotenoids. The capacity to cope with high light stress in C. crispus increased with increasing duration of the induction phase. Prolonged exposures to high irradiance induced a substantial decline in the potential quantum yield of photosynthesis ( F v / F m ) and progressive pigment destruction that may be responsible for the damage stage of stress. In plants exposed to elevated PAR (3600 μmol m −2 s −1 ) and UVR (57.3 and 3.6 W m −2 of UVRA and UVRB, respectively), photoinhibition of F v / F m exceeded 95% of control. Even after 20 h in low irradiance it was similar to values measured immediately after stress, indicating severe photodamage. The 1800 μmol m −2 s −1 PAR treatment also decreased the pigment content and F v / F m , although damage was not permanent and the tissue gradually recovered. In contrast, naturally high doses of UVR (37.7 and 2.3 W m −2 of UVRA and UVRB, respectively) resulted in less photoinhibition of photosynthesis with rapid recovery of F v / F m and pigment content, indicating the dynamic nature of photosynthetic acclimation to growth irradiance. Thus, photoinhibitory PAR damage and its repair predominate in subtidal C. crispus during the process of acclimation to a full-sun environment. Comparison between the acclimation conditions suggests that fluorescence quenching is related to the concentration of carotenoids. The increase in concentration, not only in the first but also after repeated exposures to PAR and UVR, was attributed to a protection of the photosynthetic apparatus. Additionally, accumulation of mycosporine-like amino acids (MAAs), mainly during the repeated exposures to UVR, led to substantially less inhibition of photosynthesis than expected given the practically double UVR dose. This suggests incomplete protection of C. crispus by MAAs during UVR shock. Thus, these experiments indicate that a few basic physiological strategies seem to be active during acclimation to high solar irradiance: a prolonged induction phase, dynamic photoinhibition, increased concentration of carotenoids, and accumulation of MAAs, UV-screening substances.

Extracts of two Chilean carrageenophytes, S. crispata and G. skottsbergii, were prepared by two industrial processes: a mild alkaline extraction with sodium hydroxide and a more vigorous alkaline extraction with lime. The resulting kappa-2 containing carrageenans were separated into gelling and non-gelling fractions by leaching with 2.5% KCl. The weeds were also separated into gametophytes and sporophytes which were extracted separately. C. crispus was included in the study for comparison. Part I of this work presented the carrageenan disaccharide repeat units as determined by sugar analysis and by glycosyl linkage analysis. In Part II the performance of the extracts and fractions was evaluated in two commercial dairy applications: chocolate milk powder for home preparation of a drink with cold milk and hot processed, dairy-bottled chocolate milk. The performance advantages and limitations of the kappa-2 extracts were supported by the disaccharide repeat unit analyses. Des extraits de deux carraghenophytes chiliens, S. crispata et G. skottsbergii sont prepares selon deux procedes industriels. Dans cette partie II, la performance des extraits et des fractions est evaluee dans deux applications laitieres du commerce : de la poudre de chocolat au lait pour une preparation a la maison d'une boisson avec du lait froid et du lait chocolate fabrique a chaud et mis en bouteille.

1An improved method for purifying hexose oxidase (d-hexose: O2 1-oxidoreductase, EC 1.1.3.5) from the marine red alga Chondrus crispus is described for obtaining enzyme suitable for structural characterization and use in bioconversion of lactose to lactobionic acid. This involved extracting enzyme from finely ground lyophilized tissue in sodium phosphate buffer (pH 7) containing 20% ammonium sulfate, eliminating the previously used solvent extraction and protease treatments, and by applying Poros perfusion chromatography media to achieve rapid separations of high resolution. Primary separation of contaminating phycobiliproteins and carrageenans was achieved using Poros DEAE-50. Sequential HPLC purification steps using Poros HP2 and Poros HQ were followed by Sephacryl S200 h chromatography. Enzyme activity was determined with a peroxidase-coupled assay using 2,2′-azino-bis (3-ethylbenzthiazoline-6 sulfonic acid) substrate. A final specific activity of 69 U/mg was obtained, representing a 100-fold purification with an activity recovery of about 10%. A native size of approximately 117,000 Da was determined by size exclusion chromatography, and SDS-PAGE revealed the presence of 38,000 and 29,000 Da polypeptides that appear to be derived from a 65,000 Da subunit. Further properties of the enzyme are described.

Extracts of two Chilean carrageenophyte red seaweeds, Sarcothalia crispata and Gigartina skottsbergii, were prepared by each of two industrial processes: a mild alkaline extraction with aqueous sodium hydroxide and a more vigorous aqueous alkaline extraction with lime. The resulting extracts, recovered by precipitation with isopropyl alcohol, were separated into gelling and non-gelling fractions by leaching with 2.5% KCl. These processes were also applied to Chondrus crispus and to separated gametophyte and sporophyte samples of the Chilean seaweeds for comparative purposes. The carrageenan compositions of these extracts and fractions were determined using both chemical and spectroscopic techniques. In addition, a set of decision rules is proposed and applied to convert data from glycosyl linkage analysis to carrageenan composition. The gametophyte extracts contained mixtures/hybrids of kappa and iota carrageenans (and also mu and nu carrageenans, depending on the extraction conditions used). The tetrasporophyte extracts contained lambda carrageenan (and also theta carrageenan, depending on the extraction conditions used). Extractive fractionation of mixed life phase samples using 2.5% KCl yielded insoluble, 'gelling' carrageenans quite similar to those from a gametophyte extract of the same species, but the soluble, non-gelling fractions were not the same as the corresponding sporophyte extracts. Une gamme d'echantillons de carraghenanes est preparee par extraction en utilisant des procedes commerciaux classiques et ces echantillons sont ensuite soumis a une analyse structurale. Le fractionnement avec KCl a 2,5% produit des carraghenanes insolubles gelifiants tres similaires a ceux obtenus a partir d'un extrait gametophyte de la meme espece mais les fractions solubles different des extraits sporophytes correspondants.

The induction of UV-absorbing compounds known as mycosporine-like amino acids (MAAs) by red, green, blue, and white light (43% ambient radiation greater than390 nm) was examined in sublittoral Chondrus crispus Stackh. Fresh collections or long-term cultures of sublittoral thalli, collected from Helgoland, North Sea,Germany, and containing no measurable amounts of MAAs, were exposed to filtered natural radiation for up to 40 days. The MAA palythine (max 320 nm) wassynthesized in thalli in blue light to the same extent observed in control samples in white light. In contrast, thalli in green or red light contained only trace amounts ofMAAs. After the growth and synthesis period, the photosynthetic performance of thalli in each treatment, measured as pulse amplitude modulated chlorophyllfluorescence, was assessed after a defined UV dose in the laboratory. Thalli with MAAs were more resistant to UV than those without, and exposure to UV-A+B wasmore damaging than UV-A in that optimal (Fv/Fm) and effective (II) quantum yields were lower and a greater proportion of the primary electron acceptor of PSII,Q, became reduced at saturating irradiance. However, blue light-grown thalli were generally more sensitive than white light control samples to UV-A despite havingsimilar amounts of MAAs. The most sensitive thalli were those grown in red light, which had significantly greater reductions in Fv/Fm and II and greater Qreduction. Growth under UV radiation alone had been shown previously to lead to the synthesis of the MAA shinorine (max 334 nm) rather than palythine. In furtherexperiments, we found that preexposure to blue light followed by growth in natural UV-A led to a 7-fold increase in the synthesis of shinorine, compared with growthin UV-A or UV-A+B without blue light pretreatment. We hypothesize that there are two photoreceptors for MAA synthesis in C. crispus, one for blue light and onefor UV-A, which can act synergistically. This system would predispose C. crispus to efficiently synthesize UV protective compounds when radiation levels are rising,for example, on a seasonal basis. However, because the UV-B increase associated with artificial ozone reduction will not be accompanied by an increase in blue light,this triggering mechanism will have little additional adaptive value in the face of global change unless a global UV-B increase positively affects water column clarity.

The coil-to-helix transition and temperature dependence of the viscosity of commercial κ/ι-hybrid carrageenans produced by the red algae Sarcothalia crispata, Mazaella laminarioides, and Chondrus crispus were studied using rheometry and optical rotation. The structure of these κ/ι-hybrid carrageenans was determined by 1H and 13C NMR spectroscopy combined with monosaccharide composition analysis. The coil-to-helix transitions, measured by polarimetry and rheometry, of the κ/ι-hybrid carrageenans are significantly different from those of pure κ- and ι-carrageenan, and from hand-made mixtures thereof. This provides evidence that the κ/ι-hybrid carrageenans are mixed chains, containing both κ- and ι-repeating units. © 2001 Elsevier Science Ltd. Chemicals/CAS: Carrageenan, 9000-07-1; Monosaccharides; Potassium Chloride, 7447-40-7