Fixação de carbono através de microalgas nativas (Chlamydomonas sp.) cultivadas em diferentes concentrações de CO2

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Ambiental, Florianópolis, 2013.Devido ao atual problema do aumento das emissões de Gases de Efeito Estufa (GEE), especialmente de dióxido de carbono (CO2), diversas pesquisas vêm sendo realizadas a fim de obter tecnologias que reduzam estas emissões ou retirem estes gases da atmosfera. Neste sentido, é crescente a aplicação do cultivo de microalgas no campo da Biotecnologia Ambiental, buscando fixação de CO2 de emissões atmosféricas e obtenção de energia da biomassa. Entretanto, para essas aplicações se tornarem economicamente viáveis, é necessária a adoção de estratégias para baixar o custo de produção de microalgas, bem como, faz se necessário o uso de microalgas que apresentem elevadas taxas de crescimento, produtividade e biofixação de CO2 quando cultivadas sob a introdução de elevadas concentrações deste gás. Sendo assim, este trabalho avaliou a influência da injeção de atmosferas com diferentes concentrações de dióxido de carbono (0,038, 5, 10, 15 e 20%) sobre o crescimento, produtividade e biofixação de CO2 nos cultivos de Chlamydomonassp. nativas de Santa Catarina, utilizando como meio de cultura efluente doméstico tratado (EDT). Também, foi avaliado o efeito do uso do EDT como meio de cultura alternativo sobre o crescimento e a produtividade do cultivo. Os cultivos foram submetidos a diferentes tratamentos distribuídos em quatro experimentos. Foram avaliados parâmetros de crescimento, produtividade, fixação de CO2, remoção de nutrientes e potencial para de utilização da biomassa na produção de biodiesel. Os resultados demonstram que o efluente doméstico tratado tem potencial para ser utilizado como meio de cultura para o cultivo de Chlamydomonassp. Os cultivos com introdução de ar com concentrações de 5 e 10% de CO2 foram os que apresentaram os maiores valores de crescimento, produtividade e fixação de CO2, entretanto, foi possível o cultivo das microalgas sob concentrações de 15 e 20% de CO2, sugerindo fixação de CO2 também nessas concentrações elevadas. Contudo, a eficiência de utilização do CO2 introduzido deve ser ampliada. As espécies estudadas se mostraram potencialmente adequadas para a fixação de CO2 de emissões atmosféricas quando cultivadas em EDT. No entanto, apenas uma das espécies estudadas apresentou potencial como matéria prima para a produção de biodiesel.Abstract : Due to the current problem of rising emissions of Greenhouse Gases (GHGs ) , especially carbon dioxide ( CO2 ) , several studies have been performed in order to reduce emissions or remove these gases from the atmosphere . In this sense , there is a growing application of microalgae culture in the field of Environmental Biotechnology, with the objectives on fixation of atmospheric CO2 and obtaining energy from biomass. However , for these applications to be economically viable , it is necessary to adopt strategies to lower the cost of production of microalgae, as well, work with microalgae that have high growth rates, productivity and CO2 fixation, when the culture grown under introducing high concentrations of this gas. Thus , this study evaluated the influence of injection different concentrations of carbon dioxide ( 0.038 , 5 , 10 , 15 and 20 % ) on the growth , productivity and CO2 fixation on Chlamydomonas sp strains that is indigenous of Santa Catarina State, using as culture medium treated wastewater (TW). Also, it was evaluated the effect of the use of TW as alternative culture medium on growth and productivity of the strains. The cultures were subjected to different treatments over four experiments. Parameters of growth, productivity , CO2 fixation , nutrient removal and the potential of the use of biomass in the production of biodiesel were evaluated. The results indicate that treated wastewater can be used as culture medium for Chlamydomonas sp. strains. The introduction of air concentrations of 5 and 10% CO2 shown the highest values of growth, productivity and CO2 fixation. However, it was possible grown this strains in concentrations of 15 and 20% CO2 , suggesting, also, CO2 fixation in such high concentrations. However, the efficiency of use introduced CO2 must be increase. The studied strains have shown potentially suitable for fixing CO2 from atmospheric emissions when grown in TW. However, only one of the strains studied showed potential as raw material for biodiesel production

Influência da frequência alimentar sobre o desempenho de juvenis de robalo peva Centropomus parallelus

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em Aqüicultura

Drying and Quality of Microalgal Powders for Human Alimentation

The demand for natural foods with high protein content and functional properties is constantly growing in the last years. In this context, microalgae as Spirulina (Arthrospira spp.), Chlorella spp., Haematococcus pluvialis, Dunaliella salina, and others, assume a key role to diversify the offer of nutritious and functional ingredients and supplements. Microalgae are commercialized, mostly, as dried powders to facilitate their use as food ingredients and to allow easy transportation and long-term stability. Microalgal powder quality and storage stability depend mainly on drying method, packaging, and storage conditions. Most of the studies that approach the subject of microalgal drying evaluate the efficiency of the process and suitability for this raw material. However, studies that assess the effect of traditional and innovative drying methods on quality of microalgal powder for human consumption are rare in literature. In this chapter, the state of the art of drying processing technology for microalgae was reviewed, discussing the effect of dehydration on quality and stability of microalgal powders with potential use in human alimentation

Concepts and Trends for Extraction and Application of Microalgae Carbohydrates

The proposed chapter aims to provide a more in-depth explanation of the composition of carbohydrates in microalgae biomass, focusing on separation methods, chemistry, molecular characterization, as well as their application in several areas. The purpose of this review chapter is to show that biological products from microalgae have potential in health, food, and industry applications (materials and biofuel production). Steps for extraction and purification will be discussed, as well as the relationship between the type of microalgae and its composition, as a way of optimizing protocol selection and product making, without breaking down the cell to begin with (total carbohydrate extraction present in the cell). An overall overview of the current and prospective trends and methodologies for the use of microalgae carbohydrate will be included as starting points to shed light on some of the possible issues that currently do not allow the development and feasibility of microalgae biorefineries

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost