Navegando por Orientadores "SCHNEIDER, Maria Paula Cruz"

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Acesso aberto (Open Access)
Análise do crescimento e perfil bioacumulativo da cianobactéria Geitlerinema unigranulatum UFV-E01 na presença de arsenato de sódio
(Universidade Federal do Pará, 2012-07-31) GOMES, Laise de Azevedo; SCHNEIDER, Maria Paula Cruz; http://lattes.cnpq.br/3901112943859155
Arsenic is a toxic metalloid that has become a public health problem worldwide. In order to reduce the environmental contamination by this metalloid, which is derived from natural and anthropogenic activities, the use of micro-organisms in bioremediation process has shown to be a promising strategy. A filamentous homocitada cyanobacterium belonging to the order Pseudanabaenales, Geitlerinema unigranulatum UFV-E01, was isolated from an environment contaminated by arsenic, suggesting an ability to deal with the toxic effect of this metalloid. In view of this, this study aimed to characterize the resistance to sodium arsenate and quantify the total arsenic extracellular cyanobacterium G. unigranulatum UFV-E01. Analyses of sodium arsenate resistance showed that the cyanobacterium was able to grow in 50 mM for 20 days. Furthermore, the cyanobacterium G. unigranulatum UFV-E01 accumulated sodium arsenate for 10 days, reducing up to 67% arsenic extracellular. From the data obtained in this study, the cyanobacterium G. unigranulatum UFV-E01 was able to withstand high concentrations of sodium arsenate, although other analysis, the characterization of the metabolic pathways involved in the resistance must be taken to consider their use in environments impacted by arsenic.
Acesso aberto (Open Access)
Cianobactérias e poluição da água: uma sequência didática para o ensino de ciências ambientais
(Universidade Federal do Pará, 2018-12-05) ATROCH, Rosa de Fátima Silva; MALCHER, Maria Ataide; http://lattes.cnpq.br/5418062253829906; SCHNEIDER, Maria Paula Cruz; http://lattes.cnpq.br/3901112943859155
This dissertation describes the process of elaboration, implementation and validation of a didactic sequence (SD) to explore the theme "Cyanobacteria and water pollution" with 6th grade students. The purpose of this study is to propose a didactic sequence to facilitate the practical approach of the subject by science teachers to 6th grade students, to test SD with teachers and to evaluate the use of SD in the learning process on the subject. This study was carried out in three state schools that offer the 6th year of elementary education in the urban area of the municipality of Soure, Marajó Island (PA). They are: School in Agreement Regime Stella Maris Institute, State School of Elementary and Middle School Professor Edda de Sousa Gonçalves and Escola Estadual de Ensino Fundamental e Médio Gasparino Batista da Silva. The teaching strategies used to formulate the SD and reach the learning objectives were thought based on the integrated constructivist model of Martine Méheut, which is based on the concepts of Didactic Engineering. The stages of SD elaboration, implementation and validation followed the following methodological organization: 1) The previous analysis: in order to define SD objectives and requirements, on-site observations and questionnaires were applied to teachers. 2) Conception: stage of planning and review of the activities that constitute the didactic sequence. 3) SD experimentation, implementation, validation and analysis: this stage was divided in validation and analysis with teachers, where SD was presented to the teachers in the form of a workshop and evaluated from an array of requirements by the five Science teachers of the three state schools present in the municipality of Soure - Marajó - Pará. And experimentation, implementation and validation with students with application of a pre-test and a post-test to 43 students distributed in two classes of the 6th year of the Stella Maris school. The data were analyzed by the qualitative method, and it was possible to conclude that the didactic sequence was validated as a resource applicable to the science classes in the context of the three state schools located in Soure. For the present study, which represents the first use of the didactic sequence produced, the results were satisfactory. However, they are not definitive, since SD should be tested, reviewed, used and validated in future contexts.
Acesso aberto (Open Access)
Cianotoxinas em ostras e em águas de cultivo da costa norte do Brasil
(Universidade Federal do Pará, 2016-08-31) CABRAL, Jardecicléia Patrícia da Silva; SCHNEIDER, Maria Paula Cruz; http://lattes.cnpq.br/3901112943859155
Cyanobacteria are photosynthetic prokaryotic organisms and under conditions favorable to their growth can form blooms. They are also capable of producing cyanotoxins, secondary metabolites that have a toxic effect on eukaryotic organisms including man. As part of phytoplankton the cyanobacteria participate in the food chains, thus the ingestion of shellfish, that have been continuously fed toxic cyanobacteria and accumulated the toxins in their tissues generates the possibility of transfer to the man through their consumption bringing serious risks to their health. There is still very little research on the contamination (by cyanotoxins) of shellfish intended for human consumption. Therefore, this study was to verify the occurrence of cyanotoxins in culture waters and in the tissue of oysters destined for human consumption. The water and oyster samples were collected from two municipalities located in the northeast of Pará. The cyanotoxins research was performed using High Performance Liquid Chromatography (HPLC). The cyanobacteria present in the water, isolated and cultured from oyster shells were identified. No microcystins and saxitoxins were detected in water samples and oyster extracts from both growing sites. However, three genera of cyanobacteria - Aphanizomenon, Oscillatoria and Phormidium were identified in Curuçá and three genera of cyanobacteria in São Caetano de Odivelas - Aphanothece, Oscillatoria and Phormidium, all known to contain toxic species. The presence of saxitoxins in extracts from cyanobacterial cultures was detected from the oyster shells of both growing sites, indicating the presence of toxic species despite the absence of bloom. In this study, it was verified that the cultivation of oyster sites are suitable for consumption, free of contamination by microcystins and saxitoxins, however, it is necessary to implement specific legislation and the monitoring of these crops in order to ensure consumer health.
Acesso aberto (Open Access)
Monitoramento por sensoriamento remoto da concentração de clorofila-a e das florações de cianobactérias no Baixo Tapajós : audiovisual praias do Tapajós para gerações presentes e futuras
(Universidade Federal do Pará, 2020-02-10) ARAÚJO, James Leão de; MALCHER, Maria Ataíde; http://lattes.cnpq.br/5418062253829906; SCHNEIDER, Maria Paula Cruz; http://lattes.cnpq.br/3901112943859155
The Tapajós River is the fifth largest river in the Amazon Basin. From Aveiro to Santarém, it resembles a lake and favors the eutrophication process. It is under pressure such as: deforestation, gold mining, use as a waterway and tourism. The beaches between Santarém and Belterra, gained evidence when in 2009 the newspaper The Guardian, chose Alter do Chão as the best beach in Brazil. The growth of tourist activities and infrastructure was notable. In 2015 after bathing water quality analyzes, Alter do Chão was banned. The increase in planktonic blooms has been observed by popular researchers since the 1990s. Extending the studies, 2450 km2 of remote sensing was monitored from Aveiro to Santarém, obtaining the blooming areas of cyanobacteria, concentrations of chlorophyll-a, nutrient pollution and risk levels for contact activities. The occurrence of cyanobacteria is linked to variations in rainfall and river level. The greatest health risks occur at the maximum points of drought in November and flooding in May. The areas with the highest occurrence of blooms and the highest concentrations of chlorophyll-a are upstream from the beaches of intense use. The increase in human activities and the occupation of the soil, may be responsible for the increase in flowering. This information must be disseminated through a didactic-informative product for Basic Education. An audiovisual was produced for application in Basic Education called “Praias do Tapajós For Present and Future Generations”, as the time of 23’16” divided into 07 blocks related to the researched content. The audiovisual was applied in six classes of two schools of basic education, in the High School, being one in Belém the Federal Institute of Pará and another in Santarém the São Raimundo Nonato State School, totaling eleven hours of application. The audiovisual product was validated through a 'likert' questionnaire, observing conceptual points related to the acquired knowledge, relationship with studied contents, involvement in environmental issues and quality of the material presented. The average rejection rates were always below 25% while approval was always above 75%.
Acesso aberto (Open Access)
Reconstrução e modelagem in silico da via de biossíntese de ácidos graxos da bactéria psicotrófica Exiguobacterium antarticum linhagem B7
(Universidade Federal do Pará, 2016-04-04) FRANCÊS, Regiane Silva Kawasaki; SCHNEIDER, Maria Paula Cruz; http://lattes.cnpq.br/3901112943859155
Mathematical modeling in silico based restrictions is an approach adopted by systems biology to analyze metabolic networks. The Gram-positive bacterium Exiguobacterium antarticum B7 is an extremophile organism able to survive in cold environments as glacial ice and permafrost. The ability of these microorganisms of adaptation to cold attracts great biotechnological interest. An important factor for the understanding of cold adaptation process is related to the chemical modification of fatty acids constituting the cell membrane of psicotrophic bacteria in order to maintain membrane fluidity to avoid freezing ofthe bacteria. In this work, the metabolic pathway of fatty acid biosynthesis of the bacterium E. antarticum B7 was rebuilt from its annotated genome. The software tools KEGG (Kyoto Encyclopedia of Genes and Genomes) and RAST (The Rapid Annotation Server) were used to generate a preliminary network model. The next step was to cure manually the genomic, biochemical and physiological informations available in different databases and specific literature. During this process, the FabZ and DesK enzymes responsible for adding carbon-carbon unsaturations in the fatty acid chain during synthesis have been identified in the genome, though in a truncated form. The fluxome metabolic pathway was defined, describing the routes of the main reactions since the first monomer, Acetyl-CoA, to the final product, the Hexadecenoic acid. A computational modeling was done using the software MATLAB® with toolboxes and specific tools for systems biology. The quantification of metabolites produced via was performed by the method constraint-based Flux Balance Analysis (FBA). To evaluate the influence of the gene expression in the fluxome analysis, the FBA method was also calculated using the log2FC values obtained in the transcriptome analysis at 0ºC and 37ºC. The fatty acid biosynthesis pathway showed a total of 13 elementary flux modes, four of which showed routes for the production of hexadecenoic acid. The reconstructed pathway demonstrated the capacity of E. antarcticum B7 to produce fatty acid molecules. Under the influence of the transcriptome, the fluxome was altered, promoting the production of short-chain fatty acids. The calculated models contributes to better understand the bacterial adaptation at cold environments.
Acesso aberto (Open Access)
Resistência e bioacumulação de arsênio na cianobactéria Phormidium sp
(Universidade Federal do Pará, 2012-07-31) FERREIRA, Anna Rafaella dos Santos; SCHNEIDER, Maria Paula Cruz; http://lattes.cnpq.br/3901112943859155
Environmental contamination by arsenic has been increasing in recent years, either through natural or anthropogenic sources, which can cause greater exposure of humans to this toxic compound. Several studies have been developed to analyze the capacity of cyanobacterial species in bioremediation. The filamentous cyanobacterium Phormidium sp. excels due to well developed mechanisms to adapt to different environmental conditions. The present study aimed to analyze the resistance profile of Phormidium sp. at different concentrations of sodium arsenate. The cyanobacterium was inoculated in tubes containing 4 ml of BG-11 liquid medium and different concentrations of arsenate (5, 10, 30, 50, 100, 130, 150, 200 and 250 mM) without the presence of metalloid (control) and cultured for 20 days at 25 ° C without agitation and with a photoperiod of 12/12 h light / dark. The toxicity of arsenate to Phormidium sp. has been characterized by growth inhibition being determined by the concentration of chlorophyll a. All conditions were performed in triplicate. The determination of total arsenic in the samples was obtained using the technique of optical emission spectrometry with inductively coupled plasma, the Instituto Evandro Chagas. The resistance of Phormidium sp. to arsenate was observed up to 50 mM of compound (p>0.05). Growth inhibition was observed above 100mM of arsenate (p<0.05). The analyzes of the total dose of arsenic in the culture medium showed that during the first day of experiment, the concentration of arsenic in the culture medium was lowered, followed by a gradual increase in the concentration of this metalloid. Probably, this cyanobacteria can accumulate arsenic and later excrete this metalloid to the extracellular medium. The results indicate the ability of the cyanobacterium Phormidium sp. has to grow in medium containing high concentrations of arsenic. However, other analyzes become fundamental for elucidating the metabolic pathways involved in the process of resistance to this metalloid.