During 1982 benthic and floating filamentous algal mats appeared in the maturation ponds of the Grahamstown Sewage Disposal Works. These mats clogged the ponds and reduced the efficiency by which the effluent was purified. As they continued to be a problem despite numerous efforts to remove them, this study was initiated to investigate the alga, establish why it was successful in the pond environment, and how its growth could be controlled. The physico-chemical environment of a representative maturation pond was characterised while laboratory studies were conducted to investigate the growth, photosynthetic and respiratory characteristics in the alga. The alga was identified as Rhizoclonium riparium (Roth) Harv. although its morphological variability was greater than that reported in the literature. Growth and photosynthetic studies indicated that the alga favoured temperatures between 20 and 30⁰C and relatively high light intensity (700μE.m⁻².s⁻¹) and that it was highly productive. In addition, the alga exhibited photoadaptive ability, although it seemed to be sensitive to photoinhibition. Its success in the maturation pond was attributed to the favourable physico-chemical environment, particularly the high transparency of the effluent which allowed the penetration of PAR to the pond floor and to the alga's ability to adapt to the change in environment when it floated from the pond floor to its surface. Although the algal mats contribute to the oxidation of the effuent within the maturation pond, they are generally detrimental to the system because they shade the water column and inhibit wind-induced mixing. Recommendations on methods of controlling of the mats are presented. / KMBT_363 / Adobe Acrobat 9.53 Paper Capture Plug-in

The aim of this work is to evaluate the effect of caprolactam on the process of photosynthesis in model representatives of green algae (Scenedesmus quadricauda) through the dynamics of the release of oxygen into the solution of medium.

The genus Stigeoclonium is taxonomically very problematic. The relationships between species of this genus are very little known. There are only a few studies that deal with only morphological revision of the genus Stigeoclonium. Hovewer, up to now no phylogenetic analysis of this genus exists. This study summarizes the knowledge about the genus Stigeoclonim in the Czech Republic and shows the first phylogenetic analysis of this genus.

Orientador: Fosca Pedini Pereira Leite / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-10T23:42:00Z (GMT). No. of bitstreams: 1 Ferreira_DanielRibeiroJansen_M.pdf: 2723695 bytes, checksum: 38a11a800e856f56b9ccab1f11a03a97 (MD5) Previous issue date: 2008 / Resumo: A variação sazonal da composição, diversidade e densidade da fauna de anfipodes de Caulerpa racemosa foi avaliada em função da biomassa da alga e quantidade de sedimento por ela retido, no costão rochoso de duas praias do litoral norte do Estado de São Paulo, a das Cigarras, em São Sebastião e da Fortaleza, em Ubatuba. A praia da Fortaleza é considerada abrigada, enquanto a de Cigarras é moderadamente abrigada. Em cada local e estação do ano, foram realizadas coletas aleatórias de 3 amostras que foram constituidas das frondes das algas e do sedimento retido por seus rizóides. Foi coletado também sedimento para caracterização da granulometria e teor de matéria orgânica de cada praia. Na Praia das Cigarras, predomina areia média e na Fortaleza, areia muito fina com menor porcentagem de matéria orgânica que a Praia das Cigarras. Neste local obteve-se valores mais elevados de densidade, riqueza, diversidade e dominância de anfípodes; enquanto que na Praia da Fortaleza, a equidade foi maior. A análise de MDS e de similaridade evidenciaram que as amostras de inverno foram as que mais se separaram das demais. A composição faunística se diferenciou entre as praias, contudo a distribuição sazonal foi similar. Na praia da Cigarras, as espécies mais abundantes foram Hyale nigra, Cymadusa filosa e Shoemakerella nasuta; e na praia da Fortaleza: Elasmopus rapax e Hyale nigra. Os valores da estrutura das comunidade obtidos apresentaram diferenças sazonais que podem ser atribuídas em parte aos fatores que relacionam a arquitetura e complexidade da alga com o sedimento por ela retido e, em parte, por diferenças no hidrodinamismo e pelo grau de influência antrópica refletido indiretamente pela granulometria e pelos teores de matéria orgânica disponível para os anfípodes / Abstract: The seasonal variance of the faunal composition, diversity and density of the amphipods associated to the green algae Caulerpa racemosa evaluated according to algae biomass and sediment trapped by it, was studied in two beaches of the northern coast of State of São Paulo: Cigarras at São Sebastião and Fortaleza, at Ubatuba. The Fortaleza Beach is considered sheltered, while the Cigarras Beach is considered moderately sheltered. In each place and season, 3 random samples were collected from algal frond with sediment hold by the rizoids. Sediment was also gathered, for granulometric characterization and organic matter content analysis. In Cigarras Beach, the sediment was mainly medium sand and in the Fortaleza Beach, very fine sand with less organic matter than Cigarras. In this beach, was obtained higher values of density, richness, diversity and dominance of amphipods, while in Fortaleza Beach, only the eveness was higher. In the MDS and cluster analysis, the samples from winter were the more isolated of all. The composition of the species differed in the two beaches; however it didn't differ seasonally. While in Cigarras Beach, the most abundant species were Hyale nigra, Cymadusa filosa and Shoemakerella nasuta; in Fortaleza Beach, the most abundant species were Elasmopus rapax and Hyale nigra. The values of community structure obtained presented seasonal differences which, at least in part, can be attributed to factors concerning the algal architecture and complexity as well as the sediment trapped by it, and in part too, to the degree of anthropic influence indirectly reflected by the organic matter content available to amphipods / Mestrado / Mestre em Ecologia

O crescimento acelerado da aqüicultura no estado de São Paulo, ou seja, a implantação de pesque-pagues e pisciculturas pode estar causando uma série de problemas ambientais. A contribuição para o processo de eutrofização é uma das conseqüências desses empreendimentos, pois tanto os tanques utilizados na piscicultura como os afluentes em torno desses estabelecimentos, estão sendo eutrofizados pelo excesso de nutrientes. Uma das conseqüências da eutrofização é o aparecimento de florações de cianobactérias, e a principal preocupação está nas toxinas liberadas por estas cianobactérias, que se ingeridas pelos seres humanos e animais, podem causar efeitos de intoxicação, como fraqueza, cefaléia, vômito e dependendo da concentração ingerida pode levar à morte. Desta forma é necessário que haja um programa de controle da qualidade da água dos tanques e reservatórios e também dos peixes que ali são criados, pois florações de cianobactérias vêm sendo encontradas em diversos corpos d\'água. Este estudo teve como foco a determinação da cianotoxina microcistina-LR, empregando técnicas como a extração em fase sólida e a cromatografia líquida para a detecção e quantificação da microcistina-LR em amostras de florações de cianobactérias. Os testes feitos com a extração em fase sólida demonstraram que esse procedimento não se faz necessário para todas as amostras, pois houve casos em que não se obteve diferença nos picos interferentes mais próximos ao tempo de retenção do analito de estudo. Como as matrizes desse tipo de amostras são muito complexas e variam muito conforme o meio em que se encontram, recomenda-se que sejam avaliados caso à caso a necessidade de se promover a extração em fase sólida, pois o mesmo é um processo que demanda um tempo maior de análise e conseqüente aumento nos custos. Foi determinado e validado um método cromatográfico considerado capaz de fornecer dados reproduzíveis e confiáveis, por meio de testes de seletividade, limite de detecção e de quantificação, linearidade, precisão, exatidão e recuperação, conforme critérios de aceitação da Resolução n°899 de 2003, da ANVISA. O limite de detecção do método ficou estipulado em 0,1 µg mL-1, e o limite inferior de quantificação em 0,5 µg mL-1, determinados conforme a relação sinal-ruído proposta pelo Guia de Validação de Métodos Bioanalíticos da ANVISA. A quantificação da microcistina-LR foi feita utilizando o método de superposição de matriz, que minimiza e/ou compensa o efeito de matriz ou de possíveis interferentes presentes na amostra, e a curva analítica obtida y = 1,5888+21,849 x, com um coeficiente de correlação de 0,997 mostra uma boa linearidade. Foram analisadas amostras de florações de cianobactérias, coletadas em pesque-pagues e pisciculturas situadas na região do Alto Mogi (subdivisão da bacia do Mogi Guaçu), conforme o método de extração e análise estudado. / The rapid growth of aquaculture in the state of São Paulo may be causing a number of environmental problems. The contribution to the eutrophication process is among the consequences of these undertakings, given that the tanks used in fish farming as well as the changes around these establishments are becoming eutrophic systems due to excessive nutrients. A frequent consequence of eutrophication in waters is the massive development of cyanobacteria.The occurrence of these blooms induces severe problems, as Microcystis aeruginosa, the most widespread distributed cyanobacteria, which can produce microcystin-LR. Toxic effects of MC have been described in liver, lungs, stomach, and intestine. Deaths in wildlife, livestock and human beings were also associated with microcystin exposition, which can occur directly by ingestion, inhalation, contact, intravenous inoculation of contaminated water (hemodialysis) or indirectly, by the consumption of animals, as fish and mollusks, the major ingestors of cyanobacteria and its toxins. Thus we need a program to control the quality of water tanks and reservoirs and also the fish breeded there, as cyanobacteria blooms have been found in various water bodies. This study focused on the determination of the cyanotoxins microcystin-LR, using techniques such as solid phase extraction and liquid chromatography for the detection and quantification of microcystin-LR in samples of cyanobacteria blooms. Tests performed with solid phase extraction showed that this procedure is not necessary for all the samples because there were cases where no difference was obtained in interfering peaks near the retention time of the analyte studied. As the parent of such samples are very complex and vary greatly, because the extracts contained too much coextrated material that interfered in the LC-UV detection, and depending on the way in which it is recommended to be assessed, case by case, the solid phase extraction needs to be promoted, because it is a process that demands a longer period of analysis and consequently an increase in costs. A liquid chromatography method was established and validated, which is deemed capable of providing reproducible and reliable data, by testing for selectivity, limit of detection and quantification, linearity, precision, accuracy and recovery, in accordance with the acceptance criteria of Resolution No. 899 of 2003 of ANVISA. The detection limit of the method was set at 0.1 µg mL-1, and the lower limit of quantification at 0.5 µg mL-1 determined according to the signal to noise ratio proposed by the Validation Guide of Bioanalytical Methods, ANVISA. Quantification of microcystin-LR was performed using the matrix-matched method, which minimizes and/or offsets the effect of possible matrix interference or present in the sample. The analytical curve obtained y = 1.5888 + 21.849 x, with a coefficient of correlation of 0.997 shows a good linearity. Real aquaculture samples were analyzed that were detected and quantified according to the method developed.

O uso intensificado de combustíveis fósseis como fonte de energia, vê-se a necessidade do desenvolvimento de novas tecnologias, principalmente as renováveis, como o hidrogênio, que possui vantagens por ser elemento abundante no universo, ser renovável e não poluente. A utilização de microalgas e cianobactérias é uma alternativa para a produção de biohidrogênio a partir da quebra da água e de compostos orgânicos. De acordo com isso, nesta pesquisa foram testados diversos fatores físico-químicos e nutricionais nas condições de cultivo de cepas de Chlamydomonas spp. e Anabaena spp. Para tanto, cepas selecionadas foram cultivadas em duas fases experimentais, a primeira aeróbia e a segunda anaeróbia, para proporcionar produção de hidrogênio por biofotólise direta anaeróbia, via hidrogenase, sob privação de enxofre para a clorofícea, e de nitrogênio para a cianobactéria, estimulando para esta também a produção por biofotólise indireta, via nitrogenase. A cepa com melhor produtividade de hidrogênio, de cada gênero, foi selecionada para a etapa de otimização das fases experimentais de cultivo. Durante os ensaios foram realizadas análises de produção máxima, velocidade de produção, volume e produtividade de hidrogênio, além de análises de concentração de biomassa, físico-químicas, bioquímicas e geração de subprodutos. O método utilizado foi eficiente para produção de hidrogênio e ficou comprovada a diferença de produção de hidrogênio entre diferentes cepas. Anabaena sp. obteve produtividade média de hidrogênio quatro vezes maior, aproximadamente de 76,8 µmol.L-1.h-1, comparada a C. reinhardtii, com média de 18,6 µmol.L-1.h-1. / The intensifying use of fossil fuels as energy source, one sees the need to develop new technologies, especially renewable, such as hydrogen. This has advantages because hydrogen is an abundant element in the universe, be renewable and non-polluting. The use of microalgae and cyanobacteria is an alternative for the production of bio-hydrogen of breaking water and organic compounds. Accordingly, in this study were tested several physic-chemical factors and nutrition in growing conditions of Chlamydomonas spp. and Anabaena spp. strains. For this purpose, strains selected were cultured in two experimental phases, first aerobic and second anaerobic, to hydrogen production by direct biofotolise anaerobic, via hydrogenase, under sulfur deprived to chlorofycea, and nitrogen to cyanobacterium, for this also to production by indirect biofotolise, via nitrogenase. The strain with highest productivity of hydrogen, of each gender, was selected for the optimization of the experimental stages of cultivation. During the tests were analyzes of maximum production, velocity, volume and productivity of hydrogen, and analysis of biomass concentration, physic-chemical, biochemical and generation of by-products. The method used was efficient for the production of hydrogen and was different between strains. Anabaena sp. obtained average yield four times highest, approximately 76.8 µmol. L-1.h-1compared to C. reinhardtii, averaging 18.6 µmol. L-1.h-1.

The symbiotic relationships often represent not only the permanent cohabitation of two organisms, but they can evolve and change over time. Many papers published so far focused on the the specificity of lichens, characterising both highly specific species and those that can establish a symbiosis with many algal genotypes. In this second case we can imagine the possibility of a photobiont exchange during the life of lichen - the dynamics of lichen symbiosis. In this thesis I compared the occurence and diversity of photobionts within the thalli of lichens growing on the disturbed localities and on the the localities without the disturbance. These two types of localities were similar to species richness of photobionts, but the disturbed localities dominated by the number of photobiont genera. These localities also reached a higher value of phylogenetic diversity. Conversely, non-phylogenetic analysis revealed the higher level of photobiont diversity on non-disturbed localities, where the core of diversity was formed by different lineages of Trebouxia. I have also found the lichens, which cooperate with different algae on disturbed and non-disturbed localities. The photobiont distribution presented in this paper shows the possibility of photobiont exchange during the community succesion. The...

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The brine shrimp lethality assay was used as a preliminary tool to screen eighteen seaweeds collected from the South African coast. Of the seaweeds tested, the red algae Plocamium corallorhiza and Hypnea rosea, and the green alga Halimeda sp., showed the most potent activity. The chemical investigation of P. corallorhiza resulted in the isolation and structural elucidation of five previously undescribed secondary metabolites, along with three known compounds and four possible artifacts of the extraction process. Standard spectroscopic methods and comparison with known compounds were used to determine the structures of the new metabolites. The new compounds included the linear halogenated monoterpenes 4,8-dibromo-1, 1-dichloro-3,7-dimethyl-2,6-octadiene (99), 4,6-dibromo-l, 1-dichloro-3,7-dimethyl-2,7-octadiene (100), 4,8-dibromo-l, 1,7-trichloro-3,7-dimethyl-2,5-octadiene (101) and 3,4,6,7-tetrachloro-3,7-dimethyl-l-octene (102) and the cyclic monoterpene 5-bromo-5-bromomethyl-I-chlorovinyl-2,4-dichloro-methylcyclohexane (103) while the known compounds were identified as 4-bromo-5-bromomethyl-1chlorovinyl-2,5-dichloro-methylcyclohexane (35), 1,4,8-tribromo-3, 7 -dichloro-3,7-dimethyl-1,5-octadiene (94) and 8-bromo-1,3,4,7-tetrachloro-3,7-dimethyl-1,5-octadiene (96). The four methoxylated compounds (104-107) were presumably formed via a standard substitution reaction between the halogenated monoterpenes 96 and 101 and MeOH, which was used as a component in the extraction solvent. With over 100 000 natural products having been reported, it has become necessary to employ an efficient dereplication strategy to quickly identify known compounds. A simple Gas Chromatography-Mass Spectrometry (GC-MS) method for the efficient physicochemical screening, identification and dereplication of Plocamium metabolites was developed. In this study the crude extracts of P. corallorhiza, P. cornutum and P. maxillosum were screened by GC-MS and the retention times and mass spectral fragmentation patterns of compounds 94, 96, 99 - 107 were used to quickly identify known and new compounds in the crude extracts of P. cornutum and P. maxillosum. This data indicated that compounds 99, 100, 103 were present in both P. corallorhiza and P.cornutum, while compound 102 was found to be present in P. corallorhiza, P. cornutum and P. maxillosum. These studies also indicated that ecotypes and chemotypes are not a significant feature of P. corallorhiza and P. cornutum. Different species of Plocamium (namely: P. corallorhiza, P. cornutum, and P. maxillosum) have very different chemical profiles, and GC may therefore have appreciable taxonomic application in the identification of the different Plocamium spp. which are endemic to South Africa.

Marine microorganisms are a key vector in global carbon cycling, supporting an annual flux of 5 – 12 gigatons of carbon to the ocean interior via the biological carbon pump. While methodological advances over the last half century have greatly advanced our understanding of the factors influencing variability in this flux, the contributions of individual components in the microbial food web remain poorly resolved. Utilizing a combination of laboratory, field and remote sensing studies, this dissertation addresses several different aspects of this challenge. In the second chapter, unsupervised learning methods are applied to a global bio-optical data set from biogeochemical Argo floats to identify six oceanic biomes characterized by distinct seasonal trends in vertical phytoplankton distributions. This study demonstrated the great potential for using data from autonomous profiling floats to generalize seasonal trends in vertical phytoplankton distributions across vast regions of the global ocean, while also providing new insight on the hydrological and biogeochemical drivers of this variability. The third chapter reports the development of a novel method for the direct measurement of chlorophyll a attributable to individual phytoplankton groups in natural samples via cell sorting by flow cytometry. Critically, this approach makes it possible to evaluate phytoplankton community structure in terms of a parameter measured by autonomous platforms, while simultaneously quantifying sources of variability not captured by existing methods. The fourth chapter investigates the environmental drivers of phytoplankton distributions within the Western Tropical South Pacific, providing a case study for the biogeographical provinces identified in chapter 2 while also investigating how biogeochemical gradients influence linkages between heterotrophic groups central to carbon cycling within the microbial food web. Chapter five reports series of experiments investigating cell physiology as a driver of predator-prey interactions between heterotrophic bacteria and algal phagomixotrophs—eukaryotic algae that supplement requirements for carbon and/or nutrients by ingesting smaller cells. By validating the predictions of a gene-based model of algal trophic modes, the results from these experiments point toward the potential widespread occurrence of phagomixotrophy amongst green algae, while highlighting potential sources of bias in field and laboratory studies of bacterivory. With global climate change expected to produce rapid changes in ocean circulation and biogeochemistry, the urgency of understanding the role of marine microbes in global biogeochemical cycling has never been greater. This dissertation represents an advance in this larger goal, providing an expanded framework for the broad distribution of microbial communities in addition to novel insight into the environmental and physiological drivers of microbial community structure from the global to cellular scale.