Made available in DSpace on 2014-12-17T14:06:53Z (GMT). No. of bitstreams: 1 CelinaMOLMpdf.pdf: 4472262 bytes, checksum: 97155ddc7b087b9fcfe3f9151a0b8996 (MD5) Previous issue date: 2009-05-22 / The red ceramic industry is recognized as of major importance in Piau? State. The State capital, Teresina, is the greatest producer of this material ( production about 18 million peaces), which is used mainly for masonry sealing blocks. One of the most frequent problems in this kind of products is the efflorescence. This work has the main objective of studying the influence of gypsum addition on non-glazed tiles, by using the local industry production standards. The raw materials were characterized by FRX, DRX, TGA, DTA and AD. Extruded test specimens were made with the addition of 1, 3 and 5% of gypsum in the ceramic paste, burned at 850oC, 950oC and 1050oC and submitted to further technological tests and microestrutural analysis by the scanning electron microscope. In order to accelerate the aging of bodies of evidence, they were immersed in successive water baths and posterior drying. The reference ceramic paste showed tendency to efflorescence formation after drying and consolidated efflorescence after burning, but no affecting the technological results / A ind?stria de cer?mica vermelha ? refer?ncia no Estado do Piau?. Constitui o maior p?lo produtor localizado na capital, Teresina, com produ??o m?dia mensal de 18 milh?es de pe?as, principalmente, de telhas cer?micas. Uma das principais patologias observadas nesse tipo de produto ? o surgimento de efloresc?ncias. Este trabalho visa estudar a influ?ncia da gipsita no surgimento de efloresc?ncias em telhas cer?micas n?o esmaltadas, utilizando padr?es de produ??o da ind?stria local. As mat?rias-primas foram caracterizadas por fluoresc?ncia de raios-X, an?lise mineral?gica por difra??o de raios-X, ensaios t?rmicos e determina??o de sais sol?veis em sulfatos. Foram confeccionados corpos-de-prova por extrus?o, adicionando-se percentuais de 1%, 3% e 5% de gipsita ? massa cer?mica, queimados a 850oC, 950oC e 1050oC. Ap?s sinteriza??o, os corpos-de-prova foram submetidos a ensaios tecnol?gicos e caracteriza??o microestrutural. Para acelerar o envelhecimento, os corpos-de-prova foram submetidos a sucessivos banhos de imers?o em ?gua e posterior secagem. As amostras com adi??o de 1% e 3% de gipsita n?o apresentaram efloresc?ncia ap?s queima. As amostras com adi??o de 1% e 3% de gipsita conduzem a resultados tecnol?gicos satisfat?rios ap?s queima a 950oC, por?m a gipsita n?o reagente aflora ? superf?cie dos corpos-de-prova logo ap?s a primeira imers?o em ?gua.Os corpos-de-prova com 5% de gipsita apresentaram efloresc?ncia de secagem que se consolidou ap?s queima. Os resultados demonstram que o sulfato de c?lcio, oriundo da gipsita, provoca o surgimento de efloresc?ncia

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:03:29Z No. of bitstreams: 5 nathalia.pdf: 1483380 bytes, checksum: acf5f07f37d0cff8f8dc49c87a364666 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T09:40:07Z (GMT) No. of bitstreams: 5 nathalia.pdf: 1483380 bytes, checksum: acf5f07f37d0cff8f8dc49c87a364666 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T09:40:07Z (GMT). No. of bitstreams: 5 nathalia.pdf: 1483380 bytes, checksum: acf5f07f37d0cff8f8dc49c87a364666 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-21 / O vinho ? uma das bebidas mais antigas e tradicionais produzidas e consumidas pela humanidade. Nas ?ltimas d?cadas a busca por qualidade nos produtos aliment?cios impulsionaram a pesquisa em t?cnicas anal?ticas capazes de fornecer resultados mais r?pidos e precisos. Neste contexto, m?todos anal?ticos que possam mensurar par?metros de qualidade de forma simult?nea para um grande n?mero de amostras constitui-se ferramenta desej?vel para processo de escala industrial. A espectroscopia no infravermelho pr?ximo (NIR) aparece como uma ferramenta de consider?vel import?ncia para a ind?stria de vinhos, permitindo o estabelecimento de in?meras metodologias anal?ticas. Dessa forma, o trabalho desenvolvido nesta disserta??o teve por objetivo usar a espectroscopia no infravermelho pr?ximo e ferramentas de an?lise multivariada de dados para o estabelecimento de protocolo quimiom?trico de an?lise da qualidade f?sico-qu?mica de vinhos tintos. As amostras de vinho foram analisadas quanto a 21 par?metros f?sico-qu?micos por meio de m?todos laboratorias enol?gicos de refer?ncia e por espectroscopia na regi?o eletromagn?tica do infravermelho pr?ximo. Os dados das t?cnicas de refer?ncia e os dados espectrosc?picos foram analisados utilizando diferentes tipos de regress?o (regress?o linear m?ltipla, regress?o por componentes principais e regress?o por m?nimos quadrados parciais) e pr?-processamentos para avalia??o de correla??o entre os dados. Os par?metros de acidez total, acidez fixa, cinzas e rela??o etanol/extrato seco obtiveram excelentes modelos de calibra??o. Os par?metros de a??cares redutores totais, extrato seco, glicerol, glicose e intensidade da cor, obtiveram bons modelos de calibra??o. Os par?metros de s?lidos sol?veis totais, compostos fen?licos, a??cares redutores, taninos e tonalidade obtiveram modelos de calibra??o capazes de separar corretamente os altos, m?dios e baixos valores. Para os par?metros de pH, antocianinas, di?xido de enxofre livre, di?xido de enxofre total e sulfatos totais foram obtidos modelos de calibra??o ruins. Os dados obtidos demonstraram que a espectroscopia no infravermelho pr?ximo combinada a ferramentas de an?lise multivariada de dados aplica-se na determina??o de alguns analitos enol?gicos. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012. / ABSTRACT The wine is one of the oldest beverage produced and consumed by humanity. In the last years, the research in food quality are looking for a new analytical techniques more precise, faster and accurate. In this way, the wineries demand for new analytical methods that can provide simultaneous data for a large number of analyses. The near infrared spectroscopy (NIR) is a very important analytical tool in wine industry, allowing the establishment of numerous analytical methodologies. In that way, the work developed for this dissertation aimed use near infrared spectroscopy and multivariate data analysis tools for the establishment of chemometric analysis of physicochemical quality of red wines. The wine samples was analyzed for 20 parameters using enological laboratorial methods and by using near infrared spectroscopy. The chemical an spectroscopic data was analyzed using different types of regression (multiple linear regression, principal components regression and least partial squares) and preprocessing tools to evaluate the correlation between the data. The total acidity, fixed acidity, ash, ethanol/dry extract relation had a excellent correlation model. The total reducing sugar, dry extract, glycerol, glucose and color intensity had a good correlation model. The total soluble solids, phenolic compounds, reducing sugar, tannins and tonality had a calibration model able to separate correctly the high, meddle and low values. The ethanol, pH, anthocyanins, free sulfur dioxide, total sulfur dioxide, total sulfates and volatile acidity had a bad correlation model. The results showed that near infrared spectroscopy and multivariate analysis tools can be used for determinations in enological quality control.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:44Z No. of bitstreams: 5 ale.pdf: 2255523 bytes, checksum: 7080bc1f5ac0e98cef0030c1f04a51b3 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T10:24:21Z (GMT) No. of bitstreams: 5 ale.pdf: 2255523 bytes, checksum: 7080bc1f5ac0e98cef0030c1f04a51b3 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T10:24:21Z (GMT). No. of bitstreams: 5 ale.pdf: 2255523 bytes, checksum: 7080bc1f5ac0e98cef0030c1f04a51b3 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-21 / Na atualidade, n?o se pode desconsiderar a necessidade de desenvolvimento de tecnologias que suportem as demandas por energias renov?veis. Uma das vias para a produ??o de energia renov?vel ? a transforma??o de biomassas vegetais em combust?veis l?quidos. Os res?duos agroindustriais s?o candidatos potenciais como insumos para essa nova ind?stria de energia. Dessa forma a presente disserta??o teve por objetivo avaliar o potencial da torta de caro?o de algod?o e do baga?o de malte com farinha de pupunha como mat?rias-primas para a produ??o de etanol de segunda gera??o e otimizar etapa de pr?-tratamento ?cido do material lignocelul?sico necess?ria para a utiliza??o da celulose. Inicialmente foi determinada a composi??o centesimal da torta de caro?o de algod?o e do baga?o de malte em rela??o aos valores percentuais de umidade, cinzas, extrato et?reo, prote?na bruta, a??cares sol?veis totais, amido, hemicelulose, celulose, lignina, fibra em detergente neutro e fibra em detergente ?cido. Com os resultados da caracteriza??o qu?mica p?de-se estimar uma produ??o potencial superior a 300 L de etanol/tonelada de cada res?duo. Para a otimiza??o do pr?-tratamento ?cido para remo??o da fra??o hemicelul?sica foi aplicada metodologia de Planejamento Fatorial atrav?s de Delineamento Composto Central Rotacional. O programa STATISTICA Vers?o 8.0 (Statsoft Inc., Tulsa,) foi utilizado para an?lise dos dados. A qualidade do ajuste da equa??o do modelo foi expressa pelo coeficiente de determina??o (R?) e sua signific?ncia estat?stica condicionada pelo teste-F. O material insol?vel recuperado ap?s o pr?-tratamento otimizado teve as fra??es hemicelul?sicas e de amido completamente removidas. O hidrolisado obtido em condi??es otimizadas de pr?-tratamento apresentou 15,7% de a??cares redutores para o baga?o de malte e pupunha e 5,9% de a??cares redutores para a torta de caro?o de algod?o. O tratamento dos hidrolisados com carv?o ativado removeu n?o menos que 58% dos compostos fen?licos a? presentes. Os testes de fermentabilidade com Saccharomyces cerevisiae e Pichia stipitis foram promissores. A fermenta??o com S. cerevisiae apresentou um YP/S de 0,30 para a torta de caro?o de algod?o e 0,37 para o baga?o de malte. Os rendimentos fementativos com P. stipitis variaram de 9% a 25% para os res?duos agroindustriais. Os dados experimentais indicam que a torta de caro?o de algod?o (Gossypium hirsutum L.) e baga?o malte com farinha de pupunha tem elevado potencial para a produ??o de bioetanol. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012. / ABSTRACT Nowadays, one cannot ignore the need for developing technologies that support the demands for renewable energy. One of the pathways for production of renewable energy is the transformation of vegetal biomass to liquid fuels. The agro-industrial residues as raw materials are potential candidates for this new energy industry. Thus the aim of the present dissertation was to evaluate the potential of cottonseed cake and crushed malt with peach palm flour as raw materials for the production of second generation ethanol and optimize step of acid pretreatment of lignocellulosic material. Initially was determined the chemical composition of cotton seed cake and crushed malt in relation to the percentages of moisture, ash, ether extract, crude protein, total soluble sugars, starch, hemicellulose, cellulose, lignin, neutral detergent fiber and acid detergent fiber. With the results of chemical characterization it was possible to estimate a potential yield of more than 300L of ethanol / ton of each residue. For the optimization of acid pretreatment for hemicelluloses removal was applied a Central Composite Design. The software STATISTICA Version 8.0 (Statsoft Inc., Tulsa,) was used for data analysis. The goodness of fit of the model equation was expressed by the coefficient of determination (R?) and its statistical significance conditioned by F-test. The insoluble material recovered after the optimized pretreatment had starch and hemicellulose fractions completely removed. The hydrolyzate obtained under optimized conditions of pretreatment showed 15.7% of reducing sugars to the crushed malt and 5.9% of reducing sugars for cottonseed cake. The treatment of the hydrolysates with activated charcoal removed no less than 58% of the phenolic compounds present there. Fermentability tests with Saccharomyces cerevisiae and Pichia stipitis have been promising. Fermentation with S. cerevisiae showed a YP/S of 0.30 for cottonseed cake and 0.37 for the crushed malt. Fermentative yields with P. stipitis ranged from 9% to 25% for agro-industrial residues. The experimental data indicate that the cottonseed cake (Gossypium hirsutum L.) and crushed malt has a high potential for the production of bioethanol.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:45Z No. of bitstreams: 5 wil.pdf: 5662404 bytes, checksum: fbb7ee80707ec5b04e9341e471b178d8 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T10:42:14Z (GMT) No. of bitstreams: 5 wil.pdf: 5662404 bytes, checksum: fbb7ee80707ec5b04e9341e471b178d8 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T10:42:14Z (GMT). No. of bitstreams: 5 wil.pdf: 5662404 bytes, checksum: fbb7ee80707ec5b04e9341e471b178d8 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-20 / O Cerrado apresenta grande diversidade de esp?cies vegetais nativas, muito utilizadas na medicina popular e com pouco ou nenhum estudo cient?fico. Entre essas esp?cies, destaca-se a Blepharocalyx salicifolius (Kunth) O. Berg (Myrtaceae), conhecida como ?Maria-preta?, ?Guamirim? ou ?Murta?. A medicina tradicional recomenda o uso das folhas na forma de infus?o, como antidiarreico, contra infec??es urin?rias e respirat?rias. Estudos evidenciam atividade antimicrobiana do ?leo essencial e leishmanicida do extrato etan?lico das folhas. Estudos fitoqu?micos revelaram a presen?a de compostos fen?licos no extrato e terpenos no ?leo essencial. Geralmente, a constitui??o qu?mica de ?leos essenciais oriundos de um mesmo esp?cimen vegetal e obtidos de plantas de uma mesma esp?cie pode apresentar varia??es qualitativas e quantitativas, em virtude de fatores gen?ticos, ambientais e ontog?nicos. ? importante estudar essas varia??es qu?micas, pois isso pode apresentar implica??es nas atividades biol?gicas de produtos da planta. Al?m disso, tais estudos podem servir para determina??o de marcadores qu?micos ou auxiliar no controle de qualidade do ?leo essencial. Assim, este trabalho teve como principal objetivo observar varia??es qualitativa e quantitativa na composi??o qu?mica do ?leo essencial extra?do de folhas de quatro esp?cimens (BS1, BS2, BS3 e BS4) de B. salicifolius, em tr?s per?odos do dia e nas quatro esta??es do ano. Realizou-se a coleta em habitat natural da esp?cie, na Reserva Guapuruvu da Arcelor Mittal, em Itamarandiba-MG. Procedeu-se a extra??o dos ?leos essenciais de folhas frescas atrav?s de hidrodestila??o em Aparato de Clevenger. Calculou-se o rendimento de cada amostra extra?da (v/m). Efetuou-se a an?lise qualitativa e quantitativa dos componentes dos ?leos essenciais por Cromatografia Gasosa acoplada ? Espectrometria de Massas (CG/EM) e ?ndice de Reten??o Relativa (IRR). O maior rendimento extrativo de ?leo essencial, para todos os esp?cimens, ocorreu no ver?o, e o BS4 foi o que apresentou o maior rendimento m?dio, 0,80% ? 0,12. Verificou-se a ocorr?ncia de varia??es qualitativa e quantitativa dos componentes majorit?rios das amostras analisadas. Assim, houve varia??es qu?micas entre diferentes indiv?duos da esp?cie estudada provenientes de um mesmo habitat, o que pode sugerir diferen?as gen?ticas e/ou ontog?nicas, embora a fase de desenvolvimento fosse semelhante entre os esp?cimens estudados, interferindo no metabolismo secund?rio. Constatou-se, tamb?m, a ocorr?ncia de varia??es qu?micas intraindividuais, sugerindo que as varia??es ambientais (sazonais e circadianas) interferem na composi??o qu?mica dos ?leos essenciais. No entanto, observou-se a presen?a constante, com varia??es quantitativas, de quatro terpenoides (?-pineno, trans-cariofileno, espatulenol e ?-humuleno) em todos os ?leos essenciais analisados. A quantidade de sesquiterpenos identificados sempre foi superior ? de monoterpenos, em todas as amostras. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2011. / ABSTRACT The Cerrado comprise great diversity of native vegetal species, widely used in folk medicine although with little or no scientific study. Among these species, stands out Blepharocalyx salicifolius (Kunth) O. Berg (Myrtaceae), known as ?Maria-preta?, ?Guamirim? or ?Murta?. Traditional medicine recommends the use of fresh leaves infusions as antidiarreic, against urinary and respiratory tracts infections. Some studies showed antibiotic activity of essential oil and leishmanicidal activity of ethanolic extract from leaves. Phytochemical studies revealed the presence of phenolic compounds in the extract and terpenes in the essential oil. Generally, the chemical composition of essential oils from the same vegetal specimen and the same species presents quantitative and qualitative variations, due to genetic, environmental and ontogenetic reasons. It is important to study these chemical changes, because this may have implications in the biological activities of plant products. Furthermore, such studies can serve for determination of chemical markers or assist in quality control of essential oil. Thus, this study aimed to observe quantitative and qualitative variations in the chemical composition of essential oil extracted from leaves of four specimens (BS1, BS2, BS3 e BS4) of B. salicifolius, in three period of the day in the four seasons. The leaves were collected on natural habitat of the specie, in Reserva Guapuruvu, Arcelor Mittal, in Itamarandiba-MG. It was proceeded the extraction of essential oils from fresh leaves by hydrodistillation in a Clevenger apparatus. It was calculated the yield of the extracted sample (v/w). The qualitative and quantitative analysis of essential oils compounds were performed by gas chromatography/mass spectrometry (GC/MS) and Relative Retention Index (RRI). The higher yield of essential oil extraction, for all specimens, occurred in the summer and BS4 was presented the highest yield, 0.80% ? 0.12. There was the occurrence of qualitative and quantitative variations of the major components of the samples. Thus, there were chemical variations between different individuals of the species studied from the same habitat, which may suggest genetic differences and/or ontogeny, although the stage of development was similar among the specimens studied by interfering with secondary metabolism. It was found, also, the occurrence of chemical intraindividual variations, suggesting that environmental variations (seasonal and circadian) interfere with the chemical composition of essential oils. However, there was a constant presence, with quantitative variations in all four terpen?ides (?-pinene, trans-caryophyllene, ?-humulene and spathulenol) in essential oils analyzed. The amount of sesquiterpenes identified was always higher than that of monoterpenes in all samples.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:45Z No. of bitstreams: 5 hil.pdf: 1837336 bytes, checksum: 915b40a5d9c4387507e76471c6ae2ca7 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T11:01:25Z (GMT) No. of bitstreams: 5 hil.pdf: 1837336 bytes, checksum: 915b40a5d9c4387507e76471c6ae2ca7 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T11:01:25Z (GMT). No. of bitstreams: 5 hil.pdf: 1837336 bytes, checksum: 915b40a5d9c4387507e76471c6ae2ca7 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-20 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Para a manuten??o das pr?ticas econ?micas e s?cio-culturais constru?das sobre a explora??o e transforma??o do petr?leo, faz-se necess?rio criar alternativas que n?o rompam de forma estanque com as pr?ticas industriais hoje vigentes. Nesse contexto, o uso de biomassas para a produ??o de combust?veis l?quidos que alimentem motores ? combust?o permite sustentar pr?ticas antigas com novos benef?cios. Dessa forma, a presente disserta??o teve por objetivo avaliar o potencial da torta de maca?ba, um coproduto da ind?stria de ?leos vegetais, como insumo para produ??o de bioetanol. Tal objetivo foi trabalhado atrav?s de estudos de sacarifica??o da torta de maca?ba com posterior processo fermentativo. A biomassa em quest?o foi caracterizada quimicamente, o que indicou a presen?a de aproximadamente 50% de carboidratos, distribu?dos em, 23,16 ? 0,95 % de amido, 11,49 ? 1,08% de celulose, 9,6 ? 0,79% de hemicelulose e 11,48 ? 0,62 % de a??cares sol?veis. Para a primeira interven??o da despolimeriza??o dos polissacar?deos presentes na torta de maca?ba foi realizado um planejamento experimental fatorial 25-1 com 5 fatores e 4 pontos centrais com as seguintes vari?veis: concentra??o de ?cido sulf?rico, tempo de pr?-tratamento ?cido, raz?o s?lido/l?quido, concentra??o de amiloglicosidase e concentra??o de celulase. Na sequ?ncia, o processo de sacarifica??o foi otimizado com o uso de delineamento composto central rotacional 23, com 3 fatores, 4 pontos centrais e 6 pontos axiais, onde foram avaliadas as concentra??es de ?cido sulf?rico, amiloglicosidase e celulase. Um hidrolisado obtido em condi??o otimizada com 92% de efici?ncia foi submetido ? destoxifica??o com carv?o ativado e, em seguida, foram realizados ensaios de fermentabilidade conduzidos como as leveduras Saccharomyces cerevisiae e Pichia stipitis. A levedura S. cerevisiae se mostrou resistente ao hidrolisado n?o destoxificado, apresentando YP/S de 0,49. P. stipitis mostrou-se suscept?vel ao meio n?o destoxificado, mas foi capaz de converter 99% dos a??cares redutores presentes no meio destoxificado. A torta de maca?ba apresentou potencial consider?vel para produ??o de bioetanol. A partir dos dados de bancada ? poss?vel estimar uma produ??o de 104l de etanol por tonelada de torta de maca?ba. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2011. / ABSTRACT For the maintenance of economic and socio-cultural practices built on the exploitation and processing of oil it is necessary to create alternatives that do not break so tight with current industrial practices. In this context, the use of biomass to produce liquid fuels that are fed into to combustion engines allows to sustain old practices with new benefits. Thus, this dissertation aimed to evaluate the potential of macaw palm coconut cake, a co-product of vegetable oil industry, as an input for bioethanol production. This goal was worked out through studies of the process of saccharification of macaw palm coconut cake with subsequent fermentation. The biomass in question was characterized chemically, what indicated the presence of approximately 50% of carbohydrates, among which, 23,16 ? 0,95% of starch, 11,49 ? 1,08% of cellulose, 9,6 ? 0,79% of hemicellulose and 11,48 ? 0,62% of soluble sugars. For the first intervention of deconstruction of the polysaccharides present in the macauba cake it was held a 25-1 factorial experimental design with five factors and four central points with the following variables: concentration of sulfuric acid, time of acid pretreatment, solid / liquid ratio, amyloglucosidase and cellulose concentrations. Following, the saccharification process was optimized using central composite rotational design 23, with three factors, four central points and six axial points, whereas the concentrations of sulfuric acid, cellulose and amyloglucosidase were evaluated. A hydrolyzed obtained in optimum condition with 92% efficiency was subjected to detoxification with activated charcoal and then, fermentability assays were carried out with yeasts Saccharomyces cerevisiae and Pichia stipitis. The yeast S. cerevisiae has proved resilient to the non-detoxified hydrolyzate and presented YP/S of 0.49. P. stipitis was found to be susceptible to the non-detoxified medium, but it was able to convert 99% of reducing sugars present in the detoxified medium. The macaw palm coconut cake showed considerable potential for bioethanol production. From the lab bench data it is possible to estimate a production of 104 l of ethanol per ton of macaw palm coconut cake.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:46Z No. of bitstreams: 5 tel.pdf: 9429138 bytes, checksum: 55c9c9a1eb3f75db9e65b286cec95dda (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T11:03:29Z (GMT) No. of bitstreams: 5 tel.pdf: 9429138 bytes, checksum: 55c9c9a1eb3f75db9e65b286cec95dda (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T11:03:29Z (GMT). No. of bitstreams: 5 tel.pdf: 9429138 bytes, checksum: 55c9c9a1eb3f75db9e65b286cec95dda (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-20 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / A hidrazina ? uma subst?ncia utilizada como inibidora de corros?o, antioxidante, catalisador, emulsificante, agente redutor, combust?vel para propuls?o de foguete, inseticidas, e na prepara??o de diversos derivados farmac?uticos. Por?m, a hidrazina ? um material t?xico, sendo, portanto, necess?rio um m?todo sens?vel para a sua determina??o. Neste trabalho um sensor foi desenvolvido para determina??o de hidrazina mediante modifica??o de um eletrodo de carbono v?treo com ftalocianina de cobalto adsorvido em nanotubos de carbono de paredes m?ltiplas. A caracteriza??o eletroqu?mica e de superf?cie foi feita por voltametria c?clica, microscopia eletr?nica de varredura, FT-IR e Espectroscopia de Energia dispersiva de Raios-X. Os estudos de superf?cie deixaram evidente que os NTCPM e a CoPc formam um material comp?sito. Os estudos eletroqu?micos mostraram a ocorr?ncia de processos redox de superf?cie e ainda h? ind?cios de uma limita??o da transfer?ncia de carga. O n?mero de el?trons para a rea??o de oxida??o de hidrazina bem como a constante de velocidade heterog?nea foram estimados a partir dos coeficientes linear e angular das curvas de Koutecky-Levich sendo, respectivamente, 4,1 e 1,51 x 103 M-1s-1. Os par?metros operacionais de tr?s t?cnicas eletroanal?ticas (Amperometria, VPD e VOQ) foram otimizados em rela??o ? determina??o de hidrazina com o uso do ECV/NTCPM/CoPc, sendo que a VOQ apresentou maior sensibilidade, tendo sido, portanto, escolhida para a determina??o da hidrazina em ?gua de caldeira. Uma curva anal?tica final para a determina??o de hidrazina em amostra da ?gua de caldeira foi feita utilizando-se eletrodos impressos, sob condi??es experimentais otimizadas, apresentando resposta linear no intervalo de concentra??o de 99 a 7630 ?mol L-1, com R igual a 0,999. Foram obtidos valores de LD e LQ iguais a 50 e a 99 ?mol L-1, respectivamente. O sensor permitiu uma boa recupera??o para a hidrazina nas amostras de ?guas de caldeiras analisadas, com valores de recupera??o compreendidos entre 98,41 e 103,62%, atestando a exatid?o do m?todo proposto. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2011. / ABSTRACT Hydrazine is used as a corrosion inhibitor, antioxidant, catalyst, emulsifier, reducing agents, fuel for rocket propulsion, insecticides, and pharmaceutical preparation of various derivatives. However, the hydrazine is a toxic material and therefore requires a sensitive method for its determination. In this paper a sensor was developed for determination of hydrazine by modifying a glassy carbon electrode with cobalt phthalocyanine adsorbed on mutiwalled carbon nanotubes. The surface and electrochemical characterization was carried out by cyclic voltametry, scanning electron microscopy and energy dispersive spectroscopy X-ray. Surface studies shows that NTCPM and CoPc are a composite material. Electrochemical studies have shown the occurrence of redox processes of surface and also an indication of a limited transfer of load transfer. The number of electrons for the reaction of oxidation of hydrazine and the observed average rate constant of the process were estimated from the coefficients of linear and angular curves Koutecky-Levich being, respectively, 4,1 and 1,51 x 103 M-1s-1. The operational parameters of three electroanalytical techniques (amperometry, VOQ and VPD) were optimized for the determination of hydrazine with the use of ECV / NTCPM / CoPc, although the VOQ showed greater sensitivity and was therefore chosen for the determination of hydrazine in boiler water. A final analytical curve for the determination of hydrazine in boiler water sample was made using electrodes printed under optimized experimental conditions, with linear response over the concentration range of 99 mmol L-1 to 7630 ?mol L-1, with R equal to 0.999. We obtained values ??of LOD and LOQ equal to 50 and 99 ?mol L-1, respectively. The sensor allowed a good recovery for hydrazine in boiler water samples analyzed, with recovery values ??ranging between 98.41 and 103.62%, attesting to the accuracy of the proposed method.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:46Z No. of bitstreams: 5 vin.pdf: 2622756 bytes, checksum: 227e0c0c8c2f323aee0f3cf8565b6072 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T11:16:41Z (GMT) No. of bitstreams: 5 vin.pdf: 2622756 bytes, checksum: 227e0c0c8c2f323aee0f3cf8565b6072 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T11:16:44Z (GMT). No. of bitstreams: 5 vin.pdf: 2622756 bytes, checksum: 227e0c0c8c2f323aee0f3cf8565b6072 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Esp?cies do g?nero Byrsonima s?o conhecidas popularmente como ?muricis? e h? relatos na literatura de muitos usos medicinais dessas plantas, alguns deles j? comprovados, como atividade anti-inflamat?ria, antimicrobiana e antioxidante. Este trabalho objetivou analisar fitoquimicamente a esp?cie Byrsonima coccolobifolia Kunth e fazer um estudo de atividade biol?gica nos extratos de B. coccolobifolia, B. verbascifolia e B. intermedia, investigando a atividade antioxidante, a a??o inibit?ria da acetilcolinesterase e atividade antimicrobiana nessas esp?cies. As partes a?reas das plantas foram coletadas no Vale do Jequitinhonha-MG e secas a temperatura ambiente. Folhas e galhos foram separados, pulverizados e submetidos ? extra??o exaustiva com solventes de polaridade crescente (hexano, acetato de etila e metanol), que foram removidos por evaporador rotat?rio. Os extratos em hexano e em acetato de etila de B. coccolobifolia foram submetidos a m?todos cromatogr?ficos cl?ssicos e, atrav?s de t?cnicas espectrosc?picas (IV e RMN de 1H e 13C), foi poss?vel elucidar nos extratos das folhas as seguintes subst?ncias: friedelina, ?-sitosterol, mistura de ?-amirina e ?-amirina e derivados do ?cido olean?lico e urs?lico. Na identifica??o dos compostos presentes no extrato metan?lico de folhas e galhos de B. coccolobifolia, utilizou-se a t?cnica de espectrometria de massas por electrospray (ESI-MS), por inser??o direta dos extratos dissolvidos em metanol. Identificaram-se tr?s classes de metab?litos no extrato metan?lico: ?cidos fen?licos e derivados (galato de metila, ?cido qu?nico, ?cidos mono-, di-, tri- e tetragaloilqu?nico), proantocianidinas (d?mero e tr?mero epicatequina) e flavon?ides (quercetina e derivados glicosilados). As esp?cies B. coccolobifolia e B. intermedia apresentaram os melhores resultados para conte?do fen?lico e para atividade antioxidante de captura de radical e de poder redutor. Isso mostrou o potencial dos extratos polares dessas plantas como recurso para a busca de subst?ncias ?teis na preven??o ou no tratamento de doen?as associadas a radicais livres. No que diz respeito ? atividade inibit?ria da acetilcolinesterase (AChE), tamb?m investigada nas tr?s esp?cies de Byrsonima, o extrato hex?nico dessas plantas apresentou maior quantidade de compostos ativos frente a enzima AChE. E somente a esp?cie B. coccolobifolia apresentou atividade contra os microrganismos testados (Staphylococcus aureus, Bacillus cereus, Escherichia coli e Candida albicans). Sendo assim, o presente trabalho mostrou a import?ncia de continuar estudando a flora do cerrado brasileiro e as esp?cies do g?nero Byrsonima, sejam seus aspectos qu?micos ou medicinais. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2011. / ABSTRACT Byrsonima species are popularly known as "murici" and there are reports in previous work of many medicinal uses of these plants, some of them already confirmed as anti-inflammatory, antimicrobial and antioxidant activities. The aim of this study was to analyze phytochemically Byrsonima coccolobifolia Kunth and to make a study of biological activity in extracts of B. coccolobifolia, B. verbascifolia and B. intermedia, investigating the antioxidant activity, acetylcholinesterase inhibitory action and antimicrobial activity in these species. The aerial parts of plants were collected in Jequitinhonha Valley, Minas Gerais, Brazil, and dried at room temperature. Leaves and branches were separated, powdered and subjected to exhaustive extraction with solvents of increasing polarity (hexane, ethyl acetate and methanol), that were removed by rotary evaporator. The extracts in hexane and ethyl acetate of B. coccolobifolia were submitted at classical chromatographic methods and, by spectroscopic methods (IR and 1H and 13C NMR), it was possible to elucidate the following substances in leaves extracts: friedelin, ?-sitosterol, a mixture of ?-amyrin and ?-amyrin and oleanolic and ursolic acid derivatives. In the identification of compounds in methanol extracts of leaves and branches of B. coccolobifolia was used mass spectrometry with electrospray (ESI-MS) by direct infusion of the extracts dissolved in methanol. Three classes of metabolites were identified in methanol extracts: phenolic acids and derivatives (methyl gallate, quinic acid, mono-, di-, tri- and tetragalloylquinic acids), proanthocyanidins (epicatechin dimer and trimer) and flavonoids (quercetin and glycosides derivatives). The species B. coccolobifolia and B. intermedia showed better results for phenolic content and antioxidant activity of radical scavenging and reducing power. This showed the potential of polar extracts of these plants as a resource to search for substances useful in preventing or treating diseases associated with free radicals. Concerning the inhibitory activity of acetylcholinesterase (AChE), also investigated in three Byrsonima species, hexane extract of these plants had higher amounts of active compounds against AChE. And only B. coccolobifolia revealed activity against the microorganisms tested (Staphylococcus aureus, Bacillus cereus, Escherichia coli and Candida albicans). Thus, this investigation supported the importance of further studying the flora of Brazilian cerrado and the species of the genus Byrsonima, in their chemical or medicinal aspects.

Made available in DSpace on 2014-12-17T14:10:25Z (GMT). No. of bitstreams: 1 AbinadabeJM_DISSERT.pdf: 2202389 bytes, checksum: c6fb8bcc059666158ed3af8030f88987 (MD5) Previous issue date: 2012-07-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Industrial activities, oil spills and its derivatives, as well as the incomplete combustion of fossil fuels have caused a great accumulation of hydrocarbons in the environment. The number of microorganisms on the planet is estimated at 1030 and prokaryotes the most abundant. They colonized diverse environments for thousands of years, including those considered extreme and represent an untapped source of metabolic and genetic diversity with a large biotechnological potential. It is also known that certain microorganisms have the enzymatic capacity to degrade petroleum hydrocarbons and, in many ecosystems, there is an indigenous community capable of performing this function. The metagenomic has revolutionized the microbiology allowing access uncultured microbial communities, being a powerful tool for elucidation of their ecological functions and metabolic profiles, as well as for identification of new biomolecules. Thus, this study applied metagenomic approaches not only for functional selection of genes involved in biodegradation and emulsification processes of the petroleum-derived hydrocarbons, but also to describe the taxonomic and metabolic composition of two metagenomes from aquatic microbiome. We analyzed 123.116 (365 ? 118 bp) and 127.563 sequences (352 ? 120 bp) of marine and estuarine metagenomes, respectively. Eight clones were found, four involved in the petroleum biodegradation and four were able to emulsify kerosene indicating their abilities in biosurfactants synthesis. Therefore, the metagenomic analyses performed were efficient not only in the search of bioproducts of biotechnological interest and in the analysis of the functional and taxonomic profile of the metagenomes studied as well / Atividades industriais, derramamentos de petr?leo e seus derivados, bem como a combust?o incompleta de combust?veis f?sseis t?m causado um grande ac?mulo de hidrocarbonetos no meio ambiente. O n?mero de microrganismos no planeta ? estimado em 1030, sendo os procariotos os mais abundantes. Eles colonizaram diversos ambientes durante milhares de anos, incluindo aqueles considerados extremos e representam uma fonte inexplorada de diversidade gen?tica e metab?lica com um grande potencial biotecnol?gico. Sabe-se que muitos microrganismos possuem vias metab?licas complexas atuando na biodegrada??o de hidrocarbonetos derivados de petr?leo e, em muitos ecossistemas, existe uma comunidade aut?ctone capaz de realizar essa fun??o. A metagen?mica tem revolucionado a Microbiologia permitindo o acesso ?s comunidades microbianas n?o cultiv?veis, sendo uma potente ferramenta para elucida??o de suas fun??es ecol?gicas, dos perfis metab?licos, bem como para identifica??o de novas biomol?culas. Assim, o presente estudo aplicou abordagens metagen?micas n?o apenas para sele??o funcional de genes envolvidos nos processos de biodegrada??o e biossurfacta??o de hidrocarbonetos derivados do petr?leo, mas tamb?m para descri??o da composi??o taxon?mica e metab?lica de dois metagenomas de microbiota aqu?tica. Foram analisadas 123.116 (365 ? 118 pb) e 127.563 sequ?ncias (352 ? 120 pb) dos metagenomas marinho e estuarino, respectivamente. Oito clones foram encontrados, sendo quatro envolvidos na biodegrada??o de petr?leo e quatro capazes de emulsificar querosene, indicando a habilidade de sintetizar biossurfactantes. Portanto, as an?lises metagen?micas realizadas foram eficientes n?o apenas na busca de bioprodutos de interesse biotecnol?gico como tamb?m na an?lise do perfil funcional e taxon?mico dos metagenomas estudados

Made available in DSpace on 2014-12-17T15:14:57Z (GMT). No. of bitstreams: 1 EzequielSS_TESE.pdf: 5032633 bytes, checksum: f9ceb1f9a83a0768f2db67ed0af6938d (MD5) Previous issue date: 1997-09-26 / Neste trabalho investigamos aspectos da propaga??o de danos em sistemas cooperativos, descritos por modelos de vari?veis discretas (spins), mutuamente interagentes, distribu?das nos s?tios de uma rede regular. Os seguintes casos foram examinados: (i) A influ?ncia do tipo de atualiza??o (paralela ou sequencial) das configura??es microsc?picas, durante o processo de simula??o computacional de Monte Carlo, no modelo de Ising em uma rede triangular. Observamos que a atualiza??o sequencial produz uma transi??o de fase din?mica (Ca?tica- Congelada) a uma temperatura TD ≈TC (Temperatura de Curie), para acoplamentos ferromagn?ticos (TC=3.6409J/Kb) e antiferromagn?ticos (TC=0). A atualiza??o paralela, que neste caso ? incapaz de diferenciar os dois tipos de acoplamentos, leva a uma transi??o em TD ≠TC; (ii) Um estudo do modelo de Ising na rede quadrada, com dilui??o temperada de s?tios, mostrou que a t?cnica de propaga??o de danos ? um eficiente m?todo para o c?lculo da fronteira cr?tica e da dimens?o fractal do aglomerado percolante, j? que os resultados obtidos (apesar de um esfor?o computacional relativamente modesto), s?o compar?veis ?queles resultantes da aplica??o de outros m?todos anal?ticos e/ou computacionais de alto empenho; (iii) Finalmente, apresentamos resultados anal?ticos que mostram como certas combina??es especiais de danos podem ser utilizadas para o c?lculo de grandezas termodin?micas (par?metros de ordem, fun??es de correla??o e susceptibilidades) do modelo Nα x Nβ, o qual cont?m como casos particulares alguns dos modelos mais estudados em Mec?nica Estat?stica (Ising, Potts, Ashkin Teller e C?bico)

Made available in DSpace on 2014-12-17T15:18:11Z (GMT). No. of bitstreams: 1 AmandaLSS.pdf: 2422936 bytes, checksum: d5a0f2bb2f42d87bacd7a1d2c3f5c6bc (MD5) Previous issue date: 2009-03-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Bacteria trom Shewanella and Geobacter ganera are the most studied iron-reducing microorganisms particularly due to their electron transport systems and contribution to some industrial and environmental problems, including steel corrosion, bioenergy and bioremediation of petroleum-impacted sites. The present study was focused in two ways: the first is an in silico comparative ecogenomic study of Shewanella spp. with sequenced genomes, and the second is an experimental metagenomic work to detect iron-reducing Shewanella through PCR-DGGE of a metabolic gene. The in silico study resulted in positive correIation between copy number of 16S rDNA and genome size in Shewanella spp., with clusters of rrn near lhe origin of replication. This way, the genus is inferred as opportunist. There are no compact genomes and their sequences length varied, ranging from 4306142 nt in S. amazonensis SB2B to 5935403 nt in S. woodyi ATCC 51908, without correIation to temperature range characteristic of each specie. Intragenomic 16S rDNA sequences possess little divergence, but reasonable to resuIt in different phyIogenetic trees, depending on the sequence that is chosen to compare. For moIecuIar detection of iron-reducing Shewanella, it is proposed the mtrB gene as new biomarker. because it codes to a fundamental protein at Fe (III)-reduction. The specific primers were designed and evaluated in silico and resulted in a fragment of 360 pb. In the second study, these primers were tested in a genomic sample from S. oneidensis MR-1, amplifying the expected region. After this successfuI resuIt, the primer set was used as a tool to assess the iron-reducing communities of ShewaneIla genus under an environmental stress, i.e. crude oil contamination in mangrove sediment in Rio Grande do Norte State (Brazil). The primers presented high specificity and the reactions performed resulted in one single band of ampIification in the metagenomic samples. The fingerprinting obtained at DGGE reveaIed temporal variation of Shewanella spp. in analyzed samples. The resuIts presented show the detection of a biotechnological important group of microorganisms, the iron-reducing Shewanella spp. using a metabolic gane as target. It is concluded there are eight or more 16S rDNA sequences in Shewanella genus, with little divergence among them that affects the phylogeny; the pair of primers designed to ampIify mtrB sequences is a viable alternative to detect iron-reducing ShewanelIa in metagenomic approaches; such bacteria are present in the mangrove sediment anaIyzed, with temporal variations in the samples. This is the first experimental study that screened the iron-reducing Shewanella genus in a metagenomic experiment of mangrove sediments subjected to oil contamination through a key metabolic gene / Bact?rias dos g?neros Shewanella e Geobacter s?o os microrganismos redutores de ferro mais estudados. Esse interesse ocorre particularmente devido aos seus sistemas de transporte de el?trons e contribui??o em alguns problemas industriais e ambientais, tais como corros?o de oIeodutos, bioenergia e biorremedia??o de locais contaminados com petr?leo. O presente estudo foi tocado em duas partes: a primeira ? um estudo ecogen?mico comparativo de ShewanelIa spp. com genomas seq?enciados, e a segunda ? um trabalho metagen?mico experimental para detectar Shewanella redutoras de ferro atrav?s de PCR-DGGE de um gene metab?lico. O estudo in silico resultou em correla??o positiva entre o n?mero de c?pias 16S rDNA e tamanho do genoma em ShewaneIla spp., com agrupamentos de rrn. pr?ximo ? origem de replica??o. Desta maneira, o g?nero ? inferido como oportunista. N?o existem genomas compactos e o tamanho de suas sequ?ncias variam de 4306142 nt em S. amazonensis SB2B at? 5935403 nt em S. woodyi ATCC 51908, sem correla??o com a faixa de temperatura caracter?stica de cada esp?cie. Sequ?ncias intragen?micas de 16S rDNA possuem pouca diverg?ncia. mas razo?vel para resultar em diferentes ?rvores filogen?ticas. dependendo da sequ?ncia que ? escolhida para compara??o. Para a detec??o moIecuIar de ShewanelIa redutoras de ferro, ? proposto o gene mtrB como um novo biomarcador, por ser codante de uma prote?na fundamental na redu?ao de Fe (III). Os primers espec?ficos foram desenhados e avaliados in silico e resultou em um fragmento de 360 pb. No segundo estudo, esses primers foram testados em . amostra gen?mica de S. oneidensis MR-1, amplificando a regi?o esperada. Depois desse resultado favor?vel, o par de primers foi utilizado como ferramenta para acessar as comunidades redutoras de ferro do g?nero ShewanelIa sob um stress ambiental - contamina??o com ?leo cru em sedimento de mangue, no Estado do Grande do Norte (Brasil). Os primers apresentaram alta especificidade e as rea??es resultaram em banda ?nica de amplifica??o das amostras metagen?micas. O perfil obtido no DGGE revelou varia??o temporal de ShewanelIa spp. nas amostras analisadas. Os resultados apresentados mostram a defec??o de um grupo de microrganismos biotecnologicamente importante. ShewaneIla spp. redutoras de ferro, usando um gene metab?lico como alvo. Concluiu-se que existem oito ou mais sequ?ncias 16S rDNA no g?nero ShewaneIla, com pouca diverg?ncia entre elas que afetam a filogenia; o par de primers desenhados para amplificar sequ?ncias mtrB ? uma alternativa vi?vel para detectar Shewanella redutoras de ferro em abordagens metagen?micas; tais bact?rias est?o presentes no sedimento de mangue analisado, com varia??es temporais nas amostras. Este ? o primeiro estudo experimental que examina Shewanella redutoras de ferro em um experimento metagen?mico de sedimento de mangue submetido a contamina??o por ?leo atrav?s de um gene metab?lico