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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Phycocyanin production assessment for the marine microalgae Arthrospira platensis, cultivated in fish effluent / AvaliaÃÃo da produÃÃo de ficocianina pela microalga marinha Arthrospira platensis cultivada em efluente piscÃcola

Igor Gabriel Rodrigues Ferreira Gomes 22 February 2016 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / The phycocyanins are water-soluble proteins that function as accessory pigments and exhibit various properties, as immunostimulatin, cholesterol lowering effect, anti-inflammatory, antiviral, anticancer and antioxidant action, in addition to application as a natural dye. The focus of the commercial production of phycocyanin has fallen in most of the microalgae Arthrospira platensis. This cyanophyceae is rich in compounds as proteins, vitamins, essential amino acids, minerals, essential fatty acids, antioxidants, pigments, among others. Aquaculture is an activity of great importance, generating income and producing quality protein for human consumption. However, their activity generates large amounts of effluents with high nutrient load. The use of microalgae for aquaculture waste production is quite used, yielding good results in the cultivation of several species. This study aimed to evaluate the production of phycocyanin by A. platensis microalgae grown in fish effluent. For this, the microalgae was exposed to growing in Venkataraman modified medium and effluent from the Nile tilapia farming, in indoor and outdoor systems. After the end of the crop, the biomass obtained was exposed to phycocyanin extraction process, which consisted of freezing and thawing of wet biomass obtained from the culture in indoor system and subsequent extraction in sodium acetate buffer pH 5.0 for 48 h. The biomass produced in the outdoor system was dried at 60  C for 24 h in an oven with recirculating air. The dried biomass was resuspended in sodium acetate buffer pH 5.0 for 48 h. After that, the extracts were centrifuged at 4,700 rpm at 4 ÂC for 30 min. The supernatant was collected and evaluated in a spectrophotometer at 280 nm wavelength for proteins, 615 nm for phycocyanin,and and 652 nm for allophycocyanin. After this process, the crude extracts obtained from phycocyanin were subjected to purification by ion exchange chromatography. There wasnt significant difference between the performance of algae grown under the same conditions. However, algae exposed to outdoor system showed superior results. The phycocyanin concentrations were higher in the treatments that used Venkataraman medium, while the proportions of the pigment found in indoor systems were higher. The process of purification by ion exchange chromatography resulted in higher concentrations of pigment for fractions eluted with 0.2 M NaCl to all crude extracts of phycocyanin. / As ficocianinas sÃo proteÃnas solÃveis em Ãgua que funcionam como pigmentos acessÃrios e apresentam diversas propriedades, como aÃÃo imunoestimulante, efeito redutor do colesterol, efeitos anti-inflamatÃrio, antiviral, anticÃncer, antioxidante, alÃm de aplicaÃÃo como corante natural. O foco da produÃÃo comercial de ficocianina tem caÃdo em maior parte sobre a microalga Arthrospira platensis. Essa cianofÃcea à rica em proteÃnas, vitaminas, aminoÃcidos essenciais, minerais, Ãcidos graxos essenciais, pigmentos antioxidantes, dentre outros. A aquicultura à uma atividade de grande importÃncia, geradora de renda e produtora de proteÃna de qualidade para alimentaÃÃo humana. No entanto, sua atividade gera grandes quantidades de efluentes com alta carga de nutrientes. O uso de efluentes aquÃcolas para a produÃÃo de microalgas à bastante empregado, gerando bons resultados no cultivo de diversas espÃcies. Este trabalho teve como objetivo avaliar a produÃÃo de ficocianina pela microalga A. platensis cultivada em efluente piscÃcola. Para isto a microalga foi exposta à cultivo em meio Venkataraman modificado e efluente, proveniente de cultivo de tilÃpias do Nilo, em sistemas indoor e outdoor. ApÃs o tÃrmino dos cultivos a biomassa obtida foi exposta a processo de extraÃÃo de ficocianina que consistiu no congelamento e descongelamento da biomassa Ãmida obtida do cultivo em sistema indoor e posterior extraÃÃo em tampÃo acetato de sÃdio pH 5,0 durante 48 h. A biomassa produzida no sistema outdoor foi seca a 60 ÂC durante 24 h em estufa com recirculaÃÃo de ar. A biomassa seca foi ressuspendida em tampÃo acetato de sÃdio pH 5,0 durante 48 h. ApÃs isso, os extratos foram centrifugados a 4.700 rpm a 4 ÂC durante 30 min. O sobrenadante foi coletado e avaliado em espectrofotÃmetro nos comprimentos de onda de 280 nm, para proteÃnas, 615 nm, para ficocianina e 652, para aloficocianina. ApÃs esse processo, os extratos brutos de ficocianina obtidos foram submetidos a purificaÃÃo por cromatografia de troca iÃnica. NÃo houve diferenÃa significativa entre o desempenho das algas cultivadas nas mesmas condiÃÃes. No entanto, as algas expostas ao sistema outdoor mostraram resultados superiores. As concentraÃÃes de ficocianina foram superiores para os tratamentos que utilizaram o meio Venkataraman, enquanto que as proporÃÃes do pigmento encontradas nos tratamentos expostos ao sistema indoor foram maiores. O processo de purificaÃÃo por cromatografia de troca iÃnica resultou em maiores concentraÃÃes do pigmento para as fraÃÃes eluÃdas com NaCl 0,2 M para todos os extratos brutos de ficocianina.

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