EQA - Escola de Química e Alimentos
URI permanente desta comunidadehttps://rihomolog.furg.br/handle/1/1610
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9 resultados
Resultados da Pesquisa
- ItemSimultaneous Cultivation of Spirulina platensis and the Toxigenic Cyanobacteria Microcystis aeruginosa(2006) Costa, Jorge Alberto Vieira; Morais, Michele Greque de; Dalcanton, Francieli; Reichert, Carolina da Cruz; Durante, Andrei JoséMangueira Lagoon, located in the extreme south of Brazil, has water with physicochemical characteristics such as alkaline pH and carbonate levels propitious for the growth of the cyanobacterium Spirulina platensis. Previously published studies have shown that Mangueira Lagoon water supplemented with small quantities of carbon and nitrogen is suitable for S. platensis cultivation and can significantly reduce production costs. We studied mixed cultures of Spirulina platensis and the toxic cyanobacterium Microcystis aeruginosa using a 23 factorial design in which the three factors were the initial biomass concentration of S. platensis and M. aeruginosa and the type of culture medium (100% Zarrouk’s medium or 80% Mangueira Lagoon water plus 20% Zarrouk’s medium). The highest S. platensis maximum specific growth rate (μmax) occurred in the culture with the highest M. aeruginosa biomass concentration and when undiluted culture medium was used (μmax = 0.283 dÐ1). The highest M. aeruginosa specific death rate (k) was obtained in the presence of S. platensis (k = 0.555 dÐ1) and was independent of the initial M. aeruginosa biomass concentration and culture medium, demonstrating that S. platensis cultures are not susceptible to contamination by M. aeruginosa. The culture medium had no significant influence (p > 0.05) on S. platensis μmax values, indicating that production costs could be reduced by using a medium consisting of 80% Mangueira Lagoon water plus 20% Zarrouk’s medium.
- ItemIsolation and Characterization of a New Arthrospira Strain(2008) Morais, Michele Greque de; Reichert, Carolina da Cruz; Dalcanton, Francieli; Durante, Andrei José; Marins, Luis Fernando Fernandes; Costa, Jorge Alberto VieiraA filamentous microorganism, morphologically similar to the cyanobacterium Arthrospira, was isolated from Mangueira Lagoon in Brazil, from which Arthrospira has not previously been isolated. Random amplified polymorphic DNA (RAPD) comparison with the standard Arthrospira platensis strains LEB 52 and Paracas indicated that the organism isolated was an Arthrospira isolate, which we denominated strain LEB 18. The RAPD analysis showed conserved sequences which indicated that the three strains belonged to the same genus, and were all Arthrospira species, but there were sufficient differences between them suggesting that they were separate strains. The strain LEB 18 was cultivated in undiluted Zarrouk medium and in 60% and 20% (v/v) Zarrouk medium diluted with sterilized Mangueira Lagoon water (MLW) using illuminance rates of 32.5, 45.5 and 58.5 μmol mÐ2 sÐ1 according to a complete 32 factorial design with a triplicate central point. The strains LEB 52 and Paracas were cultived in the conditions central point. Our new isolate produced the highest specific growth rate (μmax = 0.22 dÐ1) in 60% Zarrouk medium diluted with MLW and illuminated with 58.5 μmol mÐ2 sÐ1 and the highest protein content (86.0% w/w).
- ItemPerfil de Ácidos Graxos de Microalgas Cultivadas Com Dióxido de Carbono(2008) Morais, Michele Greque de; Costa, Jorge Alberto VieiraAs microalgas são consideradas fontes potenciais de diversos compostos químicos. Os ácidos graxos obtidos da biomassa podem apresentar efeitos terapêuticos em humanos e podem ser usados para produção de biodiesel. Objetivou-se, neste trabalho verificar o conteúdo lipídico e o perfil dos ácidos graxos das microalgas Spirulina sp., Scenedesmus obliquus, Chlorella kessleri e Chlorella vulgaris cultivadas em diferentes concentrações de dióxido de carbono e bicarbonato de sódio. A microalga Chlorella kessleri cultivada com 12% de CO2 apresentou a maior concentração de lipídios na biomassa seca (9,7% p/p). A máxima concentração de ácidos graxos insaturados foi 72,0% (p/p) para C. vulgaris cultivada com 12% de CO2. Para os ácidos graxos saturados o maior valor encontrado foi 81,6% (p/p), quando a microalga Spirulina sp. foi cultivada com 18% de CO2 e 16,8 g.L-1 de bicarbonato de sódio.
- ItemSpirulina platensis biomass cultivated in Southern Brazil as a source of essential minerals and other nutrients(Academic Journals, 2013) Moreira, Lidiane Muniz; Ribeiro, Anelise Christ; Duarte, Fábio Andrei; Morais, Michele Greque de; Soares, Leonor Almeida de SouzaThe aim of this study was to determine elemental constituent of microalgal biomass Spirulina platensis LEB-18 grown on the shores of Mangueira Lagoon, South of Brazil. The spread of inoculum was performed in standard Zarrouk medium. When the microalgae concentration reached 0.50 g L-1, the biomass was separated by filtration and dried in a tray dryer at 50°C for 5 h. The harvested biomass was then ground in a ball mill, sieved to achieve a particle size of 88 μm (~ 300 mg) in triplicate, digested with concentrated HNO3 and diluted with up to 5% HNO3 for subsequent quantification. Mineral content was determined by inductively coupled plasma optical emission spectrometry with axial view and other nutrients by standard methods. Among the macro minerals, in μg g-1 ± standard deviation, calcium (15.108±529), sodium (14.6552±485) and potassium (14.036±109) were found in the largest amount. The micro mineral present in greater quantity, in μg g-1 ± standard deviation, was the iron (956±9) and nutrients present in the following order: protein (58.5%), ash (12.0%), carbohydrate (7.5%), lipid (7.0%) and crude fiber (0.95%). Results were compared with the values of minerals for human consumption recommended by the Food and Drug Administration and also with the Recommended Daily Intake (RDI) of minerals by Brazilian Legislation. The findings proved promising for the use of S. platensis strain LEB-18 as an alternative source of essential minerals and other nutrients for the human body.
- ItemThe role of biochemical engineering in the production of biofuels from microalgae(2011) Costa, Jorge Alberto Vieira; Morais, Michele Greque deEnvironmental changes that have occurred due to the use of fossil fuels have driven the search for alternative sources that have a lower environmental impact. First-generation biofuels were derived from crops such as sugar cane, corn and soybean, which contribute to water scarcity and deforestation. Second-generation biofuels originated from lignocellulose agriculture and forest residues, however these needed large areas of land that could be used for food production. Based on technology projections, the third generation of biofuels will be derived from microalgae. Microalgae are considered to be an alternative energy source without the drawbacks of the first- and second-generation biofuels. Depending upon the growing conditions, microalgae can produce biocompounds that are easily converted into biofuels. The biofuels from microalgae are an alternative that can keep the development of human activity in harmony with the environment. This study aimed to present the main biofuels that can be derived from microalgae.
- ItemVertical tubular photobioreactor for semicontinuous culture of Cyanobium sp(2011) Henrard, Adriano Seizi Arruda; Morais, Michele Greque de; Costa, Jorge Alberto VieiraWe evaluated the kinetic culture characteristics of the microalgae Cyanobium sp. grown in vertical tubular photobioreactor in semicontinuous mode. Cultivation was carried out in vertical tubular photobioreactor for 2 L, in 57 d, at 30 °C, 3200 Lux, and 12 h light/dark photoperiod. The maximum specific growth rate was found as 0.127 d−1, when the culture had blend concentration of 1.0 g L−1, renewal rate of 50%, and sodium bicarbonate concentration of 1.0 g L−1. The maximum values of productivity (0.071 g L−1 d−1) and number of cycles (10) were observed in blend concentration of 1.0 g L−1, renewal rate of 30%, and bicarbonate concentration of 1.0 g L−1. The results showed the potential of semicontinuous cultivation of Cyanobium sp. in closed tubular bioreactor, combining factors such as blend concentration, renewal rate, and sodium bicarbonate concentration
- ItemPilot scale semicontinuous production of spirulina biomass in southern Brazil(2009) Morais, Michele Greque de; Radmann, Elisangela Martha; Souza, Michele da Rosa Andrade Zimmermann de; Teixeira, Gilson Gonçalves; Brusch, Lucio Renato de Fraga; Costa, Jorge Alberto VieiraWe evaluated the feasibility of the pilot scale production of Spirulina strain LEB-18 in southern Brazil and assessed the quality of biomass produced in relation to its kinetics characteristic, nutritional value, heavy metal content and microbial content. The maximum mean biomass concentration was 1.24 g L− 1 and the maximum productivity was 69.16 g m− 2 d− 1. The biomass showed 84.0% digestibility, 86.0% (w/w) protein and 3.3% (w/w) lipid content. Analyses showed that the concentration (mg kg− 1) of heavy metals (As, 0.28 ± 0.01; Cd, < 0.05; Hg, < 0.01; and Pb, 0.17) and the microbial load (7.1 × 105 colony forming units per gram) were lower than the internationally accepted standards. These results show that pilot scale cultivation of Spirulina LEB-18 in southern Brazil is feasible and that the biomass produced is within the internationally recognized standards for use as a food additive for increasing the nutritional potential of conventional products.
- ItemBiscoitos de chocolate enriquecidos com spirulina platensis: características físicoquímicas,sensoriais e digestibilidade(2006) Morais, Michele Greque de; Miranda, Martha Zavariz de; Costa, Jorge Alberto VieiraAs microalgas, como Spirulina, podem ser fonte de proteínas para alimentação humana, com a possibilidade de obter outros produtos como biopigmentos,vitaminas e lipídios. A biomassa obtida pode ser introduzida diretamente na dieta podendo auxiliar em casos de desnutrição. O objetivo deste trabalho foi avaliar as características físico-química, sensorial e digestibilidade de biscoitos de chocolate enriquecidos com a microalga Spirulina platensis. Foram elaborados quatro biscoitos de chocolate: controle (sem Spirulina) e biscoitos contendo 1,0;3,0 e 5,0% de Spirulina platensis. O biscoito com adição de 5,0% de Spirulina platensis apresentou o conteúdo protéico 7,7% maior que o controle. Os biscoitos com adição de 1,0% de S. platensis apresentaram maior digestibilidade (86,9%)que os demais. Volume específico, espessura e fator de expansão não foram alterados pela adição de Spirulina. Não houve diferença significativa entre o biscoito controle e os biscoitos com adição de 5,0% nos atributos cor, crocância, mastigabilidade e maciez. Na avaliação questionamento de intenção de compra, comparando os biscoitos com adição de S. platensis, a amostra com maior aceitação pelos julgadores foi com 1,0% de S. platensis.
- ItemBioprocessos para remoção de dióxido de carbono e óxido de nitrogênio por microalgas(2008) Morais, Michele Greque de; Costa, Jorge Alberto VieiraThe aim of this work was to study the removal of CO2 and NO by microalgae and to evaluate the kinetic characteristics of the cultures. Spirulina sp. showed μmax and Xmax (0.11 d-1, 1.11 g L-1 d-1) when treated with CO2 and NaNO3. The maximum CO2 removal was 22.97% for S. obliquus treated with KNO3 and atmospheric CO2. The S. obliquus showed maximum NO removal (21.30%) when treated with NO and CO2. Coupling the cultivation of these microalgae with the removal of CO2 and NO has the potential not only to reduce the costs of culture media but also to offset carbon and nitrogen emissions.