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Bioproducts from seaweeds: a review with special focus on the Iberian Peninsula

Cardoso, Susana M.; Carvalho, Loic G.; Silva, Paulo J.; Rodrigues, Mara S.; Pereira, Olívia R.; Pereira, Leonel
Fonte: Bentham Science Publicador: Bentham Science
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.21%
Seaweeds, i.e. macroalgae that occupy the littoral zone, are a great source of compounds with diverse applications; their types and content greatly determine the potential applications and commercial values. Algal polysaccharides, namely the hydrocolloids: agar, alginate and carrageenan, as well as other non-jellifying polysaccharides and oligosaccharides, are valuable bioproducts. Likewise, pigments, proteins, amino acids and phenolic compounds are also important, exploitable compounds. For the longest time the dominant market for macroalgae has been the food industry. More recently, several other industries have increased their interest in algal-derived products, e.g. cosmetics, pharmaceuticals and more recently, as a source of feedstock for biorefinery applications. This manuscript reviews the chemical composition of dominant macroalgae, as well as their potential added-value products and applications. Particular attention is devoted to the macroalgal species from the Iberian Peninsula. This is located in the Southwest of Europe and is influenced by the distinct climates of the Mediterranean Sea and the Atlantic Ocean, representing a rich spot of marine floral biodiversity.

Precipitação de CaCO3 em algas marinhas calcárias e balanço de CO2 atmosférico: os depósitos calcários marinhos podem atuar como reservas planetárias de carbono?; CaCO3 precipitation in marine calcareous seaweeds and the atmospheric CO2 concentration: can the marine calcareous deposits act as planetary carbon sinks?

Amancio, Carlos Eduardo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/09/2007 PT
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As atividades humanas nos últimos dois séculos vêm provocando um aumento na concentração de dióxido de carbono (CO2) atmosférico. Um dos efeitos desse aumento é um incremento na produtividade primária de algumas espécies vegetais terrestres, que dessa maneira atuam como sequestradoras de carbono. Nos oceanos, o CO2 é armazenado principalmente na forma de carbonato de cálcio (CaCO3), e o aumento na sua concentração leva a uma acidificação da água do mar e a uma menor disponibilidade de íons carbonato. Os animais que precipitam CaCO3 não serviriam como sequestradores de carbono porque o processo de calcificação produz CO2. Porém, a maioria das medidas de balanço de CO2 em comunidades calcárias marinhas negligenciam as formações de algas. Nas algas calcárias o CO2 produzido pela calcificação é aproveitado pela fotossíntese. Além disso, aumentos na concentração de CO2 podem levar a aumentos na taxa de crescimento, embora essas taxas possam ser afetadas por uma queda na disponibilidade de íons carbonato. O objetivo deste trabalho foi verificar se o aumento na concentração de CO2, e a acidificação da água do mar por ela causada, afetam o crescimento de algas calcárias. Tendo em vista a ausência de referências sobre trabalhos desse tipo com algas calcárias e considerando que as coralináceas não-articuladas...

Estudos químicos e biológicos de algas marinhas do gênero Bostrychia Montagne (Rhodomelaceae, Rhodophyta) e fungos endofíticos associados; Chemical and biological studies in the seaweeds of Bostrychia Montagne (Rhodomelaceae, Rhodophyta) genus and endophytic fungi associated.

Erbert, Cíntia
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 25/04/2011 PT
Relevância na Pesquisa
37.21%
O ambiente marinho, pela própria diversidade orgânica que representa, tem sido reconhecido como fonte promissora de metabólitos secundários biologicamente ativos. Algas marinhas produzem grande variedade de substância terpenoídicas, aromáticas e de origem policetídica, e bioensaios têm demonstrado importante potencial biológico relativo a estes metabólitos. Micro-organismos associados às algas, tais como fungos endofíticos, também representam importante e promissora fonte de produtos naturais com esqueletos estruturalmente diversos. Bostrychia é um gênero algal fisiológica e biogeograficamente bem estudado mas são escassas as informações quanto à sua composição química, predominando a descrição de polióis e de moléculas de baixo peso molecular. Neste trabalho, os resultados da comparação dos perfis cromatográficos de espécies de Bostrychia representam uma primeira abordagem qualitativa dos constituintes polares do conjunto de espécies desse gênero ocorrentes no litoral norte do estado de São Paulo, e deverá ser complementado por meio do isolamento e identificação estrutural de seus constituintes majoritários. O isolamento de fungos endofíticos a partir de B. radicans (coletadas em ambiente de costão rochoso e manguezal) e B. tenella (coletadas no costão rochoso) possibilitou a preservação de 135 linhagens disponíveis para estudos posteriores. Dentre as linhagens isoladas de B. radicans costão...

Extratos de algas marinhas como agentes antioxidantes e antimicrobianos e seus efeitos na qualidade de Minced de tilápia (Oreochromis niloticus); Seaweeds extracts as antioxidants and antimicrobial agents and their effects on quality of tilapia Minced (Oreochromis niloticus)

Cabral, Ingridy Simone Ribeiro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 04/05/2012 PT
Relevância na Pesquisa
27.76%
A extração de Carne Mecanicamente Separada de tilápia tem se destacado como um processo atraente pela possibilidade de maior recuperação da carne após a filetagem. Porém, a separação mecânica aumenta a superfície de exposição, levando à incorporação de oxigênio e consequentemente ao "off flavor" devido à rancidez, tornando necessário o uso de aditivos para sua conservação. A tendência é utilizar produtos naturais como alternativas aos aditivos químicos. Entre os produtos naturais, as algas marinhas apresentam, em sua composição, metabólitos secundários com alta atividade antioxidante e antimicrobiana. Esta pesquisa teve como objetivo avaliar a composição química e a atividade biológica de quatro algas marinhas e seus efeitos, quando aplicados em Minced de tilápia. As algas Nori, Kombu, Hijiki e Wakame foram extraídas por 2 e 7 dias, em temperatura ambiente, com etanol 60, 80 e 100%. O teor de compostos fenólicos, a atividade antioxidante e a antimicrobiana in vitro foram determinados. A atividade antioxidante por métodos acelerados, Rancimat e Oxipres, também foi avaliada. As algas bioativas tiveram seu perfil químico elucidado por cromatografia líquida e gasosa. Essas algas foram aplicadas em Minced de tilápia...

Antioxidant potential of two red seaweeds from the Brazilian coasts

Cerqueira, M. A.; Martins, Joana; Quintas, Mafalda A. C.; Ferreira, António C.; Teixeira, J. A.; Vicente, A. A.; Souza, B. W. S.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
Publicado em //2011 ENG
Relevância na Pesquisa
37.21%
In this work, in vitro antioxidant activity of two Brazilian red seaweeds, Gracilaria birdiae and Gracilaria cornea, was characterized. The total phenolic content, the radical-scavenging activity and the antioxidant activity were determined in two solvent extracts of the algae. Liquid chromatography mass spectrometry (LC MS/MS) allowed identification of important antioxidant compounds. The ethanol extract of G. birdiae was found to have the highest value of total phenolic content: 1.13 mg of gallic acid equiv (GAE)/g of extract.The radical-scavenging activity of G. birdiae and G. cornea extracts has been evaluated at different extract concentrations; the IC50 values of ethanolic extracts of G. cornea and G. birdiae were 0.77 and 0.76mgmL 1, respectively, while formethanolic extracts, the IC50 values of G. cornea and G. birdiae were 0.86 and 0.76mgmL 1, respectively. The antioxidant activities of these two seaweeds’ extracts as assessed by the ß-carotene linoleic acid assay were equally high, achieving values of ß-carotene oxidation inhibition of up to 40%. Finally, in the methanolic extracts, LC MS/MS allowed identification in both algae of two important antioxidants: apigenin and gallic acid.

Nutritional value of selected macroalgae

Patarra, Rita F.; Paiva, Lisete S.; Neto, Ana I.; Lima, Elisabete M. C.; Baptista, José A. B.
Fonte: Springer Science+Business Media Publicador: Springer Science+Business Media
Tipo: Artigo de Revista Científica
Publicado em /04/2011 ENG
Relevância na Pesquisa
27.49%
Copyright © Springer Science+Business Media B.V. 2011.; Macroalgae are traditionally used in human and animal nutrition. Their protein and fiber content have been widely studied and differ according to the species, their geographic origin and their seasonal conditions. In addition to their value for human nutrition, seaweeds have multiple therapeutically applications (e.g., weight control, hypocholesterolemic, antioxidant and antitumor activities, others) and, in general, contribute and promote human health. In the archipelago of the Azores, the consumption of seaweeds is widespread and accepted as a common practice in some islands. This work is aimed at providing information on the protein and fiber content of the locally consumed species, to promote this regional food product that can be potentially profitable from the biotechnology and commercial perspective, and also benefit public health, particularly, taking into account the low level of marine pollution in the Azores archipelago. Protein and fiber content of eight seaweeds (Porphyra sp., Osmundea pinnatifida, Pterocladiella capillacea, Sphaerococcus coronopifolius, and Gelidium microdon, Rhodophyta; Cystoseira abies-marina and Fucus spiralis, Phaeophyta; Ulva compressa, Chlorophyta) were determined using the Kjeldahl method and the Weende method...

Bioprospecting for bioactives from seaweeds: potential, obstacles and alternatives

Pereira,Renato C.; Costa-Lotufo,Leticia V.
Fonte: Sociedade Brasileira de Farmacognosia Publicador: Sociedade Brasileira de Farmacognosia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2012 EN
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37.38%
Seaweeds are potential sources of high biotechnological interest due to production of a great diversity of compounds exhibiting a broad spectrum of biological activities. On the other hand, there is an urgent need for management options for a sustainable approach to the use of marine organisms as a source of bioactive compounds. This review discusses the bioprospection for bioactive seaweed compounds as pharmaceuticals and antifouling agents, encompassing their potential and possible obstacles and alternatives. In spite of their potential, research on pharmaceuticals and antifouling agents from seaweeds includes mainly the search for molecules that exhibit these biological activities, but lacks of consideration of fundamental and limiting aspects such as the development of alternatives to sustainable supply. However, for the complete development of pharmaceuticals and antifouling compounds in Brazil, marine bioprospection should be more comprehensive, associating the search for molecules with an analysis of their supply. In this way, it is possible to promote sustainable development and conservation of biodiversity, as well as to assert the economic development of Brazil.

Feeding preference of the sea urchin Lytechinus variegatus (Lamarck, 1816) on seaweeds

Souza,Camilla Ferreira; Oliveira,Aline Santos de; Pereira,Renato Crespo
Fonte: Universidade de São Paulo, Instituto Oceanográfico Publicador: Universidade de São Paulo, Instituto Oceanográfico
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2008 EN
Relevância na Pesquisa
37.49%
Seaweeds exhibit different strategies to minimize the damage caused by herbivores and also to influence the feeding preference of these consumers. This study evaluated the feeding preference of the sea urchin Lytechinus variegatus through multiple-choice experiments using the seaweeds Caulerpa racemosa, Dictyota menstrualis, Osmundaria obtusiloba, Plocamium brasiliense, Sargassum sp., and Ulva sp. In order to verify the importance of morphological and chemical aspects on this feeding preference, two assay-types were carried out using live and powdered macroalgae, respectively. Two different methods were employed to analyze the results obtained: comparison between biomass losses versus autogenic changes, and inclusion of autogenic values in biomass loss through herbivory. In both experiments a clear differential consumption of certain species of seaweeds by L. variegatus was observed, in the following decreasing order of preference: C. racemosa ≈ Ulva sp. > O. obtusiloba ≈ Sargassum sp. > P. brasiliense > D. menstrualis. It was also verified that both methods of analysis used yielded similar results. According to the results obtained, feeding preference of L. variegatus is probably established by the defensive chemicals produced by P. brasiliense and D. menstrualis...

Antiulcer, wound healing and hepatoprotective activities of the seaweeds Gracilaria crassa, Turbinaria ornata and Laurencia papillosa from the southeast coast of India

Senthil,Kulandhaisamy Arul; Murugan,Annappan
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
Relevância na Pesquisa
27.49%
Seaweeds have bioactive compounds of interest in the pharmaceutical industry. In India, seaweeds are used exclusively for phycocolloids production and have not yet received consideration as a dietary supplement. So, it has become imperative to explore the biomedical potential of seaweeds and promote their utilization as a functional food. The seaweeds Turbinaria ornata, Gracillaria crassa and Laurencia papillosa, collected from the Tuticorin coast of the Southeast coast of India and selected based on preliminary screening, were extracted with acetone and evaluated for antiulcer, wound healing and hepatoprotective activities. L. papillosa showed the highest level of gastric protection activity (81%) at 200 mg/kg, comparable to the standard drug ranitidine (90%). G. crassa followed with 76%. G. crassa and L. papillosa, showed marked wound-healing activity. G. crassa at 200 mg/kg, showed a marked effect on the serum marker enzymes indicating prominent hepatoprotective activity. The noteworthy wound-healing and hepato-protective properties of G. crassa besides anti-ulcer activity next to L. papillosa were indicative of its potential for further consideration.

Chemically rich seaweeds poison corals when not controlled by herbivores

Rasher, Douglas B.; Hay, Mark E.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.76%
Coral reefs are in dramatic global decline, with seaweeds commonly replacing corals. It is unclear, however, whether seaweeds harm corals directly or colonize opportunistically following their decline and then suppress coral recruitment. In the Caribbean and tropical Pacific, we show that, when protected from herbivores, ~40 to 70% of common seaweeds cause bleaching and death of coral tissue when in direct contact. For seaweeds that harmed coral tissues, their lipid-soluble extracts also produced rapid bleaching. Coral bleaching and mortality was limited to areas of direct contact with seaweeds or their extracts. These patterns suggest that allelopathic seaweed-coral interactions can be important on reefs lacking herbivore control of seaweeds, and that these interactions involve lipid-soluble metabolites transferred via direct contact. Seaweeds were rapidly consumed when placed on a Pacific reef protected from fishing but were left intact or consumed at slower rates on an adjacent fished reef, indicating that herbivory will suppress seaweeds and lower frequency of allelopathic damage to corals if reefs retain intact food webs. With continued removal of herbivores from coral reefs, seaweeds are becoming more common. This occurrence will lead to increasing frequency of seaweed-coral contacts...

Water-Borne Cues of a Non-Indigenous Seaweed Mediate Grazer-Deterrent Responses in Native Seaweeds, but Not Vice Versa

Yun, Hee Young; Engelen, Aschwin H.; Santos, Rui O.; Molis, Markus
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 12/06/2012 EN
Relevância na Pesquisa
27.73%
Plants optimise their resistance to herbivores by regulating deterrent responses on demand. Induction of anti-herbivory defences can occur directly in grazed plants or from emission of risk cues to the environment, which modifies interactions of adjacent plants with, for instance, their consumers. This study confirmed the induction of anti-herbivory responses by water-borne risk cues between adjoining con-specific seaweeds and firstly examined whether plant-plant signalling also exists among adjacent hetero-specific seaweeds. Furthermore, differential abilities and geographic variation in plant-plant signalling by a non-indigenous seaweed as well as native seaweeds were assessed. Twelve-day induction experiments using the non-indigenous seaweed Sargassum muticum were conducted in the laboratory in Portugal and Germany with one local con-familiar (Portugal: Cystoseira humilis, Germany: Halidrys siliquosa) and hetero-familiar native species (Portugal: Fucus spiralis, Germany: F. vesiculosus). All seaweeds were grazed by a local isopod species (Portugal: Stenosoma nadejda, Germany: Idotea baltica) and were positioned upstream of con- and hetero-specific seaweeds. Grazing-induced modification in seaweed traits were tested in three-day feeding assays between cue-exposed and cue-free ( = control) pieces of both fresh and reconstituted seaweeds. Both Fucus species reduced their palatability when positioned downstream of isopod-grazed con-specifics. Yet...

Evaluation of the proximate, fatty acid and mineral composition of representative green, brown and red seaweeds from the Persian Gulf of Iran as potential food and feed resources

Rohani-Ghadikolaei, Kiuomars; Abdulalian, Eessa; Ng, Wing-Keong
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.64%
The proximate, fatty acid and mineral composition were determined for green (Ulva lactuca and Enteromorpha intestinalis), brown (Sargassum ilicifolium and Colpomenia sinuosa) and red (Hypnea valentiae and Gracilaria corticata) seaweeds collected from the Persian Gulf of Iran. Results showed that the seaweeds were high in carbohydrate (31.8–59.1%, dry weight) and ash (12.4–29.9%) but low in lipid content (1.5–3.6%). The protein content of red or green seaweeds was significantly higher (p < 0.05) compared to brown seaweeds. The fatty acid composition of various seaweed lipids varied considerably with 51.9–67.4% of saturates, 22.0–32.9% of monoenes and 9.2–19.1% of polyunsaturated fatty acids (PUFA). E. intestinalis contained the highest total n-3 PUFA content with the lowest n-6/n-3 ratio. Persian Gulf seaweeds contained higher concentrations of all the minerals examined (K, Mg, Fe, Mn, Cu, Zn and Co) compared to terrestrial vegetables. Seaweeds could potentially be used as a food or feed additive in Iran.

Radical scavenging and singlet oxygen quenching activity of extracts from Indian seaweeds

Sachindra, N. M.; Airanthi, M. K. W. A.; Hosokawa, M.; Miyashita, K.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.49%
Free radicals and singlet oxygen are responsible for oxidative stress related diseases and many natural compounds are known to have antioxidant properties. In this study, extracts from brown and red seaweeds of Indian origin were evaluated for their ability to scavenge different radicals and quench singlet oxygen. The crude extract in methanol and its fractions in different solvents were evaluated for their activity. The methanol extract and its fractions from brown seaweed exhibited higher 2,2′-azinobis(3-ethylbenzothizoline-6-sulfonic acid) radical scavenging activity with more than 90% scavenging in butanol and ethyl acetate fractions and correlated with polyphenol content. There was a significant difference (p≤0.001) in hydroxyl radical scavenging activity between different fractions of the same seaweed. Among the crude extracts, extract from Gracilaria corticata showed the highest (14.0%) activity. Crude extract from brown seaweeds showed higher peroxyl radical scavenging activity compared to red seaweeds. In fractions from brown seaweed extracts, highest activity was observed in ethyl acetate fraction (>88%) followed by hexane fraction (>40 %). Ethyl acetate fraction from crude extract showed higher inhibitory activity against hemoglobin induced linoleic acid oxidation. Singlet oxygen quenching activity of the crude extract from brown seaweed was lower (<13%) compared to red seaweeds (16.4–20.5%).

Strategies for the production of high concentrations of bioethanol from seaweeds: Production of high concentrations of bioethanol from seaweeds

Yanagisawa, Mitsunori; Kawai, Shigeyuki; Murata, Kousaku
Fonte: Landes Bioscience Publicador: Landes Bioscience
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.57%
Bioethanol has attracted attention as an alternative to petroleum-derived fuel. Seaweeds have been proposed as some of the most promising raw materials for bioethanol production because they have several advantages over lignocellulosic biomass. However, because seaweeds contain low contents of glucans, i.e., polysaccharides composed of glucose, the conversion of only the glucans from seaweed is not sufficient to produce high concentrations of ethanol. Therefore, it is also necessary to produce ethanol from other specific carbohydrate components of seaweeds, including sulfated polysaccharides, mannitol, alginate, agar and carrageenan. This review summarizes the current state of research on the production of ethanol from seaweed carbohydrates for which the conversion of carbohydrates to sugars is a key step and makes comparisons with the production of ethanol from lignocellulosic biomass. This review provides valuable information necessary for the production of high concentrations of ethanol from seaweeds.

Assessment of Dual Life Stage Antiplasmodial Activity of British Seaweeds

Spavieri, Jasmine; Allmendinger, Andrea; Kaiser, Marcel; Itoe, Maurice Ayamba; Blunden, Gerald; Mota, Maria M.; Tasdemir, Deniz
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 22/10/2013 EN
Relevância na Pesquisa
27.57%
Terrestrial plants have proven to be a prolific producer of clinically effective antimalarial drugs, but the antimalarial potential of seaweeds has been little explored. The main aim of this study was to assess the in vitro chemotherapeutical and prophylactic potential of the extracts of twenty-three seaweeds collected from the south coast of England against blood stage (BS) and liver stage (LS) Plasmodium parasites. The majority (14) of the extracts were active against BS of P. falciparum, with brown seaweeds Cystoseira tamariscifolia, C. baccata and the green seaweed Ulva lactuca being the most active (IC50s around 3 μg/mL). The extracts generally had high selectivity indices (>10). Eight seaweed extracts inhibited the growth of LS parasites of P. berghei without any obvious effect on the viability of the human hepatoma (Huh7) cells, and the highest potential was exerted by U. lactuca and red seaweeds Ceramium virgatum and Halopitys incurvus (IC50 values 14.9 to 28.8 μg/mL). The LS-active extracts inhibited one or more key enzymes of the malarial type-II fatty acid biosynthesis (FAS-II) pathway, a drug target specific for LS. Except for the red seaweed Halopitys incurvus, all LS-active extracts showed dual activity versus both malarial intracellular stage parasites. This is the first report of LS antiplasmodial activity and dual stage inhibitory potential of seaweeds.

Spatial distributions of floating seaweeds in the East China Sea from late winter to early spring

Mizuno, S.; Ajisaka, T.; Lahbib, S.; Kokubu, Y.; Alabsi, M. N.; Komatsu, T.
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.57%
Floating seaweeds play an important role as a habitat for many animals accompanying or attaching to them in offshore waters. It was in 2000 that the first report described abundant distributions of floating seaweeds in offshore waters in the East China Sea in spring. Young individuals of the yellowtail Seriola quinqueradiata are captured for aquaculture purposes from floating seaweeds in the East China Sea. Therefore, a sound understanding of the distributions of floating seaweeds in the East China Sea is needed. Detailed information is especially important during the late winter to early spring, which corresponds to the juvenile period of the yellowtail. Thus, field surveys using R/V Tansei-Maru were conducted in the Japanese Exclusive Economic Zone in the East China Sea from late winter to early spring in 2010 and 2011. We obtained positions of the vessel by GPS and transversal distances from the vessel to a raft by visual observation. Distance sampling method (Thomas et al. 2010) was applied to estimation of floating seaweed densities (rafts km−2). Seaweed rafts were also randomly sampled using nets during the research cruises. In the East China Sea, seaweed rafts were distributed mainly on the continental shelf west of the Kuroshio...

Ecological impacts of invading seaweeds: a meta-analysis of their effects at different trophic levels

Maggi, E.; Benedetti-Cecchi, L.; Castelli, A.; Chatzinikolaou, E.; Crowe, T.P.; Ghedini, G.; Kotta, J.; Lyons, D.A.; Ravaglioli, C.; Rilov, G.; Rindi, L.; Bulleri, F.
Fonte: Wiley Publicador: Wiley
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
Relevância na Pesquisa
37.73%
Aim: Biological invasions are among the main threats to biodiversity. To promote a mechanistic understanding of the ecological impacts of non-native seaweeds, we assessed how effects on resident organisms vary according to their trophic level. Location: Global. Methods: We performed meta-analytical comparisons of the effects of non-native seaweeds on both individual species and communities. We compared the results of analyses performed on the whole dataset with those obtained from experimental data only and, when possible, between rocky and soft bottoms. Results: Meta-analyses of data from 100 papers revealed consistent negative effects of non-native seaweeds across variables describing resident primary producer communities. In contrast, negative effects of seaweeds on consumers emerged only on their biomass and, limited to rocky bottoms, diversity. At the species level, negative effects were consistent across primary producers' response variables, while only the survival of consumers other than herbivores or predators (e.g. deposit/suspension feeders or detritivores) decreased due to invasion. Excluding mensurative data, negative effects of seaweeds persisted only on resident macroalgal communities and consumer species survival, while switched to positive on the diversity of rocky-bottom consumers. However...

Feeding preference of the sea urchin Lytechinus variegatus (Lamarck, 1816) on seaweeds

Souza, Camilla Ferreira; Oliveira, Aline Santos de; Pereira, Renato Crespo
Fonte: Universidade de São Paulo. Instituto Oceanográfico Publicador: Universidade de São Paulo. Instituto Oceanográfico
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 01/09/2008 ENG
Relevância na Pesquisa
37.49%
Seaweeds exhibit different strategies to minimize the damage caused by herbivores and also to influence the feeding preference of these consumers. This study evaluated the feeding preference of the sea urchin Lytechinus variegatus through multiple-choice experiments using the seaweeds Caulerpa racemosa, Dictyota menstrualis, Osmundaria obtusiloba, Plocamium brasiliense, Sargassum sp., and Ulva sp. In order to verify the importance of morphological and chemical aspects on this feeding preference, two assay-types were carried out using live and powdered macroalgae, respectively. Two different methods were employed to analyze the results obtained: comparison between biomass losses versus autogenic changes, and inclusion of autogenic values in biomass loss through herbivory. In both experiments a clear differential consumption of certain species of seaweeds by L. variegatus was observed, in the following decreasing order of preference: C. racemosa ≈ Ulva sp. >; O. obtusiloba ≈ Sargassum sp. >; P. brasiliense >; D. menstrualis. It was also verified that both methods of analysis used yielded similar results. According to the results obtained, feeding preference of L. variegatus is probably established by the defensive chemicals produced by P. brasiliense and D. menstrualis...

Produtos Naturais de Algas Marinhas Bentônicas; Marine Natural Products from Seaweeds

Valéria L. Teixeira; Universidade Federal Fluminense
Fonte: Revista Virtual de Química Publicador: Revista Virtual de Química
Tipo: ; Formato: binary/octet-stream
Publicado em 04/07/2013 PT
Relevância na Pesquisa
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Produtos naturais de algas marinhas bentônicas são estudados com o objetivo de se buscar novas substâncias de valor industrial, para o conhecimento de seu papel ecológico e como uma ferramenta poderosa no estabelecimento dos limites taxonômicos de espécies, gêneros e famílias de algas marinhas. A presente revisão mostra as principais características dos produtos naturais de macroalgas marinhas pertencentes as Divisões Chlorophycta – Classe Ulvophyceae (macroalgas verdes marinhas), Ochrophyta – Classe Phaeophyceae (macroalgas pardas marinhas) e Rhodophyta (macroalgas vermelhas). São apresentados os principais exemplos de produtos naturais isolados de espécies da costa brasileira, suas principais atividades biológicas observadas, sua importância ecológica, taxonômica e evolutiva. DOI: 10.5935/1984-6835.20130033; Natural products from seaweeds have been studied with the aim of finding new drugs of industrial value, understanding their ecological role, and well as establishing the limits of taxonomic species, genera and families of marine algae. The present review shows the main features of natural products from seaweeds of the Divisions Chlorophyta – Class Ulvophyceae (green seaweeds), Ochrophyta – Class Phaeophyceae (Brown seaweeds) and Rhodophyta (red seaweeds). The most important examples of natural products isolated in the Brazilian coast are presented along with their main biological activities and their ecological...

Floristic and phytogeographic aspects of the seaweeds of the bays at Santa Catarina Island, SC, Brazil; Aspectos florísticos e fitogeográficos das macroalgas marinhas das baías da Ilha de Santa Catarina, SC, Brasil

Bouzon, Janayna L.; Universidade Federal de Santa Catarina; Salles, José P.; Universidade Federal de Santa Catarina; Bouzon, Zenilda; Universidade Federal de Santa Catarina; Horta, Paulo A.; Universidade Federal de Santa Catarina
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; Formato: application/pdf
Publicado em 01/01/2006 POR
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Santa Catarina's coast presents a great number ofworks involving seaweeds, however, Santa Catarina Island Bay was poor1y described and represents an environment that comes suffering severe humans interferences with the urbanization advances. The present work had for objective to carry through the survey of the seaweeds of this bay, contributing for the knowledge of the marine biodiversity of the State and the south of the country. Twelve stations had been selected to represent the distinct physiognornies inside the bays. 107 taxa infrageneric had been identified. Some taxa are cited for the first time to south region, as Pleonosporium polysthicum E. C. Oliveira, Acinetospora crinita (Carmichael ex Harvey in Hooker) Kommann and Neosiphonia sphaerocarpa (Børgesen) M. -S. Kim & I. K. Lee. Feldmann and Cheney's index for Santa Catarina Island Bay had characterized it as part of the Warm Temperate province, as well as analyzed previously for other authors, however presenting inferior values to these studies. More urbânized areas had demonstrated to be outside of the described phytogeographic standards previously, mainly due to distinct vulnerability that some groups of seaweed present situations ahead of stress, such as the Phaeophyceae. It means the urbanization impacts of coastal environments have the potential to modify the ecological and even biogeographic standards of marine environments...