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1
Gris, Lara Regina Soccol. "Produção da microalga Nannochloropsis oculata em fotobiorreator airlift". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/29403.
Testo completoAbstract (sommario):
Microalgas são micro-organismos fotossintetizantes que convertem CO2 majoritariamente em lipídios, proteínas e carboidratos. A produção de microalgas é indicada atualmente como alternativa para biomitigação de CO2 e para geração de biocombustíveis, a partir da conversão da biomassa através de processos químicos e biotecnológicos. As vantagens das microalgas estão na sua maior velocidade de crescimento em relação a vegetais oleaginosos superiores e em seu teor lipídico, que para algumas espécies pode chegar a valores maiores que 50%. Apesar do potencial envolvendo as microalgas, muitos desafios ainda precisam ser superados para tornar viável a aplicação desses micro-organismos para fins energéticos. São necessários desenvolvimentos nas mais diversas áreas, abordando os seguintes aspectos: seleção e melhoramento genético de espécies, alcance de maior eficiência fotossintética, desenvolvimento de sistemas de produção e de seu escalonamento, desenvolvimento de sistemas e processos de colheita, extração e processamento, aproveitamento de nutrientes provenientes de resíduos, otimização de condições operacionais, dentre outros. Este trabalho teve por objetivo determinar as melhores condições de crescimento da microalga marinha Nannochloropsis oculata em um fotobiorreator airlift. Os experimentos foram realizados seguindo um delineamento composto central rotacional com temperatura, (19 a 29 °C), concentração de nitrato no meio de cultivo (f/2) (25 a 125 mg.l-1) e intensidade luminosa (3636 a 10364 lux) como variáveis de estudo. Uma planta laboratorial com 12 fotobiorreatores foi construída, permitindo realizar os experimentos do referido planejamento em dois blocos. As variáveis de resposta estudadas e os respectivos melhores resultados experimentais obtidos foram de 482,7 mg.l-1 para a máxima concentração de biomassa, nas condições de 21 °C, 105 mg.l-1 de NaNO3 e 9000 lux, taxa instantânea de crescimento no período exponencial de 0,5624 d-1, nas condições de 24 °C, 75 mg.l-1 de NaNO3 e 7000 lux e percentual de lipídios em biomassa liofilizada de 30,36%, nas condições de 21 °C, 45 mg.l-1 de NaNO3 e 5000 lux.Microalgae are photosynthetic microorganisms that convert CO2 mainly into lipids, proteins and carbohydrates. Microalgae production is currently pointed out as an alternative for CO2 biomitigation and generation of renewable biofuels, from biomass conversion by chemical and biotechnological processes. Microalgae advantages are fastest growth comparing with oil crops and their higher lipid content, which for some species can reach values above 50%. Despite the potential involving microalgae, many challenges remain to be overcome to make feasible the application of these microorganisms for energy purposes. We need to develop several areas, addressing the following issues: selection and genetic improvement of species, reaching higher photosynthetic efficiency, development of production systems and their scale up, development of systems and procedures for harvest, extraction and processing, use of nutrients from flue gases and wastewater, optimization of operating conditions, etc. This study aimed to determine the best conditions for growth of the marine microalgae Nannochloropsis oculata in airlift phootobioreactor. Experiments were carried out following a central composite design of the following variables: temperature (19 to 29 ° C), nitrate concentration in the culture medium (f/2) (25 to 125 mg.l-1) and irradiance (3636 to 10364 lux). A laboratory plant was built with 12 photobioreactors, allowing perform the central composite design in two blocks. The response variables studied and the best experimental results obtained were 482,7 mg.l-1 for maximum biomass concentration under conditions of 21 °C, NaNO3 concentration 105 mg.l-1 and 9000 lux, instantaneous rate of increase in exponential period equal to 0.5624 d-1 under the conditions of 24 °C, NaNO3 concentration 75 mg.l-1 and 7000 lux and percentual lipid content in lyophilized biomass of 30.36% under the conditions of 21 °C, NaNO3 concentration 45 mg.l-1 and 5000 lux.
2
Pandeirada, Carolina Oliveira. "Characterization of carbohydrates from Nannochloropsis oculata and their use in microarrays". Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22402.
Testo completoAbstract (sommario):
Mestrado em Bioquímica - Bioquímica AlimentarMarine microalgae are of easy culturing and able to accumulate compounds, such as polysaccharides (PS) and glycolipids (GL), which have been attributed biological activities. The present work aimed to study the structural features of the PS and the carbohydrates of the GL of the marine microalga Nannochloropsis oculata using carbohydrate analyses and microarrays. Biomass was defatted, extracted with hot-water (HW), and ultrafiltered. This yielded a residue rich in (1→4)-Glc that was assigned to the presence of a cellulose cell-wall, one filtrate rich in mannitol, and one rentante (Mw>10 kDa) that comprised the soluble PS. The soluble PS were fractionated through ethanol precipitation giving three fractions, Et50, Et85 and EtSN. The PS in Et85 were further fractionated through an anion-exchange chromatography, yielding fractions #1, #2, and #3. All PS fractions comprised uronic acids and sulfate groups, being this content almost negligible in fraction #1. Carbohydrate analyses together with microarrays experiments using proteins with known carbohydrate-binding specificities allowed to verify that the PS in Et50 are dominated by (β1→4)-Glc and exhibited also domains of (β1→3, β1→4)-glucans. PS in Et85 and EtSN fractions were composed by Rha and Man, comprising other sugars in lower content, Xyl, Fuc, and Gal. Fractions Et85, #1, #2, #3, and EtSN comprised mainly (1→2)-Rha with a branching point occurring at position C-3. Fractions Et85, #2, and #3 included also the substituted residue 2,3,4-Rha. In fraction Et85, the sulfate group occurred at position C-3, and simultaneously at positions C-3 and C-4 of (1→2)-Rha. Fractions #2 and #3, besides Rha residues, contained Xyl, Fuc, and Gal, suggesting that these are part of anionic sulfated heteropolysaccharides. The Man, in Et85 and EtSN, occurred mainly as (1→3)- and (1→4)-Man residues, being these part of non-anionic PS in fraction Et85. Carbohydrate microarrays highlighted that Man may be present in α-configuration due to the interaction with ConA. The protein BT0996 of the Bacteroides thetaiotaomicron, a human gut bacteria, used in microarrays, displayed that the PS in fractions Et50, Et85, #1, and #3 may share a common epitope. This interaction is remarkable as it shows that these PS are probably metabolized in the human gut. The GL occur mainly as mono- and digalactolipids, being the presence of galactolipids confirmed through microarrays by interaction with RCA120. Carbohydrate analyses highlighted that the lipid fraction may comprise sulfoquinovosyl diacylglycerol. Considering the results obtained, the joint use of carbohydrate analyses with microarrays showed to be a suitable approach to identify the structural features of the PS and the GL of the marine microalga N. oculata.
As microalgas marinhas são fáceis de cultivar e acumulam compostos, como polissacarídeos (PS) e glicolípidos (GL), aos quais têm sido atribuídas atividades biológicas. O presente trabalho teve como objetivo estudar as características estruturais dos PS e dos hidratos de carbono dos GL da microalga marinha Nannochloropsis oculata. A biomassa foi desengordurada, extraída com água quente (HW) e ultrafiltrada. Isto originou um resíduo rico em (1→4)-Glc, atribuído à presença de celulose na parede celular, um filtrado rico em manitol e um retentato (Mw>10 kDa) que continha os PS solúveis. Os PS solúveis foram fracionados por precipitação em etanol originando três frações, Et50, Et85 e EtSN. Os PS da fração Et85 foram sujeitos a fraccionamento por cromatografia de troca aniónica, obtendo-se as frações #1, #2 e #3. Todas as frações contiveram ácidos urónicos e grupos sulfato, sendo este conteúdo quase negligenciável na fração #1. As análises de açúcares, juntamente com os microarrays usando proteínas de especificidades conhecidas, permitiram verificar que os PS da fração Et50 são constituídos por (β1→4)-Glc, exibindo também domínios de (β1→3, β1→4)-glucanas. Os PS das frações Et85 e EtSN incluíram maioritariamente Rha e Man, contendo também outros açúcares em menores quantidades, Xyl, Fuc e Gal. As frações Et85, #1, #2 e #3, e EtSN possuiram principalmente (1→2)-Rha, com uma ramificação na posição C-3. As frações Et85, #2 e #3 continham também o resíduo substituído 2,3,4-Rha. Na fração Et85 os grupos sulfato encontraram-se na posição C-3, e simultaneamente nas posições C-3 e C-4 de (1→2)-Rha. As frações #2 e #3, além de resíduos de Rha continham Xyl, Fuc e Gal, sugerindo que estes fazem parte de heteropolissacarídeos aniónicos sulfatados. A Man, nas frações Et85 e EtSN, encontrou-se maioritariamente como (1→3)- e (1→4)-Man, fazendo parte de PS não-aniónicos na fração Et85. A análise por microarrays evidenciou que a Man deve encontrar-se em configuração α devido à interação com a ConA. A proteína BT0996 da bactéria Bacteroides thetaiotaomicron, do sistema digestivo humano, usada nos microarrays, mostrou que os PS nas frações Et50, Et85, #1 e #3 podem conter um epítopo comum. Esta interação evidencia que os PS de N. oculata poderão ser metabolizados no sistema digestivo humano. Os GL de N. oculata ocorrem principalmente como mono- e digalactolipídos, sendo a sua presença confirmada pelos microarrays por interação com a proteína RCA120. A análise de açúcares evidenciou também que a fração lipídica deve conter sulfoquinovosil diacilglicerol. Considerando os resultados obtidos, a combinação das análises de açúcares com os microarrays mostraram ser uma abordagem adequada para identificar as características estruturais dos PS e GL da microalga N. oculata.
3
LIMA, K. F. F. "Extração de bio-óleo via base úmida a partir da microalga da espécie nannochloropis oculata". Universidade Federal do Espírito Santo, 2018. http://repositorio.ufes.br/handle/10/8450.
Testo completoAbstract (sommario):
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Previous issue date: 2018-02-23As pesquisas atuais têm demonstrado um grande interesse em microalgas pela sua capacidade de captura do CO2 da atmosfera, gás nocivo ao meio ambiente além de armazenar um óleo com alto valor agregado. Entretanto, a extração do óleo de microalgas representa uma etapa de alta demanda energética, sendo necessário o desenvolvimento de um processo viável sob este aspecto. Neste contexto, o presente trabalho objetiva a extração do bio-óleo a partir da microalga da espécie Nannochloropsis oculata via base úmida, a fim de retirar a etapa de secagem do processo de extração. Para isso foi utilizado um planejamento experimental do tipo fatorial (3²) com mais dois pontos centrais, totalizando 11 experimentos para cada solvente (etanol e hexano). As variáveis estudadas no planejamento foram o tempo de aplicação do ultrassom e o tempo de extração por Soxhlet. A extração com a aplicação de ultrassom por 60minseguida de Soxhlet por 8h com hexano mostrou-se melhor rendimento (20,29%) de bio-óleo. A produção de bio-óleo nas mesmas condições com etanol foi de 16,83%. O menor gasto energético em relação a produção de 1g de óleo se deu nas condições de aplicação de 60 min de ultrassom e 4h de extração sólido-líquido. Também comparou-se o gasto energético via base seca e úmida com os dois solventes. Na extração via base seca o rendimento foi inferior a via base úmida. Pela análise de GC-MS percebeu-se que secagem influencia no perfil dos ácidos graxos, diminuindo a porcentagem de ácidos graxos monoinsaturados e poliinsaturados. Conclui-se que a extração via base úmida é a melhor opção, pois secagem deteriora o bio-óleo e não influencia significativamente no rendimento do bio-óleo.
4
Borges, Cauã Brum. "Biomassa de microalgas : separação da microalga marinha nannochloropsis oculata por coagulação, floculação e flotação por ar dissolvido". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/108478.
Testo completoAbstract (sommario):
As microalgas são microrganismos fotossintetizantes que possuem uma alta produtividade por área e não necessitam de terrenos agriculturáveis, nem água agriculturável. Neste trabalho foi avaliado um processo de coleta com uso dos processos físico-químicos de coagulação, floculação e flotação por ar dissolvido (FAD) para a microalga marinha Nannochloropsis oculata. Uma varredura com coagulantes inorgânicos (Al2(SO4)3 e FeCl3), polieletrólitos catiônicos naturais (Veta Organic®, Tanfloc SL®, Tanfloc SG® e amido de milho modificado) e floculantes catiônicos sintéticos (polímeros catiônicos da SNF Floerger®) de diferentes características foi realizada. Este trabalho demostrou ser possível atingir altas eficiências de coleta mesmo para uma alga de tamanho reduzido (2-4 m) em meio marinho, além de utilizar reagentes orgânicos renováveis que não precisam ser removidos no processamento e ser um método rápido que pode ser aplicado em regime contínuo. Eficiências de remoção das microalgas da suspensão maiores que 90% foram atingidas nas seguintes condições: a) FeCl3 100 mg.g-1; b) FeCl3 80 mg.g-1 e 3,75 mg.g-1 FO SH 4800; c) FeCl3 32,5 mg.g-1 e 12,5 mg.g-1 amido de milho modificado; d) Tanfloc SL® 640 mg.g-1; e) Veta Organic® 750 mg.g-1; f) Veta Organic® 490 mg.g-1 e 12,5 mg.g-1 amido de milho modificado, sendo a flotação conduzida com 30% de reciclo e 392,27 kPa de pressão de saturação. A quantidade de reagentes utilizados e a eficiência dos processos foram similares aos utilizados na literatura. Contudo, este trabalho demonstra a eficácia de polieletrólitos orgânicos provenientes de taninos. Além disso, encontraram-se bons resultados com o uso de amido de milho como floculante em meio com salinidade 33 g.L-1 próxima a da água do mar.Microalgae are photosynthetic microorganisms that have a high yield per area and do not require fertile land or agricultural quality water. This study evaluated the physical-chemical processes of coagulation, flocculation and dissolved air flotation (DAF) to harvest marine microalgae Nannochloropsis oculata. A scan of inorganic coagulants(Al2(SO4)3 e FeCl3), cationic natural polyelectrolytes (Veta Organic®, Tanfloc SL®, Tanfloc SG® and modified corn starch)and cationic synthetic flocculants and with different characteristics (SNF Floerger® cationic polymers) was performed. The main contribution of this work was to achieve high efficiencies even for harvesting of small size microalgae (2-4 m); also it used renewable organic reagents which do not need be removed downstream. The process is quick and can be applied on a continuous regime. Removal efficiencies greater than 90 % were achieved in the following scenarios: a) FeCl3 100 mg.g-1;b) FeCl3 80 mg.g-1 e 3,75 mg.g-1 FO SH 4800; c) FeCl3 32,5 mg.g-1 e 12,5 mg.g-1 modified corn starch; d) Tanfloc SL® 640 mg.g-1; e)Veta Organic® 750 mg.g-1; f) Veta Organic® 490 mg.g-1 e 12.5 mg.g-1 modified corn starch. The flotation process was conducted with 30% recycle and 392,27kPasaturation pressure. The amount of reagents and process efficiency were similar to those found in the literature. However, this work demonstrates the effectiveness of organic polyelectrolytes from tannins in sea water which have not been studied yet. Furthermore, good results were found using corn starch as a flocculant in 33 g.L-1salinity medium.
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SALES, Rafael de Oliveira Jaime. "Cultivo de juvenis de cavalos-marinhos Hippocampus reidi usando uma pasta da microalga Nannochloropsis oculata produzida por floculação". reponame:Repositório Institucional da UFPE, 2015. https://repositorio.ufpe.br/handle/123456789/13937.
Testo completoAbstract (sommario):
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Dissertação Rafael de Oliveira Jaime Sales PPGO 2015.pdf: 1128460 bytes, checksum: 04c217b30f08a8b8e6bc4438894b8030 (MD5)Made available in DSpace on 2015-05-15T13:20:09Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Rafael de Oliveira Jaime Sales PPGO 2015.pdf: 1128460 bytes, checksum: 04c217b30f08a8b8e6bc4438894b8030 (MD5) Previous issue date: 2015-04-23
CNPq, CAPES
A produção de alimento-vivo representa grande parte dos custos de produção em empreendimentos de aquicultura, as microalgas contribuem com cerca de 30 a 40% desse custo. Uma alternativa para diminuir os custos é o uso de pastas de microalgas em substituição à produção destas na própria fazenda. Muito embora estas pastas são caras e de difícil aquisição, limitando seu uso. O presente estudo propõe uma nova metodologia para produzir a pasta da microalga Nannochloropsis oculata. A pasta foi produzida por floculação adicionando NaOH e o floculante FLOPAM FO4800SH, e armazenada em geladeira a +4º C por quatro semanas. Foi avaliada a capacidade da pasta em manter sua composição bioquímica (proteínas e carboidratos) e a porcentagem de células vivas, taxa de crescimento (k) e densidade celular máxima (DCM) da pasta recém produzida e na 4ª semana de armazenamento. Posteriormente, cultivou-se juvenis de cavalo-marinho Hippocampus reidi, recém-nascidos até 15 dias em três tratamentos adicionando a pasta da microalga produzida por floculação (PF), microalga viva (MV), e uma pasta comercial (PC). Os juvenis foram alimentados com prole do copépode Tisbe biminiensis e artêmia recém eclodida do 2º ao 5º dia. A partir do 6º dia foi ofertado prole de copépode e artêmia enriquecida (24h). Avaliou-se o desempenho dos cavalos-marinhos (sobrevivência, altura, comprimento total, peso seco e taxa de ingestão). A concentração de proteínas se manteve constante, já a concentração de carboidratos diminuiu na quarta semana de armazenamento. Além disso, 100% das células permaneceram vivas e se reproduzindo até a quarta semana, não havendo também diferença dos valores de k e de DCM entre as semanas de armazenamento. A taxa de sobrevivência, a taxa de ingestão e o peso seco não variaram de forma significativa entre os tratamentos. A altura e o comprimento total dos juvenis no tratamento PF foram iguais ao MV e maiores que o PC. A pasta floculada pode ser armazenada por pelo menos quatro semanas e utilizada como substituto à microalga viva e também apresentou eficiência semelhante à pasta comercial.
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Catalá, Esteve Lucía. "Contribución al estudio del crecimiento y las posibilidades del aprovechamiento termoquímico de las microalgas Nannochloropsis gaditana y Nannochlorpsis oculata". Doctoral thesis, Universidad de Alicante, 2013. http://hdl.handle.net/10045/36415.
Testo completo
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Belettini, Frank. "Utilização das microalgas Thalassiosira weissflogii e Nannochloropsis oculata no cultivo de Litopenaeus vannamei em sistemas de berçários, sem renovação de água". reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/93466.
Testo completoAbstract (sommario):
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Aquicultura, Florianópolis, 2010.Made available in DSpace on 2012-10-24T22:43:03Z (GMT). No. of bitstreams: 0Bitstream added on 2015-03-18T20:25:05Z : No. of bitstreams: 1 280838.pdf: 1468630 bytes, checksum: b28d9d7eb0825fb75824cb7665320148 (MD5)
O sistema de berçários intensivos é uma das etapas de cultivo das pós-larvas de camarões marinhos. Nesta fase as larvas ficam em condições semelhantes àquelas que irão encontrar nos viveiros de engorda. O desempenho de duas espécies de microalgas, Thalassiosira sp. (Diatomácea) e Nannochloropsis sp. (Eustigmatophyceae), em berçários intensivos de Litopenaeus vannamei foi avaliado neste estudo. Três tratamentos (controle, Thalassiosira, Nannochloropsis), com quatro repetições cada, foram conduzidos no Setor de Berçários do Laboratório de Camarões Marinhos, a fim de observar a influência destas microalgas sobre os parâmetros de qualidade de água, parâmetros microbiológicos (bactérias totais e vibrionáceas), parâmetros de qualidade larval e a relação destes com o desempenho dos animais durante o cultivo. A densidade de cultivo foi de 65 Pls por litro e além das microalgas, as larvas também foram alimentadas com rações comerciais de alto valor protéico (40 a 55%). As variáveis de qualidade de água: temperatura, oxigênio, pH, salinidade e alcalinidade, concentração de nitrito e nitrato, mantiveram-se dentro dos valores normais para a espécie Litopenaeus vannamei. Níveis elevados de amônia e fosfato foram observados, mas sem influenciar na sobrevivência. A disponibilidade de nutrientes favoreceu o aumento de bactérias patogênicas do gênero Vibrio. Em relação ao desempenho zootécnico, as diferenças verificadas nos tratamentos quanto à sobrevivência, nível de proteína bruta nas pós-larvas, resposta ao teste de stress, tamanho e qualidade larval das pós-larvas, não foram significativas. Diferenças foram encontradas no ganho de peso. O tratamento com a microalga Thalassiosira weissfloggi apresentou os melhores valores médios de peso seco e por conseqüência, maior ganho de peso e biomassa final foram observados.
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Hodgson, Paul Andrew. "The effects of environmental variables upon the lipid class and fatty acyl composition of a marine microalga, Nannochloropsis oculata (Droop) Eustigmatophyceae (Hibberd)". Thesis, University of Stirling, 1990. http://hdl.handle.net/1893/25425.
Testo completoAbstract (sommario):
Detailed analyses of the lipid class and fatty acid composition were carried out for the marine microalgal species Nannoch/oropsis oculata (Droop) (CCAP strain no. 849/1) of the division Eustigmatophyceae (Hibberd). The alga was grown in batch and continuous culture using a novel culturing apparatus, the cage culture turbidostat, the construction of which is detailed in full. The total lipid extract yielded by the alga varied in a growth-phase dependent manner within the range 25 % to 80 % of the lyophilised cell mass. Of this between 40 % and 70 % was recovered as fatty acid methyl esters (FAME) upon transesterification. The total fatty acid composition of N. oculata consisted mainly of 16:0, 16:1 and 20:5(n-3), these three fatty acids often accounting for greater than 80 % of the total fatty acid mass. Between 9 % and 50 % of the mass of total FAME was accounted for by 20:5(n-3), the balance being accounted for by variations in the relative proportions of 16:0, 16:1, 18:1, 18:2 and 20:4. During periods of low cellular division rate, such as the lag- and stationary-phases, the proportion of polyunsaturated fatty acids (PUFA) (mainly 20:5(n-3» decreased. The total fatty acids became increasingly saturated as higher proportions of shorter chain length fatty acids accumulated, mainly in triacylglycerols (TAO). Increased cellular proportions of total lipid resulted from TAO accumulation which occurred on account of preferential partitioning of carbon into TAO biosynthesis whilst cellular division was suspended. The fatty acid composition of the TAO was more saturated at high synthesis rate and vice-versa at lower rates. The galactolipids, monogalactosyldiacylglycerol (MODO) and digalactosyldiacyl glycerol (DODO) were rich in 20:5(n-3) during exponential cell division containing up to 77 % and 53 % 20:5(n-3) respectively. Phosphatidylcholine (PC) was the only cl~s to contain significant proportions of CIS fatty acids during exponential growth, thus implicating its involvement in the acyl chain elongation reactions between the Cl6 and C20 fatty acids. Culture incubation temperature in the range 5 °C to 25°C did not influence the fatty acid composition of N. oculata. The effect of temperature upon culture dynamics at the lower culture incubation temperatures gave an apparent decrease in the PUFA content of the total fatty acid at a given point on the cultures growth curves. By expressing the data in tenns of culture doubling periods during the exponential-phases of growth it was found that temperature had no real effect upon fatty acid unsaturation or chain length. at either the total or the individual lipid class FAME level after the cells had passed through five doubling periods. Increasing the culture medium salinity from one quarter to one and a half times that of normal seawater decreased the un saturation and chain length of the fatty acids at both total and individual lipid class levels. The change resulted from the progressive accumulation of 18:1 and 18:2"at the expense of 20:5. Variation of salinity did not affect the dynamics of the cultures in the same respect as temperature in that a lag-phase was not observed on the cultures growth curves. However. such a phase was evident in the fatty acid profile of the cells in the period following inoculation. The 'effects of culture illumination intensity in the range 45 Jill m-2 sec-I to 170 Jill m 2 sec-! were examined under continuous culture conditions using the cage culture turbidostat Accumulation of saturated TAG by the cells at the higher illumination intensities gave an apparent decrease in the rate of PUFA biosynthesis. The polar lipid classes were found to be more highly unsaturated at higher illumination intensities. At lower illumination intensity TAG accumulation was reduced and the total fatty acid composition was accordingly more unsaturated. The fatty acid composition of the TAG component was more unsaturated but those of the polar lipid classes were less unsaturated than at higher illumination intensity. Increased illumination increased the degree of un saturation of the polar lipid cl~sses. Excess fixed carbon was partitioned into TAG biosynthesis. primarily as 16:0 and 16:1. The net accumulation of this lipid class even at high cell division rates resulted in a low overall unsaturation level. The effects of decreasing nitrate concentration in the range 1.0 mM N03 - to 0.001 mM N03 - had a similar basis to those of illumination in that the changes in the total fatty acid composition were largely governed by the rate of TAO accumulation. At high nitrate concentrations the cellular division rate was relatively high and the proportion of TAO in the total lipid extract was low. Consequently, both total and individual lipid classes contained high proportions of unsaturates, particularly 20:5(n-3). However, when the nitrate concentration was decreased, such that it began to limit the rate of cellular division, TAG accumulated Cursory analyses of the molecular species of the galactolipid classes, MODO and DODO, and phospholipid class PC are presented. The effects of environmental variables are discussed in tenns of the changes which may occur in the growth phase distribution of the cells in asynchronous culture, along with the concommitant changes in the lipid composition of the cells. The potential linkage of the elongation and desaturation reactions with both MODO and PC is also discussed briefly with reference to future research.
9
Borges, Lucélia do Valle. "Efeitos do uso de floculantes e da variaçãode fatores abióticos sobre os lipídiose ácidos graxos das microalgas marinhas Nannochloropsis oculata e Thalassiosira weissflogii". reponame:Repositório Institucional da FURG, 2011. http://repositorio.furg.br/handle/1/4385.
Testo completoAbstract (sommario):
Tese(doutorado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2011.Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-12-15T17:48:26Z No. of bitstreams: 1 LUCELIA.pdf: 1063843 bytes, checksum: d9a3275320eb091ac6c93c7e1b9d854d (MD5)
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Microalgas marinhas são organismos ricos em lipídios e ácidos graxos, de grande interesse devido ao seu potencial biotecnológico. O objetivo desta tese foi determinar possíveis efeitos sinergéticos da intensidade luminosa (40 e 400mol fótons m-2s-1), temperatura (15 e 30°C), fonte de nitrogênio (NO3- e NH4+) e fase de crescimento (logarítmica e estacionária), sobre o conteúdo e a produtividade de lipídios e ácidos graxos de duas microalgas marinhas Nannochloropsis oculata e Thalassiosira weissflogii. Além disso, foi avaliado, também, como o uso de floculantes aniônicos e catiônicos podem influenciar a extração de lipídio e o perfil de ácidos graxos produzidos por estas microalgas. Os maiores conteúdos e produtividade dos lipídios para ambas as espécies ocorreram em tratamentos com maior intensidade luminosa (400 mol fótons m-2 s-1) e utilizando nitrato como fonte de Nitrogênio. N. oculata acumulou mais lipídios na fase estacionária, enquanto que em T. weissflogii maiores concentrações de lipídios só ocorreram na fase estacionária de tratamentos com menor temperatura (15º C). As duas espécies apresentaram maior produtividade de lipídios em tratamentos com maior produção de biomassa de microalgas. Entretanto, células de N. oculata que cresceram no tratamento com amônio e elevada luminosidade apresentaram grande produtividade de lipídio devido a elevados níveis de concentração deste elemento nas células e não devido ao maior crescimento celular. Portanto uma maior produtividade pode ser obtida empregando estratégias de cultivo que beneficiam, simultaneamente, o crescimento celular e/ou o acúmulo de lipídios nas células. Os ácidos graxos com maior conteúdo em ambas as espécies foram C14:0, C16:0, C16:1, C18:1 e C20:5. Para as duas espécies, maiores concentrações de ácidos graxos saturados e monoinsaturados foram obtidos em tratamentos com maior temperatura (30º C). Ácidos graxos poli-insaturados (PUFAS), especialmente o ácido eicosapentaenóico (C20:5), foi produzido em maior quantidade por N. oculata em tratamentos com baixa luminosidade e Nitrato. O uso de floculantes não alterou a quantidade de lipídios extraídos de ambas as espécies. Entretanto, o floculante aniônico diminuiu o conteúdo de C20:5 em N.oculata, enquanto que em T. weissflogii, os floculantes aniônico e catiônico reduziram os conteúdos de C18:0 e C18:1n9c
Marine microalgae are rich in lipids and fatty acids. These microorganisms are of great interest, mainly due to their biotechnological potential. The aim of this thesis was to determine possible synergistic effects of light intensity (40 and 400 mol photons m-2s-1), temperature (15 and 30° C), nitrogen source (NO3- and NH4+), and growth phase (logarithmic and stationary) in the productivity, content of lipids and fatty acids in two marine microalgae: Nannochloropsis oculata and Thalassiosira weissflogii. Moreover, it was evaluated if the use of anionic and cationic flocculants can influence the extraction of lipids and fatty acid profiles produced by these species. The higher lipid content and productivity for both microalgae occurred in treatments with higher light intensity (400 mol photons m-2 s-1), and with nitrate as nitrogen source. N. oculata accumulated more lipids in the stationary phase, while higher concentrations of lipid in T. weissflogii occurred only in stationary phase from treatment with a lower temperature (15° C). The two microalgae species showed higher lipid yields in treatments with higher biomass production. However, during N. oculata cells grown, the treatment with ammonium and high light showed large lipid productivity due to high concentrations of this element in the cells, and not due to increased cell growth. Therefore highest lipid productivity can be achieved using cultivation strategies that benefit both cell growth and accumulation of lipids in cells. The fatty acids with greater content of both species were C14:0, C16:0, C16:1, C18:1 and C20:5. Higher concentrations of saturated and monounsaturated fatty acids were obtained in treatments with higher temperature (30° C) in both species. Polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (C20:5), was produced in greater amounts by N. oculata in treatments with low light and nitrate. The use of flocculants did not alter the amount of lipids extracted from both species. However, the anionic flocculant decreased content of C20:5 in N. oculata, while for T. weissflogii, the cationic and anionic flocculants reduced content of C18:0 and C18:1n9c.
10
YEH, YI-TING, e 葉奕廷. "Flocculation of Nannochloropsis Oculata with Algal Sedimentary Symbiotes". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/83fvn6.
Testo completo
11
Liu, Ching-Yu, e 劉景育. "Culture Optimization and Applications of Nannochloropsis Oculata (TF-11)". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7g3u55.
Testo completoAbstract (sommario):
碩士國立中山大學
海洋環境及工程學系研究所
105
The nutrient salts and carbon dioxide (CO2) required for the growth of microalgae can be respectively obtained from waste water and flue gases emitted by wastewater plants and power plants. Therefore, a microalgae culture system can simultaneously attain multiple goals such as mciroalgae cultivation, water purification, and carbon storage. The produced microalgae can be used as fish feeds or processed and converted to economic by-products, including fertilizers, biodiesels, and health food. The growth of microalgae is affected by nitrogen and carbon sources as well as other environmental factors such as illumination. Experiments were first conducted to investigate the effects of various environmental and operating factors on the biomass and oil accumulation of Nannochloropsis oculata (TF-11); these factors were nitrogen concentration, phosphorous concentration, salinity, pH, aeration ratio, high- and low-concentration nitrogen sources, light intensity, and carbon sources. According to the experimental results, the most influential growth factors, namely, salinity, nitrogen sources, and carbon sources, were selected to optimize the cultivation cost. Finally, experiments were conducted to examine whether N. oculata (TF-11) can be used to perform secondary treatment for fish farm and municipal wastewater to purify water and produce high-biomass algal solutions as animal feeds. Applying various salinity levels (0.76–40 PSU) confirmed the euryhaline property of N. oculata (TF-11); in particular, the microalgae could grow under a salinity of merely 0.76 PSU. Regarding light intensity (300–6000 lux), the growth of N. oculata differed nonsignificantly between 3000 and 6000 lux. The experiment on municipal wastewater showed that N. oculata completely removed 30.36 ± 0.54 mg L−1 total inorganic nitrogen in approximately 5 days, and the experiment on fish farm wastewater confirmed that the algae completely removed 2.95 ± 0.24 mg L−1 total inorganic nitrogen in approximately 3 days, attaining a removal rate of 76%. The culture optimization experiment on the CO2 influx rate showed that the culture medium only required a CO2 influx of 4.4 mL min−1 L−1 to reduce the pH by 2.4; this influx rate was only 1/13 of the conventional method.
12
Chien, Yin-Husan, e 簡胤軒. "Experiment and Modeling Analysis on Cell-Wall Fracture of Nannochloropsis Oculata". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/64802515380878710445.
Testo completo
13
Lin, Chi-Jui, e 林奇叡. "The study on anti-inflammatory effects of the extract from Nannochloropsis oculata". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/q467ek.
Testo completoAbstract (sommario):
碩士國立中山大學
海洋生物科技暨資源學系研究所
102
New bioactive compounds in microalgae increase their commercial values for healthy food. Nannochloropsis oculata is mostly used for juvenile feed, while application for health is unavailable so this research isolated the compositions of the anti-inflammatory ingredients from N. oculata. The results showed growth of N. oculata yielded well in 110 rpm, 25 oC, 15000 lux, and 2.8% salinity; additional nutrients and CaCO3 slightly increased production. The analysis of N. oculata anti-inflammatory ingredients was based on the inhibition ratios of iNOS and COX-2 protein expression in RAW 264.7 under LPS induction. TLC separation showed that highly polar molecules inhibited iNOS and COX-2 expressions. AWP2-11-1 and AWP2-11-3 compounds were from acetone partition. In RP-C18 separation of the extracts, A3-19-21 compound inhibited iNOS and COX-2 expressions by 99% and 95%, respectively. HP2-69-70 compound from n-hexane partition inhibited iNOS expression by 64%. The resulting compounds were identified for their structures via 1H-NMR, 13C-NMR, 2 D NMR, and mass spectrometries.
14
CHENG, YU-CHUNG, e 鄭有中. "Application of Nannochloropsis oculata to the Sewage Treatment under Whole Plant Design". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/02324589925463610970.
Testo completoAbstract (sommario):
碩士中華大學
土木工程學系碩士班
103
The purpose of sewage treatment is to reduce the concentration of pollutants in sewage to make its effluents to comply with National Discharge Standards, Taiwan Environmental Protection Agency and not to cause secondary pollution. The quality in design of sewage treatment plant has strong impact on treatment efficiency and stabilization, and the costs of plant set-up and operating. However, domestic wastewater treatment plant design practice is often not based on the functional design, mainly because of the lack of experimental data as a basis for the design parameters during the various stages of the plant development. In tertiary treatment processes, wastewater containing nutrients: nitrogen, phosphorus and trace elements, which are required for algae to growth. Many research found algae could be used in production of bio-fuels, fertilizers, nutrition products, fish and animal feed, and cosmetics as well as the wastewater treatment as Taiwan green industries was prosperously developed in recent years. Therefore, this study will establish the criteria for sewage plant functional design, and discuss the design and operation in the application of the proposed algae to the tertiary treatment. This study clearly illustrates the theoretical basis of the functional design in each treatment unit and recommend the proper mode of operation. Also with the settling tests and dynamic simulation for equalization tank, the case study was used for illustration of sewage whole plant design and for the required size of the reactor / equipment. The results show that under national discharge standard and the three principles of energy conservation, reduction of resources, saving space, the maximum efficiency of treatment equipment can be achieved. In application of algae in design of tertiary treatment, the wastewater from a pig farm was treated under the conditions of 5000-lux light intensity and continuous aeration rate of 1200 mL/min. The results show that the removal efficiency of nutrient sources such as NO3-N, NO2-N, NH4+-N, and PO4-P in a batch test in five days of incubation time were 29.4%, 97%, 98.3%, 73%, respectively, indicating it can effectively remove the nutrients in tertiary treatment without the traditional design problem in poor removal efficiency for adding chemicals to removal of the nitrogen and phosphorus.
15
Chen, Sin-Yu, e 陳欣榆. "Investigation on anti-fatigue properties of Nannochloropsis oculata cultured by deep sea wate". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/26346390751340781982.
Testo completoAbstract (sommario):
碩士國立臺灣海洋大學
食品科學系
101
The purpose of this study is to compare the proximate composition and anti-fatigue effect of the extracts of Nannochloropsis oculata cultured by surface sea water (SSW) and deep sea water (DSW). Under the same culture condition, the growth rate and the appearance of N. oculata cultured by different sea water showed insignificant difference. The crude protein and carbohydrate content of N. oculata cultured by DSW were higher than cultured by SSW, on the contrary, the crude fat and ash content higher in SSW cultured extracts than DSW cultured extracts. It showed N. oculata cultured by different sea water had influence on their growth. After the ultrasound treatment, the soluble protein and total sugar content of the extracts of N. oculata cultured by DSW were higher than SSW. However the ash content was vice versa for the different cultured extracts. Both extracts of N. oculata cultured by SSW and DSW did not showed any significant difference in the other mineral content, except for sodium content. The antioxidant capacity of DSW cultured N. oculata extracts were significantly higher than SSW cultured extracts. This may be causing with polysaccharide’s amount and composition, and composition of free amino acid of extract. The results of the animal experiments, showed the lactic acid increment of DSW group were significantly better than the control group. The exhausting time, lactic acid elimination, blood urea nitrogen and liver glycogen content were not significantly different from the treatment group and control group. The anti-fatigue effect of the extracts of N. oculata were not significant. However, in comparison to SSW, DSW had potential benefit for anti-fatigue effect.
16
Chi, Yu-Pei, e 陳玉佩. "Studies on the heavy metals Cu、Pb、Cd、Zn absorption of Nannochloropsis oculata". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/m7ghv4.
Testo completoAbstract (sommario):
碩士國立臺灣海洋大學
環境生物與漁業科學學系
102
This study was to analyze the effects on adsorption when various algae concentrations of Nannochloropsis oculata (30 cells / ml and 50 cells / l) were under exposed to copper, lead , cadmium and zinc in different concentrations (3, 5 and 8 ppm). As observed in the experiment, all of the metal ions were found to have the fastest adsorption during the initial 20 minutes, reaching a saturation of 90% and gradually decreasing to almost equilibrium adsorption after 120 minutes. The adsorption of the first 20 minutes was significantly higher than the other exposure times (p <0.05). The adsorption capacity of algae increased to 68.30, 85.44 and 106.39 mg/g, while exposed to 3, 5 and 8 ppm Cu2+ concentrations. But the absorption rate decreased to 37.32%, 29.11% and 21.76%, respectively. The adsorption capacity of algae increased to 118.64, 146.90 and 161.72 mg/g, while exposed to 3, 5 and 8 ppm Pb2+ concentrations. But the absorption rate decreased to 39.63%, 34.25% and 22.68%, respectively. The adsorption capacity of algae increased to 24.31, 28.91 and 36.71 mg/g, while exposed to 3, 5 and 8 ppm Cu2+ concentrations. But the absorption rate decreased to 14.99%, 12.57% and 5.62%, respectively. The adsorption capacity of algae increased to 7.53, 9.69 and 21.32 mg/g, while exposed to 3, 5 and 8 ppm Cu2+ concentrations. But the absorption rate decreased to 11.10%, 8.52% and 7.13%, respectively. In different algae ambient concentration, the effect of heavy metals adsorption was significantly improved with increasing concentrations of algae (p<0.05). The metal adsorption rate of algae in ambient concentration of 50 cells/l were significantly higher than the concentration of 30 cells/l (p<0.05). The adsorption ratio of marine algae to heavy metals in the order is Pb> Cu> Cd> Zn. The maximum adsorption for copper, cadmium and zinc were 39.63%, 37.32%, 14.99% and 11.10%, respectively. The adsorption of copper and lead were significantly higher than cadmium and zinc (p<0.05).
17
Hsu, Tzu-Yen, e 許自研. "The Cost-benefit Analysis for Cultivate Nannochloropsis oculata by LED to Produce Biodiesel". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/26576395612866001213.
Testo completoAbstract (sommario):
碩士國立高雄海洋科技大學
水產養殖研究所
101
Due to the depletion of global energy crisis today, the price of the fossil fuel continues to skyrocket and the development of biomass energy gets the attention again. Nannochloropsis oculata is a kind of excellent biofuel crop that is oil-rich, fast-growing and does not occupy much land area. LED is saving, long lasting, with high luminous efficiency. Due to the rapid and successful development in recent years, it can now be used the light source of the plants as well. This research uses LED as a light source to cultivate Nannochloropsis oculata at night, and to explore the optimum growth conditions, harvesting methods, biodiesel conversion yield and to analyze its cost. The experiment was conducted with three kinds of lights (natural sunlight, full LED lighting, LED lighting at night), three kinds of salinity (10,20,30‰)and three kinds of nutrient concentrations (ammonium sulfate, urea, superphosphate ratio of 60,30,30 mg/L; 180,90,90 mg/L; 300,150,150 mg/L). In the test results, the best cultivation conditions is with LED lighting at night; 20‰; ammonium sulfate, urea, superphosphate ratio of 60,30,30 mg/L. Harvesting method was carried out by multiple poly aluminum coagulation, dosage is 1 g/L for the best. Conversion yield of biodiesel is 58.90 L per year; therefore it is assessed that this mode is not workable. If it is changed to produce Nannochloropsis oculata powder to analyze the cost, the annual output value would be 1,440,000 NTD, the total investment cost would be about 583,578 NTD, 856,422 NTD of net profit as, PE ratio would be 0.68, and return would be 146.75%.
18
Chen, Chih-wei, e 陳志瑋. "Optimal Ingredient Condition for the Prodution of Fatty acids on Microalga Nannochloropsis oculata". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/10927200606318123702.
Testo completoAbstract (sommario):
碩士國立中興大學
生物產業機電工程學系所
98
This study was aimed at investigating the influence of elements of mediu in algae cell density increase, lipid content and fatty acid composition. The first experiment conducted was a comparison of two normal media Walne medium and f/2 medium to culture Nannochloropsis occulata. The result had shown that f/2 medium was better than Walne medium for cultivating N. occulata. To investigate the influence of elements of medium in algae cell density increase, lipid content and fatty acid composition, the ingestion of nitrate and phosphorus content was ingested in the f/2 medium over 48 hours of the testing period for each later experiment.The experimental result obtained a high negative correlation of the concentrations of nitrate and orthophosphate in culture medium with microalgae density, and the correlation coefficients were -0.905 and -0.954, respectively. The multiple linear regression analyzing result obtained a good linear relationship, and the coefficient of determination R2 was 0.909. Moreover,the fatty acid C16:1n-7 in microalgae had a high negative correlation with C18:2n-6 and C18:3n-3 during the test, and the correlation coefficients R were -0.916 and -0.965, respectively. The nitrate and orthophosphate concentrations in culture medium had a high negative correlation with fatty acid C18:2n-6 and C18:3n-3, and the correlation coefficients R achieved were -0.894 and -0.860 and -0.964 and -0.983, respectively. In addition to the results of the first experiment, Taguchi method of S/N ratios for Larger-the-Better cases was used to test the optimization parameters for macroelements (nitrogen, phosphorus and carbon) and microelements (iron, copper, cobalt, molybdenum, manganese, zinc and magnesium) in microalgae cultivation, respectively.Macroelement testing results had shown that f/2 medium containing 22.055mg/l sodium dihydrogen phosphate (NaH2PO4) obtained the best algae cell density, lipid content,fatty acids,C18:1n-9,C18:2n-6,C20:5n-3 content and nitrate assimilation content. Microelement testing also showed that f/2 medium containing 0.0345mg/l iron chloride hexahydrate (FeCl3•6H2O) obtained the best algae cell density, fatty acid C16:1n-7,C20:5n-3 content and assimilation orthophosphate content. Furthermore, f/2 medium containing 0.27mg/l manganese chloride tetrahydrate (MnCl2•4H2O) also obtained a considerable amount of lipid content production. The study suggests that further research and explorations are needed to gain a more accurate test results; past research studies and other references on microalgae cultivated medium for industry production can also be added in future studies to provide better comparisons and analysis.
19
Lin, Hsiao-Wen, e 林曉汶. "Effect of Magnetic Field and Nitrate Concentration on the Growth of Nannochloropsis oculata". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/06226734039676798460.
Testo completoAbstract (sommario):
碩士國立雲林科技大學
環境與安全衛生工程系
102
With the rapid increase in energy demand, resulting in depletion of energy and global warming and other environmental problems, thus derive a number of alternative energy development.Bio-fual is an alternative energy is currently the most widely used. Most sources of materials is the food crops that produce food shortages. Bio-fual materials of microalgae are of concern in recent years. In order to achieve a balance between supply and demand, enhance its growth is a key element.In this study,by changing the magnetic field strength and sodium nitrate concentration(NaNO3) of environmental factors in cultured Nannochloropsis oculata. Investigate Specific growth rate of Nannochloropsis oculata of optimal conditions,and using response surface methodology (RSM) to investigate the impact of each factor on the growth of Nannochloropsis oculata and find the best operating conditions.The study is divided into two parts, first, changing the magnetic field strength and NaNO3 concentration in batch experiments and find the best range of Nannochloropsis oculata growth.Second, using response surface methodology to explore the role of each factor influence and determine the optimal operating parameters.The results showed that different magnetic field strength cultured,the optimum Specific growth range of Nannochloropsis oculata is 100 G to 300 G and the different NaNO3 concentration cultured,the optimum Specific growth range of Nannochloropsis oculata is 100 mg/L to 200 mg/L. Response surface methodology that obtained if the magnetic field intensity and NaNO3 concentrations were adjusted 175.4 G and 136.8 mg/L, respectively, the Specific growth rate of Nannochloropsis oculata is 0.24 d-1. The lipid content of Nannochloropsis oculata is rises under applied with no magnetic field or low magnetic field strength, with the reduction of nitrate concentration. In lipid productivity of Nannochloropsis oculata,when the magnetic field intensity and NaNO3 concentrations were adjusted 168.4 G and 140.6 mg/L,the lipid productivity of Nannochloropsis oculata is 278 mg/L. Suitable to be applied magnetic field strength will help Nannochloropsis oculata absorb the culture medium nitrate and can reduce the initial nitrate.
20
Chu, Shu-Hsien, e 朱書賢. "The Study Of Fed-Batch Culture And Construction Of Recombinant Plasmid In Nannochloropsis oculata". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/71565883388623430588.
Testo completoAbstract (sommario):
碩士國立中正大學
化學工程研究所
100
Due to rapidly global economic development, human heavy use of fossil fuels such as coal, oil and gas resulted in a substantial increase in carbon dioxide and greenhouse gases emissions, causing the destruction of the global carbon cycle and the global warming. One of possible solution to the problem of global warming is the use of microalgal photosynthesis for atmospheric carbon dioxide mitigation. Microalgaes can grow quickly and fix carbon dioxide to reduce carbon dioxide emission by manufacture factories; and because of its oil-rich they can be used for the production of renewable biofuel by extraction and transesterification. Thus the microalgal biofixation of carbon dioxide has considerable economic potential, and the ability to slow down the effects of global warming. This study uses the photobioreactor culture to investigate the feeding effects on the light intensity and CO2 concentration of Nannochloropsus oculata. In the study, we found that microalgal biomass yield increased in 66.2% if the Walne’s medium were replased by modified Walne’s medium. Using the modified medium the biomass yield of N. oculata in fed-batch culture was 1.25 times higher than that in batch culture. Also, in the fed-batch culture the microalgal growth rate in modified Walne’s medium was 1.32 times higher than that in Walne’s medium. Light intensity was an important factor of microalgal growth in the high cell density culture. As the light intensity increased up to 2.5 times, microalgal growth increased from 4.1 to 29.4%, depending on the initial algal concentration. Under the conditions for high cell density culture, the highest microalgal biomass could be achieved in 2% CO2. In this study, we also tried to construct a recombinant plasmid that could express the target gene encoding foreign protein in microalgae. The recombinant plasmid includes RBCs1 promoter, RBCs1 terminator and zeocin-resistance gene. In the study of N. oculata resistance to zeocin, we found that CC50 with N. oculata to zeocin concentration was 0.01-0.1 μg/ml. In the future, we can use 0.1 μg/ml zeocin for the screening of transgenic N. oculata based on these preliminary results.
21
Lin, Lin-Yen, e 林伶燕. "The Dynamic Influence of Photodynamic Theatment to the Association Between Nannochloropsis Oculata and Bacteria". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/62441935962615913044.
Testo completoAbstract (sommario):
碩士輔仁大學
生命科學系碩士班
102
Nannochloropsis oculata can be considered as a potential biomass for aquaculture, greenhouse gas reduction, healthy food and bio-diesel production. However bacteria, fungi and viruses often caused decreased productivity in large-scale cultivation. The first aim of this survey is using Photodynamic treatment (PDT) techniques to inactive the completely organisms that may interfere the productivity of N. oculata. LED, a cheaply and energy efficiently light source were used in these experiment. Several conditions of PDT, like power intensities, radiation time and light-sensitive agent were tested. Results showed that PDT can remove over the 93.85 % (±1 %) of the microbes in the algae broth under 0.1 mM light-sensitive agent, 700 mW/cm2 LED light source power and one minute illumination time. PDT can improve production efficiency of N.oculata for 33.6 % (after 27 days) under 0.1 mM light-sensitive agent, 225 mW/cm2 LED light source power and one minute illumination time. Howerve, the PDT is the non-specific sterilizations, so some probiotics may also be removed in these processes. Therefore, a second object of this study is to identify the probiotics organisms which were remove by PDT and define the effects of N. oculata. We find three microbial 4c、4e and 5b can improve the production rate of N.oculata for 23, 49 and 33 %, respectively.
22
Cho, Yueh-Cheng, e 卓岳正. "Supercritical fluids anti-solvent precipitation of zeaxanthin fractionated by elution chromatography from Nannochloropsis oculata". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/tvr2m5.
Testo completoAbstract (sommario):
碩士國立中興大學
化學工程學系所
99
This study examined column elution fractionation and supercritical anti-solvent (SAS) process applied for purification and micronization of zeaxanthin from micro-algal Nannochloropsis Oculata. Crude extract containing 24.3 mg/gext zeaxanthin obtained from ultrasonic stirred extraction subjected to a pilot-scale column chromatography was successfully to yielding the product containing zeaxanthin with purity of 349.4 mg/g and recovery of 85%. Response surface methodology designed supercritical anti-solvent process with feed flow rates ranged from 0.1ml/min to 0.3ml/min and injection times ranged from 12min to 48min were investigated afterwards. Nanoparticles with mean sizes ranged from 211nm to 2567nm having high purity of 84.5% (wt) were obtained from the SAS process at suitable conditions. Anti-oxidative ability of the 2,2-diphenyl-1-picrylhydrazyl was also studied. This work provided a low cost and environmental friendly process to produce pharmaceutical grade algal zeaxanthin using supercritical fluid micronization.
23
Sun, Ko-Ping, e 孫可蘋. "A Stable-transmitted Transgenic Microalgae, Nannochloropsis oculata, Harbors a DNA Fragment Encoding a Viral Protein". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/22782484489721483836.
Testo completoAbstract (sommario):
碩士臺灣大學
海洋研究所
95
Microalga, Nannochloropsis oculata, is the commonly useful foodstuff for finfish and shellfish larvae in aquaculture. In this study, we attempt to generate transgenic N. oculata strain which can enhance the quality of larvae. White spot syndrome virus (WSSV) causes severe mortality in shrimp industry. VP28 is a major envelope protein of WSSV and enables to stimulate disease-resistant ability of shrimp. We constructed a plasmid, pCB740-VP28, in which the VP28 cDNA is driven by a heat shock 70A (hsp70A) promoter combined with a ribulose bisphospate carboxylase small subunit 2 (rbcs2) promoter of Chlamydomonas reinhartii, and transferred into N. oculata by electroporation. The transformants containing pCB740-VP28 were screened, and 23 stable-transmitted transgenic algae were selected, and the transferred pCB740-VP28 is present over one-and-a-half-year passage. The success rate of stable-transmitted transgenic algal clones was 4.6% of the examined transgenic algae (n=497). We selected a stable transgenic clone-D5, in which VP28 protein is highly expressed after induction. After we cultured this transgenic alga and induced with heat shock treatment, its mRNA was extracted and detected by reverse transcription-polymerase chain reaction (RT-PCR). Results showed that a RT-PCR-product with a 650-bp was generated, which was corresponding to that of RT-PCR-product amplified from VP28 mRNA template. Furthermore, when we extracted total proteins from this recombinant microalga and analyzed the protein profile by SDS-PAGE, we found that a band near 28-kDa was observed in the transgenic alga, but not present in the wild-type alga. And, compared to the transgenic alge before induction, the intensity of this band greatly increased after induction, indicating that the exogenous VP28 protein was significantly heat-induced from a basal leaky. The result of Western blotting analysis with polyclonal antibody VP28-IgG also showed that transgenic alga could produce VP28 envelope protein by heat shock induction. According to biological assay of vaccination experiment result, we demonstrated that feeding transgenic algae containing an exogenous viral protein enables to protect shrimps from WSSV infection in shrimp cultivation.
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Tsai, Ya-Yi, e 蔡雅宜. "Nannochloropsis Oculata In Optimized Fed-Batch Cultivation And Its Application For Expressing Trehalose Synthase Gene". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/05345717914623586274.
Testo completoAbstract (sommario):
碩士國立中正大學
化學工程研究所
102
The characteristics of microalgae are nutrient-rich, strong environmental adaptability, growth rate fast and easy to culture. This microalgae can grow by photosynthetic that is converted water and carbon dioxide into biomass using light as an energy source. In nutrient-adequate cultivate environment, the light is major limiting factor which affecting the growth of microalgae. In the study, Nannochloropsis oculata was cultured in 2X modified Walne’s medium by photobioreactor. The effect of light intensity and tolerance of carbon dioxide was investigated during fed-batch cultivation. In order to studied the effect of light intensity the result demonstrated that the illuminated three different light intensity was separately used to studied as 4000, 10,000 and 40,000 Lux under a photoperiod of 12 hr (light):12 hr (dark) cycle and included air (0.03%CO2). An N. oculata biomass concentration of 0.545 g dry wt/L and specific growth rate of 0.192 d-1 were achieved when the microalgae was illuminated 40,000 Lux. This result showed that the maximum biomass yield of N. oculata was obtained at 40,000 Lux of illuminated the light intensity under fed-batch cultivation condition. Therefore, the fed-batch cultivation using the high light intensity illumination was suitable. For the effect of carbon dioxide, the tolerance capability of carbon dioxide of N. oculata was studied under light intensity of 40,000 Lux. N. oculata cultivation was aerated with different CO2 concentrations including 0.03% (air), 2%, 5%, 7.5%, 10% and 15% CO2. Results showed that the N. oculata cultivation at 2% CO2 could yield the maximum biomass of 2.240 g/L and the maximum specific growth rate of 0.328 d-1. Moreover, the N. oculata could grow at CO2 concentration as high as 15%. The biomass and specific growth rate achieved at 1.518 g dry wt/L and 0.288 d-1, respectively. When aerated with 2% CO2, the use of 40,000 Lux of light intensity promoted the production of biomass in 2.43 and 3.11 times, in comparison with 10,000 Lux and 4000 Lux of light intensity, respectively. In conclusion, the high light intensity could enhance microalgae photosynthetic efficiency. Also, the cultivation at 2% CO2 could enhance growth rate of N. oculata and reduce the mutual shading effect. Therefore, microalgae cells could be cultivated to high cell density at the conditions of 2% CO2 and 40000 Lux of light intensity. Moreover, N. oculata could tolerate high CO2 concentration, suggesting that this microalgae could be used for capturing CO2 from industrial process. Finally, the gene of trehalose synthase from Pseudomonas putida F1 was amplified and cloned into a plasmid vector. The restlant recombinant plasmid pRBCptH-TS was then transformed to N. oculata by electroporation. Four stains of recombinant N. oculata were screend from the plate containing antibiotics in Walne medium.
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Lu, Hsin-Hsien, e 呂信賢. "Investigation of Light Factors Condition on the Bio-Synthesis Content of Nannochloropsis oculata Fatty Acids". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/36020110672318403512.
Testo completoAbstract (sommario):
碩士國立中興大學
生物產業機電工程學系所
98
The purpose of this study is to investigate light factors about microalgal reproduction, lipid content and relations of fatty acid compositions in microalgal cultivation. The different tests include in light quality factor tests, optimal light factor tests, light change tests and optimal light change tests. Light quality factor tests used Nannochloropsis oculata to test 48 hours in exponential reproduction period, and used blue light(455~480nm), white light(400~700nm) and red light(625~690nm) to proceed the tests. The experimental results showed obvious influence of microalgal reproduction, oil content and relations of fatty acid compositions in light quality. The experimental results found the red light group to have the best result in reproduction which was up to the initial microalgal cells density of 2.5 times. The white light group was 1.75 times and the worst was the blue light group of 1.6 times only. The result of the revealed a rapid decrease of the lipid content of unit cell in the red light group, lipid content experiment while the white light group, and the blue light group could maintain more lipid content. The results had shown the reproduction of the microalgae grew faster and unit lipid content decreased in exponential reproduction period. Light quality to microalgae of fatty acid compositions results presented the red light group was better on saturated fatty acid of C16:0 and unsaturated fatty acids of C18:2n6. Besides, the blue light group was better on unsaturated fatty acids of C16:1n7, C18:1n9, C18:3n3 and C20:5n3. The white light group did not affect the fatty acid compositions. The optimal light factor tests used on orthogonal array L9(34) were done using the Taiguchi Method to choose light factors of environment, which include light quality, light intensity, initial cells density and light period to obtain the optimization of microalgal reproduction, lipid content and fatty acid compositions. The optimization result revealed that due to red light, light intensity 2,000lux, initial density 1,000×104 cells/ml and light period 24/0 hr(light/dark), the microalgal reproduction was the best. The optimal unit lipid content used blue light, light intensity 2,000lux, initial density 2,000×104 cells/ml and light period 8/16 hr. The test resulted to optimal content condition of fatty acid compositions；it could divide into two parts of red light C16:0, C18:2n6 and blue light C16:1n7, C18:1n9, C18:3n3, C20:5n3, respectively. The best content of EPA-C20:5n3 could be via blue light, light intensity 1,000lux, initial density 2,000×104 cells/ml and light period 8/16 hr to get. The results of light change proved that the microalgae turned into other light quality environment from origin light quality environment in cultivation, microalgal cells had trend to change with microalgal cells reproduction, microalgal cells lipid content and fatty acid compositions. After 48 hours, the test changed from blue light cultivation to red light cultivation and kept cultivation to 72 hours, the microalgal cells density originally of 1511±93.4×104 in 48 hours increased to 2401±78.3×104 cells/ml in 72 hours. It was 1.29 times higher than the unchanged light cells density 1865±54.5×104 cells/ml in 72 hours. However, the unit lipid content originally of 21.3±0.58% in 48 hours decreased to 14.5±0.48% in 72 hours, and it was 1.15 times lower than the of unchanged light unit lipid content 16.8±0.77%. It showed that the content of unsaturated fatty acid EPA-C20:5n3 arrived at 3.23±1.00%, and was 2.13 times lower than the unchanged light content 6.87±0.53%. Besides, the test changed from red light cultivation in 48 hours to blue light cultivation and kept cultivation to 72 hours, the microalgal cells density originally of 1788±70.3×104 in 48 hours increased to 1990±104.9×104 cells/ml in 72 hours. It was 1.28 times lower than the unchanged light cells density 2542±86.8×104 cells/ml, while the unit lipid content originally of 17.9±0.85% in 48 hours decreased to 15.1±0.37% in 72 hours as 1.29 times higher than the unchanged light unit lipid content 11.7±0.92% in 72 hours. It also showed that the content of unsaturated fatty acid EPA-C20:5n3 arrived at 4.41±0.49%, and was 2.25 times higher than the unchanged light content 1.96±0.73%. The results had shown the method of change light quality could control microalgal cells density, microalgal unit lipid content and fatty acid compositions effectively, and could reach optimal content of microalgal cells density, lipid content and fatty acid compositions. The results presented here show the relations of light factors cultivation parameters, and it supports a principle and effective microalgae control using the cultivation bioreactor in the future.Moreover, the relations of light factors cultivation parameters can not only increase the cultivation density but also raise microalgal lipid content and value of fatty acid compositions.
26
Μπίρκου, Μαρία. "Κινητικές αύξησης και μελέτη λιπιδίων μικροφυκών (Nannochloropsis oculata και Chlorella sp.) και του τροχοζώου Brachionus plicatilis". Thesis, 2011. http://nemertes.lis.upatras.gr/jspui/handle/10889/4794.
Testo completoAbstract (sommario):
Στην παρούσα ερευνητική εργασία μελετήθηκε η σύσταση σε λιπαρά οξέα των λιπιδίων (ολικών, φωσφολιπιδίων, γλυκολιπιδίων και σφιγγολιπιδίων, ουδετέρων) των μικροφυκών Nannochloropsis oculata και Chlorella sp. και μεικτών καλλιεργειών των ανωτέρω στελεχών καθώς επίσης και τροχοζώων του είδους Brachionus plicatilis καλλιεργούμενων σε βιοαντιδραστήρες μεγάλης κλίμακας υπό διαφορετικές συνθήκες αύξησης.
Η καλλιέργεια των μικροφυκών πραγματοποιήθηκε σε βιοαντιδραστήρες βιομηχανικής κλίμακας 300 L, ο φωτισμός ήταν συνεχής και η θερμοκρασία παρέμενε σταθερή στους 28±3 οC κατά την περίοδο της άνοιξης και στους 22±3 οC κατά την περίοδο του φθινοπώρου και του χειμώνα. Το Chlorella sp., συνέθεσε λιπίδια πλούσια σε α-λινολενικό και παλμιτικό οξύ, ενώ στα λιπίδια του Nannochloropsis oculata τα υπερέχοντα λιπαρά οξέα ήταν τα οξέα παλμιτικό, εικοσιπεντανοϊκό (EPA) και παλμιτελαϊκό. Μετά από κλασμάτωση των λιπιδίων του Chlorella sp. βρέθηκε ότι το κλάσμα των ουδέτερων λιπιδίων (NL) ήταν το σημαντικότερο ποσοτικά, σε όλες τις φάσεις αύξησης. Στις πρώτες φάσεις αύξησης τα φωσφολιπίδια (P) υπερείχαν των γλυκο- και σφιγγο- λιπιδίων (G+S) ενώ καθώς η καλλιέργεια εξελισσόταν τα ποσοστά των P μειωνόταν προς όφελος των G+S. Τέλος, στη μεικτή καλλιέργεια όπου επικρατές στέλεχος ήταν το Nannochloropsis oculata τα λιπαρά οξέα με τα υψηλότερα ποσοστά ήταν τα οξέα παλμιτικό, παλμιτελαϊκό και EPA. Μεταξύ των λιπιδιακών κλασμάτων η αναλογία των NL ήταν σημαντικά υψηλότερη, ακολουθούσε εκείνη των G+S και τέλος των P.
Τα τροχόζωα καλλιεργήθηκαν σε βιοαντιδραστήρες βιομηχανικής κλίμακας 2,500 L. Για τη διατροφή τους χρησιμοποιήθηκαν καλλιέργειες μικροφυκών (Nannochloropsis oculata, Chlorella sp.), ζύμη αρτοποιίας και διάφορα εμπλουτιστικά περιέχοντα σε υψηλά ποσοστά EPA και εικοσιδυεξανοϊκό (DHA). Η ανάλυση των λιπιδίων των τροχοζώων έδειξε ότι η σύσταση τους σε λιπαρά οξέα εξαρτάται από την τροφή την οποία καταναλώνουν. Διατροφή με καλλιέργειες μικροφυκών είχε ως αποτέλεσμα τη σύνθεση λιπιδίων που περιείχαν σε σημαντικά ποσοστά EPA. Μεταξύ των λιπιδιακών κλασμάτων, η αναλογία των NL ήταν σημαντικά υψηλότερη, ακολουθούσε των P και τέλος των G+S.
Με τη χρήση εμπλουτιστικών τα λιπίδια των τροχοζώων που συσσωρεύτηκαν ήταν πλούσια σε EPA και DHA.Το λιπιδιακό κλάσμα με τα υψηλότερα ποσοστά ήταν το κλάσμα των NL, ακολουθούσε το κλάσμα των P ενώ αυτό των G+S εμφανίστηκε σε σημαντικά χαμηλότερα ποσοστά.In this MSc thesis, fatty acids composition of lipids (total, phospholipids, glyco- and sphingolipids, neutral) synthesized by Nannochloropsis oculata, Chlorella sp. and mixed cultures of the above mentioned microalgae as well as by the rotifer Brachionus plicatilis, cultivated in industrial scale bioreactors under several growth conditions, were studied. Microalgae were cultivated in industrial scale bioreactors 300 L, under full sunlight and artificial light during night-time and at a constant temperature, 28±3 οC at sprint and 22 ±3 οC at autumn and winter. In Chlorella sp. the most abundant fatty acids were α- linolenic and palmitic acids, whereas in Nannochloropsis oculata palmitic, eicosapentaenoic (EPA) and palmitoleic acids were predominant. Neutral lipids (NL) fraction was found in higher proportions. Among polar lipids Phospholipids (P) fraction was higher at the initial growth steps while Glyco- plus Sphingolipids (G+S) fraction predominates as growth proceeded. In the mixed culture, where Nannochloropsis oculata was the dominant strain palmitic, palmitoleic and EPA were the major fatty acids. NL was the major fraction followed by G+S and P. Rotifers were cultivated in 2,500 L tanks. Rotifers fed with microalgae’s culture (Nannochloropsis oculata, Chlorella sp.), baker’s yeast and artificial diets with high level of EPA and docosahexaenoic acids (DHA). Rotifers fatty acid composition depended on the fatty acid composition of the feed. Rotifers fed microalgae cultures were rich in EPA, while when artificial diets were used, lipids rich in EPA and DHA were accumulated. Among lipid fractions, the proportion of NL was the highest, followed by P and G+S.
27
Hsu, Chih-Sheng, e 許志聖. "The effects of magnetic field on lipid content of Nannochloropsis oculata and nutrient utilization in swine wastewater". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/29018408381401403971.
Testo completoAbstract (sommario):
碩士國立雲林科技大學
環境與安全衛生工程系碩士班
101
This study aimed to explore the influences of different magnetic fields (0 G, 50 G, 100 G, 150 G, 250 G, and 350 G) on facilitating the growth of Nannochloropsis oculata, and N. oculata activity, lipid content, and utilization of nutrients (nitrogen and phosphorous) with different percentages of swine wastewater (10%, 20%, 30%, and 40%) and 2% of CO2. This study found that with proper magnetic fields, the algae volume and the lipid content were increased. The highest lipid content and algae amount were reached with the magnetic fields of 50 G and 250 G, which were 36.0% and 54.7% higher compared with the control groups. As for adding swine wastewater in the magnetic field for the growth of N. oculata, the growth was the highest with the percentage of 20%. The utilization rates of nutrients NH4+-N and NO3- -N were not high. PO4-3-P was absorbed first. In the aspect of lipid content, it increased as the percentage of wastewater increased. Especially, with 40% of swine wastewater and 50 G of magnetic field, the lipid content could reach 46.19%. 2% of CO 2 was added to different magnetic fields (0 G, 50 G, and 250 G) with 20% of swine wastewater. It was found that the growth rate and dry weight of the algae both increased while the magnetic fields were 50 G and 250 G compared with the control groups. The growth rates were 0.12 day -1 and 0.17 day -1, respectively. The algae dry weights increased by 43.05% and 44.41%, respectively. In the aspect of nutrients, due to the magnetic fields, the increase of N. oculata activity also lead to the increase of utilization rate of nutrients. Under different magnetic fields (0 G, 50 G, and 250 G), compared with the control groups, the lipid content increased from 9.25% to 14.16%, from 16.79% to 18.16%, and from 13.74% to 14.48%, respectively.
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HSU, CHENG-HUANG, e 徐正皇. "A Recycle System for High Cell Density Culture of Rotifer and the Construction of Transgenic Plasmid for Nannochloropsis oculata". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/45094568929717611630.
Testo completo
29
Hong, Siang-En, e 洪祥恩. "Production of Nano-sized Zeaxanthin-contained Particulates from Sea Water Cultivated Nannochloropsis Oculata Using Supercritical Fluids Extraction and Anti-solvent Crystallization". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/05107972866263481475.
Testo completoAbstract (sommario):
碩士國立中興大學
化學工程學系所
99
This work investigated supercritical carbon dioxide (CO2) anti-solvent recrystallization of zeaxanthin-containing particulates from microalgal Nannochloropsis Oculata species. The extract of the algae containing 3.613 mg/g zeaxanthin using ultrasonic stirred acetone extraction subjected to column elution fractionation for increasing the amount of zeaxanhin in the fraction to 425.6 mg/g by weight with the recovery of 82.7 %. Supercritical anti-solvent (SAS) precipitation of the column fraction at 215 bar, 50 oC, 36 g/min of CO2 flow rate, 0.5 ml/min of feed solution containing, 1.5 mg/ml of feed concentration results in 659.3 mg/g of zeaxanthin in the precipitates. However, another SAS precipitation of acetone solution at the 2.0 mg/ml of feed concentration yields 479.0 mg/g of zeaxanthin. A three-factor center composited schemed response surface method by changing feed concentration, CO2 flow rate, and pressure designed for the SAS precipitation was carried out in finding total yield, purity, recovery and particle size of the precipitates. The highest purity is 841.7 mg/g of zeaxanthin with 85.3 % recovery, obtained at feeding concentration of 1.5 mg/ml, CO2 flow rate of 48.6 g/min and pressure of 135 bar. The decreasing pressure favored dispersible precipitates.The mean particle size of these non-uniform nano-sized tabular precipitates ranged from 103 to 327 nm.
30
Garzon, Sanabria Andrea J. "Bioprocessing of Microalgae for Bioenergy and Recombinant Protein Production". Thesis, 2013. http://hdl.handle.net/1969.1/151229.
Testo completoAbstract (sommario):
This dissertation investigates harvesting of marine microalgae for bioenergy and production of two recombinant proteins for therapeutic applications in Chlamydomonas reinhardtii. The first study describes harvesting of marine microalgae by flocculation using aluminum chloride (AlCl_3), natural polymer chitosan, and synthetic cationic polymers.
Harvesting and concentration process of low concentration microalgae cultures ranging from 1 to 2 g dry weight per liter was affected by algogenic organic matter (AOM), ionic strength, cell concentration, polymer charge density, and media pH. Marine microalgae flocculation was greatly affected by the presence of AOM independently of the flocculant chemistry. Presence of AOM demanded extra flocculant dosage i.e., 3-fold of AlCl3, 7-fold of highly charged synthetic cationic polymer, and 10-fold of chitosan. Flocculant dosage required for > 90 % flocculation efficiency in the presence of AOM was 160 mg/L, 50 mg/L, and 20 mg/L when using AlCl_3, chitosan, and best (more efficient) synthetic polymer respectively. The high-ionic strength of saline water did not have a significant effect on flocculation efficiency when using AlCl_3. However, to achieve efficient algal biomass removal, application of highly-charged synthetic polymers was required to overcome the presence of electrolytes. The best synthetic cationic polymer tested herein, which achieved greater than 90 % flocculation efficiency at 20 mg/L dosage, was a polymer with 99 % cationic charge density. Cell concentration also affected flocculant dosage requirement; low density cultures (10^6 cells/mL) required 6-fold greater dosages than cultures grown until early stationary phase (10^7 cells/mL).
The second study addresses cultivation, extraction and purification challenges of two complex recombinant proteins, an immunotoxin molecule (MT51) and malaria vaccine antigen (Pfs25) produced in the chloroplast of C. reinhardtii. Main challenges identified were i) low transgene expression level, ii) proteolytic instability of MT51 immunotoxin, and iii) aggregation of Pfs25 antigen. Optimal expression and accumulation of Pfs25 antigen required growing C. reinhardtii cultures to late exponential phase (10^6 cells/mL) and inducing transgene expression for 24 h at a photon irradiance of 120 µmol/m^2s.
31
Schulze, Peter Simon Claus. "Effects of light quality supplied by light emitting diodes (LEDs) on microalgal production". Master's thesis, 2014. http://hdl.handle.net/10400.1/8328.
Testo completoAbstract (sommario):
Dissertação de mestrado, Aquacultura, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2014Light-emitting diodes (LEDs) will become one of the world´s most important light sources and their integration in microalgal production systems (photobioreactors) needs to be considered. Microalgae need a balanced mix of wavelengths for normal growth, responding to light differently according to the pigments acquired or lost during their evolutionary history. In the present study, Nannochloropsis oculata and Tetraselmis chuii were exposed to different light qualities, and their effects on growth, biochemical components (carbohydrate, protein, total lipid and fatty acids) and morphologic traits (cell shape, size, growth phase, absorption spectrum, N-P-C elemental composition in biomass) were investigated. An additional experiment employed different LEDs in order to obtain di- and multichromatic tailored light to increase biomass production. Both N. oculata and T. chuii showed a higher maximal volumetric ash free dry weight content in the culture when exposed to blue (465 nm) and red (660 nm) light, respectively. However, balanced light quality, provided via fluorescent light (FL) and dichromatic blue and red light treatment, was found to be beneficial for biomass growth rates of both algae. Significant changes in the biochemical composition were observed among treatments. Furthermore, algae treated with monochromatic blue light (λe = 405 and 465 nm) often displayed higher nutrient uptake and different morphological traits as compared to algae exposed to red light (λe = 630 and 660 nm). It is suggested that differential response to light quality is partially influenced by observed changes in nutrient consumption and biomass productivity. In terms of biomass per input energy, the most efficient light sources were those with photon output peaks at 660 nm (e.g. LED 660 and FL for plant growth). Research and the application of LED technology to microalgal production is often hindered by inadequate light quantity measurements as well as by inadequate LED manufacture and engineering, leading to the use of inefficient LED modules, which, in turn, may affect microalgal growth and biochemistry.