Examensarbete.

Os xenóbioticos são potenciais contaminantes dos recursos hídricos, o que interfere no equilíbrio ecológico e na saúde humana. Uma potencial solução para tais problemas ambientais é a introdução da técnica de biorremediação. Para tanto, é necessário investigar genes da comunidade microbiana com potencial genético para degradação e resistência desses contaminantes e, assim, desenvolver biotecnologias para a descontaminação de ambientes poluídos. O presente estudo teve como objetivo extrair o DNA da microbiota total, da microbiota cultivável e dos isolados bacterianos provenientes de amostras de água superficial de mananciais e fontes do estado de São Paulo para investigar e padronizar reações de Multiplex PCR para os genes de degradação e resistência aos diferentes xenobióticos alvo do presente projeto de pesquisa. Os genes pesquisados foram amplamente encontrados no DNA da fração total, sendo os genes alkB, alk e merA os mais prevalentes na fração cultivável, indicando que micro-organismos portadores desses genes podem ser isolados para uso em processos de biorremediação. Os genes puhA e puhB foram detectados em menor frequência, tanto na fração total, quanto na cultivável, demonstrando pouca dispersão desses genes nas amostras estudadas. Os gêneros bacterianos portadores de genes de degradação isolados em maior frequência nas amostras de água analisadas foram Bacillus e Aeromonas e os genes mais frequentes nesses isolados foram o atzA, o alk e o merA. Para otimizar a detecção dos genes envolvidos na biodegradação da atrazina, dos hidrocarbonetos aromáticos policíclicos, alcanos e resistência ao cobre, duas reações de Multiplex PCR foram padronizadas / Xenobiotics are potential contaminants of water resources, which interfere in the ecological balance and human health. A potential solution to such environmental problems is the introduction of the bioremediation. Therefore, it is necessary to investigate genes from the microbial community with degrading and resistance genetic potential to these contaminants and, thus, to develop biotechnologies for the decontamination of polluted environments. The present study aimed to extract DNA from the total microbiota, cultivable microbiota and bacterial isolates from 19 surface water samples from sources of the São Paulo State to investigate and standardize Multiplex PCR reactions for degradation and resistance genes to the different xenobiotics target of the present research project. The studied genes were widely found in the DNA from the total fraction, being the alkB, alk and merA genes the most prevalent in the cultivable fraction, indicating that microorganisms carrying these genes can be isolated for use in bioremediation processes. The puhA and puhB genes were detected at lower frequency, both in the total and in the cultivable microbiota, showing little dispersion of these genes in the studied samples. Bacillus and Aeromonas were the most frequent bacterial genera with degradation genes isolated in the analyzed water samples, and the most frequent genes in these isolates were atzA, alk and merA. To optimize the detection of the genes involved in the biodegradation of atrazine, polycyclic aromatic hydrocarbons, alkanes and copper resistance, two reactions of Multiplex PCR were standardized.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2009. / Härtill 4 uppsatser.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-07-27T15:07:10Z No. of bitstreams: 1 DAYVISON JOSÉ NUNES DO NASCIMENTO - DISSERTAÇÃO (PPGECA) 2016.pdf: 2467199 bytes, checksum: 6112558d9b477651302684cf6df39802 (MD5) / Made available in DSpace on 2018-07-27T15:07:10Z (GMT). No. of bitstreams: 1 DAYVISON JOSÉ NUNES DO NASCIMENTO - DISSERTAÇÃO (PPGECA) 2016.pdf: 2467199 bytes, checksum: 6112558d9b477651302684cf6df39802 (MD5) Previous issue date: 2016-08-26 / Capes / Corpos hídricos superficiais são mais susceptíveis à contaminação por agrotóxicos devido às atividades agrícolas desenvolvidas em suas áreas de recarga. Este trabalho avaliou a presença de agrotóxicos do grupo carbamato e piretróide em águas brutas e tratadas dos reservatórios Epitácio Pessoa (Boqueirão), a montante, e Argemiro de Figueiredo (Acauã), a jusante da região hidrográfica do médio curso do rio Paraíba, por meio de metodologia analítica por cromatografia líquida de alta eficiência. Os resultados indicaram que as metodologias apresentaram seletividade, linearidade (R² ≥ 0,9982), precisão e exatidão (DPR ≤ 4,27 %) e robustez, dentro das especificações estabelecidas pela ANVISA e Inmetro. Do grupo químico carbamato, foram detectados os agrotóxicos aldicarbe sulfona, carbaril e metiocarbe no reservatório de montante e aldicarbe sulfona no reservatório de jusante. Todas as concentrações mantiveram-se dentro dos limites exigidos pelos padrões de potabilidade de água de consumo humano, nacional e/ou internacionais. Apenas o agrotóxico carbaril não apresentou conformidade com a Resolução CONAMA 357/2005, que define as concentrações máximas permitidas para enquadramento de águas superficiais. Do grupo químico piretróide foram detectados os agrotóxicos ciflutrina e flumetrina em ambos os reservatórios estudados. A concentração do agrotóxico cilfutrina manteve-se dentro do padrão de potabilidade internacional, no entanto o princípio ativo flumetrina não apresenta valores limites indicados nos padrões de potabilidade nacional e internacionais. O tratamento convencional para potabilização de água empregado na área de estudo não se mostrou eficiente para a remoção de agrotóxicos. / Superficial water bodies are more susceptible to pesticide contamination due to agricultural activities in their recharging areas. This study evaluated the presence of carbamate and pyrethroid pesticides group in raw and treated waters from the upstream reservoir Epitácio Pessoa (Boqueirão) and the downstream reservoir Argemiro de Figueiredo (Acauã), in the hydrographic region of the middle course of Paraiba River, northern Brazil, through an analytical methodology by high-performance liquid chromatography. Results indicated that the methodology presented selectivity, linearity (R² ≥ 0.9982), accuracy and precision (RSD ≤ 4.27%) and robustness within the specifications set by ANVISA and Inmetro. Of Chemical group carbamate, the pesticides aldicarb sulfone, carbaryl and methiocarb were detectes in the upstream reservoir and aldicarb sulfone was detectes in the downstream reservoir. All concentrations have remained within the limits required by the national and/or international drinking water standards. Only the pesticide carbaryl did not show compliance with Resolution 357/2005, of Brazilian Environment Ministry, which defines the maximum allowable concentrations for classification of surface waters. The pyrethroid chemical group the cyfluthrin and flumethrin pesticides were detected in both studied reservoirs. The concentration of the pesticide cilfutrina remained within the international potability standard, however the active flumethrin principle has no limits indicated in the standards of national and international potability. Conventional water treatment applied in the study area did not show ability for the removal of carbamate pesticides.

Thesis (M. Tech. - Dept. of Chemistry, Faculty of Applied and Computer Sciences) -- Vaal University of Technology, 2010 / The increased production and application of pesticides for agricultural and non-agricultural purposes has caused the pollution of air, soil, ground and surface water. This has a negative impact on the environment as well as human health due to direct exposure or through residues in food and drinking water. The continuous monitoring of pesticides residues in environmental samples has great importance and demands high efficiency, unique selectivity and high sensitivity techniques. Gas chromatography and high performance liquid chromatography have been established for years as the techniques for the analysis of pesticides residues. The dissertation deals with the qualitative and quantitative determination of selected pesticides in the Southern Gauteng region using Liquid- liquid extraction solid-phase extraction, high performance liquid chromatography, gas chromatography equipped with electron capture detector and gas chromatography mass spectrometry. Liquid-liquid extraction and solid-phase extraction using dichloromethane, hexane and ethyl acetate as the extracting solvent were optimized and evaluated for the determination of pesticides in surface water in the Southern Gauteng region. From the developed method the techniques were applied to water samples taken from different rivers selected namely: Zuikerbosch, Rand Water barrage and Kliprivier for sampling. Dichloromethane was used as a solvent in this study since a recovery test was done between dichloromethane, Ethyl acetate and n-hexane. The percentage recovery test for 4,4-DDT, 4,4-DDE, 2,4-DDD and Endosulfan 1 & 2 ranged from 89.9% -97.3% for dichloromethane, 87.3%-96.8% for hexane 88.4%-97.1% for ethyl acetate. The extracts obtained were subjected to column chromatography for clean up. Thereafter 1µl of the cleaned extracts were injected into the Gas chromatography equipped with an electron capture detector. Organochlorines 4,4-DDT and its metabolites, Organophosphate Chlorypyriphos and carbamates were detected using Gas chromatography electron capture, Gas chromatography mass spectrometry and high performance liquid chromatography.