95 research outputs found

    On the GRAS status of seaweeds. I. Observations on the association between antibacterial activity of ethanolic extracts and metal levels present in selected seaweeds.

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    The relationship between antibacterial activity and levels of 24 metals in 19 selected southern African seaweeds was examined. The antibacterial activity of ethanolic extracts of these seaweeds was assessed by agar diffusion against selected Gram positive and Gram negative test bacteria. Metal levels associated with seaweeds were determined using X-ray fluorescence (XRF) analysis. Extracts of the Phaeophyta exhibited the highest level of antibacterial activity, followed by the Rhodophyta and then the Chlorophyta, in decreasing order. Metal levels, however, were highest in the examples studied from the Rhodophyta and then the Phaeophyta and Chlorophyta, in decreasing order. There was no relationship between the observed antibacterial activity of the crude extracts tested and the levels of metals occurring in their tissues. Thus the antimicrobial activity of extracts from the seaweeds tested should also be generally recognised as safe (GRAS)

    Carrageenans from Red Seaweeds As Promoters of Growth and Elicitors of Defense Response in Plants

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    Plants incessantly encounter abiotic and biotic stresses that limit their growth and productivity. However, conversely, plant growth can also be induced by treatments with various abiotic and biotic elicitors. Carrageenans are sulfated linear polysaccharides that represent major cellular constituents of seaweeds belonging to red algae (Rhodophyta). Recent research has unraveled the biological activity of carrageenans and of their oligomeric forms, the oligo carrageenans (OCs), as promoters of plant growth and as elicitors of defense responses against pests and diseases. In this review, we discuss the molecular mechanisms by which carrageenans and OCs mediate plant growth and plant defense responses. Carrageenans and OCs improve plant growth by regulating various metabolic processes such as photosynthesis and ancillary pathways, cell division, purine and pyrimidine synthetic pathways as well as metabolic pathways involved in nitrogen and sulfur assimilation. Carrageenans and OCs also induce plant defense responses against viroids, viruses, bacteria, fungi and insects by modulating the activity of different defense pathways, including salicylate, jasmonate and ethylene signaling pathways. Further studies will likely substantiate the beneficial effects of carrageenans and of OCs on plant growth and plant defense responses and open new avenues for their use in agriculture and horticultural industry

    Cultivation of tropical red seaweeds in the BIMP-EAGA region

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    The Bruneiā€“Indonesiaā€“Malaysiaā€“Philippines East Asia Growth Area (BIMP-EAGA) is located within the Coral Triangle, known to have the worldā€™s richest biodiversity in marine flora and fauna. This region lies within the 10Ā° N and 10Ā° S of the Equator where natural populations of both Kappaphycus and Eucheuma grow luxuriantly and abundantly. It is in this same region where commercial cultivation of Kappaphycus and Eucheuma began in the Philippines around the mid-1960s. Commercial farming of Kappaphycus (which was originally called Eucheuma) was successful in the Philippines from the early 1970s, after which the technology was transferred to Indonesia and Malaysia in the late 1970s. No seaweed cultivation has been reported in Brunei. At present, carrageenophytes are cultivated in sub-tropical to tropical countries circumferentially around the globe within the 10Ā° N and S of the Equator. However, their combined production is still low as compared to Indonesia, the Philippines, and Malaysia. Notably, few improvements in farming techniques have been made since its first introduction. Some of the major improvements were the introduction of deep-water farming using hanging long lines, multiple rafts, and spider webs in the Philippines; the use of short and long ā€˜loopsā€™, instead of plastic ā€˜tie-tieā€™ in Indonesia; and mechanization in harvesting and use of solar ā€œgreenhouseā€ drying in Malaysia. Commercial cultivation of tropical red seaweeds in the BIMP-EAGA region is dominated by Kappaphycus and Eucheuma (carrageenophytes) and Gracilaria (agarophytes) and the area became the major region for the production of carageenophytes and agarophytes globally. In particular, Indonesia is a major center for the production of Gracilaria. There is an increasing demand for other agarophytes / carrageenophytes in the international market such as Gelidium spp., Pterocladia spp., Porphyroglossum sp., and Ptilophora sp. for paper and ethanol production in Indonesia and Malaysia, and Halymenia for phycoerythrin pigments in the Philippines currently pursued in an experimental stage. A summary of the present status, problems, sustainability, and challenges for the cultivation of tropical red seaweeds in the BIMP-EAGA region are discussed in this paper

    AnĆ”lise comparativa dos ficocolĆ³ides produzidos por algas carragenĆ³fitas usadas industrialmente e algas carragenĆ³fitas portuguesas

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    As Carragenanas (E-407) constituem um dos principais aditivos usados pela indĆŗstria alimentar, como agentes gelificantes, emulsionantes, estabilizantes e espessantes. SĆ£o ingredientes naturais, usados hĆ” vĆ”rias dĆ©cadas na Ć”rea alimentar e sĆ£o considerados como seguros, tendo obtido a classificaĆ§Ć£o GRAS (Generally Recognised As Safe). Neste trabalho foram analisadas a percentagem de peso seco e a composiĆ§Ć£o quĆ­mica (por FTIR e FT-Raman) das carragenanas produzidas pelas carragenĆ³fitas (Gigartinales, Rhodophyta) oriundas de diversos paĆ­ses: Kappaphycus alvarezzi (TanzĆ¢nia, IndonĆ©sia, Filipinas); Kappaphycus striatum (MadagĆ”scar); Eucheuma denticulatum (TanzĆ¢nia, Filipinas e MadagĆ”scar); Betaphycus gelatinum (Filipinas); e Sarcothalia crispata (Chile). Para comparaĆ§Ć£o foram tambĆ©m analisadas algas carragenĆ³fitas da costa portuguesa (Gigartinales, Rhodophyta): Chondrus crispus, Mastocarpus stellatus; Gigartina pistillata; Chondracanthus teedei var. lusitanicus; Chondracanthus acicularis; Calliblepharis jubata; Gymnogongrus crenulatus; e Ahnfeltiopsis devoniensis. Os principais resultados a reter sĆ£o: a maior percentagem de peso seco em carragenanas foi obtida a partir das algas carragenĆ³fitas Kappaphycus alvarezzi (Filipinas), com 84.4% e Gigartina pistillata (Praia do Norte, Viana do Castelo), com 65.4%. Relativamente Ć  natureza dos ficocolĆ³ides produzidos pelas carragenĆ³fitas estudadas, as nossas anĆ”lises espectroscĆ³picas permitiram determinar a presenƧa de um leque diversificado de carragenanas: carragenana iota pura; carragenana kappa quase pura; uma sĆ©rie de carragenanas hĆ­bridas kappa-iota, com diferentes rĆ”cios iota/kappa; carragenanas kappa-beta, xi-tetha e xi-lambda

    Ascophyllum nodosum-Based Biostimulants: Sustainable Applications in Agriculture for the Stimulation of Plant Growth, Stress Tolerance, and Disease Management

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    Abiotic and biotic stresses limit the growth and productivity of plants. In the current global scenario, in order to meet the requirements of the ever-increasing world population, chemical pesticides and synthetic fertilizers are used to boost agricultural production. These harmful chemicals pose a serious threat to the health of humans, animals, plants, and the entire biosphere. To minimize the agricultural chemical footprint, extracts of Ascophyllum nodosum (ANE) have been explored for their ability to improve plant growth and agricultural productivity. The scientific literature reviewed in this article attempts to explain how certain bioactive compounds present in extracts aid to improve plant tolerances to abiotic and/or biotic stresses, plant growth promotion, and their effects on root/microbe interactions. These reports have highlighted the use of various seaweed extracts in improving nutrient use efficiency in treated plants. These studies include investigations of physiological, biochemical, and molecular mechanisms as evidenced using model plants. However, the various modes of action of A. nodosum extracts have not been previously reviewed. The information presented in this review depicts the multiple, beneficial effects of A. nodosum-based biostimulant extracts on plant growth and their defense responses and suggests new opportunities for further applications for marked benefits in production and quality in the agriculture and horticultural sectors

    Ballistic protective properties of material representative of English civil war buff-coats and clothing

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    One type of clothing system used in the English Civil War, more common amongst cavalrymen than infantrymen, was the linen shirt, wool waistcoat and buff-coat. Ballistic testing was conducted to estimate the velocity at which 50% of 12-bore lead spherical projectiles (V50) would be expected to perforate this clothing system when mounted on gelatine (a tissue simulant used in wound ballistic studies). An estimated six-shot V50 for the clothing system was calculated as 102 m/s. The distance at which the projectile would have decelerated from the muzzle of the weapon to this velocity in free flight was triple the recognised effective range of weapons of the era suggesting that the clothing system would provide limited protection for the wearer. The estimated V50 was also compared with recorded bounce-and-roll data; this suggested that the clothing system could provide some protection to the wearer from ricochets. Finally, potential wounding behind the clothing system was investigated; the results compared favourably with seventeenth century medical writings

    A Longitudinal Study of Medicaid Coverage for Tobacco Dependence Treatments in Massachusetts and Associated Decreases in Hospitalizations for Cardiovascular Disease

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    Thomas Land and colleagues show that among Massachusetts Medicaid subscribers, use of a comprehensive tobacco cessation pharmacotherapy benefit was followed by a substantial decrease in claims for hospitalizations for acute myocardial infarction and acute coronary heart disease

    TascoĀ®, a Product of Ascophyllum nodosum, Imparts Thermal Stress Tolerance in Caenorhabditis elegans

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    TascoĀ®, a commercial product manufactured from the brown alga Ascophyllum nodosum, has been shown to impart thermal stress tolerance in animals. We investigated the physiological, biochemical and molecular bases of this induced thermal stress tolerance using the invertebrate animal model, Caenorhabiditis elegans. TascoĀ® water extract (TWE) at 300 Ī¼g/mL significantly enhanced thermal stress tolerance as well as extended the life span of C. elegans. The mean survival rate of the model animals under thermal stress (35 Ā°C) treated with 300 Ī¼g/mL and 600 Ī¼g/mL TWE, respectively, was 68% and 71% higher than the control animals. However, the TWE treatments did not affect the nematode body length, fertility or the cellular localization of daf-16. On the contrary, TWE under thermal stress significantly increased the pharyngeal pumping rate in treated animals compared to the control. Treatment with TWE also showed differential protein expression profiles over control following 2D gel-electrophoresis analysis. Furthermore, TWE significantly altered the expression of at least 40 proteins under thermal stress; among these proteins 34 were up-regulated while six were down-regulated. Mass spectroscopy analysis of the proteins altered by TWE treatment revealed that these proteins were related to heat stress tolerance, energy metabolism and a muscle structure related protein. Among them heat shock proteins, superoxide dismutase, glutathione peroxidase, aldehyde dehydrogenase, saposin-like proteins 20, myosin regulatory light chain 1, cytochrome c oxidase RAS-like, GTP-binding protein RHO A, OS were significantly up-regulated, while eukaryotic translation initiation factor 5A-1 OS, 60S ribosomal protein L18 OS, peroxiredoxin protein 2 were down regulated by TWE treatment. These results were further validated by gene expression and reporter gene expression analyses. Overall results indicate that the water soluble components of TascoĀ® imparted thermal stress tolerance in the C. elegans by altering stress related biochemical pathways

    TascoĀ®: A Product of Ascophyllum nodosum Enhances Immune Response of Caenorhabditis elegans Against Pseudomonas aeruginosa Infection

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    The effects of TascoĀ®, a product made from the brown seaweed (Ascophyllum nodosum) were tested for the ability to protect Caenorhabditis elegans against Pseudomonas aeruginosa infection. A water extract of TascoĀ® (TWE) reduced P. aeruginosa inflicted mortality in the nematode. The TWE, at a concentration of 300 Āµg/mL, offered the maximum protection and induced the expression of innate immune response genes viz.; zk6.7 (Lypases), lys-1 (Lysozyme), spp-1 (Saponin like protein), f28d1.3 (Thaumatin like protein), t20g5.7 (Matridin SK domain protein), abf-1 (Antibacterial protein) and f38a1.5 (Lectin family protein). Further, TWE treatment also affected a number of virulence components of the P. aeuroginosa and reduced its secreted virulence factors such as lipase, proteases and toxic metabolites; hydrogen cyanide and pyocyanin. Decreased virulence factors were associated with a significant reduction in expression of regulatory genes involved in quorum sensing, lasI, lasR, rhlI and rhlR. In conclusion, the TWE-treatment protected the C. elegans against P. aeruginosa infection by a combination of effects on the innate immunity of the worms and direct effects on the bacterial quorum sensing and virulence factors
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