Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-10-03T11:42:26Z No. of bitstreams: 2 Dissertação - Renata Klícia Mendes Caetano - 2018.pdf: 2847916 bytes, checksum: 2eaea78563b91986afd782253b20323a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-10-03T11:47:01Z (GMT) No. of bitstreams: 2 Dissertação - Renata Klícia Mendes Caetano - 2018.pdf: 2847916 bytes, checksum: 2eaea78563b91986afd782253b20323a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-10-03T11:47:01Z (GMT). No. of bitstreams: 2 Dissertação - Renata Klícia Mendes Caetano - 2018.pdf: 2847916 bytes, checksum: 2eaea78563b91986afd782253b20323a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-08-29 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The growing interest in bioactive compounds from renewable natural sources has stimulated more and more studies aimed at increasing the supply of this market. An example is phycobiliproteins, dyes used in various areas, such as food, pharmacological and cosmetic. The microalgae arthrospira platensis (Spirulina platensis) is one of the organisms that stands out most in the production of these dyes, producing allophycocyanin and phycocyanin; these two dyes are the ones that today have more demand in the market. These proteins have their application determined from their degree of purity obtained with the absorbance ratio read at 620 nm of the extract used for the absorbance read at 280 nm. For use of these dyes, in the food area, a purity value greater than 0.7 should be obtained, and for use in the analytical area, the purity should be greater than 4.0. In view of the importance of these dyes and their degree of purity, in order to develop means of obtaining phycobiliproteins in a purity satisfactory for use in food industries, phase separation techniques were used in aqueous biphasic systems (ABS) to evaluate the action of pH, phosphate salt concentration and the concentration of low chlorine content cationic polymer and polyethylene glycol 4000 (PEG 4000) on the efficiency of the extraction and purification process of Spirulina crude extract and also in the pre-purified extract of phycocyanin obtained by centrifugation. For this, a first experiment was carried out using a factorial design 2 4 to evaluate the variables that most influenced the extraction and purification of phycocyanin, allophycocyanin and purity of the extract. Values of 2.6 mg.mL -1 were reached for phycocyanin concentration, 1.4 mg.mL -1 for the allophycocyanin concentration and 1.6 for the purity of the extract. The significance of the PEG 4000 and PBC polymers was observed for extraction and purification of phycobiliproteins. Then, a second design was carried out, a Rotational Central Composite Design (RCCD) 2 2 , fixing the phosphate salt, pH and varying the PEG and low chlorine content cationic polymer concentrations. At the end of the extraction, it was possible to find concentrations of 2.7 mg.mL -1 for Phycocyanin, 1.3 mg.mL -1 of allophycocyanin and 2.5 for the purity of the extract, evidencing that the techniques used are effective for the extraction process and purification of phycobiliproteins, in which the levels achieved allow their use and application in food industry. / O crescente interesse por compostos bioativos de fontes naturais renováveis tem estimulado cada vez mais estudos que visam aumentar a oferta deste mercado. Um exemplo são as ficobiliproteínas, corantes utilizados em diversas áreas, como alimentícia, farmacológica e cosmética. A microalga Arthrospira platensis (Spirulina platensis) é um dos organismos que mais se destaca na produção destes corantes, produzindo a Aloficocianina e, principalmente, a Ficocianina, sendo estes dois corantes os que, hoje, mais têm demanda no mercado. Essas proteínas têm sua aplicação determinada a partir de seu grau de pureza, obtido com a relação da absorbância lida a 620 nm do extrato utilizado pela absorbância lida de 280 nm. Para utilização destes corantes na área alimentícia, deve-se obter valor de pureza maior que 0,7 e para sua utilização na área analítica, a pureza deve ser maior que 4,0. Tendo em vista a importância destes corantes e seu grau de pureza, a fim de se desenvolver meios de obtenção das ficobiliproteínas em um grau de pureza satisfatório para utilização em indústriasalimentícias, foram utilizadas técnicas de separação por fases em sistemas aquosos bifásicos (SAB) para avaliar a ação do pH, da concentração de sal fosfato, e da concentração dos polímeros catiônicos com baixo teor de cloro e polietilenoglicol 4000 (PEG 4000) na eficiência do processo de extração e purificação do extrato bruto da Spirulina, e também, em extrato pré-purificado de ficocianina obtido por processo de centrifugação. Para tal, realizou-se um primeiro experimento utilizando um planejamento fatorial 2 4 para a avaliação das variáveis que mais influenciaram na extração e purificação da ficocianina, da aloficocianina e da pureza do extrato. Foram atingidos valores de 2,6 mg.mL -1 para concentração de ficocianina, valor de 1,4 mg.mL -1 para concentração de aloficocianina e 1,6 mg.mL -1 para a pureza do extrato. Foi observada a significância dos polímeros PEG 4000 e polímeros catiônicos com baixo teor de cloro para extração e purificação das ficobiliproteínas. Então foi realizado um segundo delineamento, sendo um DCCR - Composto Central Rotacional 2 2 , fixando as variáveis de sal fosfato e pH; e variando as concentrações de PEG 4000 e polímeros catiônicos com baixo teor de cloro. Ao final da extração, foi possível encontrar concentrações de 2,7 mg.mL -1 para Ficocianina, 1,3 mg.mL -1 de Aloficocianina e 2,5 para pureza do extrato, evidenciando que as técnicas utilizadas são eficazes para o processo de extração e purificação das ficobiliproteínas;em que os níveis alcançados permitem sua utilização e aplicação em indústrias do setor alimentício.

A cianobactéria Arthrospira (Spirulina) platensis, uns dos microrganismos fotossintetizantes mais estudados e cultivados no planeta, tem uma composição particular de biomassa que inclui: elevado conteúdo de proteínas, ácidos graxos poliinsaturados, pigmentos naturais e outras substâncias de interesse nas indústrias alimentícia, farmacêutica e cosmética. Estudos recentes demonstram que devido a sua composição de biomassa, está sendo estudada para a extração de biocompostos e para a produção de biocombustíveis. O uso de fontes de nitrogênio de baixo custo, como a uréia, pode contribuir para a viabilização da produção deste microrganismo. A. platensis foi cultivada em fotobiorreatores tubulares fechados de capacidade de 3,5 L, com intensidade luminosa de 120 µmol fótons.m-2.s-1 utilizando processo descontinuo alimentado com uréia como fonte de nitrogênio com adição intermitente. O planejamento experimental utilizado foi de modelo fatorial 22, acrescido dos pontos centrais, mais configuração estrela que permitiu avaliar o efeito das variáveis independentes temperatura (T) e vazão molar de alimentação diária de uréia (K). Os resultados foram avaliados com auxílio da metodologia de superfície de resposta que permitiu verificar, através da otimização simultânea das variáveis independentes, uma condição ótima de T = 32 °C e K = 1,16 mM.dia-1 para o crescimento de A. platensis durante 8 dias de cultivo, conseguindo-se nestas condições, concentração celular máxima de 4186 ± 39 mg.L-1, produtividade celular de 757 ± 8 mg.L-1.d-1 e fator de conversão de nitrogênio em células de 14,3 ± 0,1 mg.mg-1. Os valores de Xm obtidos experimentalmente correspondem a 0,4 % a menos do que os valores máximos estimados pelo modelo matemático. O teor de lipídeo da biomassa não foi influenciado pelas condições experimentais adotadas neste trabalho, sendo os valores obtidos dentro da faixa citada na literatura para este microrganismo (aproximadamente 7 %). O teor de proteína da biomassa foi dependente da temperatura e da vazão molar de alimentação diária de uréia. Para vazões molares de uréia até 0.717 mM. dia-1, o aumento da temperatura diminui o teor de proteínas na biomassa. Por outro lado, para valores de vazão de uréia maiores (≥ 0,883 mM.dia-1), o aumento da temperatura leva ao aumento do teor de proteínas na biomassa. O maior valor de teor de proteína obtido neste trabalho foi de 39,49 % (T = 33 ºC, K = 1,879 mM.dia-1). / The cyanobacterium Arthrospira (Spirulina) platensis, ones of the most studied and cultivated photosynthetic microorganisms in the planet, has a unique biomass composition that includes: high protein content, polyunsaturated fat acids, natural pigments and other substances of interest in food, pharmaceutical and cosmetic industries. Recent studies demonstrate that due to its biomass composition, it has being studied for biocomponents extraction and bio-fuels production. The use of low cost nitrogen sources, such as urea, can contribute to the viability of this microorganism production. A. platensis was cultivated in 3.5-liters closed tubular photobioreactors, under luminous intensity of 120 µmol fótons.m-2.s-1, using fed-batch cultivation process with urea as nitrogen source, added intermittently. The utilized experimental design was one of a factorial model 22, increased of the central points and star configuration, which allowed evaluating the effect of the independent variables, such as temperature (T) and urea daily molar flow-rate (K). The results were evaluated with response surface methodology (RSM) that allowed verifying, through the simultaneous optimization of the independent variables, an optimum condition of T = 32 °C and K = 1.16 mM.dia-1 for the growth of A. platensis during 8 days of culture, obtaining maximum cellular concentration of 4186 ± 39 mg.L-1, cellular productivity of 757 ± 8 mg.L-1.d-1 and nitrogen-to-cells factor of 14.3 ± 0.1 mg.mg-1. The Xm values obtained experimentally corresponds to 0.4 % less than the maximum values estimated by the mathematical model. The biomass lipid content was not influenced by the experimental conditions adopted in this work, being the obtained values within the range mentioned in the literature for this microorganism (approximately 7 %). The biomass protein content was dependent of the temperature and urea molar flow-rate. For the latter parameter, values up to 0.717 mM.dia-1, the increase in temperature diminished biomass protein content. On the other hand, for higher urea molar flow-rate values (≥ 0,883 mM.dia-1), the increase of temperature leads to increase of biomass protein content. The highest value of biomass protein content obtained in this work was of 39.49 % (T = 33 ºC, K = 1.879 mM.dia-1).

A ligação de Cu(II) à superfície de espécies mistas e liofilizadas da microalga Spirulina foi estudada em pH 6.0 por titulação potenciométrica com eletrodo íon-seletivo para Cu(II). Três materiais foram estudados: a suspensão completa da alga (Suspensão Total), a água de lavagem obtida por centrifugação da suspensão total (Fração Solúvel) e a suspensão das células lavadas com água (Fração Insolúvel). Os métodos de Scatchard e de Funções Diferenciais de Equilíbrio (DEF) foram usados para tratamento de dados. Os gráficos de Scatchard possibilitaram a determinação de duas classes de sítios de complexação, sendo que os valores de log K* para os sítios mais fortes variaram entre 7,3 e 7,9. Para os sítios mais fracos os valores de log K* foram determinados entre 3,5 e 3,9. As concentrações totais dos sítios de ionização foram determinadas em pH 6,0 por titulação potenciométrica com solução de NaOH, resultando 1,6±0, 1; 1,5±0,5 e 0,92±0,08 mmol g-1 para a Suspensão Total, Fração Solúvel e Fração Insolúvel, respectivamente. O método DEF revelou uma variação linear dos valores de log KDEF em função do log θ (θ = grau de ocupação dos sítios de complexação), sendo que os valores de log KDEF decresceram de 9 para 4 em conseqüência do aumento de log θ de -2,5 para -0,25. Os graus de heterogeneidade determinados por DEF ficaram na faixa entre 0,4 e 0,5 para os três materiais estudados. / The binding of Cu(II) to the surface of mixed species of lyophilized Spirulina was studied at pH 6.0 by potentiometric titration monitored with a copper ion selective electrode. Three materials were studied: the total suspension of alga (Total Suspension), the washing water that resulted from centrifugation of the total suspension {Soluble Fraction), and the water-washed cells (Insoluble Fraction). The Scatchard method and the Differential Equilibrium Functions (DEF) were used for the treatment of the titration data. The Scatchard plots determined two classes of binding sites, with log K* values for stronger sites varying between 7.3 and 7.9. For the weaker sites the log K* values ranged between 3.5 and 3.9. The total concentration of binding sites at pH 6.0 were determined by potentiometric titration with NaOH solution, resulting 1.6±0.1, 1.5±0.5 and 0.92±0.08 mmol g-1 for the Total Suspension, Soluble Fraction, and Insoluble Fraction, respectively. The DEF approach revealed a linear variation of log KDEF as a function of log θ (θ = degree of site occupation), with log KDEF decreasing from 9 to 4 as a consequence of increasing log e from -2.5 to -0.25. The degree of site heterogeneity determined by the DEF approach was between 0.4 and 0.5 for the three materials studied.

Thesis (MPhil)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: trout was conducted at the Jonkershoek trout research station of the Division of Aquaculture, University of Stellenbosch. Treatments consisted of ten experimental diets containing increasing levels of Spirulina (0%, 0.05%, 0.1%, 0.15%, 0.3%, 0.6%, 1.25%, 2.5%, 5% and 10%). The data was analyzed through means of a one-way ANOVA and Tukey’s pair wise comparison test for significant differences between treatments for the various parameters of flesh pigmentation and growth. The results indicates that the inclusion of Spirulina in the diets of rainbow trout will cause a undesirable yellowing of fillets, particularly at levels of inclusion at 5 percent and above, which may limit its use in diets for rainbow trout. There was an inconsistent increase in b* (yellowblue) and Chroma values with increasing levels of Spirulina inclusion, which may indicate the deposition of carotenoids (yellow-orange colour range) instead of the desired deposition of xanthophylls (pink-red colour range) in the flesh of the rainbow trout. This increase in b* (yellow-blue) values was significantly higher (P<0.05) at inclusion levels above 5 percent. Spirulina had no significant effect on weight gain of rainbow trout at any level of inclusion. No significant differences (P>0.05) were observed in any of the other production performance parameters (growth rate, feed intake, feed conversion ratio, viscerosomatic index, hepatosomatic index, and liver lipid content) that were evaluated. Low mortality rates were observed with no significant differences between treatments. A trend of decreased feed intake with increased levels of Spirulina inclusion became significant at the 2.5 percent level of inclusion, caused by deterioration in the palatability of the feed. A significantly higher dress-out percentage was observed at levels of Spirulina inclusion above 5 percent. A trend of decreased liver lipid content with increased Spirulina inclusion was observed, though not significant at any level of Spirulina inclusion. This observation justifies further investigation because of its potential to improved carbohydrate metabolism in carnivorous fish Results confirm that up to 10% Spirulina can effectively replaced soybean meal in the control diets for rainbow trout while simultaneously improving carcass dress-out at high inclusion levels. / AFRIKAANSE OPSOMMING: rantsoen van reënboog forel te evalueer. Die eksperiment is opgestel by die Akwakultuur Divisie, van die Universiteit van Stellenbosch, se navorsingstelsel in Jonkershoek, buite Stellenbosch. Reënboog forel (Oncorhynchus mykiss) vingerlinge van gemiddeld 20 gram is gebruik en ingedeel in 20 ronde tenks volgens kommersieële digthede (250 per tenk). Die rantsoene is gemeng met verskeie vlakke van Spirulina insluiting (0%, 0.05%, 0.1%, 0.15%, 0.3%, 0.6%, 1.25%, 2.5%, 5% en 10%). Twee herhalings van elke rantsoen is gevolg vir ‘n periode van 3 maande. Die vis is ad lib (volgens behoefte) gevoer, drie maal per dag. Daar was ‘n neiging tot ‘n verhoging in b* (geel-blou) en Chroma waardes met verhoogde insluitingsvlakke van Spirulina. Hierdie is wel ‘n aanduiding van die deponeering van karoteen, maar val in die geel-oranje kleur reeks en is nie die verlangde pienk-rooi (xantofil) kleur in die spier weefsel van die vis nie. Die verhoging in b* (geel-blou) waardes was statisties betekenisvol (P<0.05) bo die 5% insluitings vlak. In vergelyking met die kontrole (0%) rantsoen, was daar geen betekenisvolle massa toename na afloop van die proef tussen die verskeie behandelings nie. Behalwe vir ‘n verskil in voer inname, was daar geen statisties betekenisvolle verskil (P>0.05) waarneembaar tussen die verskillende behandelings ten opsigte van die verskeie produksie prestasie parameters nie. Daar was wel ‘n afnemende neiging in voer inname met verhoogde vlakke van Spirulina wat betekenisvol geraak het bo 2.5% insluitingsvlak. Smaaklikheid kan die moontlike rede hiervoor wees. Baie lae mortaliteite is ervaar by al die insluitings vlakke. Daar was ook ‘n neiging in hoër uitslag persentasie by verhoogde insluitingsvlakke van Spirulina wat betekenisvol geraak het bo 5 % insluiting. ‘n Afnemende vlak van lewer lipied inhoud is waargeneem maar was nie betekenisvol by enige van die insluitingsvlakke nie. Resultate van die proef dui daarop dat 10% Spirulina insluiting effektief kan dien as ‘n gedeeltelike plaasvervanger vir soyaboon meel in forel rantsoene. Die hoër uitslag persentasies hou belofte in. Die onverlangde vergeeling van die filette mag die gebruik van Spirulina beperk by reënboog forel rantsoene veral bo 5 % insluitings vlakke. Die verlaging in lewer lipied vlakke by ‘n verhoging van Spirulina insluiting regverdig vêrdere navorsing oor die potensiaal van Spirulina om die metabolisme van koolhidrate te verbeter by karnivoor visspesies.

M. Tech (Biosciences, Faculty of Applied and Computer Sciences), Vaal University of Technology. / The mass production of algae for commercial purposes has predominately been carried out in open ponds systems. However, open ponds systems have a number of disadvantages such as poor light utilization, requirement for large areas of land and high risks of contamination. On the other hand, photobioreactors have attracted much interest because they allow a better control of the cultivation conditions than open systems. With photobioreactors, higher biomass productivities are obtained and contamination can be easily prevented. Photobioreactors can also be engineered to manipulate the light and dark photosynthetic reactions thus enhancing biomass productivity. The main objective of this study was to construct a novel tubular photobioreactor which had the ability to expose the cultured alga to light and dark phases with the aim of optimizing the algal biomass production. A novel tubular photobioreactor with the ability to manipulate the cultured alga’s light and dark photosynthetic reactions was constructed in this study. The alga Spirulina platensis was chosen as the test organism in this novel tubular photobioreactor due to a number of reasons such as its globally socioeconomic importance, its tolerance of higher pH and temperature values which makes it almost impossible to contaminate. The cultivation process of Spirulina in the photobioreactor was investigated through alternating light and dark cycles in an attempt to increase the photosynthetic efficiency of the culture. The effect of different light intensities on the growth of Spirulina in the novel tubular photobioreactor was investigated and it was found that the best light condition that favored higher biomass formation was at 600 μ mol m-2 s-1. Five different light/ dark ratios were evaluated at a light intensity of 600 μ mol m-2 s-1 during a batch mode of operation of the novel tubular photobioreactor. The light/ dark ratio of 1:0.25 was found to be the best ratio because it gave the highest biomass in the shortest period of time when compared to the other ratios used. These results seem to suggest that longer light cycle relative to dark cycle results in higher biomass production. The ratio of 1:0.25 was then used to operate the novel tubular photobioreactor in a continuous mode. A maximum biomass productivity of 25 g/m2/day was achieved which corresponded to a net photosynthetic efficiency of 5.7 %. This result was found to be higher than what most photobioreactors could achieve but it was 2.8 g/m2/day lower than the highest ever reported productivity in a photobioreactor when Spirulina is cultivated. The 2.8 g/m2/day lower was attributed to the different materials used in the construction of these two photobioreactors. The photobioreactor which achieved 27.8 g/m2/day was made up of a clear glass whereas the novel tubular photobioreactor was made up of a PVC tubing. PVC tubes tend to change from clear to a milky colour after a certain period when it is used at higher temperature and pH values hence blocks a certain amount of light. Therefore the main recommendation in this study is to use a PVC tubing with a longer life span when used at a higher temperature and pH values.

Orientador: Lisiane Fernandes de Carvalho. / Coorientador: Carolina Krebs de Souza. / Dissertação (Mestrado em Engenharia Química) - Programa de Pós-Graduação em Engenharia Química, Centro de Ciências Tecnológicas, Universidade Regional de Blumenau, Blumenau.

L'agriculture en milieu contrôlé, et notamment la culture sous serre, est une des réponses possibles aux besoins alimentaires d'une population mondiale en constante croissance. Elle permet aussi d'optimiser les terres cultivables et d'éviter les pesticides néfastes à l'Homme. Afin de s'affranchir des cycles des saisons et d'avoir une production annuelle continue, l'éclairage artificiel a été introduit dans les serres. L'éclairage horticole a suivi l'évolution des technologies d'éclairage pour arriver aujourd'hui jusqu'à la LED. Cet éclairage donne certes des résultats corrects mais il peut être amélioré tant au niveau de la quantité que de la qualité spectrale de lumière. De ce point de vue, les LEDs présentent deux grands avantages : la possibilité de recomposer un spectre idéal à partir de différentes longueurs d'ondes et de moduler l'intensité de la lumière. Ainsi, elles permettent de fournir un éclairage adapté aux besoins de la plante et ce, en fonction du stade de sa croissance. L'objectif de ce travail de thèse est de proposer un système d'éclairage optimal pour la croissance des plantes en milieu contrôlé. A partir du rendement photosynthétique moyen des plantes, nous avons donc établi des modèles de systèmes d'éclairage à LEDs optimisés pour les plantes. Ces modèles sont basés sur la combinaison de plusieurs LEDs monochromes obtenues à partir de la décomposition de la courbe RQE par des fonctions de Pearson VII. Nous avons appliqué ces résultats théoriques à la culture d'une algue bleue-verte : la Spiruline Platensis. Le choix de cette plante-bactérie repose sur plusieurs critères : cycle de culture court, applications en cosmétique, en médecine et forte valeur nutritionnelle. Ainsi, nous avons pu étudier l'influence de paramètres de culture tels que l'intensité lumineuse, la photopériode, la température sur sa croissance. Par ailleurs, nous avons mis en œuvre deux méthodes basées sur la réflectance optique pour quantifier la biomasse produite par la spiruline. / Agriculture in a controlled environment, and in particular greenhouse cultivation, is one of the responses to the food needs of a growing population. It also makes it possible to optimize the surface of arable land and avoid pesticide and fertilizer releases harmful to man. In order to free of the cycles of the seasons and annual production, artificial lighting was introduced greenhouses since decades. Horticultural lighting followed the evolution of lighting technologies to arrive today up to LED. This lighting gives correct results, but it can be improved both in terms of quantity and spectral quality of light. From this point of view, LEDs have two main advantages : the possibility of recompose an ideal spectrum from different wavelengths and modulate the intensity of the light. Thus, they provide adapted lighting to the needs of the plant and this, in depending on the stage of its growth. The objective of this thesis is to propose an optimal lighting system for the growth of plants in a controlled environment. From the yield photosynthesis of plants, we established models of LED lighting systems optimized. These models are based on the combination of several monochrome LEDs obtained from the decomposition of the curve RQE by Pearson VII functions. We applied these theoretical results to the cultivation of a blue-green algae, the Spirulina Platensis. The choice of this plant-bacterium is based on several criteria : short crop cycle, applications in cosmetics, medicine and high nutritional value. Thus, we were able to study the influence of culture parameters such as light intensity, photoperiod, temperature on its growth. In addition, we have implemented two methods based on optical reflectance to quantify the biomass produced by spirulina.

Thesis (M.Tech.:Biotechnology)-Dept. of Biotechnology, Durban University of Technology, 2007 xvi, 185 leaves / Spirulina is a blue-green, multicellular, filamentous cyanobacterium that can grow to sizes of 0.5 millimetres in length. It is an obligate photoautotroph and has a pH growth range from 8.3 to 11.0.The large-scale production of Spirulina biomass depends on many factors, the most important of which are nutrient availability, temperature and light. These factors can influence the growth of Spirulina and the composition of the biomass produced by changes in metabolism. Brine effluent from cooling towers of electricity generating plants may provide an ideal growth medium for Spirulina based on its growth requirements, i.e. high alkalinity and salinity. The aim of this research was to optimise brine effluent from cooling towers by supplementing it with salts, in order to use this optimised effluent in a small open laboratory raceway pond in an attempt to increase the biomass production of Spirulina.

Thesis (M.Tech.:Biotechnology)-Dept. of Biotechnology, Durban University of Technology, 2007 xvi, 185 leaves / Spirulina is a blue-green, multicellular, filamentous cyanobacterium that can grow to sizes of 0.5 millimetres in length. It is an obligate photoautotroph and has a pH growth range from 8.3 to 11.0.The large-scale production of Spirulina biomass depends on many factors, the most important of which are nutrient availability, temperature and light. These factors can influence the growth of Spirulina and the composition of the biomass produced by changes in metabolism. Brine effluent from cooling towers of electricity generating plants may provide an ideal growth medium for Spirulina based on its growth requirements, i.e. high alkalinity and salinity. The aim of this research was to optimise brine effluent from cooling towers by supplementing it with salts, in order to use this optimised effluent in a small open laboratory raceway pond in an attempt to increase the biomass production of Spirulina.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em Ciência dos Alimentos. / Made available in DSpace on 2012-10-22T08:36:55Z (GMT). No. of bitstreams: 1 241186.pdf: 1994526 bytes, checksum: 177edf327b3ccdfe696073dd05d1fa33 (MD5) / Este estudo teve como objetivo a utilização de rejeito de dessalinizador no cultivo de Arthrospira platensis, cultivada em fotobiorreatores de 4 L, sob condições laboratoriais controladas de 30°C, iluminação de 140 µmol.m-2.s-1, fotoperíodo de 12 horas claro/escuro e insuflação constante de ar atmosférico. Utilizaram-se os seguintes meios de cultura: Paoletti (controle), Paoletti suplementado com 1,0 g.L-1 de NaCl (água salinizada) e rejeito de dessalinizador adicionado de 50% dos sais do Paoletti. Foram avaliadas a biomassa produzida, velocidade específica de crescimento, produtividade em células, teor total de proteínas, perfil aminoacídico, lipídios totais e composição de ácidos graxos. Os cultivos foram mantidos até o declínio do crescimento celular. Os maiores valores de biomassa (4,954 g.L-1) e produtividade em células (0,225 g.L-1) foram encontrados no rejeito de dessalinizador, enquanto que a velocidade específica de crescimento máxima (0,393 dia-1) ocorreu no cultivo em meio Paoletti. Os teores de proteína total foram de 56,17% no rejeito e 48,59% na água salinizada e, com exceção de lisina e triptofano, todos os aminoácidos essenciais encontram-se acima dos valores mínimos requeridos pela FAO. Foram obtidos teores de lipídios de 4,54% e 4,69% no rejeito e água salinizada, respectivamente, sendo que destes, 57,69% e 54,79% eram compostos de ácidos graxos saturados.