In extensive animal husbandry, natural or artificial ponds allow direct access of cattle to water but result in degradation of water quality and in increased health risks. Under such circumstances eutrophication occurs and consequently algal bloom, among them toxigenic cyanobacteria. The present study aimed to report the occurrence of cyanobacteria in the drinking water of cattle and to describe their physical and chemical parameters, as pH, temperature and dissolved oxygen. Nineteen samples of natural ponds or water troughs formed predominantly as result of rainfall from six farms located in the Southeast and Midwest regions of Brazil were analyzed for the presence of cyanobacteria, and pH, temperature and dissolved oxygen was measured. Microcystis and/or Merismopedia were detected in two ponds; one of them was covered with intense flowering. The values of pH, temperature and dissolved oxygen in 19 collections were pH 7.2-9.7, 31-34ºC and 7.8-30mg/l respectively. Also non-pathogenic algae of several genera were detected besides the occurrence or not of cianogenics. Under these conditions, the common practices of drinking water supply for extensively raised cattle and the possibilities of eutrophication and cyanobacterial growth bring potential risks for animal health. | Na pecuária extensiva, os bebedouros naturais ou artificiais possibilitam o acesso direto dos bovinos ao seu interior e trazem como consequência a degradação da qualidade da água e o aumento dos riscos sanitários. Em tais circunstâncias ocorre a eutrofização e consequentemente a floração de algas, dentre elas cianobactérias toxigênicas. O presente estudo teve por objetivo verificar a ocorrência de cianobactérias de interesse sanitário em água de dessedentação de bovinos e descrever os seus parâmetros físico-químicos pH, temperatura e oxigênio dissolvido. Foram examinadas 19 amostras de água de cacimbas ou bebedouros naturais formados predominantemente em decorrência da precipitação pluviométrica, coletadas em seis propriedades rurais localizadas nas regiões Sudeste e Centro-Oeste, para a presença de cianobactérias e mensurados os valores de pH, temperatura e oxigênio dissolvido. Microcystis e/ou Merismopedia foram detectadas em dois bebedouros; em um dos quais havia intensa floração. Os valores de pH, temperatura e oxigênio dissolvido nas 19 coleções oscilaram entre pH 7,2-9,7, 31-34ºC e 7,8-30mg/l, respectivamente. Foram detectadas ainda algas consideradas não patogênicas de diversos gêneros, em conjunto ou não com a ocorrência das cianofíticas. Nessas condições, as práticas comuns de oferta de água de dessedentação na bovinocultura extensiva, as possibilidades de eutrofização e a contaminação por cianobactérias trazem potenciais riscos à saúde dos animais.

Las microcistinas son toxinas hepatotoxicas producidas por cianobacterias del género Microcystis, Anabaena, Oscillatoria y Nostoc(Merel et al., 2013). Debido a que se ha evidenciado la presencia de estas cianobacterias en lagunas de tratamiento en Costa Rica, se ha evaluado la presencia de microcistinas y su relación con la abundancia de cianobacterias en estos sistemas. | Microcystins are hepatotoxic toxins produced by cyanobacteria of the genus Microcystis, Anabaena, Oscillatoria and Nostoc (Merel et al., 2013). Because the presence of these cyanobacteria has been evidenced in treatment lagoons in Costa Rica, the presence of microcystins and its relationship with the abundance of cyanobacteria in these systems has been evaluated. | Universidad Nacional, Costa Rica | Escuela de Ciencias Biológicas

Proyecto de Graduación (Licenciatura en Ingeniería en Biotecnología) Instituto Tecnológico de Costa Rica, Escuela de Biología, 2020 | Las cianotoxinas son contaminantes cada vez más frecuentes a nivel mundial en el agua potable procedente de aguas superficiales, debido a que las condiciones del cambio climático pueden aumentar la proliferación de las cianobacterias. La presencia de estas toxinas en el agua potable puede generar diferentes problemas a la salud como: daño hepático y daño a nivel neurológico. En Costa Rica, los análisis de cianobacterias en agua potable se realizan en casos excepcionales como cuando ocurren intoxicaciones masivas, por lo tanto, actualmente son escasos los datos que se tienen sobre las cianobacterias y sus toxinas: En 1994, Peinador aisló tres especies de cianobacterias de la Planta Potabilizadora de Tres Ríos, y en el año 2006 Avendaño y Arguedas encontraron en el agua cruda de la Planta Potabilizadora de Tres Ríos concentraciones superiores a lo establecido en la normativa. En este estudio se analizaron los datos suministrados por el ICE (Instituto Costarricense de Electricidad) sobre el embalse El Llano (fuente de la planta potabilizadora de Cartago) de los parámetros de temperatura, pH, fósforo total y amonio de las épocas entre 2016-2018, para determinar si con las características históricas del embalse, se podrían desarrollar las cianobacterias; además se empleó la técnica de espectrofotometría con el kit comercial Mycrocistest® para determinar la concentración de microcistinas tóxicas en el agua cruda y tratada de la planta potabilizadora de Cartago. Tras el análisis de los datos históricos se encontró que, con las características históricas de los parámetros analizados, si era posible el crecimiento de las cianobacterias y por ende de la producción de toxinas. Al realizar los ensayos, no se detectaron microcistinas (Mcs) en concentraciones iguales o superiores a 0,25 μg/L, lo que podría deberse a algunos factores como la presencia de sedimentos en el embalse, la biodegradación de las Mcs por parte de los microorganismos que crecen en el embalse, el corto tiempo de retención del embalse, entre otros. No obstante, no se descarta en el futuro, la presencia de cianobacterias, ni de cianotoxinas, por lo que se recomienda establecer un monitoreo de vigilancia de las densidades de cianobacterias presentes en el agua cruda de la planta y en caso de detectar densidades importantes, realizar una prueba de toxidad. | Cyanotoxins are an increasingly frequent pollutant worldwide in drinking water from surface waters, as the conditions of climate change can increase the proliferation of cyanobacteria. The presence of these toxins in drinking water can generate different health problems, such as liver damage and neurological damage. In Costa Rica, the analysis of cyanobacteria in drinking water is carried out in exceptional cases such as when massive intoxications occur, therefore, currently there is little data on cyanobacteria and their toxins: In 1994, Peinador isolated three species of cyanobacteria of the Tres Ríos drinking water treatment Plant, and in 2006 Avendaño and Arguedas found in the raw water of the same plant concentrations higher than that established in the regulations. In this study, the data provided by the ICE (Instituto Costarricense de Electricidad) on the El Llano reservoir (source of the Cartago drinking water treatment plant) of the parameters of temperature, pH, total phosphorus and ammonium of the periods between 2016-2018 were analyzed, to determine if with the historical characteristics of the reservoir, cyanobacteria could be developed. In addition, the spectrophotometric technique was used with the commercial Mycrocistest® kit to determine the concentration of toxic microcystins in the raw and treated water of the Cartago drinking water treatment plant. After analyzing the historical data, it was found that with the historical characteristics of the analyzed parameters, there is the possible for the growth of cyanobacteria and therefore the production of toxins. When performing the tests, no microcystins (Mcs) were detected in concentrations equal to or greater than 0.25 μg / L, which could be due to some factors such as the presence of sediments in the reservoir, the biodegradation of the Mcs by the microorganisms that grow in the reservoir, the short retention time of the reservoir, among others. However, the presence of cyanobacteria or cyanotoxins is not ruled out in the future, so it is recommended to establish surveillance monitoring of the densities of cyanobacteria present in the raw water of the plant and in case of detecting significant densities, perform a toxicity test.

This research analyzed three green microalgae (Scenedesmus sp., Chlamydomonas sp., and Chlorella sp.) and two cyanobacteria (Synechocystis sp. as unicellular strain and Nostoc sp. as filamentous strain) native from Costa Rica to remove high concentrations of ammonium and phosphate. Cultures were exposed for 120 h to initial concentrations of 70 mgL-1 ammonium and 9 mgL-1 phosphate, under constant light intensity of 60 µmol m-2s-1. Chlorella sp. showed the highest growth rate, followed by Chlamydomonas sp. and the cyanobacteria Nostoc sp. In contrast, Scenedesmus sp. and Synechocystis sp. cultures grew less than the other ones. The highest percentage of ammonium removal was achieved with Chlorella sp. followed by Chlamydomonas sp. and Synechocystis sp., then Scenedesmus sp. and Nostoc sp. Microalgae removed totally the initial phosphate concentration within 72 h, while cyanobacteria Synechocystis sp. and Nostoc sp. removed phosphate partially. These microorganisms are promising for wastewater reclamation. | La presente investigación utilizó las microalgas Scenedesmus sp,. Chlamydomonas sp. y Chlorella sp. y las cianobacterias Synechocystis sp. y Nostoc sp. nativas de Costa Rica, con el propósito de analizar la capacidad de remoción de amonio y fosfato. Las cepas se colocaron en medio de cultivo sintético, con concentraciones iniciales de amonio de 70 mgL-1 y fosfato de 9 mgL-1. El cultivo se realizó durante 120 h, con luz constante a una intensidad de 60 µmol m-2s-1. Se cuantificaron las siguientes variables cada 24 h en todos los cultivos: a) la tasa de crecimiento (µ), b) productividad (mgL-1h-1), c) concentración de amonio y fosfato. La microalga Chlorella sp. presentó la mayor tasa de crecimiento, luego Chlamydomonas sp. y la cianobacteria Nostoc sp. Los cultivos Scenedesmus sp. y Synechocystis sp. presentaron un menor crecimiento. La mayor remoción de nitrógeno se presentò en Chlorella sp., seguida por Chlamydomonas sp. y Synechosystis sp., Scenedesmus sp. y Nostoc sp. El fosfato se removió en forma total por las microalgas antes de las 72 h, mientras que en Synechocystis sp. y Nostoc sp. fue removido parcialmente. El estudio indica potenciales aplicaciones especialmente de la microalga Chlorella sp. en la remoción de amonio y fosfato en aguas residuales urbanas.

Brenes Tortós, G. (2020). Relación entre la concentración de microcistinas en lagunas de tratamiento de agua residual en Cañas-Guanacaste y la abundancia de cianobacterias. [Tesis de Licenciatura]. Universidad Nacional, Heredia, Costa Rica. | Las microcistinas (MC) son toxinas hepatotóxicas producidas por numerosos géneros de cianobacterias bajo condiciones específicas. En este estudio se evaluó la concentración de MC en el sistema lagunar de tratamiento de agua residual de Cañas (Guanacaste) administrado por el Instituto de Acueductos y Alcantarillados (AyA), mediante un ensayo de inmunoabsorción ligado a enzimas (ELISA). Además, se evaluó la abundancia de cianobacterias, mediante la técnica de conteo celular con cámara Sedgewick-Rafter y metagenómica. Se realizaron extracciones de ADN de agua filtrada, secuenciación NGS mediante la amplificación de las regiones V3-V4 del gen 16S y el análisis de las secuencias utilizando el paquete estadístico Dada2 de Rproject 3.4.3®. El conteo en cámara determinó que los géneros de cianobacterias más abundantes fueron Planktothrix Arthrospira y Microcystis en las cuatro lagunas. Así mismo, se encontraron diferencias significativas entre estas y los muestreos. Por otra parte, los análisis de metagenómica mostraron mayor riqueza de variantes de secuencia de amplicón (ASVs) en las lagunas 1 y 2 y mayor presencia del filo Cyanobacteria, en todas las lagunas; así mismo el género Planktothrix predominó en las lagunas 1 y 2, mientras que Cyanobium en las lagunas 3 y 4, a su vez mostró mayor riqueza de cianobacterias que el obtenido mediante el conteo celular. Las mediciones de MC determinaron niveles entre 0,5 ppb y 3,0 ppb en las lagunas 2 y 3 en el mes de septiembre y niveles inferiores a 0,5 ppb en los demás muestreos. Las diferencias en la abundancia de cianobacterias en las lagunas y periodos de muestreo se pueden deber a la existencia de condiciones físicas, químicas y ambientales que podrían modificar la estructura poblacional, así mismo los géneros microbianos y cianobacterianos encontrados concuerdan con otros estudios lo que evidencia que la composición poblacional de estos organismos cumple una función en la remediación de los sistemas de tratamiento de agua residual. La presencia de organismos productores de MC no es el único factor que se debe tomar en cuenta para explicar las variaciones en la concentración de esta toxina, ya que factores genéticos, físicos, ecológicos y ambientales influyen en la concentración de cianotoxinas en el agua. Por último, se muestra la importancia de complementar la técnica tradicional de conteo en cámara para la determinación de abundancia con la técnica de metagenómica, ya que esta mostró ser más sensible y permite identificar géneros menos representativos en las muestras. | Microcystins (MC) are hepatotoxic toxins produced by numerous genera of cyanobacteria under specific conditions. In this study, the concentration of MC was evaluated in the lagoon wastewater treatment system of Cañas (Guanacaste) administered by the Instituto de Acueductos y Alcantarillados (AyA), by means of an enzyme-linked immunosorbent assay (ELISA). In addition, the abundance of cyanobacteria was evaluated using the cell counting technique with a Sedgewick-Rafter camera and metagenomics. DNA extractions from filtered water, NGS sequencing by amplifying the V3-V4 regions of the 16S gene and sequence analysis using the Rproject 3.4.3® Dada2 statistical package were performed. The chamber count determined that the most abundant genera of cyanobacteria were Planktothrix Arthrospira and Microcystis in the four lagoons. Likewise, significant differences were found between these and the samplings. On the other hand, the metagenomic analyzes showed a greater richness of amplicon sequence variants (ASVs) in lagoons 1 and 2 and a greater presence of the Cyanobacteria phylum in all lagoons; Likewise, the genus Planktothrix predominated in lagoons 1 and 2, while Cyanobium in lagoons 3 and 4, in turn, showed a greater richness of cyanobacteria than that obtained by cell count. The MC measurements determined levels between 0.5 ppb and 3.0 ppb in lagoons 2 and 3 in the month of September and levels lower than 0.5 ppb in the other samplings. The differences in the abundance of cyanobacteria in the lagoons and sampling periods may be due to the existence of physical, chemical and environmental conditions that could modify the population structure, likewise the microbial and cyanobacterial genera found agree with other studies, which shows that The population composition of these organisms plays a role in the remediation of wastewater treatment systems. The presence of MC-producing organisms is not the only factor that must be taken into account to explain the variations in the concentration of this toxin, since genetic, physical, ecological and environmental factors influence the concentration of cyanotoxins in water. Lastly, the importance of complementing the traditional camera counting technique for determining abundance with the metagenomics technique is shown, since it proved to be more sensitive and allows the identification of less representative genera in the samples. | Universidad Nacional, Costa Rica | Escuela de Ciencias Biológicas

RESUMEN: El embalse Riogrande II, ubicado en la parte central del departamento de Antioquia, es empleado como reservorio de agua para potabilización y generación de energía. Sus principales tributarios (ríos Grande y Chico) son receptores de aguas ricas en nutrientes y como resultado se ha presentado un proceso de eutrofización del sistema que favorece el crecimiento masivo de cianobacterias potencialmente productoras de microcistina LR. Entre el año 2014 y 2015 se realizaron cuatro muestreos en tres estaciones del embalse. En cada estación se evaluaron variables fisicoquímicas y se determinó la biomasa y el potencial tóxico de las cianobacterias de los Ordenes Nostocales y Chroococcales. La densidad y biovolumen de cianobacterias se correlacionaron con el nitrógeno total disuelto, nitrógeno orgánico disuelto, nitratos y amonio, importantes para el crecimiento y probablemente para la producción de toxinas. Los géneros de cianobacterias con mayor frecuencia durante el estudio fueron Sphaerospermopsis y Aphanocapsa en mayo y abril de 2015. De otro lado, las mayores densidades y biovolúmenes se registraron en diciembre 2014, abril y mayo 2015 para Dolichospermum sp.1 y en mayo 2015 para Microcystis wesenbergii. Se evaluaron 5 primers para la detección del gen de microcistinas mcyE y mcyD en muestras de agua del embalse Riogrande II y se detectó la presencia de cepas portadoras del gen mcy en el Orden Chroococcales en todas las estaciones y muestreos. La presencia del gen mcy indica claramente que en el embalse Riogrande II los florecimientos de cianobacterias del orden Chroococcales podrían representar un riesgo importante desde el punto de vista ambiental y para la salud de los consumidores del recurso agua. En consecuencia, es importante avanzar en el conocimiento de los factores ambientales que podrían estar favoreciendo la expresión del gen en el embalse. | COL0009832 | Maestría | Magíster en Ciencias Ambientales

Este trabalho objetivou adaptar um método de controle de larvas do mexilhão dourado (Limnoperna fortunei) com a utilização de radiação ultravioleta e verificar seu efeito sobre cianobactérias e cianotoxinas presentes na água. Limnoperna fortunei (Dunker, 1857), conhecido vulgarmente como mexilhão dourado é proveniente do sudeste asiático. Foi, provavelmente, introduzido nos nossos mananciais, não intencionalmente, através da água de lastro, com os primeiros registros na América do Sul, em 1991, no Rio da Prata, nas proximidades de Buenos Aires, Argentina. No Brasil foi visto pela primeira vez na área do Delta do Jacuí, em frente ao porto de Porto Alegre, RS, no ano de 1998. Além de ameaçar à biodiversidade de ecossistemas, vem provocando a obstrução das tubulações e trocadores de calor junto às estações de tratamento de água e indústrias que utilizam água bruta para resfriamento. As estações de tratamento, além de enfrentarem problemas com o entupimento pelo mexilhão, defrontam-se também com as florações de cianobactérias. As florações, conhecidas também como blooms, são eventos de multiplicação e acumulação de microalgas ou cianobactérias nos corpos hídricos, que podem durar de algumas horas ao longo do dia a meses. As cianobactérias podem liberar cianotoxinas que estão presentes principalmente no interior das células, e são liberadas na lise celular, que ocorre principalmente por senescência natural. Os experimentos foram realizados em uma unidade piloto, onde concentrações conhecidas de larvas do mexilhão dourado foram submetidas a doses de radiação ultravioleta, na faixa de 200 a 800 mWs/cm2. As amostras de água bruta utilizadas nos testes foram avaliadas por meio de métodos analíticos adequados (APHA, 2005). Foram determinados os parâmetros de temperatura (°C), pH, turbidez (NTU), dureza (mgCaCO3/L) e sólidos suspensos (mg/L), os quais poderiam influenciar nas condições dos testes. As mesmas condições testadas para o mexilhão foram utilizadas nos experimentos com cianobactérias. As larvas de mexilhão dourado e a água bruta utilizada no experimento foram obtidos no delta do Jacui, Porto Alegre, Rio Grande do Sul, Brasil. A cianobactéria Microcystis aeruginosa, produtora de microcistina, foi cultivada em laboratório. A mortalidade instantânea das larvas aproximou-se dos 100% nas condições do teste com a dosagem de 781mWs/cm2 , com DL50 de 324 mWs/cm2. Na água residual dos experimentos de exposição à radiação UV, foram realizados ensaios ecotoxicológicos crônicos com Pimephales promelas, Ceriodaphnia dubia e Selenastrum capricornutum, a fim de detectar a presença de subprodutos que poderiam gerar toxicidade aos organismos de diferentes níveis tróficos. Os resultados desta avaliação ecotoxicológica não demonstraram toxicidade residual. Os dados obtidos demonstraram-se satisfatórios no controle daslarvas de mexilhão, entretanto não promoveram a lise das células de M. aeruginosa e a conseqüente liberação de microcistinas nas condições testadas. | L. fortunei (Dunker, 1857), commonly known as golden mussel comes from Southeast Asia. It might have been unintentionally introduced in our water sources through ballast water, with the first records in 1991, in Rio de la Plata, near Buenos Aires, Argentina, South America. In Brazil it was first seen in 1998, in Jacuí Delta, opposite Porto Alegre’s harbor. Besides threatening the biodiversity of ecosystems, this mussel has caused the obstruction of pipes and heat exchangers along the water treatment plants and industries that use raw water for cooling. Treatment plants facing problems with the clogging of mussels also have to contend with the cyanobacterial blooms. The blooms are events of multiplication and accumulation of algae or cyanobacteria in water bodies that can last from a few hours to days or months. The cyanobacteria may release cyanotoxins present mainly in cells and are released upon cell lysis, which occurs primarily by natural senescence. Thus, the aim of study is to adapt a control method of golden mussel larvae (L. fortunei) using ultraviolet radiation and verify its effect on cyanobacteria and cyanotoxins in the water. The experiments were performed in a pilot unit, where known concentrations of mussel larvae were subjected to doses of ultraviolet radiation ranging from 200 to 800 mWs/cm2, and the quality of water used, evaluated. The same conditions tested for the mussels were used in experiments with cyanobacteria. Mussel larvae and raw water used in the experiments were obtained from the Jacuí Delta, Porto Alegre, Rio Grande do Sul, Brazil. The cyanobacteria Microcystis aeruginosa, witch produces microcystin, was grown in culture in our laboratory. The instantaneous mortality of larvae was approximately 100% with 781mWs/cm2 in test conditions, with LD50 of 324 mWs/cm2. Ecotoxicological tests were performed with Pimephales promelas, Ceriodaphnia dubia, and Selenastrum capricornutum, to detect the presence of byproducts that could cause toxicity to organisms of different trophic levels in the residual water. The results of ecotoxicological evaluation showed no residual toxicity. The data showed to be satisfactory in larvae control, but did not cause lysis in cells of M. aeruginosa and the consequent release of microcystins in the water.

Interview réalisée dans le cadre d'une visite à l'Université de Concepción et à la Direction des Relation Internationale | Universidad de Concepción | 6. Clean water and sanitation | 4. Quality education

Las cianobacterias se caracterizan por ser fotoautótrofas, son los únicos organismos procariotas que desarrollan fotosíntesis oxigénica y capaces de sintetizar un sin número de moléculas con aplicaciones que van desde la industria alimentaria, producción de biocombustibles, bioplásticos, cosmética, agricultura y la farmacéutica considerando la producción de hasta 260 compuestos con utilidad terapéutica como antivirales, antitumorales, antimicrobianas y antiinflamatorias. En el presente trabajo se llevó a cabo la identificación y análisis preliminar de los compuestos de interés biotecnológico sintetizados por las especies de cianobacterias Nostoc sp. y Synechococcus elongatus aisladas de cuerpos de agua del departamento del Atlántico, obtenidas del Cepario del Laboratorio de Desarrollo Biotecnológico de la Facultad de Ciencias Naturales y Exactas de la Universidad Libre, y mantenidas bajo condiciones de laboratorio. Para el crecimiento y mantenimiento de las cepas seleccionadas, se utilizó el medio de cultivo Gibco TM BG-11. Este medio permitió un aumento de la biomasa en ambas cepas estudiadas. En el caso de Synechococcus elongatus, se alcanzó una densidad máxima de 1x106 células/ ml, mientras que para Nostoc sp. Se obtuvo una densidad de 1x105 células/ml. Posteriormente la biomasa (4.5 L) fue liofilizada a temperatura de -105°C, obteniendo una cantidad suficiente para realizar la caracterización de los compuestos producidos. La identificación se llevó a cabo mediante la técnica de Espectroscopia Infrarroja por Transformada de Fourier (FT-IR) usando un equipo FT/IR – 4X JASCO. Los resultados mostraron espectros con regiones similares en ambas formas de muestras (liofilizada y líquida), con intervalos de frecuencia entre 3344-1559 cm-1 Para Nostoc sp. la absorción fue de 3335-1559 cm-1 mientras que para Synechococcus elongatus osciló entre 3344-1536 cm-1 y 3332-1532 cm-1 . Estos resultados confirmaron la presencia de los mismos grupos funcionales, como O-H (carboxílico) y C=C (aromático), en ambas cianobacterias, evidenciando una huella dactilar infrarroja similar. Por otra parte, se evidenció compuestos de interés biotecnológico con diversas aplicaciones en la industria farmacéutica, presentes en las cianobacterias que fueron analizadas. | Universidad Libre Seccional Barranquilla -- Facultad de Ciencias de la Salud, Exactas y Naturales -- Maestría en Biotecnología | Cyanobacteria are characterized by being photoautotrophic, they are the only prokaryotic organisms that develop oxygenic photosynthesis and are capable of synthesizing a countless number of molecules with applications ranging from the food industry, production of biofuels, bioplastics, cosmetics, agriculture and pharmaceuticals, considering the production of up to 260 compounds with therapeutic utility such as antivirals, antitumor, antimicrobial and anti-inflammatory. In the present work, the identification and preliminary analysis of the compounds of biotechnological interest synthesized by the cyanobacterial species Nostoc sp. and Synechococcus elongatus isolated from bodies of water in the department of Atlántico, obtained from the Cepario of the Biotechnological Development Laboratory of the Faculty of Natural and Exact Sciences of the Universidad Libre, and maintained under laboratory conditions. For the growth and maintenance of the selected strains, Gibco TM BG-11 culture medium was used. This medium allowed an increase in biomass in both strains studied. In the case of Synechococcus elongatus, a maximum density of 1x106 cells/ml was reached, while for Nostoc sp. A density of 1x105 cells/ml was obtained. Subsequently, the biomass (4.5 L) was freeze-dried at a temperature of -105°C, obtaining a sufficient quantity to carry out the characterization of the compounds produced. The identification was carried out by the Fourier Transform Infrared Spectroscopy (FT-IR) technique using a FT/IR – 4X JASCO equipment. The results showed spectra with similar regions in both forms of samples (lyophilized and liquid), with frequency intervals between 3344-1559 cm-1 For Nostoc sp. the absorption was 3335-1559 cm-1 while for Synechococcus elongatus it ranged between 3344-1536 cm-1 and 3332-1532 cm-1. These results confirmed the presence of the same functional groups, such as O-H (carboxylic) and C=C (aromatic), in both cyanobacteria, evidencing a similar infrared fingerprint. On the other hand, compounds of biotechnological interest with various applications in the pharmaceutical industry were evident, present in the cyanobacteria that were analyzed.

The periphyton community structure in freshwater shallow lakes is lake community structure is determined by processes at different spatial and temporal scales, including the hydrodynamics of the system, nutrients, herbivores, light, substrate and temperature, as climate change stressors. The studies presented in this thesis aimed to understand the periphyton and the factors affecting this community in freshwater shallow lakes. Using an observational approach, we evaluated which limnological variables affect the biological traits of periphyton in shallow lakes located in the Upper Paraná River floodplain. The sampling sites were established according to the percentage of macrophyte coverage Eichornia azurea (0-35, 50-75 and 75-100%), and other limnological variables were sampled. Overall the biological traits were influenced mainly by temperature. However, other factors also influenced the community, such as water level, nutrients and more weakly by macrophyte coverage percentage of 0-35%. Using an experimental approach, we tested how biovolume and species composition of periphyton response in environmental conditions and in front of environmental disturbance in form heat wave (+5°C). The results showed that the heat wave stimulated the growth of cyanobacteria and diatoms, green algae have been adversely affected. Furthermore, the heat wave directed the prevalence of some taxons, thus changing the species of composition. | A estrutura da comunidade do perifíton em lagos rasos de água doce é resultado de um número de processos que operam em diferentes escalas espaciais e temporais, como por exemplo a hidrodinâmica do sistema, nutrientes, herbivoria, luz, substrato e a temperatura. Os estudos propiciaram a compreensão do perifíton e os fatores que afetam essa comunidade em lagos rasos de água doce. Utilizou-se uma abordagem observacional, para identificar as variáveis limnológicas afetam os traços biológicos do perifíton em lagos rasos, localizados na planície de inundação do alto Rio Paraná. Os pontos de amostragem foram estabelecidos de acordo com a porcentagem de cobertura da macrófita aquática Eichornia azurea (0-35, 50-75 e 75-100%) e outras variáveis limnológicas. No geral os traços biológicos foram influenciados principalmente pela temperatura. No entanto, outros fatores também influenciaram esta comunidade, como nível de água, nutrientes e mais fracamente a porcentagem de cobertura de macrófitas de 0-35%. Utilizou-se uma abordagem experimental, para testar como o biovolume e a composição de espécies do perifíton respondem em condições ambientais e frente a uma perturbação ambiental na forma de onda de calor (+5°C). Os resultados mostraram de acordo com o nível de nutrientes que a onda de calor estimulou o crescimento de cianobactérias e diatomáceas, já as algas verdes foram afetadas negativamente. Além disso, a onda de calor direcionou a prevalência de alguns táxons, assim, mudando a composição de espécies. | PhD