487 resultados para clorofila-a


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The seaweed Gracilaria domingensis is a common species in the coast of Rio Grande do Norte. This species lives in the intertidal zone, where colour strains (red, green and brown) co-occur during the whole year. Seaweeds that live in this region are exposed to daily changes and to the rhythm of the tide. During the low tide they are exposed to dissection, hiper-or hipo-osmotic shock, high temperatures and high irradiance. The aim of this study was to analyze whether the pigment and protein content of the colour strains of G. domingensis is affected by some environmental parameters in a temporal scale. The seaweeds were collected during 10 months in the seashore of Rio do Fogo (RN). The total soluble proteins and the phycobiliprotein were extracted in phosphate buffer and the carotenoids were analyzed by a standardized method through HPLC-UV. The pigments analysis showed that phycoerithrin is the most abundant pigment in the three strains. This pigment was strongly correlated with nitrogen and the photosynthetically active radiation. Chlorophyll presented higher concentrations than carotenoids during the whole, but the ratio carotenoid/chlorophyll-a was modified by incident radiation. The most abundant carotenoid was ß-carotene and zeaxanthin, which had higher concentrations in the higher radiation months. The concentration increase of zeaxanthin in this period indicated a photoprotective response of the seaweed. The three strains presented a pigment profile that indicates different radiation tolerance profile. Our results pointed that the green strain is better adapted to high irradiance levels than the red and brown strains

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The eutrofization is a natural process of accumulation of nutrients in aquatic´s body that it has been accelerated for the human´s actives, mainly the related with the activities of camp, industrial and the inadequate disposition of the domestic sewage. The enrichment of the aquatic´s body with nutrients, mainly the nitrogen and the phosphorus, and the consequent proliferation of algae and Cyanobacteria can commit the quality of the water for the public provisioning, for the fish farming and for other ends. The problem becomes more critical when there is a shortage of water naturally as in the semi-arid area of the Brazilian northeast. Before that problem this work had as objective evaluates the trophic state of six reservoirs of the basin of River Seridó of Rio Grande of Norte and also estimate the capacity of load of match of the reservoir and risk probabilities based on the established limits by the resolution Conama 357/05. The results demonstrate that the six reservoirs are eutrofization, with concentration of total phosphorus and cloro a in the water upster to 50 e 12 μg l-1. The results show that space homogeneity exists in the state trophic of the reservoirs, but a significant variation interanual in function of the increase of the concentrations of nutrients and decrease of the transparency of the water with the reduction of the body of water accumulated in the reservoirs.The results of the simulation risk estocastic show that the reservoirs could receive annually from 72 to 216 Kg of P, assuming a risk of 10% of increasing in more than 30 μg l-1 the annual medium concentrations of total match in the water of these reservoirs. This load could be high in until 360 kg of P a year in case the managers assume a risk of 10% of increasing in more than 50 μg l-1 the annual medium concentrations of total phosphorus in the waters of these reservoirs

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Top-down (grazing) and bottom-up (nutrient, light) controls are important in freshwater ecosystems regulation. Relative importance of these factors could change in space and time, but in tropical lakes bottom-up regulation has to been appointed as more influent. Present study aimed to test the hypothesis that phytoplankton growths rate in Armando Ribeiro reservoir, a huge eutrophic reservoir in semi-arid region of Rio Grande do Norte state, is more limited by nutrient available then zooplankton grazing pressure. Bioassay was conduced monthly from September (2008) to August (2009) manipulating two levels of nutrients (with/without addition) and two level of grazers (with/without removal). Experimental design was factorial 2X2 with four treatments (X5), (i) control with water and zooplankton from natural spot ( C ), (ii) with nutrient addition ( +NP ), (iii) with zooplankton remove ( -Z ) and (iv) with zooplankton remove and nutrient addition ( -Z+NP ). For bioassay confection transparent plastic bottles (500ml) was incubate for 4 or 5 days in two different depths, Secchi`s depth (high luminosity) and 3 times Secchi`s depth (low luminosity). Water samples were collected from each bottle in begins and after incubates period for chlorophyll a concentration analysis and zoopalnktonic organisms density. Phytoplankton growths rates were calculated. Bifactorial ANOVA was performance to test if had a significant effect (p<0,005) of nutrient addition and grazers remove as well a significant interaction between factors on phytoplankton growths rates. Effect magnitude was calculated the relative importance of each process. Results show that phytoplankton growth was in generally stimulated by nutrient addition, as while zooplankton remove rarely stimulated phytoplankton growth. Some significant interactions happening between nutrient additions and grazers remove on phytoplankton growth. In conclusion this study suggests that in studied reservoir phytoplankton growth is more controlled by ascendent factors than descendent

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It is important to evaluate the quality of water for proper management of these resources, since the increase of environmental degradation and the multiple use of water resources are decreasing the quality of water consumed by living beings. The objective of this study was to characterize the phytoplankton community and its variations during periods of dray and rain in Jiqui Lake located in Parnamirim, RN. It was also aimed to analyze the physical and chemical factors of this environment, in order to contribute to the knowledge of water quality used for human consumption. The collection of water samples were carried out in September 2008 to August 2009. The collection of the phytoplankton community was carried out in four sampling sites (surface, bottom, margin of the lake without macrophytes and site dominated by macrophytes). Phytoplankton was collected using plankton net of 20m. The analysis of nutrients and identification of phytoplankton were performed in the laboratory. The results indicate that concentration of chlorophyll a was high in the bottom with mean value of 1.07 μgL-1 (SD ± 1.61). During the study period there was a dominance of the following species: Euglena gracilis, Trachelomonas sp, Cyclotellas sp, Gomphonema apuncto, Navicula cuspidata var. cuspidata, Navicula sp, Rhopalodia gibba. There was homogeneity between limnological values in the four study sites, with significant difference between the periods of drought and rain. The Jiqui Lake is considered oligotrophic due to its low concentrations of chlorophyll a, high transparency and low levels of nutrients. The values of BOD and chlorophyll a concentration remained below the permitted standards existing for freshwaters in Brazil, thus the water from Lake Jiqui is of good quality, suitable for human consumption.

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O trabalho teve por objetivo avaliar a dinâmica de nitrogênio, em cultivo heterotrófico, a partir da cianobactéria Aphanothece microscopica Nägeli, sob o escopo de uma biorrefinaria. Neste sentido, foi avaliada a contribuição dos compostos nitrogenados não proteicos, na dinâmica de distribuição do nitrogênio, na biomassa gerada pelo micro-organismo em estudo, quando cultivado em sistema autotrófico e heterotrófico. Para o cultivo em condições autotróficas, foi utilizado o meio padrão BG-11, enquanto que, para o cultivo em condições heterotróficas, foi empregado o efluente da indústria de laticínios. Inicialmente, foi avaliada a contribuição dos pigmentos na fração nitrogenada não proteica tendo como base dois experimentos. No primeiro experimento foi selecionada a melhor condição para a produção de pigmentos, expressos pela clorofila-a em sistema heterotrófico, tendo como base os parâmetros C/N (20, 40 e 60), N/P (5, 10 e 15) e concentração de inóculo (100, 200 e 300 mg.L-1), mediante um planejamento fatorial 23 . Os experimentos foram conduzidos em biorreator heterotrófico a 20°C, pH 7,6 e aeração contínua de 1VVM. A melhor condição de produção de pigmento foi indicada como sendo a 200 mg.L-1 de concentração celular, razões C/N 20 e N/P 10. Com base nestes resultados, um segundo experimento foi delineado, visando avaliar a contribuição de pigmentos na fração de nitrogênio não proteico, bem como avaliar a produção de clorofila-a e ficobiliproteínas (ficocianina, aloficocianina e ficoeritrina), sob influência da luz e do meio de cultivo. Foi possível destacar teores superiores de ficobiliproteínas na biomassa gerada no cultivo heterotrófico. No entanto, com notada diferença (p≤0,05) nos teores de clorofila-a, quando são comparadas as concentrações na biomassa de meios autotróficos (10,7 mg.g-1) e heterotróficos (1,0 mg.g-1). Fato este compensado pelo menor tempo de cultivo registrado para atingir o final do experimento, quando o micro-organismo é cultivado em condições heterotróficas. Fica demonstrado assim, ainda, a importante contribuição dos pigmentos na fração de nitrogênio não proteico. Na sequência, um terceiro e quarto experimentos foram delineados, visando avaliar a influência do nitrogênio inorgânico intracelular na fração não proteica e na produção de proteína, assim como a caracterização da fração proteica quanto ao seu perfil aminoacídico. O estudo da dinâmica do nitrogênio intracelular demonstrou que o N-NH4 + foi a forma nitrogenada predominante, perfazendo importante fração de N-NP, sendo, portanto, os teores de N-NP significativamente dependente dos teores de pigmentos e nitrogênio intracelular. Os aminogramas das biomassas geradas pelos cultivos autotróficos e heterotróficos indicaram como aminoácidos majoritários o ácido glutâmico e aspártico, seguidos por valina, leucina e isoleucina, e como minoritários, lisina, glicina e metionina. O perfil aminoacídico caracterizou-se por apresentar aminoácidos essenciais como isoleucina, metionina + cisteína, fenilalanina + tirosina, valina e treonina em concentrações superiores ao preconizado pela FAO/WHO. A caracterização da fração proteica quanto ao perfil aminoacídico qualificou esta biomassa como fonte potencial de proteína. Os resultados obtidos neste trabalho demonstram a influência e dinâmica de distribuição dos compostos nitrogenados em Aphanothece microscopica Nägeli. Fica demonstrado, ainda, que a implementação do conceito de biorrefino, no tipo de agroindústria estudado, poderá representar importantes possibilidades de aproveitamento sustentável do efluente gerado.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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The environmental pollution caused by industries has increased the concentration of pollutants in the environment, especially in water. Among the most diverse contaminants, there is the metals, who may or may not to be heavy/toxic, causing effluent of difficult treatment when in low concentrations. The search for alternative measures of wastewater effluent treatment has led to studies using phytoremediation technique through the various matrices (plant, fungi, bacteria) as means of polishing treatment to remove contaminants by means of biosorption/bioaccumulation. In order to use the phytoremediation technique for removing metals of the environmental, it have been performed bioassay with the macrophyte Pistia stratiotes. The bioassays were realized with healthy plants of P. stratiotes acclimatized in a greenhouse, at room temperature and lighting conditions during 28 days of cultivate. The cultivations were performed in glass vessels containing 1 L of the hydroponic solution with chromium (VI) in the potassium dichromate form with concentration range 0.10 to 4.90 mg L-1. The experiments were performed by Outlining Central Composite Rotational (OCCR), where the kinetics of bioaccumulation and chlorophyll a fluorescence were monitored in plants of P. stratiotes during cultivation. The collections of the samples and cultive solution were performed according to the OCCR. The chromium levels were measured in samples of P. stratiotes and the remaining solutions by the methodology of atomic absorption spectrometry by flame. The tolerance of P. stratiotes in relation to exposure to chromium (VI) was analyzed by parameters of physiological activity by means of chlorophyll a fluorescence, using the portable fluorometer PAM (Pulse Amplitude Modulation). The development of P. stratiots and their biomass were related to the time factor, while bioaccumulation capacities were strongly influenced by factors of time and chromium concentration (VI). The chlorophyll fluorescence parameters were affected by chromium and the exposure time at the bioassays. It was obtained an higher metal removal from the root in relation to the sheet, reaching a high rate of metal removal in solution. The experimental data removal kinetics were represented by kinetic models Irreversibly Langmuir, Reversible Langmuir, Pseudo-first Order and Pseudo-second Order, and the best fit for the culture solution was the Reversible Langmuir model with R² 0.993 and for the plant the best model was Pseudo-second order with R² 0.760.

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Artificial lakes must differ from natural lakes in important structural and functional aspects that need to be understood so that these ecosystems can be properly managed. The aim of this work was to test the hypothesis that the artificial lakes (impoundments) in the semi-arid region of the Rio Grande do Norte State are more eutrophic and turbid and have different trophic structure when compared to the natural coastal lakes that occur in the humid eastern coast of the State. To test this hypothesis, 10 natural lakes and 8 artificial lakes with about 100 ha were sampled between September and November 2005 for the determination of some limnological variables and the abundance of the main fish species, which were grouped in three trophic guilds: facultative piscivores, facultative planktivores and omnivores. The results show that the artificial lakes had significantly higher concentrations of total nitrogen, total phosphorus, chlorophyll a , total and volatile suspended solids than the natural lakes. Results also show that the values of pH, total alkalinity, electric conductivity, turbidity as well as the coefficient of vertical attenuation of light were significantly higher in the artificial lakes than in the natural lakes. In the artificial lakes, the abundance of facultative planktivores was significantly higher, while the abundance of facultative piscivores significantly lower than in the natural lakes. There was no significant difference in the abundance of omnivorous fish between the two types of lakes. These results suggest that the increase in turbidity together with the other changes in the water quality of the artificial lakes, modifies the trophic structure of the fish communities reducing the importance of piscivores and the length of the food chains

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Air pollution can threat the environment and public health, and is assess by pollutant ́s concentration measurements in order to verify whether the limits set by environmental agencies are being respected. However, these measures do not indicate immediately the impacts to living beings. To faced this problem, plants are been investigated as potential bioindicators of air pollution and, among them, stand out bromeliads Tillandsia genus which colonize various substrates,. obtaining water and nutrients from the atmosphere directly. In this context, this research assessed the potential of epiphytic bromeliad Tillandsia recurvata (L.) L. found in urbanized areas of the city of Curitiba - PR as a bioindicator of urban air pollution. According to vehicle traffic, five sample points were selected and classified. Points P1 and P2 were classified as high-traffic vehicle due presenting trucks and urban transport; point P3 was classified as moderate traffic due the predominance of private vehicles and urban transport; and points P4 and P5 were classified as low-traffic, presenting circulation of private vehicles only. There were analyzed the abundance of T. recurvata, morphophysiological parameters (leaf area, leaf specific area, sclerophylly index, percentage dry weight / fresh weight, chlorophyll (a + b), analysis of structural mesophyll organization) and the heavy metals accumulation (Fe, Cd, Cr, Cu, Pb and Zn). The abundance analysis and the results obtained for metals analysis were correlated with the intensity of vehicular traffic, directing the sampling points P1 > P2 = P3 > P4 = P5. This result demonstrate that the abundance of T. recurvata is greater in urban air pollution impacted areas, thus indicating that T. recurvata absorbs and accumulates metals and can be used in biomonitoring of urban air pollution in areas impacted by vehicular traffic. Morphophysiological parameters analyzed shows that the internal plant ́s structure is not significantly impacted by urban air pollution due plant ́s adptations. The presence of absorbing scales, the CAM metabolism pathway and it ́s store water ability, among other features, demonstrate their potential as bio-indicator in urban areas, especially regarding heavy metals accumulation .

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O uso de plantas com potencial de associação com microrganismos é uma prática frequente em solos contaminados por metais pesados, considerada de baixo custo e ambientalmente correta. O trabalho objetivou avaliar o crescimento do Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson e o efeito da inoculação com Pisolithus microcarpus UFSC-Pt116 em solo contaminado com Zn. O delineamento experimental foi inteiramente casualizado em arranjo fatorial (2 x 6), sendo com e sem inóculo e seis doses de Zn (0, 300, 600, 900, 1200 e 1500 mg kg-1 de solo), com seis repetições. As mudas foram inoculadas e cultivadas durante 90 dias em viveiro. Após 67 dias do transplante definitivo foi avaliado o percentual de colonização ectomicorrízica, a altura de planta, diâmetro do colo, número de folhas, índice de clorofila total, volume radicular, massa seca das folhas, da haste caulinar, radicular e total, relação massa seca aérea/massa seca radicular e a relação altura/diâmetro do colo. O percentual de colonização ectomicorrízica em Corymbia citriodora é estimulado pelo acréscimo de até 1412,21 mg kg-1 de Zn no solo. O Corymbia citriodora é tolerante a adição de até 1500 mg kg-1 de zinco em solo com 81% de argila, mesmo sem a inoculação com Pisolithus microcarpus. A análise de correlação canônica evidencia que a inoculação com P. microcarpus favorece a massa seca total, radicular e da parte aérea de Corymbia citriodora cultivado em solo com 81% de argila contaminada com 600 mg kg-1 de Zn.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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La eutrofización marina es un problema que afecta a los mares europeos y particularmente a sus aguas costeras. Se trata del enriquecimiento anómalo en nutrientes de las aguas marinas, generalmente compuestos del nitrógeno y fósforo aportados por la actividad del ser humano, y que tiene como resultado consecuencias nocivas para la calidad de las aguas y la biodiversidad. La Directiva Marco de las Estrategias Marinas, que entró en vigor en 2010, recoge esta problemática y emplaza a los estados miembros para su evaluación y en su caso para la remediación de sus efectos nocivos identificando el origen de los aportes de nutrientes. Esta tarea requiere metodologías y procedimientos operativos que permitan ser implementados de forma coordinada por los estados miembros a nivel regional. En el primer capítulo de esta tesis se presenta una metodología para realizar la zonación del norte del mar Alborán a partir de imágenes de satélite de clorofila a tal que permite delimitar las áreas con características de productividad diferenciadas que pueden ser propuestas como unidades de gestión de la eutrofización y que se puedan emplear tanto en el diseño de los programas de seguimiento como en el aprovechamiento de los datos oceanográficos medidos in situ. En este capítulo se describe la metodología analítica utilizada, que está basada en la aplicación del análisis clúster de las k-medias a las imágenes de satélite de clorofila, así como su validez a partir del análisis de las series temporales de datos tomados in situ. El segundo capítulo se hace una evaluación de los indicadores de la eutrofización en una zona reducida de Alborán, donde existen multitud de datos oceanográficos, meteorológicos y ambientales. Para llevarla a cabo, se adaptó la metodología empleada en el capítulo 1 a la región ECOMALAGA. Una vez realizada la zonación, se agregaron los datos oceanográficos, meteorológicos y ambientales potencialmente relacionados con la eutrofización en cada área, y posteriormente se evaluaron las diferencias estadísticas a lo largo del ciclo estacional y entre las diferentes zonas. Con esta finalidad, se estiman las tendencias temporales de las variables ambientales en cada zona. A partir de los resultados obtenidos se infirió qué variables y/o mecanismos podrían estar influyendo sobre la concentración superficial de la clorofila a. En el tercer capítulo se ensayaron modelos aditivos generalizados (GAM) con el fin de identificar las variables más importantes que afectan a los indicadores de la eutrofización. Como variable respuesta del modelo se usó la clorofila a, pues se trata del indicador directo de la eutrofización más empleado. Las variables explicativas se componen de variables oceanográficas, meteorológicas y ambientales. En el cuarto capítulo se desarrolla un algoritmo regional para el mar de Alborán que permite obtener valores de clorofila a a partir de imágenes de satélite más ajustados a los valores que proporcionan los algoritmos disponibles que la sobreestiman considerablemente. En la discusión final y conclusiones se hace énfasis en el enfoque práctico de esta tesis doctoral, detallando la potencialidad de la metodología presentada para la evaluación de la eutrofización. Para esto, se detallan los resultados de la evaluación obtenidos para el mar Alborán empleando dicha metodología, definiendo su estado actual y las tendencias registradas, así como las causas de los problemas encontrados. Finalmente se evalúan y proponen posibles medidas para su remediación y control.

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Dissertação de mest. em Aquacultura, Unidade de Ciências e Tecnologia dos Recursos Aquáticos, Univ. do Algarve, 1997

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Existem poucos estudos sobre arborização de café conilon com seringueira. Objetivou-se avaliar o microclima, desenvolvimento e produtividade do cafeeiro conilon cultivado a pleno sol e sob sombreamento proporcionado pela seringueira. O experimento foi composto por uma lavoura de café conilon (Coffea canephora), cultivada a pleno sol e outra lavoura de café consorciada com seringueira (Hevea brasiliensis). A seringueira e o cafeeiro foram plantados no sentido Leste/Oeste, em Jaguaré, Espírito Santo, Brasil. Avaliou-se a luminosidade, temperatura e umidade relativa do ar, concentração foliar de nutrientes, medição dos internódios dos ramos plagiotrópicos e ortotrópicos, área foliar, índice relativo de clorofila, e a produtividade do cafeeiro. O sombreamento influenciou diretamente no microclima, reduzindo a temperatura do ar no verão e no inverno e aumentando a umidade relativa. A luminosidade no verão teve uma redução media de 905 lumens ft-2 ao longo de todo dia, equivalente a 72,49%, e no inverno de 1665 lumens ft-2, equivalente a 88,04%. O sombreamento proporcionou maior estiolamento dos ramos plagiotrópicos e ortotrópicos, bem como maior expansão foliar. A concentração foliar de Fe e Mn foram maiores no cafeeiro arborizado. A clorofila b e total estimada foram maior no cafeeiro cultivado a pleno sol. O denso sombreamento oferecido pela seringueira nas condições estudadas proporcionou perdas na produtividade do cafeeiro, contudo, ocorre a formação da seringueira.

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Devido ao crescente aumento do uso de aeradores artificiais em sistema de cultivo de peixes e à carência de estudos nesta área, este trabalho avaliou a influência de um aerador tipo propeller diffuser (AR 120) nas variáveis bióticas e abióticas em um viveiro de engorda de peixe. Foram demarcados três pontos de coleta localizados a 5, 10 e 23 m de distância do aerador, durante 15 dias consecutivos, sendo 5 dias antes do uso do aerador, 5 dias com o aerador ligado e 5 dias com o aerador desligado. As variáveis limnológicas estudadas não apresentaram diferenças significativas (P > 0,05) entre os três pontos de coleta, porém, em relação ao uso do aerador, variáveis como temperatura, transparência, pH, oxigênio dissolvido, bicarbonato, CO2 livre, fósforo total, ortofosfato, amônia, nitrato e nitrito diferiram significativamente (P < 0,05) com a agitação mecânica da água. Já a condutividade, alcalinidade, CO2 total e clorofila a não apresentaram diferenças significativas (P > 0,05) com o uso do aerador. A comunidade fitoplanctônica sofreu influência direta do aerador (P < 0,05), dominada pelas Chlorophyta, representando mais de 70% do total de organismos presentes, seguidas das Cyanophyta e Chrysophyta, porém estas últimas tenderam a aumentar após o uso do aerador, uma vez que estes grupos se adaptam rapidamente às mudanças do ambiente.