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‣ Adsorption of Ni(2+), Zn(2+) and Pb(2+) onto dry biomass of Arthrospira (Spirulina) platensis and Chlorella vulgaris. I. Single metal systems

FERREIRA, Livia Seno; RODRIGUES, Mayla Santos; CARVALHO, Joao Carlos Monteiro de; LODI, Alessandra; FINOCCHIO, Elisabetta; PEREGO, Patrizia; CONVERTI, Attilio
Fonte: ELSEVIER SCIENCE SA Publicador: ELSEVIER SCIENCE SA
Tipo: Artigo de Revista Científica
Português
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Adsorption of Ni(2+), Zn(2+) or Pb(2+) by dry biomass of Arthrospira (Spirulina) platensis and Chlorella vulgaris was studied as a function of contact time and initial metal concentration. The zero point of charge calculated for these biosorbents (pH(zpc) 4.0 and 3.4, respectively) and additional pH tests suggested the use of pH in the range 5.0-5.5 for the experiments. The equilibrium isotherms were evaluated in terms of maximum sorption capacity and sorption affinity. The pseudo first and second order kinetic models were considered to interpret the experimental data, and the latter best described the adsorption system. Both the Freundlich and Langmuir models were shown to well describe the sorption isotherms, thus suggesting an intermediate mono/multilayer sorption mechanism. Compared to A. platensis (q(e) = 0.354, 0.495 and 0.508 mmol g(-1) for Ni(2+), Pb(2)+ and Zn(2+), respectively), C. vulgaris behaved as a better biosorbent because of higher equilibrium sorption capacity (q(e) = 0.499, 0.634 and 0.664 mmol g(-1), respectively). The removal efficiency decreased with increasing metal concentration, pointing out a passive adsorption process involving the active sites on the surface of the biomasses. The FT-IR spectroscopy evidenced that ions removal occurred mainly by interaction between metal and carboxylate groups present on both the cell walls. (C) 2011 Elsevier B.V. All rights reserved.; Genoa University; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)...

‣ Chlorella vulgaris up-modulation of myelossupression induced by lead: The role of stromal cells

QUEIROZ, Mary L. S.; TORELLO, Cristiane O.; PERHS, Simone M. C.; ROCHA, Michelle C.; BECHARA, Etelvino J. H.; MORGANO, Marcelo A.; VALADARES, Marize C.; RODRIGUES, Ana Paula O.; RAMOS, Aline Lisie; SOARES, Chrislaine O.
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
Português
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In this study, Chlorella vulgaris (CV) was examined for its chelating effects on the ability of bone marrow stromal cell layer to display myeloid progenitor cells in vitro in lead-exposed mice, using the long-term bone marrow culture (LTBMC). In addition, the levels of interleukin (IL)-6, an important hematopoietic stimulator, as well as the numbers of adherent and non-adherent cells were also investigated. Mice were gavage treated daily with a single 50 mg/kg dose of CV for 10 days, concomitant to continuous offering of 1300 ppm lead acetate in drinking water. We found that CV up-modulates the reduced ability of stromal cell layer to display myeloid progenitor cells in vitro in lead-exposed mice and restores both the reduced number of non-adherent cells and the ability of stromal cells from these mice to produce IL-6. Monitoring of lead poisoning demonstrated that CV treatment significantly reduced lead levels in blood and tissues, completely restored the normal hepatic ALA levels, decreased the abnormally high plasma ALA and partly recovered the liver capacity to produce porphyrins. These findings provide evidence for a beneficial use of CV for combination or alternative chelating therapy to protect the host from the damage induced by lead poisoning. (C) 2008 Elsevier Ltd. All rights reserved.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Projeto do Milenio Redoxoma (CNPq/MCT); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

‣ Metal biosorption onto dry biomass of Arthrospira (Spirulina) platensis and Chlorella vulgaris: Multi-metal systems

Rodrigues, Mayla Santos; Ferreira, Lívia Seno; Carvalho, Joao Carlos Monteiro de; Lodi, Alessandra; Finocchio, Elisabetta; Converti, Attilio
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
Português
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Binary and ternary systems of Ni2+, Zn2+, and Pb2+ were investigated at initial metal concentrations of 0.5, 1.0 and 2.0 mM as competitive adsorbates using Arthrospira platensis and Chlorella vulgaris as biosorbents. The experimental results were evaluated in terms of equilibrium sorption capacity and metal removal efficiency and fitted to the multi-component Langmuir and Freundlich isotherms. The pseudo second order model of Ho and McKay described well the adsorption kinetics, and the FT-IR spectroscopy confirmed metal binding to both biomasses. Ni2+ and Zn2+ interference on Pb2+ sorption was lower than the contrary, likely due to biosorbent preference to Pb. In general, the higher the total initial metal concentration, the lower the adsorption capacity. The results of this study demonstrated that dry biomass of C. vulgaris behaved as better biosorbent than A. platensis and suggest its use as an effective alternative sorbent for metal removal from wastewater. (C) 2012 Elsevier B.V. All rights reserved.; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior [0252/10-7, 0304/10-7]

‣ The effects of Chlorella vulgaris in the protection of mice infected with Listeria monocytogenes. Role of natural killer cells

Dantas, Denise C. M.; Kaneno, Ramon; Queiroz, Mary L. S.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 609-619
Português
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In this work we have demonstrated the effects of oral administration of Chlorella vulgaris (CV) on Natural Killer cells (NK) activity of mice infected with a sublethal dose of viable Listeria monocytogenes. The treatment with C. vulgaris produced a significant increase on NK cells activity in normal (non-infected) animals compared to the animals that received only vehicle (water) (p < 0.0001). Similarly, the infection alone produced a significant increase on NK cells activity, which was observed at 48 and 72 hours after the inoculation of L. monocytogenes. Moreover, when CV was administered in infected animals, there was an additional increase in NK cells activity which was significantly higher than that found in the infected groups (p < 0.0001) CV treatment (50 and 500mg/Kg) of mice infected with a dose of 3x105 bacteria/animal, which was lethal for all the non- treated controls, produced a dose-response protection which led to a 20% and 55% survival, respectively (p < 0.0001).

‣ Cultivo de microalgas chlorella vulgaris com efluente doméstico como meio de cultura alternativo

Lúcio, Mônica Jeremias
Fonte: Florianópolis, SC. Publicador: Florianópolis, SC.
Tipo: Trabalho de Conclusão de Curso Formato: 71 f.
Português
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TCC(graduação) - Universidade Federal de Santa Catarina. Centro Tecnológico. Engenharia Sanitária e Ambiental.; O lançamento de esgoto em corpos d’água mesmo tratado pode resultar na poluição destes com uma carga rica em nutrientes fosfatados e nitrogenados, que acarreta eutrofização, entre outros problemas. As microalgas, micro-organismos fotossintetizantes, têm potencial para remover compostos inorgânicos das águas residuais e para produzir uma biomassa útil para a produção de biocombustíveis, fertilizantes e de outros bioprodutos. Dentro deste contexto, o presente trabalho teve o objetivo de avaliar o cultivo de microalgas da espécie Chlorella vulgaris com efluente doméstico como meio alternativo. O efluente doméstico foi coletado na Estação de Tratamento de Esgoto Lagoa da Conceição da CASAN, no município de Florianópolis, Santa Catarina. O procedimento metodológico dividiu-se em três etapas: isolamento da Chlorella vulgaris, teste com três espécies de microalgas (Desmodesmus sp., Chlorella vulgaris e Chlorococcales) cultivadas no efluente doméstico tratado como meio de cultura alternativo, e o experimento principal, no qual foi comparando o cultivo em meio de cultura sintético WC com o meio de cultura alternativo (efluente). Cada etapa durou em torno de 14 dias...

‣ Effect of nitrogen limitation on starch accumulation in Chlorella vulgaris

Dragone, Giuliano; Fernandes, Bruno Daniel; Abreu, Ana Paula; Vicente, A. A.; Teixeira, J. A.
Fonte: Universidade do Minho. Departamento de Engenharia Biologica Publicador: Universidade do Minho. Departamento de Engenharia Biologica
Tipo: Conferência ou Objeto de Conferência
Publicado em 28/11/2009 Português
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Due to the limited stocks of fossil fuels and the production of greenhouse gas carbon dioxide on their combustion alternative sources of energy are being investigated. Recently, microalgae have received much attention as a renewable energy resource because these photosynthetic microorganisms can convert sunlight, water and CO2 into potential biofuels (1). The microalga Chlorella vulgaris, particularly, has been considered as a potential raw material for bioethanol production because it can accumulates high levels of starch when grown under optimized culture conditions (2). The aim of the present work was to study the effect of nitrogen limitation on starch production by the microalgae C. vulgaris. C. vulgaris CCAP 211/1e (P12 strain) was obtained from the Culture Collection of Algal Laboratory, Institute of Botany, Academy of Sciences of the Czech Republic. The original (nitrogen sufficient) growth medium based on the elementary composition of algal biomass had the following initial composition (mg l−1): 1,100 (NH2) 2CO, 237 KH2PO4, 204 MgSO4∙7H2O, 40 C10H12O8N2NaFe, 88 CaCl2, 0.83 H3BO3, 0.95 CuSO4∙5H2O, 3.3 MnCl2∙4H2O, 0.17 (NH4) 6Mo7O24∙4H2O, 2.7 ZnSO4∙7H2O, 0.6 CoSO4∙7H2O, and 0.014 NH4VO3 in distilled water (3). Nitrogen limited growth medium was formulated by omitting urea from the original growth medium. The microalgae were grown in 1 l Schott flasks with 0.4 l of medium. Cultures were maintained at 30ºC under continuous...

‣ Mixotrophic cultivation of Chlorella vulgaris using industrial dairy waste as organic carbon source

Abreu, Ana Paula; Fernandes, Bruno Daniel; Vicente, A. A.; Teixeira, J. A.; Dragone, Giuliano
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2012 Português
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Growth parameters and biochemical composition of the green microalga Chlorella vulgaris cultivated under different mixotrophic conditions were determined and compared to those obtained from a photoautotrophic control culture. Mixotrophic microalgae showed higher specific growth rate, final biomass concentration and productivities of lipids, starch and proteins than microalgae cultivated under photoautotrophic conditions. Moreover, supplementation of the inorganic culture medium with hydrolyzed cheese whey powder solution led to a significant improvement in microalgal biomass production and carbohydrate utilization when compared with the culture enriched with a mixture of pure glucose and galactose,due to the presence of growth promoting nutrients in cheese whey. Mixotrophic cultivation of C.vulgaris using the main dairy industry by-product could be considered a feasible alternative to reduce the costs of microalgal biomass production, since it does not require the addition of expensive carbohydrates to the culture medium

‣ Chlorella vulgaris and Haematococcus pluvialis biomass as colouring and antioxidant in food emulsions

Sousa, Isabel; Gouveia, Luísa; Raymundo, Anabela; Batista, Ana Paula; Empis, José
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2006 Português
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The use ofmicroalgal biomass, a natural ingredi- ent, to colour oil-in-water pea protein stabilised emulsions was studied. Various levels of incorporation of Chlorella vulgaris green, Chlorella vulgaris orange (after caroteno- genesis), andHaematococcus pluvialis (red, after caroteno- genesis) were used, resulting in a wide range of appealing colours from green to orange and pink. The colour stability of the emulsionswas evaluated, through the evolution of the L∗a∗b∗ parameters (CIELAB system) along 6 weeks. The primary and secondary oxidation products of the emulsions were also determined, and an enhanced resistance to oxi- dation was evidenced by emulsions containing microalgae. Therefore antioxidant functionality was another positive aspect of its use as an ingredient. Colour stability, a va- riety of attractive hues, and added resistance to oxidation ensure an adequate compromise of sensory and functional properties for these novel emulsions.

‣ Gene transfer of Chlorella vulgaris n-3 fatty acid desaturase optimizes the fatty acid composition of human breast cancer cells

Xue,Meilan; Ge,Yinlin; Zhang,Jinyu; Wang,Qing; Hou,Lin
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 Português
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Chlorella vulgaris has the gene of n-3 fatty acid desaturase (CvFad3), which can synthesize the precursor of n-3 polyunsaturated fatty acids (PUFAs) or convert n-6 to n-3 PUFAs. The objective of the present study was to examine whether the CvFad3 gene from C. vulgaris can be functionally and efficiently expressed in human breast cancer cells and whether its expression can exert a significant effect on cell fatty acid composition. We inserted the CvFad3 gene into the plasmid pEGFP-C3 to construct the eukaryotic expression vector pEGFP-C3-n-3 and to express the n-3 Fad gene in human breast cancer cells (MCF-7 cells). Transfection of MCF-7 cells with the recombinant vector resulted in a high expression of n-3 fatty acid desaturase. Lipid analysis indicated that the ratio of n-6/n-3 PUFAs was decreased from 6:1 in the control cells to about 1:1 in the cells expressing the n-3 fatty acid desaturase. Accordingly, the CvFad3 gene significantly decreased the ratio of n-6/n-3 PUFAs of the MCF-7 cell membrane. The expression of the CvFad3 gene can decrease cell proliferation and promote cell apoptosis. This study demonstrates that the CvFad3 gene can dramatically balance the ratio of n-6/n-3 PUFAs and may provide an effective approach to the modification of the fatty acid composition of mammalian cells...

‣ Hot water extract of Chlorella vulgaris induced DNA damage and apoptosis

Yusof,Yasmin Anum Mohd; Saad,Suhana Md.; Makpol,Suzana; Shamaan,Nor Aripin; Ngah,Wan Zurinah Wan
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 Português
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OBJECTIVES: The aim of this study was to determine the antiproliferative and apoptotic effects of hot water extracts of Chlorella vulgaris on hepatoma cell line HepG2. INTRODUCTION: The search for food and spices that can induce apoptosis in cancer cells has been a major study interest in the last decade. Chlorella vulgaris, a unicellular green algae, has been reported to have antioxidant and anti-cancer properties. However, its chemopreventive effects in inhibiting the growth of cancer cells have not been studied in great detail. METHODS: HepG2 liver cancer cells and WRL68 normal liver cells were treated with various concentrations (0-4 mg/ml) of hot water extract of C. vulgaris after 24 hours incubation. Apoptosis rate was evaluated by TUNEL assay while DNA damage was assessed by Comet assay. Apoptosis proteins were evaluated by Western blot analysis. RESULTS: Chlorella vulgaris decreased the number of viable HepG2 cells in a dose dependent manner (p < 0.05), with an IC50 of 1.6 mg/ml. DNA damage as measured by Comet assay was increased in HepG2 cells at all concentrations of Chlorella vulgaris tested. Evaluation of apoptosis by TUNEL assay showed that Chlorella vulgaris induced a higher apoptotic rate (70%) in HepG2 cells compared to normal liver cells...

‣ Antioxidant enzyme activity and malondialdehyde levels can be modulated by Piper betle, tocotrienol rich fraction and Chlorella vulgaris in aging C57BL/6 mice

Aliahmat,Nor Syahida; Noor,Mohd Razman Mohd; Yusof,Wan Junizam Wan; Makpol,Suzana; Ngah,Wan Zurinah Wan; Yusof,Yasmin Anum Mohd
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 Português
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OBJECTIVE: The aim of this study was to determine the erythrocyte antioxidant enzyme activity and the superoxide dismutase, catalase, glutathione peroxidase, and plasma malondialdehyde levels in aging mice and to evaluate how these measures are modulated by potential antioxidants, including the tocotrienol-rich fraction, Piper betle, and Chlorella vulgaris. METHOD: One hundred and twenty male C57BL/6 inbred mice were divided into three age groups: young (6 months old), middle-aged (12 months old), and old (18 months old). Each age group consisted of two control groups (distilled water and olive oil) and three treatment groups: Piper betle (50 mg/kg body weight), tocotrienol-rich fraction (30 mg/kg), and Chlorella vulgaris (50 mg/kg). The duration of treatment for all three age groups was two months. Blood was withdrawn from the orbital sinus to determine the antioxidant enzyme activity and the malondialdehyde level. RESULTS: Piper betle increased the activities of catalase, glutathione peroxidase, and superoxide dismutase in the young, middle, and old age groups, respectively, when compared to control. The tocotrienol-rich fraction decreased the superoxide dismutase activity in the middle and the old age groups but had no effect on catalase or glutathione peroxidase activity for all age groups. Chlorella vulgaris had no effect on superoxide dismutase activity for all age groups but increased glutathione peroxidase and decreased catalase activity in the middle and the young age groups...

‣ Atividade biológicas das preparações obtidas das clorofíceas Chlorella vulgaris e Scenedesmus subspicatus Chodat e suas potenciais aplicações biotecnológicas

Dantas, Danielli Matias de Macêdo; Bezerra, Ranilson de Souza (Orientador); Gálvez, Alfredo Oliveira (Coorientadora)
Fonte: Universidade Federal de Pernambuco Publicador: Universidade Federal de Pernambuco
Tipo: Tese de Doutorado
Português
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As microalgas apresentam uma enorme aplicação como produtoras de compostos bioativos de interesse industrial e com potenciais atividades biológicas. Neste sentido uma revisão sobre o cultivo de microalgas no Brasil foi abordada, levando em consideração o potencial e as perspectivas aplicações biotecnológicas destes microrganismos no país. Neste sentido, a espécie Chlorella vulgaris foi selecionada para a obtenção de preparações utilizando solventes de diferentes polaridades (água, metanol, butanol, acetona e dimetilsulfóxido), e apartir destes extratos, avaliar as suas atividades antioxidante e antimicrobiana (antibacteriana e antifúngica). Adicionalmente, foi analisada a ação neuroprotetiva do extrato da C. vulgaris com a bebida alcóolica “cachaça” em ratos utilizando o modelo da depressão alastrante cortical. Visando otimizar a produção e obtenção de biomassa das espécies C. vulgaris e Scenedesmus subspicatus, foram avaliados métodos de cultivo, coleta e além disso o desenvolvimento de uma bebida alcóolica funcional a partir dessas espécies. Os resultados obtidos para atividade antioxidante utilizando os diferentes extratos de C. vulgaris testados, demostraram maior eficiência usando água e dimetilsulfóxido. Os extratos preparados com estes mesmos solventes...

‣ Examining interspecific competition between Chlorella vulgaris and Microcystis ichthyoblabe: mitigating harmful cyanobacteria algal blooms

Afzal, Sukaina
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
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The excessive proliferation of Microcystis has resulted in an increased prevalence of harmful algal blooms worldwide. Climate change and high levels of nutrient loading into aquatic environments continue to promote bloom growth that is detrimental to human and animal health. Due to the limitations associated with current mitigation techniques, it is critical to explore alternative solutions. At Leonard’s Fish Farm, in Hartington, Ontario, the presence of Chlorella vulgaris in ponds appears to result in the decline of Microcystis ichthyoblabe. This thesis examines whether interspecific competition between C. vulgaris and M. ichthyoblabe exists in order to explore an alternative bloom management technique. Both organisms were initially grown separately in five N:P conditions (5:1, 10:1, 31:1, 90:1, 180:1). Next, an experimental system was developed to explore competition dynamics between both organisms. This system consists of a dialysis bag containing one organism placed into a glass bottle containing the second organism, which enables nutrient sharing without physically mixing both organisms. There was no significant influence of nutrient conditions on either organism’s growth. Total phosphorus measurements indicated that both organisms exhibit increasing phosphorus uptake in response to decreasing N:P ratios...

‣ Bio-conversion rate and optimum harvest intervals for Moina australiensis using digested piggery effluent and Chlorella vulgaris as a food source

Ward, A.; Kumar, M.
Fonte: Elsevier Sci Ltd Publicador: Elsevier Sci Ltd
Tipo: Artigo de Revista Científica
Publicado em //2010 Português
Relevância na Pesquisa
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The bio-conversion rate of Moina australiensis fed with Chlorella vulgaris grown on digested piggery effluent at three different feeding rates was determined and a 2, 3 and 4-day harvest interval strategy was investigated. This study indicates that C. vulgaris is a suitable food source for M. australiensis. A significant difference (P < or = 0.001) in the feeding rate against mean total populations was found among treatments. The increase in the amount of algae fed accelerated the production rate, and the population density peaked faster in the high C. vulgaris fed treatment. The BCR calculated from this experiment indicates that for every 1000 mg of C. vulgaris fed there was an increase of 437.9 mg of M. australiensis biomass produced. A significant difference (P < or = 0.001) in biomass production among the different harvest interval treatments was observed. The 2-day harvest interval treatment produced 7.78 g of M. australiensis followed by 6.89 g in the 3 day and 5.01 g in the 4-day harvest interval treatment. This study provides strong evidence that M. australiensis can utilise the bacterial blooms and bio-films associated with digested piggery effluent as a food source.; A. J. Ward and M. S. Kumar

‣ Potencialidades de Chlorella vulgaris cultivada em meio à base de concentrado de dessalinização

Matos, Ângelo Paggi
Fonte: Florianópolis, SC Publicador: Florianópolis, SC
Tipo: Dissertação de Mestrado Formato: 115 p.| il., grafs., tabs.
Português
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em Ciência dos Alimentos.; O objetivo deste trabalho foi avaliar as propriedades físicoquímicas da biomassa de Chlorella vulgaris em um meio à base de concentrado de dessalinização proveniente do processo de dessalinização de águas subterrâneas na comunidade de Uruçu, no município de São João do Cariri # Paraíba. O concentrado de dessalinização possui alta concentração de sais minerais (cloretos, carbonatos e bicarbonatos) que se reincorporado ao solo podem causar o fenômeno de eritrofização, erosão e salinização do solo. Por isso, diversas pesquisas têm sido realizadas de modo a encontrar soluções de reciclagem deste concentrado. Entre estas pesquisas, o cultivo de microalgas para a produção de biomassa com finalidade biotecnológica. O cultivo autotrófico de Chlorella vulgaris foi inicialmente mantido em Bold Basal Medium (BBM). Para fazer uso do concentrado de dessalinização, realizou-se a caracterização físico-química, determinada segundo metodologia descrita no Standard Methods for the Examination of Water and Wastewater - APHA (2005). Com a aplicação da Metodologia de Superfície de Resposta foi possível avaliar o efeito de três nutrientes: NaNO3...

‣ Viabilidade económica e energética do biodiesel produzido a partir de Chlorella vulgaris

Ribeiro, Tiago Joel Pinto
Fonte: Instituto Politécnico do Porto Publicador: Instituto Politécnico do Porto
Tipo: Dissertação de Mestrado
Publicado em //2013 Português
Relevância na Pesquisa
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Contemporaneamente o Homem depara-se com um dos grandes desafios que é o de efetivar a transição para um futuro sustentável. Assim, o setor da energia tem um papel fundamental neste processo de transição, com principal enfoque no setor dos automóveis, sendo este um setor que contribui com elevadas quantidades de gases de efeito estufa libertados para a atmosfera. Também a escassez dos recursos petrolíferos constitui um ponto fundamental no tema apresentado. Com a necessidade de combater esses problemas é que se tem vindo a tentar desenvolver combustíveis renováveis e neutros quanto às emissões. A primeira geração de biocombustíveis obtidos através de culturas agrícolas terrestres preenche em parte esses requisitos, porém, não atinge os valores da procura e ainda competem com a produção de alimentos. Daí o interesse na aposta de uma segunda geração de biocombustíveis produzidos de fontes que não pertencem à cadeia alimentar e são residuais mas, que mesmo assim não permitem satisfazer as necessidades de matériaprima. A terceira geração de biocombustíveis vem justamente responder a estas questões pois assenta em matérias-primas que não competem pela utilização do solo agrícola nem são usadas para fins alimentares...

‣ Avaliação das diferentes condições de cultivo da microalga Chlorella Vulgaris visando o aumento da produtividade em biomassa

Antonio, Priscila Rodrigues; Teixeira, Claudia Maria Luz Lapa; Oliveira, M. C. R. de
Fonte: Instituto Nacional de Tecnologia Publicador: Instituto Nacional de Tecnologia
Tipo: apresentação
Português
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A Chlorella vulgaris, microalga verde e dulcícola, tem como característica crescimento rápido e alta tolerância às condições de cultivo. Esta espécie destaca-se por apresentar bom potencial para produção de biodiesel. As vantagens do uso das microalgas estão relacionadas à sua eficiência fotossintética para produção de biomassa que contém três componentes principais: carboidratos, proteínas e lipídios, sendo que para constituir uma matéria-prima de biodiesel, a biomassa deve ser rica em ácidos graxos. Existem na literatura muitos estudos referentes à alteração das condições de cultivo das microalgas a fim de maximizar a produtividade em biomassa. Este trabalho tem como objetivo avaliar diferentes condições de cultivo utilizando três variáveis: concentração inicial de nitrato, concentração celular inicial e intensidade de luz visando o aumento da produtividade em biomassa de Chlorella vulgaris. Comparado os resultados obtidos deste trabalho a condição 3 (intensidade de luz: 120 μE.m-2.s-1, densidade óptica: 0,1 e concentração de nitrato: 62 mg/L) apresentou o segundo melhor resultado em produtividade de biomassa com 0,0266 g.L-1.d-1. A condição 8 (intensidade de luz: 120 μE.m-2.s-1, densidade óptica: 0...

‣ Chlorella vulgaris for biodiesel production: evaluation of different extraction methods and culture conditions for obtaining total lipids and triacylglycerides

REZENDE, Raquel de Carvalho; MOREIRA, Daniel Mendonça; ARANDA, Donato Alexandre Gomes; TEIXEIRA, Cláudia M. L. L.
Fonte: Instituto Nacional de Tecnologia Publicador: Instituto Nacional de Tecnologia
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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The depletion of fossil fuels and the consequences of its use for the environment have created the need for greater production of fuels derived from renewable raw materials. In this sense, the use of lipids obtained from the biomass of microalgae has been described as a promising alternative to petro-diesel industry and involves steps such as cultivation of microalgae, biomass harvesting, oil extraction and its transesterification. Information on total lipid content in Chlorella spp is presented in the literature, however different values are found for different methodologies and there is little information about percentage of the raw material for biodiesel, the triacylglycerides in fat mass. The objective of this study was to compare different methods of extraction, with respect to the content of total lipids extracted and the percentage of triacylglycerides in lipid mass. For all experiments, the biomass of Chlorella vulgaris was grown under normal conditions described in the literature. Extractions of total lipids were carried out with ethanol, hexane, a mixture of chloroform and methanol in the ratio 2:1 and 1:2. Mixtures of chloroform and methanol were used to evaluate cell disruption methods such as ultrasound and Potter. Once selected the most efficient methodology...

‣ Hot water extract of Chlorella vulgaris induced DNA damage and apoptosis

Yusof, Yasmin Anum Mohd; Saad, Suhana Md.; Makpol, Suzana; Shamaan, Nor Aripin; Ngah, Wan Zurinah Wan
Fonte: Universidade de São Paulo. Faculdade de Medicina Publicador: Universidade de São Paulo. Faculdade de Medicina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/01/2010 Português
Relevância na Pesquisa
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OBJECTIVES: The aim of this study was to determine the antiproliferative and apoptotic effects of hot water extracts of Chlorella vulgaris on hepatoma cell line HepG2. INTRODUCTION: The search for food and spices that can induce apoptosis in cancer cells has been a major study interest in the last decade. Chlorella vulgaris, a unicellular green algae, has been reported to have antioxidant and anti-cancer properties. However, its chemopreventive effects in inhibiting the growth of cancer cells have not been studied in great detail. METHODS: HepG2 liver cancer cells and WRL68 normal liver cells were treated with various concentrations (0-4 mg/ml) of hot water extract of C. vulgaris after 24 hours incubation. Apoptosis rate was evaluated by TUNEL assay while DNA damage was assessed by Comet assay. Apoptosis proteins were evaluated by Western blot analysis. RESULTS: Chlorella vulgaris decreased the number of viable HepG2 cells in a dose dependent manner (p < 0.05), with an IC50 of 1.6 mg/ml. DNA damage as measured by Comet assay was increased in HepG2 cells at all concentrations of Chlorella vulgaris tested. Evaluation of apoptosis by TUNEL assay showed that Chlorella vulgaris induced a higher apoptotic rate (70%) in HepG2 cells compared to normal liver cells...

‣ Antioxidant enzyme activity and malondialdehyde levels can be modulated by Piper betle, tocotrienol rich fraction and Chlorella vulgaris in aging C57BL/6 mice

Aliahmat, Nor Syahida; Noor, Mohd Razman Mohd; Yusof, Wan Junizam Wan; Makpol, Suzana; Ngah, Wan Zurinah Wan; Yusof, Yasmin Anum Mohd
Fonte: Universidade de São Paulo. Faculdade de Medicina Publicador: Universidade de São Paulo. Faculdade de Medicina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 01/12/2012 Português
Relevância na Pesquisa
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OBJECTIVE: The aim of this study was to determine the erythrocyte antioxidant enzyme activity and the superoxide dismutase, catalase, glutathione peroxidase, and plasma malondialdehyde levels in aging mice and to evaluate how these measures are modulated by potential antioxidants, including the tocotrienol-rich fraction, Piper betle, and Chlorella vulgaris. METHOD: One hundred and twenty male C57BL/6 inbred mice were divided into three age groups: young (6 months old), middle-aged (12 months old), and old (18 months old). Each age group consisted of two control groups (distilled water and olive oil) and three treatment groups: Piper betle (50 mg/kg body weight), tocotrienol-rich fraction (30 mg/kg), and Chlorella vulgaris (50 mg/kg). The duration of treatment for all three age groups was two months. Blood was withdrawn from the orbital sinus to determine the antioxidant enzyme activity and the malondialdehyde level. RESULTS: Piper betle increased the activities of catalase, glutathione peroxidase, and superoxide dismutase in the young, middle, and old age groups, respectively, when compared to control. The tocotrienol-rich fraction decreased the superoxide dismutase activity in the middle and the old age groups but had no effect on catalase or glutathione peroxidase activity for all age groups. Chlorella vulgaris had no effect on superoxide dismutase activity for all age groups but increased glutathione peroxidase and decreased catalase activity in the middle and the young age groups...