An alkaline extract of the brown seaweed, Ascophyllum nodosum (ANE) increases plant growth and imparts resistance against biotic stresses. However, little is known of the effects of ANE on insects. Myzus persicae, green peach aphid (GPA), and Arabidopsis model were used to determine whether application of ANE confers protection from GPA infestation. GPA colonization increased in ANE treated plants, associated with improved biomass. However, ANE treated plants exhibited less cell death and also showed a greater ability to recover from GPA injury. Lower expression of SAG13, SAG21 and CHL1 and a higher expression of ARR5 was observed in ANE treated plants. Taken together, gene expression along with lower cell death suggests ANE may delay senescence in Arabidopsis. Delayed senescence in Arabidopsis following ANE treatment may be a result of increased cytokinin activity. Increased GPA numbers could be, at least in part, due to delayed senescence in Arabidopsis following ANE treatment.

The use of alternative feedstock sources to enhance the energy production of anaerobic systems, and thus their economic value, is one of the current research areas in the field of bioenergy production. Marine biomass represents a unique source of organic matter for the optimisation of anaerobic digestion systems and can be regarded as a sustainable alternative to purposely grown energy crops requiring significant amounts of water, fertiliser and land for their cultivation. Seaweeds are of particular interest as they are characterised by high biomass yields and interesting conversion rates. In temperate seas, brown seaweed species generally dominate the flora and their relative abundance on the sublittoral zone of the British coastline make them a substrate of choice for anaerobic digestion. However, little information is available on commercial-scale anaerobic digestion of seaweed for biogas production and the potential factors that could impair its successful conversion. This work was proposed in order to establish the potential and optimise the use of seaweed as an additional source of organic matter for anaerobic digesters. The study also investigated the use of the Anaerobic Digestion Model No.1 (ADM1) as a platform for process simulation. The model original structure is inadequate to accurately represent the anaerobic co-digestion of seaweed and was therefore updated with the addition of specific processes. The study was carried out in three main experimental stages. In a first stage, the effect of seaweed salinity (represented by sodium ions) on anaerobic digestion was investigated using a mesophilic laboratory-scale anaerobic digester. It was found that a rapid increase in sodium ion levels can negatively impact on biogas production and result in the accumulation of volatile fatty acids. The ADM1 does not originally take into account the inhibitory effect of sodium and was therefore modified to include a function representing the effect of sodium ions on the rate of acetate uptake. The extended model was able to reproduce experimental observations and was used to predict the effect of sodium ions in the presence of other process inhibitors. Microbial adaptation to salinity was also investigated during batch assays. It was found that a suitable period of adaptation can significantly reduce the adverse effect of salinity on methanogens. The phenomenon was successfully implemented in the model through the addition of a specific inhibition function and the calibration of kinetic parameters. The second stage of this research focused on the effect and mode of action of phlorotannin (a phenolic compound found exclusively in brown seaweed) on mixed microbial cultures through the monitoring of intracellular material leakage and transmission electron microscopy observations. Results suggested that phlorotannin induces strong extra- and intra-cellular effects on cells exposed to the compound, thus adversely impacting on energy requirements and final methane yields. The effect of phlorotannin was found to be dependent on both the degree of polymerisation of the compound and the morphology of microorganisms. Furthermore, the effect of phlorotannin during the anaerobic co-digestion of brown seaweed (Laminaria digitata) and vegetable residues was also investigated. Experimental results were successfully modelled using an extensively modified version of the ADM1, which introduces an uncompetitive function to the rate of acetate uptake in order to represent the inhibition of methanogenesis by phlorotannin. The model was also updated with a combination module for the simulation of co-digestion processes. The third stage focused on establishing operational guidelines for the anaerobic co-digestion of brown seaweed and non-saline feedstocks. Results suggested that although seaweed can be an alternative organic substrate in anaerobic digestion systems, phlorotannin content might limit its use for commercial-scale application. Whilst this study identified salinity and phlorotannin as key barriers to the use of brown seaweed as a substrate for anaerobic systems, the adaptation of operating conditions to favour microbial adaptation could lead to its effective use in large-scale applications.

Made available in DSpace on 2014-12-17T14:03:35Z (GMT). No. of bitstreams: 1 CelinaMPGD_TESE.pdf: 1816885 bytes, checksum: 1e39ca48cae61af571d696fef8f71be4 (MD5) Previous issue date: 2012-10-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The present study examines the chemical composition and their effects on free radicals, inflammation, angiogenesis, coagulation, VEGF effects and cellular proliferation of a polysaccharides from alga Sargassum vulgare. The sulfated polysaccharide was extracted from brown seaweed by proteolysis with enzymes maxataze. The presence of proteins and sugars were observed in crude polysaccharides. Fractionation of this crude extract was made with growing concentration of acetone (0.3-1.5 v) and produced four groups of polysaccharides. Anionic polysaccharides from brown seaweed Sargassum vulgare, SV1and PSV1 were fractionated (SV1) and purified (PSV1), and displayed with high total sugars and sulfate content and very low level of protein. This fucan SV1 contains low levels of protein and high carbohydrate and sulfate content. This polysaccharides prolonged activated partial thromboplastin time (aPTT) at 50 μg (>240 s). SV1 was found to have no effect on prothrombin time (PT), corresponding to the extrinsic pathway of coagulation. SV1 exhibits high antithrombotic action in vivo, with a concentration ten times higher than heparin. Polysaccharides from S. vulgare promoted direct inhibition enzymatic activity of thrombin and stimulated enzymatic activity of FXa. SV1 showed optimal inhibitory activity of thrombin (50.2?0.28%) at a concentration of 25 μg/mL. Its antioxidant action on scavenging radicals by DPPH was (22%), indicating the polymer has no cytotoxic action (hemolytic) on ABO and Rh blood types in different erythrocyte groups and displays strong anti-inflammatory action on all concentrations tested in the carrageenan-induced paw edema model, demonstrated by reduced edema and cellular infiltration. Angiogenesis is a dynamic process of proliferation and differentiation. It requires endothelial proliferation, migration, and tube formation. In this context, endothelial cells are a preferred target for several studies and therapies. The antiangiogenic efficacy of polysaccharides was examined in vivo in the chick chorioallantoic membrane (CAM) model by using fertilized eggs. Decreases in the density of the capillaries were assessed and scored. The results showed that SV1 and PSV1 have an inhibitory effect on angiogenesis. These results were also confirmed by inhibition tubulogenesis in rabbit aorta endothelial cell (RAEC) in matrigel. These compounds were assessed in Apoptosis assay (Annexin V - FITC / PI) and cell viability by MTT assay of RAEC. These polysaccharides do not affect the viability and do not have apoptotic or necrotic action. RAEC cell when incubated with SV1 and PSV1showed inhibition of VEGF secretion, observed when compounds were incubated at 25, 50 and 100 μg/μL. The VEGF secretion with the RAEC cell line for 24 h, was more effective for PSV1 at 50 μg/μL(71.4%) than SV1 100 μg/μL (75.9%). SV1 and PSV1 had an antiproliferative action (47%) against tumor cell line HeLa. Our results indicate that these sulfated polysaccharides have antiangiogenic and antitumoral actions / O presente estudo analisa a composi??o qu?mica e seus efeitos sobre os radicais livres, inflama??o, angiog?nese, coagula??o, VEGF e prolifera??o celular dos polissacar?deos de uma alga Sargassum vulgare. O polissac?rido sulfatado foi extra?do a partir de algas marrons por prote?lise com a enzima maxataze. A presen?a de prote?nas e a??cares foram observados no cru de polissacarideos. Fracionamento do o extrato bruto foi feito com concentra??es crescente de acetona (0,3-1,5 v), produzindo quatro grupos de polissacarideos. Estes compostos ani?nicos da alga S. vulgare, foram fracionados (SV1) e purificados (PSV1) exibindo com alta a??cares totais e sulfatecontent e n?vel muito baixo de prote?nas.A fucana SV1 cont?m baixos n?veis de prote?na e de hidratos de carbono e alto teor de sulfato. Este polissacar?deos prolongou o tempo de tromboplastina parcial activada (aPTT) a 50 ug (>240 s). n?o foi observado qualquer efeito de SV1 sobre o tempo de protrombina (PT), que corresponde a via extr?nseca da coagula??o. SV1 exibiu alta a??o antitromb?tica in vivo, com uma concentra??o 10 vezes maior do que a heparina. SV1 promoveu a actividade de inibi??o enzim?tica direta da trombina e estimulou a atividade enzim?tica do FXa. Mostrou tamb?m, atividade inibidora optima de trombina (50,2 ? 0,28%) a uma concentra??o de 25 ug / mL. A sua ac??o anti-oxidante de radicais scavenging por DPPH foi de (22%), indicando que o pol?mero n?o tem qualquer a??o citot?xica (hemol?tica) em tipos de sangue ABO e Rh, em diferentes grupos de eritr?citos e exibindo alta a??o anti-inflamat?ria em edema de pata de ratos Wistar em todas as concentra??es testadas induzida por carragenina. Tal processo foi demonstrado por edema e infiltra??o celular. A angiogenese ? um processo din?mico de prolifera??o e diferencia??o. Ele requer prolifera??o endotelial, migra??o, e a forma??o do tubo. Neste contexto, as c?lulas endoteliais s?o um alvo preferido para muitos estudos e terapias. A efic?cia antiangiogenico de polissacar?deos foi examinada in vivo na membrana corioalant?ica pinto (CAM) usando-se ovos fertilizados. Diminui??es na densidade dos capilares foram avaliados e pontuados. Os resultados mostraram que SV1 e PSV1 tem um efeito inibidor da angiogenese. Estes resultados foram tamb?m confirmados por tubulogenesis inibi??o na c?lula endotelial da aorta de coelho (RAEC) em matrigel. C?lulas RAEC quando foram incubadas com SV1and PSV1 demonstraram inibi??o da secre??o de VEGF, a 25, 50 e 100 ug/mL. A secre??o de VEGF com a linha de c?lulas RAEC durante 24 h, foi mais eficaz para PSV1 a 50 ug / mL (71,4%) do que SV1 100 ug / mL (75,9%). SV1 e PSV1 posuiram uma ac??o antiproliferativa (47%) contra as c?lulas tumorais tipo HeLa. Estes compostos foram avaliados tamb?m, no ensaio de apoptose (anexina V - FITC / PI) e a viabilidade celular pelo ensaio de MTT de RAEC. Estes polissacar?deos n?o afetaram a viabilidade e n?o tiveram a??o apopt?tica ou necr?tica. Nossos resultados indicam que estes polissacar?deos sulfatados t?m a??es antiangiog?nica e antitumoral e constituem um importante alvo biol?gico e farmacol?gico

As algas marrons do gênero Sargassum têm sido estudadas como potenciais candidatas ao processo de biossorção, objetivando tratar efluentes contaminados com metais pesados. A estrutura celular deste gênero de alga apresenta moléculas carregadas, como o ácido algínico, capazes de atrair e captar cátions metálicos. A proposta deste trabalho foi avaliar a capacidade de captação dos íons cobre e chumbo pela alga marinha Sargassum através de ensaios cinéticos e de acumulação com modelagem cinética e das isotermas para sistemas monocomponente e binário. O equilíbrio de captação foi atingido em 30 minutos e a cinética do processo foi representada por um modelo de segunda ordem. No sistema monocomponente, onde as soluções continham inicialmente 10 mg/L de cada íon metálico a captação no equilíbrio foi 0,06 mmol/g de íons Cu (II) e 0,02 mmol/g de íons Pb (II). Para as soluções contendo 50 mg/L a captação no equilíbrio foi 0,37 mmol/g de íons Cu (II) e 0,11 mmol/g de íons Pb (II), individualmente. A capacidade de biossorção foi reduzida no sistema binário mostrando que a presença de um segundo metal afeta a captação dos íons. Os valores de qmax para íons Pb (II) no sistema binário foi 0,6 mmol/g contra 1,2 mmol/g no sistema monocomponente; para íons Cu (II) a captação foi 0,7 mmol/g contra 1,8 mmol/g. Na biossorção binária a captação de íons Pb (II) manteve o percentual de remoção mesmo em soluções com elevadas concentrações de íons Cu (II); o contrário não foi observado para o Pb(II), indicando que íons Pb (II) interferem mais na captação de íons Cu (II). Para o estudo do equilíbrio monocomponente foram utilizados os modelos de Langmuir e Freundlich; para o sistema binário, o Langmuir competitivo, Langmuir modificado, Langmuir-Freundlich e Freundlich estendido. Os modelos não foram conclusivos, porém elucidaram aspectos relacionados ao mecanismo, apresentando alto grau de dispersão entre a captação experimental e as teóricas. / Brown seaweeds from the genus Sargassum are widely studied for use as potential candidates for biosorption purposes, particularly in the treatment of heavy-metals contaminated effluents. The cellular structure of this seaweed presents charged molecules, such as alginic acid, able to attract and recover metal cation ions. The objective of this work was to study the uptake capacity of copper and lead by the seaweed Sargassum, through kinetic and isotherm studies with the help of kinetic and isotherm models for monocomponent and binary solutions. Equilibrium uptake was reached in 30 minutes and the kinetic behavior of the process followed a second-order model. In monocomponent systems, at 10 mg/L metal concentration, equilibrium uptake indicated a recovery of 0.06 mmol Cu(II)/g biomass and 0.02mmol/g Pb(II)/g biomass. When a 50 mg/L solution was used, the individual uptake was equal to 0.37 mmol Cu(II)/g biomass and 0.11 mmol Pb(II)/g biomass. Uptake was markedly reduced by the presence of the second metal in solution indicating the interference in biosorption in a multi-ion solution. Values of qmax for Pb(II) in the binary system was equal to 0.6 mmol/g biomass, against 1.2 mmol/g biomass in the monocomponent situation; for Cu(II) the uptake was equal to 0.7 mmol/g biomass against 1.8 mmol/g biomass, in the monocomponent solution. In the binary solution, Pb(II) uptake kept the same percent removal, even in the presence of high concentrations of Cu(II); an opposite behavior was observed for Cu(II), indicating that Pb(II) interfere in the uptake of Cu(II) more than the opposite situation. In the monocomponent equilibrium models such as Langmuir and Freundlich were used to fit experimental data. In binary systems, Competitive Langmuir, Modified Langmuir, Langmuir-Freundlich and Extended Freundlich Extented were used. All the models were not conclusive to fit experimental results, however they contributed for a better understanding of the mechanism involved in biosorption, because a high level of dispersion between actual biosorption and theoretical prediction was observed.

Made available in DSpace on 2014-12-17T14:03:44Z (GMT). No. of bitstreams: 1 HugoWBA_DISSERT.pdf: 1563778 bytes, checksum: ea0b3bf4e13c36f81c11450e423c8df4 (MD5) Previous issue date: 2014-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The alginic acid or alginates are acidic polysaccharides found in brown seaweed widely used in food, cosmetic, medical and pharmaceutical industry. This paper proposes the extraction, chemical characterization and verification of the pharmacological activities of brown seaweed variegata Lobophora . The alginate was extracted from the seaweed Lobophora variegata and part was sulphated for comparative purposes. The native extract showed 42% total sugar, 65% uronic acid, 0,36 % protein and 0% of sulfate, while the sulfate showed 39% , 60%, 0.36% and 27,92 % respectively. The presence of a sulfate group may be observed by the metachromasia with toluidine blue in electrophoresis system and characteristic vibration 1262,34 cm-1 in infrared spectroscopy connections assigned to S = O. We observed the formation of films and beads of native alginate, where more concentrated solution 6% resulted in a thicker and more consistent film. Native alginate showed proliferative activity at concentrations (25 and 50 mcg), (50 mg) and (100 mg) in 3T3 cell line in 24h, 48h and 72h, respectively , as the sulfated (100 mg) in 24 . Also showed antiproliferative or cytotoxic activity in HeLa cells of strain, (25 and 100 mg), (25 and 100 mg) and (25, 50 and 100 mg), to native, now for the sulfate concentrations (100 mg) in 24 (25, 50 and 100 mg) in 48 hours, and (50 and 100 mg ) 72h. For their antioxidant activity, the sulfated alginates have better total antioxidant activity reaching 29 % of the native activity while 7.5 % of activity . For the hydroxyl radical AS showed high inhibition ( between 77-83 % ) in concentrations, but the AN surpassed these numbers in the order of 78-92 % inhibition. The reducing power of AN and AS ranged between 39-82 % . In the method of ferric chelation NA reached 100 % chelating while the AS remained at a plateau oscillating 6.5%. However, in this study , we found alginates with promising pharmacological activities, to use in various industries as an antioxidant / anti-tumor compound / Os ?cidos alg?nicos ou alginatos s?o polissacar?deos ?cidos presentes em algas marrons amplamente utilizadas na ind?stria de alimentos, est?tica, m?dica e farmac?utica. Este trabalho prop?e a extra??o, caracteriza??o qu?mica e verifica??o das atividades farmacol?gicas da alga marinha marrom Lobophora variegata. O alginato foi extra?do da alga Lobophora variegata e parte foi sulfatado para fins comparativos. O extrato nativo apresentou 42% de a??car total, 65% de ?cido ur?nico, 0,36% de prote?na e 0% de sulfato, enquanto a sulfatada apresentou 39%, 60%, 0,36% e 27,92% respectivamente. A presen?a do grupo sulfato pode ser verificada atrav?s da metacromasia com o corante azul de toluidina no sistema de eletroforese e vibra??o caracter?stica em 1262,34 cm-1 na espectroscopia de infravermelho, atribu?do a liga??es S=O. Observou-se a forma??o de filmes e esferas de alginato nativo, onde a solu??o mais concentrada 6%, resultou em um filme mais espesso e consistente. O alginato nativo apresentou atividade proliferativa nas concentra??es (25 e 50?g), (50 ?g) e (100 ?g) em linhagem celular 3T3 em 24h, 48h e 72h, respectivamente, j? o sulfatado em (100 ?g) em 24h. Apresentou tamb?m atividade antiproliferativa ou citot?xica em c?lulas da linhagem HeLa, com (25 e 100 ?g), (25 e 100 ?g) e (25, 50 e 100 ?g), para o nativo, j? para a sulfatada nas concentra??es (100 ?g) em 24h, (25, 50 e 100 ?g) em 48h, e (50 e 100 ?g) 72h. Quanto a atividade antioxidante, os alginatos sulfatados apresentam melhor atividade antioxidante total chegando a 29% de atividade enquanto o nativo 7,5% de atividade. Para o radical hidroxila o AS apresentou alta inibi??o (entre 77-83%) nas concentra??es testadas, por?m o AN superou estes n?meros na ordem de 78-92% de inibi??o. O poder redutor de AN e AS variou entre 39-82%. Na metodologia de quela??o f?rrica, o NA chegou a 100% de quela??o, enquanto o AS permaneceu em um plat? oscilando em 6,5%. Contudo, neste trabalho, pudemos constatar alginatos com promissoras atividades farmacol?gicas, com uso nas diversas ind?strias como um composto antioxidante/antitumoral

Made available in DSpace on 2014-12-17T14:13:58Z (GMT). No. of bitstreams: 1 KalineDM_DISSERT.pdf: 984274 bytes, checksum: 8150a2011f0eac140bc8113ffa4bc1ea (MD5) Previous issue date: 2011-12-02 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In the present study, six families of sulfated polysaccharides were obtained from seaweed Dictyopteris delicatula (Lamouroux, 1809) and their anticoagulant, antioxidant and antitumor activities were evaluated. All fractions showed anticoagulant activity on aPTT assay, but not on PT assay. Fractions also exhibited total antioxidant activity, superoxide radical scavenging capacity and ferric chelating property. Thus, six fractions (F0.5v, F0.7v, F1.0v, F1.3v, F1.5v e F2.0v) we obtained by proteolytic digestion, followed by acetone fractionation and molecular sieving on Sephadex G-100. Chemical analyses demonstrated that all polysaccharides contain heterofucans composed mainly of fucose, xylose, glucose, galactose, uronic acid, and sulfate. Any fractions changed the PT. However, all fractions were able on double the aPPT on a dose-dependent manner. The heterofucans F0.7v and F1.0v showed low anticoagulant activity while F1.5v presented the most prominent anticoagulant activity .When compared to Clexane?, a low molecular weight heparin, at same concentration F1.5v presented similar anticoagulant activity. The fucans F0.5v and F0.7v at 1.0 mg/mL showed high ferric chelating activity (~45%), whereas fucans F1.3v (0.5 mg/mL) showed considerable reducing power, about 53.2% of the activity of vitamin C. The fucan F1.5v presented the most prominent anticoagulant activity. The best antiproliferative activity was found with fucans F1.3v and F0.7v. However, F1.3v activity was much higher than F0.7v inhibiting almost 100% of HeLa cell proliferation. These fucans have been selected for further studies on structural characterization as well as in vivo experiments, which are already in progress / No presente estudo, seis popula??es de polissacar?deos sulfatados foram obtidas a partir da alga Dictyopteris delicatula (Lamouroux, 1809) e suas atividades anticoagulante, antioxidante e antitumoral avaliadas. Deste modo, as seis fra??es (F0.5v, F0.7v, F1.0v, F1.3v, F1.5v e F2.0v) foram obtidas por prote?lise seguida por fracionamento de acetona e gel filtra??o molecular Sephadex G-100. Todas as fra??es apresentaram atividade anticoagulante frente ao ensaio de aPTT, mas n?o sobre o ensaio de PT. As heterofucanas exibiram atividade antioxidante total, capacidade em sequestrar radicais super?xido e propriedade de quelar ferro. As an?lises qu?micas demonstraram que todos os polissacar?deos cont?m heterofucanas composta principalmente por fucose, xilose, glicose, galactose, ?cido ur?nico, e sulfato. Nenhuma das fra??es alterou o PT. Entretanto, todas as fra??es foram capazes de dobrar o aPTT de uma maneira dose dependente. As heterofucanas F0.7v e F1.0v demonstraram baixa atividade anticoagulante, enquanto a F1.5v apresentou a maior atividade anticoagulante e quando comparada com Clexane?, uma heparina de baixo peso molecular, em mesma concentra??o, apresentou antividade anticoagulante semelhante. As fucanas F0.5v e F0.7v a 1,0 mg/mL mostraram alta atividade de quela??o ferica (~ 45%), enquanto a fucana F1.3v (0,5 mg/mL) mostrou consider?vel potencial redutor, cerca de 53,2% da atividade da vitamina C. A melhor atividade antitumoral foi encontrada nas fucanas F1.3v e F0.7v. No entanto, a atividade F1.3v foi muito superior a F0,7v, quase 100% de inibi??o da prolifera??o de c?lulas HeLa (c?lula de c?ncer de colo de ?tero). Estas fucanas foram selecionadas para novos estudos sobre caracteriza??o estrutural, bem como em experimentos in vivo, que j? est?o em andamento / 2020-01-01

As algas marrons do gênero Sargassum têm sido estudadas como potenciais candidatas ao processo de biossorção, objetivando tratar efluentes contaminados com metais pesados. A estrutura celular deste gênero de alga apresenta moléculas carregadas, como o ácido algínico, capazes de atrair e captar cátions metálicos. A proposta deste trabalho foi avaliar a capacidade de captação dos íons cobre e chumbo pela alga marinha Sargassum através de ensaios cinéticos e de acumulação com modelagem cinética e das isotermas para sistemas monocomponente e binário. O equilíbrio de captação foi atingido em 30 minutos e a cinética do processo foi representada por um modelo de segunda ordem. No sistema monocomponente, onde as soluções continham inicialmente 10 mg/L de cada íon metálico a captação no equilíbrio foi 0,06 mmol/g de íons Cu (II) e 0,02 mmol/g de íons Pb (II). Para as soluções contendo 50 mg/L a captação no equilíbrio foi 0,37 mmol/g de íons Cu (II) e 0,11 mmol/g de íons Pb (II), individualmente. A capacidade de biossorção foi reduzida no sistema binário mostrando que a presença de um segundo metal afeta a captação dos íons. Os valores de qmax para íons Pb (II) no sistema binário foi 0,6 mmol/g contra 1,2 mmol/g no sistema monocomponente; para íons Cu (II) a captação foi 0,7 mmol/g contra 1,8 mmol/g. Na biossorção binária a captação de íons Pb (II) manteve o percentual de remoção mesmo em soluções com elevadas concentrações de íons Cu (II); o contrário não foi observado para o Pb(II), indicando que íons Pb (II) interferem mais na captação de íons Cu (II). Para o estudo do equilíbrio monocomponente foram utilizados os modelos de Langmuir e Freundlich; para o sistema binário, o Langmuir competitivo, Langmuir modificado, Langmuir-Freundlich e Freundlich estendido. Os modelos não foram conclusivos, porém elucidaram aspectos relacionados ao mecanismo, apresentando alto grau de dispersão entre a captação experimental e as teóricas. / Brown seaweeds from the genus Sargassum are widely studied for use as potential candidates for biosorption purposes, particularly in the treatment of heavy-metals contaminated effluents. The cellular structure of this seaweed presents charged molecules, such as alginic acid, able to attract and recover metal cation ions. The objective of this work was to study the uptake capacity of copper and lead by the seaweed Sargassum, through kinetic and isotherm studies with the help of kinetic and isotherm models for monocomponent and binary solutions. Equilibrium uptake was reached in 30 minutes and the kinetic behavior of the process followed a second-order model. In monocomponent systems, at 10 mg/L metal concentration, equilibrium uptake indicated a recovery of 0.06 mmol Cu(II)/g biomass and 0.02mmol/g Pb(II)/g biomass. When a 50 mg/L solution was used, the individual uptake was equal to 0.37 mmol Cu(II)/g biomass and 0.11 mmol Pb(II)/g biomass. Uptake was markedly reduced by the presence of the second metal in solution indicating the interference in biosorption in a multi-ion solution. Values of qmax for Pb(II) in the binary system was equal to 0.6 mmol/g biomass, against 1.2 mmol/g biomass in the monocomponent situation; for Cu(II) the uptake was equal to 0.7 mmol/g biomass against 1.8 mmol/g biomass, in the monocomponent solution. In the binary solution, Pb(II) uptake kept the same percent removal, even in the presence of high concentrations of Cu(II); an opposite behavior was observed for Cu(II), indicating that Pb(II) interfere in the uptake of Cu(II) more than the opposite situation. In the monocomponent equilibrium models such as Langmuir and Freundlich were used to fit experimental data. In binary systems, Competitive Langmuir, Modified Langmuir, Langmuir-Freundlich and Extended Freundlich Extented were used. All the models were not conclusive to fit experimental results, however they contributed for a better understanding of the mechanism involved in biosorption, because a high level of dispersion between actual biosorption and theoretical prediction was observed.

Brown macroalgae or brown seaweed is a promising source of ethanol that may avoid the challenges of arable land use, water use, lignin content, and the food vs. fuel debate associated with first generation and cellulosic ethanol sources; however, this promise is challenged by seaweed’s high water content, high ash content, and natural composition fluctuations. Notably, lifecycle studies of seaweed ethanol are lacking in the literature. To address this gap, a well-to-wheel model of ethanol production from farmed brown seaweed was constructed and applied to the case of Saccharina latissima farming in British Columbia (BC), Canada, to determine energy return on energy invested (EROI), carbon intensity (CI), and near shore seaweed farming production potential for seaweed ethanol and to examine the production cost of seaweed ethanol. Seaweed farming and ethanol production were modeled based on current BC farming methods and the dry grind corn ethanol production process; animal feed was included as an ethanol co-product, and co-product credits were considered. A seaweed ethanol yield calculation tool that accounts for seaweed composition was proposed, and a sensitivity study was done to examine case study data assumptions. In the case study, seaweed ethanol had lower CI than sugarcane, wheat, and corn ethanol at 10.1 gCO2e/MJ, and it had an EROI comparable to corn ethanol at 1.78. Seaweed ethanol was potentially profitable due to significant revenue from animal feed sales; however, the market for seaweed animal feed was limited by the feed’s high sodium content. Near shore seaweed farming could meet the current demand for ethanol in BC, but world near shore ethanol potential is likely an order of magnitude lower than world ethanol production and two orders of magnitude lower than world gasoline production. Composition variation and a limited harvest season make solar thermal or geothermal seaweed drying and storage necessary for ethanol production in BC. Varying seaweed composition, solar thermal drying performance, co-product credits, the type of animal feed produced, transport distances, and seaweed farming performance in the sensitivity study gave an EROI of over 200 and a CI of -42 gCO2e/MJ in the best case and an EROI of 0.64 and CI of 33 gCO2e/MJ in the worst case. Co-product credits and the type of animal feed produced had the most significant effect overall, and the worst cases of seaweed composition and solar thermal seaweed drying system performance resulted in EROI of 0.64 and 1.0 respectively. Brown seaweed is concluded to be a potentially profitable source of ethanol with climate benefits that surpass current ethanol sources; however, additional research into seaweed animal feed value, co-product credits, large scale seaweed conversion, and the feasibility of solar thermal or geothermal seaweed drying is required to confirm this conclusion. / Graduate

Made available in DSpace on 2014-12-17T14:03:44Z (GMT). No. of bitstreams: 1 ThiagoGC_DISSERT.pdf: 2736665 bytes, checksum: 120a3ba44fefe1ccd9373aeb0ff1629f (MD5) Previous issue date: 2014-02-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Seaweeds are a major source of biologically active compounds . In the extracellular matrix of these organisms are sulfated polysaccharides that functions as structural components preventing it against dehydration. The fraction 0.9 (FucB) rich in sulfated fucans obtained from brown seaweed Dictyota menstrualis was chemical characterized and evaluated for pharmacological activity by testing anticoagulant activity, stimulatory action on the synthesis of an antithrombotic heparan sulfate, antioxidant activity and its effects in cell proliferation. The main components were FucB carbohydrates (49.80 ? 0.10 %) and sulfate (42.30 ? 0.015 %), with phenolic compounds ( 3.86 ? 0.016 %) and low protein contamination ( 0.58 ? 0.001 % ) . FucB showed polydisperse profile and analysis of signals in the infrared at 1262, 1074 and 930 cm -1 and 840 assigned to S = O bonds sulfate esters , CO bond presence of 3,6- anhydrogalactose , β -D- galactose non- sulfated sulfate and the axial position of fucose C4 , respectively. FucB exhibited moderate anticoagulant activity , the polysaccharides prolonged time (aPTT ) 200 ug ( > 90s ) partial thromboplastin FucB no effect on prothrombin time (PT), which corresponds to the extrinsic pathway of coagulation was observed. This stimulation promoted fraction of about 3.6 times the synthesis of heparan sulfate (HS) by endothelial cells of the rabbit aorta ( RAEC ) in culture compared with cells not treated with FucB . This has also been shown to compete for the binding site with heparin. The rich fraction sulfated fucans exhibited strong antioxidant activity assays on total antioxidant (109.7 and 89.5 % compared with BHT and ascorbic acid standards ) , reducing power ( 71 % compared to ascorbic acid ) and ferric chelation ( 71 , comparing with 5 % ascorbic acid). The fraction of algae showed cytostatic activity on the RAEC cells revealed that the increase of the synthesis of heparan sulfate is not related to proliferation. FucB showed antiproliferative action on cell lines modified as Hela and Hep G2 by MTT assay . These results suggest that FucB Dictyota menstrualis have anticoagulant , antithrombotic , antioxidant potential as well as a possible antitumor action, promoting the stimulation of the synthesis of antithrombotic HS by endothelial cells and is useful in the prevention of thrombosis, also due to its inhibitory action on species reactive oxygen ( ROS ) in some in vitro systems , being involved in promoting a hypercoagulable state / Algas marinhas s?o uma das principais fontes de compostos biologicamente ativos. Na matriz extracelular desses organismos existem os polissacar?deos sulfatados que funcionam como componente estrutural prevenindo-a contra desidrata??o. A fra??o 0,9 (FucB) rica em fucanas sulfatadas obtida da alga marrom Dictyota menstrualis foi caracterizada quimicamente e avaliada quanto a atividade farmacol?gica por meio de ensaios de atividade anticoagulante, a??o estimulat?ria sobre a s?ntese de heparam sulfato antitromb?tico, atividade antioxidante e seus efeitos na prolifera??o celular. Os principais componentes da FucB foram carboidratos (49,80 ? 0,10%) e sulfato (42,30 ? 0,015%), apresentando compostos fen?licos (3,86 ? 0,016%) e baixa contamina??o prot?ica (0,58 ? 0,001%). FucB mostrou perfil polidisperso e sinais na an?lise de infravermelho em 1262, 1074 e 930 e 840 cm-1 atribu?dos a liga??es S=O de ?steres de sulfato, presen?a de liga??o C-O de 3,6-anidrogalactose, β-D-galactose n?o sulfatada e sulfato na posi??o axial do C4 da fucose, respectivamente. FucB exibiu moderada atividade anticoagulante, este polissacar?deo prolongou o tempo de tromboplastina parcial activada (aPTT) a 200 ug (>90s) n?o foi observado qualquer efeito de FucB sobre o tempo de protrombina (PT), que corresponde a via extr?nseca da coagula??o. Esta fra??o promoveu estimula??o cerca de 3,6 vezes na s?ntese de heparam sulfato (HS) pelas c?lulas endoteliais da aorta de coelho (RAEC), em cultura, quando comparadas com as c?lulas n?o tratadas com FucB. Esta tamb?m demonstrou competir pelo s?tio de liga??o com a heparina. A fra??o rica em fucanas sulfatadas exibiu forte a??o antioxidante sobre os ensaios de antioxidante total (109,7 e 89,5% comparados com padr?es BHT e ?cido asc?rbico), poder redutor (71% comparado ao ?cido asc?rbico) e quela??o f?rrica (71,5% comparando com ?cido asc?rbico). A fra??o dessa alga mostrou atividade citost?tica sobre as c?lulas RAEC revelando que o aumento da s?ntese de heparan sulfato n?o est? relacionado ? prolifera??o. FucB apresentou a??o antiproliferativa sobre linhagens celulares modificadas como Hela e Hep G2 pelo ensaio de MTT. Esses resultados sugerem que FucB de Dictyota menstrualis tem potencial anticoagulante, antitromb?tico, antioxidante bem como uma poss?vel a??o antitumoral, promovendo a estimula??o da s?ntese de HS antitromb?tico pelas c?lulas endoteliais, sendo ?til na preven??o da trombose, devido tamb?m a sua a??o inibit?ria sobre as esp?cies reativas do oxig?nio (ROS) em alguns sistemas in vitro, estando envolvidos na promo??o de estado de hipercoagulabilidade