• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 33
  • Tagged with
  • 33
  • 33
  • 23
  • 21
  • 13
  • 13
  • 13
  • 11
  • 9
  • 8
  • 8
  • 8
  • 6
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Uso da espectroscopia do infravermelho pr?ximo e t?cnicas multivariadas para diferenciar escherichia coli e salmonella enteritidis inoculadas em polpa de fruta (abacaxi)

Marques, Aline de Sousa 31 July 2013 (has links)
Made available in DSpace on 2014-12-17T15:42:13Z (GMT). No. of bitstreams: 1 AlineSM_DISSERT.pdf: 1997460 bytes, checksum: 0ad037938fab17947fef7a249102b4ec (MD5) Previous issue date: 2013-07-31 / Aiming to consumer s safety the presence of pathogenic contaminants in foods must be monitored because they are responsible for foodborne outbreaks that depending on the level of contamination can ultimately cause the death of those who consume them. In industry is necessary that this identification be fast and profitable. This study shows the utility and application of near-infrared (NIR) transflectance spectroscopy as an alternative method for the identification and classification of Escherichia coli and Salmonella Enteritidis in commercial fruit pulp (pineapple). Principal Component Analysis (PCA), Independent Modeling of Class Analogy (SIMCA) and Discriminant Analysis Partial Least Squares (PLS-DA) were used in the analysis. It was not possible to obtain total separation between samples using PCA and SIMCA. The PLS-DA showed good performance in prediction capacity reaching 87.5% for E. coli and 88.3% for S. Enteritides, respectively. The best models were obtained for the PLS-DA with second derivative spectra treated with a sensitivity and specificity of 0.87 and 0.83, respectively. These results suggest that the NIR spectroscopy and PLS-DA can be used to discriminate and detect bacteria in the fruit pulp / Visando ? seguran?a do consumidor, ? de extrema import?ncia identificar a presen?a de contaminantes patog?nicos nos alimentos, pois os mesmos s?o respons?veis por surtos alimentares que dependendo do n?vel de contamina??o pode chegar a causar a morte de quem os consome. Na industria h? uma necessidade de que essa identifica??o de contaminantes seja r?pida e rent?vel. Este estudo mostra a aplica??o e utilidade de medidas espectrais de transflect?ncia no infravermelho pr?ximo (NIR) como um m?todo alternativo para a identifica??o e classifica??o de Escherichia coli e Salmonella Enteritidis em polpa de fruta comercial (abacaxi). An?lise de Componentes Principais (PCA), Modelagem Independente por Analogia Classe (SIMCA) e An?lise Discriminante por M?nimos Quadrados Parciais (PLS-DA) foram utilizados na an?lise. N?o foi poss?vel obter uma separa??o total entre as amostras usando PCA e SIMCA. O PLS-DA apresentou bom desempenho na capacidade de predi??o alcan?ando 87,5% para E. coli e 88,3% para S. Enteritides, respectivamente. Os melhores modelos obtidos para o PLS-DA com os espectros tratados com segunda derivada apresentaram sensibilidade e especificidade de 0,87 e 0,83, repectivamente. Estes resultados sugerem que a espectroscopia NIR e PLS-DA podem ser usados para discriminar e detectar bact?rias na polpa da fruta
22

Ocorr?ncia de bact?rias endof?ticas associadas a variedades de cana-de-a??car cultivadas nos estados: Alagoas e Pernambuco / Occurrence of endophytic bacteria associated with varieties of sugar cane grown in the states: Alagoas and Pernambuco

ANTONIO, Cec?lia de Souza 20 April 2010 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-04-18T20:10:31Z No. of bitstreams: 1 2010 - Cec?lia de Souza Ant?nio.pdf: 1613209 bytes, checksum: e560fdd88ef8707b79c6d4b0120730ec (MD5) / Made available in DSpace on 2017-04-18T20:10:31Z (GMT). No. of bitstreams: 1 2010 - Cec?lia de Souza Ant?nio.pdf: 1613209 bytes, checksum: e560fdd88ef8707b79c6d4b0120730ec (MD5) Previous issue date: 2010-04-20 / CAPES / The sugar cane is one of the major agricultural products in Brazil. The crop is able to associate with diazotrophic bacteria (fix nitrogen from the air), that may be located inside the plant tissue (entophytic). The diazotrophic bacteria are capable of promoting growth of sugar cane by means of biological nitrogen fixation (BNF) or production of hormones. But little is known about populations of these bacteria present in sugar cane. This work aimed to study diversity of the population and identify the isolates by molecular and physiological methods, as well as to assess the effectiveness of some isolates to promote plant growth of sugar cane in the field. In solid potato media, there were observed the formation of seven groups, with 95% of similarity, showing the great colonies morphology variation. Many isolates showed similar characteristics to the genus Gluconacetobacter, when analyzed in semi-solid LGI-P media and solid Potato-P and LGI-P media. Two isolates were most efficient in the endolar synthesis with production over 49 ?g/mL. All isolates were classified as Gram negative. Of the 36 isolates, 27.5% were similar to the standard strain RB 11366 (Burkholderia tropica), 45% to BR 11281 strain (Gluconacetobacter diazotrophicus) and 5% to the other patterns BR 11335 (Herbaspirillum seropedicae), BR 11504 (Herbaspirillum rubrisubalbicans) and BR 11145 (Azospirillum amazonense). Through the comparison of the sequencing of 16S rDNA with the NCBI GenBank isolate 215 was identified as belonging to species Gluconacetobacter diazotrophicus, the 179-1a belonging to Burkholderia tropica and the isolated 151-B, 211-A, and 219 to the gender Burkholderia. The inoculated strains 160-1 and 215 promoted an increase in the straw dry biomass (up to 0.7 Mg ha-1) and total nitrogen of flag leaf (above 69,7 kg ha-1), respectively in the tested varieties RB 72454 and RB 918,639. Only the 160-1 isolate was able to promote increase in biomass in the RB 867515 variety. Stalk yield was higher for the variety RB 918639 with 191.96 Mg ha-1. / A cana-de-a??car ? um dos principais produtos agr?colas do Brasil. A cultura ? capaz de se associar as bact?rias diazotr?ficas (fixam nitrog?nio do ar), que podem estar no interior do tecido da planta (endof?ticas). As bact?rias diazotr?ficas endof?ticas s?o capazes de promover o crescimento da cana-de-a??car por meio da fixa??o biol?gica do nitrog?nio (FBN) ou pela produ??o de fitorm?nios. Mas pouco se conhece sobre as popula??es presentes destas bact?rias em cana-de-a??car. O presente trabalho visou estudar a diversidade da popula??o e identificar estes isolados, atrav?s de m?todos moleculares e fisiol?gicos, assim como avaliar a efici?ncia de alguns isolados na promo??o de crescimento vegetal de plantas de cana-de-a??car no campo. Foi observada em meio s?lido Batata, com 95% de similaridade, a forma??o de sete grupos mostrando a grande varia??o morfol?gica de col?nias neste meio testado. Muitos isolados apresentaram caracter?sticas similares ao g?nero Gluconacetobacter, quando analisados em meio semi-s?lido LGI-P e s?lido Batata-P e LGI-P. Dois isolados foram mais eficientes na s?ntese de ind?les com produ??es acima de 49 ?g/mL. Todos os isolados foram classificados como Gram negativos. Dos 36 isolados avaliados, 27,5% foram semelhantes ? estirpe padr?o RB 11366 (Burkholderia tropica); 45% a BR 11281 (Gluconacetobacter diazotrophicus) e 5% aos demais padr?es BR 11335 (Herbaspirillum seropedicae), BR 11504 (Herbaspirillum rubrisubalbicans) e BR 11145 (Azospirillum amazonense). Atrav?s da compara??o do seq?enciamento do gene 16S rDNA com o NCBI GenBank o isolado 215 foi identificado com pertencente a esp?cie de Gluconacetobacter diazotrophicus , o 179-1A com pertencente a esp?cie Burkholderia tropica e os isolados 151-B, 211-A e 219 ao g?nero Burkholderia. As estirpes 160-1 e 215 inoculadas promoveram aumento na produ??o de biomassa seca da palha (acima de 0,7 Mg.ha-1) e nitrog?nio total da folha bandeira (acima de 69,7 kg.ha-1), respectivamente nas variedades RB 72454 e RB 918639 testadas. Apenas o isolado 160-1 foi capaz de promover um aumento de biomassa seca na variedade RB 867515. A produ??o de colmos foi maior para a variedade RB918639 com 191,96 Mg.ha-1.
23

Processos celulares envolvidos nas respostas de defesa de Solanum tuberosum L. contra Pectobacterium carotovorum

Soares, Natasha Ruschel 25 March 2014 (has links)
Made available in DSpace on 2015-04-14T14:51:35Z (GMT). No. of bitstreams: 1 460184.pdf: 1028375 bytes, checksum: 28478eee33cfe1af70ef0f52ca6b57b9 (MD5) Previous issue date: 2014-03-25 / Solanum tuberosum is one of the most important crops worldwide being the fourth most consumed food. Despite its importance, this crop presents a high susceptibility to a wide range of pathogens, leading to an extensive yield loss. A potential approach for disease control in potato is the understanding of the mechanisms of resistance induction and their relation to strengthening of natural plant defenses. In this work, the effect of defense inducers (XTH and Acibenzolar-S-methyl - Bion?) and ethylene blocker (aminoethoxyvinylglycine AVG) in the plant metabolism was assessed. Biochemical markers for plant defense, such as POX and PPO enzymes, synthesis of phenolic compounds, flavonoid fraction and salicylic acid accumulation were also evaluated. Bion? resulted in a negative effect upon P. carotovorum inoculated plants, whilst XTH delayed disease progression. Plants cultivated in the presence of Bion+AVG showed an increase in PPO activity comparing to the control plants, although its activity was similar between XTH and Bion? plants. POX activity was promoted by Bion? at 24 hpi, however, at 72 hpi plants showed higher POX activity within XTH+AVG and Bion+AVG treated plants, compared with non-treated plants. In general, plants presented free SA levels 65% higher than conjugated one. The highest concentrations of SA (52.2 μg/g) was found in Bion+AVG treated plants, whilst the lowest concentrations (4.8 μg/g) were found in XTH and AVG treated plants. / A esp?cie Solanum tuberosum ? uma das esp?cies vegetais de maior import?ncia no mundo, sendo a batata o quarto alimento mais consumido. Por?m, apesar do uso extensivo de pesticidas, esta cultura ainda ? muito afetada por doen?as, acarretando grandes perdas econ?micas. Uma importante alternativa ao uso de qu?micos para o manejo das pragas, ? o fortalecimento das defesas naturais da planta atrav?s da promo??o de seus mecanismos de defesa. Neste trabalho foi avaliada a incid?ncia da doen?a causada por Pectobacterium carotovorum e o metabolismo vegetal relacionados ? defesa, tal como atividade das enzimas peroxidases (POX) e polifenoloxidases (PPO), s?ntese de compostos fen?licos, flavonoides e o ac?mulo de ?cido salic?lico (AS) livre e conjugado. Foram utilizados os indutores de defesa XTH e o Bion?, bem como o bloqueador da s?ntese de etileno, AVG (aminoetoxivinilglicina), em plantas de batata cultivadas in vitro. O tratamento com Bion? n?o promoveu a resist?ncia vegetal nas plantas inoculadas com P. carotovorum. Enquanto o uso do XTH foi eficiente na promo??o de resist?ncia das plantas, retardando o progresso da doen?a causada pela fitobact?ria. Em plantas cultivadas na presen?a de Bion+AVG, foi observado um aumento na atividade de PPO em compara??o com o controle, por?m a atividade desta enzima ? semelhante entre os tratamentos XTH e Bion?. Nas plantas do tratamento XTH+AVG a atividade da PPO se mant?m semelhante ?s plantas do controle e do tratamento XTH. A atividade da POX foi promovida pelo tratamento Bion? em 24 horas p?s-inocula??o (hpi), enquanto que os tratamentos XTH+AVG e Bion+AVG induziram a maior atividade desta enzima em 72 hpi. Apesar das diferen?as observadas nas atividades de PPO e POX, estas n?o apresentaram rela??o com a incid?ncia da doen?a nas plantas. Em geral, os n?veis de AS livre nos tecidos foi 65% maior que o AS conjugado. Em 24hpi, as plantas do tratamento Bion+AVG apresentaram os maiores n?veis de AS livre (52,2 μg/g), enquanto os o tratamento XTH e AVG apresentaram os menores n?veis de AS (4,87 e 4,82 μg/g, respectivamente).
24

Identifica??o de Gen?tipos de Capim-Elefante (Pennisetum purpureum Schumach.) de Alta Produ??o de Biomassa com Qualidade para Fins Energ?ticos. / Identification of elephant grass genotypes (Pennisetum purpureum Schumach.) to biomass production and characteristics to Energy Purposes.

Zanette, Juliano Br?s 27 July 2010 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2018-11-23T11:46:06Z No. of bitstreams: 1 2010 - Juliano Br?s Zanetti.pdf: 621874 bytes, checksum: 7668a4e8b8cab8a537ab2b436d55b596 (MD5) / Made available in DSpace on 2018-11-23T11:46:07Z (GMT). No. of bitstreams: 1 2010 - Juliano Br?s Zanetti.pdf: 621874 bytes, checksum: 7668a4e8b8cab8a537ab2b436d55b596 (MD5) Previous issue date: 2010-07-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES, Brasil. / The production of plant biomass for alternative renewable energy currently represents a great challenge to research. The release of CO2 from its use constitutes only the CO2 recycling that was removed from the atmosphere by photosynthesis, which in the long term, represents a valuable alternative for bio-energy. Elephant grass (Pennisetum purpureum Schum.) is, among grasses, that with possibly the highest capacity for dry matter production, with other favorable characteristics for energy production. The aim of this study was to identify elephant grass genotypes with high biomass production and nitrogen accumulation under the inoculation with a mixture of N2-fixing bacteria. Two studies were conducted in Serop?dica, Rio de Janeiro State. The first experiment was conducted in a concrete tank filled with a Ndeficient Acrisol. The experimental design was randomized blocks in split plots with four replications. The plots consisted of the inoculation treatments (inoculated and uninoculated), and sub-plots for the five elephant grass genotypes: Cameroon, BAG 02, Roxo, Clone CNPGL 93 41 1 and CNPGL 91 F06-3. The second experiment was carried out on a Planosol and the two genotypes, BAG 02 and Cameroon, with inoculation treatments, inoculation + 100 kg of N ha-1, 100 kg of N ha-1 and a zero N control. The experimental design was randomized blocks in a factorial model with four replications. In these studies the following results were obtained: 1. Dry matter production (DM) ranged from 16 to 41 Mg of MS ha-1 year-1 when the varieties were grown in the Acrisol. In the Planosol the dry biomass varied between 48 and 56 Mg MS ha-1 in two crops over a 11-month period of cultivation. 2. In relation to the total N accumulated in shoots, the values ranged between 64 and 158 kg ha-1 when the genotypes were grown in Acrisol and between 297 and 441 kg ha-1 when the genotypes were cultivated in the Planosol. For these parameters, N accumulation and biomass yield, the best genotypes were: CNPGL F 06-3 and Cameroon followed by CNPGL 93 41 1 and BAG 02 genotype. 3. The C/N ratio was directly influenced by soil type, and the ratio observed in the Acrisol was approximately 50% higher when compared to the Planosol. 4. The calorific value and fiber content, cellulose, lignin and ash, which are related to the quality of the material, in general were not affected by genotype, or by treatment. The elephant grass biomass had positive qualitative and quantitative characteristics to be used for renewable energy production and the Cameron CNPGL F 06-3 genotype, followed by BAG CNPGL 93 41 02 genotype were the most promising. The genotypes studied no showed response of biomass production or N accumulation to inoculation with diazotrophic bacteria. / A produ??o de material energ?tico alternativo renov?vel, tal como a biomassa vegetal, representa hoje um dos grandes desafios para a pesquisa. No caso da biomassa, a libera??o de CO2 pelo seu uso representa apenas a reciclagem do CO2 que foi retirado da atmosfera pela fotoss?ntese, indicando que, em longo prazo, esta ser? uma das alternativas energ?ticas mais seguras. O capim-elefante (Pennisetum purpureum Schum.) est? entre as gram?neas de maior capacidade de produ??o de mat?ria seca, com caracter?sticas qualitativas favor?veis para a produ??o de energia. O objetivo deste trabalho foi identificar gen?tipos de capim-elefante para alto rendimento de biomassa, ac?mulo de N sob a inocula??o das plantas com uma mistura de bact?rias diazotr?ficas. Foram realizados dois estudos de campo localizados no munic?pio de Serop?dica, RJ. O primeiro experimento realizado em um tanque de concreto preenchido com Argissolo pobre em N dispon?vel. O delineamento experimental foi o de Blocos ao Acaso em parcelas divididas, com quatro repeti??es. As parcelas constitu?das pelos tratamentos de inocula??o (inoculado e n?o inoculado), e as sub-parcelas compostas pelos cinco gen?tipos de capim-elefante: Cameroon, BAG 02, Roxo, Clone CNPGL 93 41 1 e CNPGL 91 F06-3. No segundo experimento, realizado no campo em um Planossolo, os dois gen?tipos, BAG 02 e Cameroon foram avaliados sob os tratamentos de inocula??o, inocula??o + 100 kg de N.ha-1, 100 kg de N.ha-1, e o controle. O delineamento experimental utilizado foi o de Blocos ao Acaso em esquema fatorial com quatro repeti??es. Nestes estudos encontraram-se os seguintes resultados: 1. A produ??o de mat?ria seca (MS) que variou entre 16 e 41 Mg de MS.ha-1.ano-1, quando os gen?tipos foram cultivados no Argissolo. No Planossolo, o rendimento de biomassa seca variou entre 48 e 56 Mg.MS.ha-1 sob duas colheitas realizadas, em 11 meses de cultivo. 2. Em rela??o ao total de N acumulado na parte a?rea, os valores variaram entre 64 e 158 kg.ha-1 quando os gen?tipos foram cultivados no Argissolo, e entre 297 e 441 kg.ha-1 quando os gen?tipos foram cultivados no Planossolo. Para os par?metros, ac?mulo de N e rendimento de biomassa, os gen?tipos que mais se destacaram foram: CNPGL F 06-3 e Cameroon seguido dos gen?tipos BAG 02 e CNPGL 93 41 1. 3. A rela??o C/N foi influenciada diretamente pelo tipo de solo, sendo que no Argissolo as rela??es encontradas foram em torno de 50% maiores, quando comparadas com o Planossolo. 4. O poder calor?fico e os teores de fibra, celulose, lignina e cinzas, que est?o relacionados ? parte qualitativa do material, em geral, n?o foram influenciados pelos gen?tipos, nem pelos tratamentos avaliados. A biomassa do capim-elefante apresentou caracter?sticas qualitativas e quantitativas positivas para ser utilizado na produ??o de energia renov?vel, sendo os gen?tipos CNPGL F 06-3 e Cameron, seguido dos gen?tipos BAG 02 e CNPGL 93 41 1 os mais indicados. Os gen?tipos em estudo n?o apresentaram resposta para rendimento e acumula??o de N pela biomassa ? inocula??o com bact?rias diazotr?ficas.
25

Usos e qualidade da ?gua em regi?o semi-?rida do nordeste brasileiro: percep??o ambiental de professores e alunos

Petrovich, Ana Carla Iorio 24 April 2009 (has links)
Made available in DSpace on 2014-12-17T15:54:55Z (GMT). No. of bitstreams: 1 AnaCLP_DISSERT_pagina 1_a_8.pdf: 8605712 bytes, checksum: a23b0324901ca6ee088750e19d1a57c3 (MD5) Previous issue date: 2009-04-24 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Density and biomass of bacterioplankton in parts of the Marechal Dutra reservoir were studied in periods of dry and rainy season. The averages of the total bacterial densities oscillated in the order of 107 organisms/ mL of sample. The cocci cells were numerically predominant, influencing considerably the total abundance of the bacterioplankton. The total bacterial biomass, was considered raised and varied from 2.431,82 to 2.739,01 ?gC.L-1, in function of the high values of biovolume of the filaments forms, and showed no marked spacial fluctuation. These high values of density and biomass alert for the necessity of a frequent monitoring of aquatic ecosystems of semi-arid region, where the quality of the water is affected by the occurrence of extensive dry periods, influencing considerably the quality of life of its population / Foram estudadas a densidade e a biomassa do bacteriopl?ncton nos per?odos seco e chuvoso em dois pontos do A?ude Marechal Dutra. As m?dias das densidades bacterianas totais oscilaram na ordem de 107 organismos por mL de amostra. As c?lulas em forma de cocos foram numericamente predominantes, influenciando consideravelmente a abund?ncia total do bacteriopl?ncton. A biomassa bacteriana total foi considerada elevada, variando de 2.431,82 a 2.739,01 ?gC.L-1 , em fun??o dos altos valores de biovolume dos filamentos. N?o foram encontradas varia??es espaciais nem sazonais marcantes. Os altos valores de densidade e biomassa encontrados alertam para a necessidade de um freq?ente monitoramento dos ecossistemas aqu?ticos de regi?o semi-?rida onde a qualidade da ?gua ? afetada pela ocorr?ncia de extensos per?odos de estiagem que influenciam a qualidade de vida de sua popula??o
26

Estudo da comunidade de bact?rias diazotr?ficas do g?nero Burkholderia em associa??o com cana-de-a??car e descri??o de Burkholderia silvatlantica / Community study of the of Burkholderia diazotrophic bacteria in association with sugarcane and description of Burkholderia silvatlantica

Perin, Liamara 15 February 2007 (has links)
Made available in DSpace on 2016-04-26T19:39:29Z (GMT). No. of bitstreams: 1 2007- Liamara Perin.pdf: 5126010 bytes, checksum: 0973e83f604e8d397ec95ef00c19da99 (MD5) Previous issue date: 2007-02-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The sugarcane crop in Brazil occupies almost six million hectares and it is economically important for the generation of jobs and energy production. Among the Poaceas species, it is the crop that receives more contributions from the biological nitrogen fixation, however until this moment it is unknown what organisms are responsible for the best results observed. Innumerable genuses of diazotrophic bacteria were found in association with sugarcane, among them the genus Burkholderia. However little is known about this genus in association with sugarcane. The objective of this study was to isolate and to characterize diazotrophic Burkholderia bacteria in association with sugarcane, and to describe a new species of diazotrophic Burkholderia bacteria. For that, samples of plants were collected in four crop areas, in different Brazilian states, for counting and isolating the bacteria community using the culture medias LGI and JMV. The isolates were characterized physiological, morphologically and molecularly. Sixty-four Burkholderia diazotrophic isolates were gotten that presented versatile metabolism, and the majority differing from the analyzed species patterns. Only five isolates were identified by the ARDRA technique, two belonging to B. tropica species and three to B. unamae. A big group, with 32 isolates, presented the same restriction profile by the ARDRA technique and differed from the analyzed species. The sequencing of the 16S rDNA region of two of these isolates showed that they don t belong to the already described species. This group, from sugarcane plants together with similar maize and pineapple isolates, was described as a new species named B. silvatlantica. The characterization of this new Burkholderia specie was confirmed by the hybridization DNA: DNA technique, presenting only 30% of similarity with the closest species, and the sequencing of the 16S rDNA region. B. Silvatlantica fixed nitrogen in microaerophilic conditions, and it had no capacity of inorganic phosphate solubilization, it did not produce vegetal hormones and had no nodulation capacity in leguminous. These results confirmed that Burkholderia is a rich genus in diazotrophics species and colonize different habitats. / A cultura da cana-de-a??car no Brasil ocupa mais de seis milh?es de hectares sendo importante economicamente pela gera??o de empregos e bastante promissora para a produ??o de energia. Dentre as Poaceas (gram?neas), ? a cultura que mais recebe contribui??es da fixa??o biol?gica de nitrog?nio, por?m ainda n?o se sabe ou n?o se conhece qual ou quais organismos s?o respons?veis pelos melhores resultados observados. In?meros g?neros de bact?rias diazotr?ficas foram encontrados em associa??o com cana-de-a??car, dentre eles o g?nero Burkholderia, at? o momento pouco estudado em associa??o com esta cultura. O objetivo deste estudo foi isolar e caracterizar bact?rias diazotr?ficas do g?nero Burkholderia em associa??o com cana-de-a??car e descrever uma nova esp?cie de bact?ria diazotr?fica do g?nero Burkholderia. Para tal, foram coletadas amostras de plantas em canaviais de quatro estados brasileiros para contagem e isolamento da comunidade de bact?rias utilizando os meios de cultura LGI e JMV. Os isolados foram caracterizados fisiologicamente, morfologicamente e molecularmente. Foram obtidos 64 isolados diazotr?ficos do g?nero Burkholderia, que apresentaram metabolismo vers?til e diferiram dos padr?es das esp?cies analisadas. Apenas cinco isolados foram identificados pela t?cnica de ARDRA, dois pertenceram a esp?cie B. tropica e tr?s a B. unamae. Um grande grupo, com 32 isolados, apresentou mesmo perfil de restri??o pela t?cnica de ARDRA e diferiu das esp?cies analisadas. O sequ?nciamento da regi?o 16S rDNA de dois destes isolados mostrou que eles n?o pertencem ?s esp?cies j? descritas. Este grupo obtido de plantas de cana-de-a??car, juntamente com isolados similares, obtidos de milho e abacaxi, foi descrito como uma nova esp?cie de nome B. silvatlantica. A nova esp?cie de Burkholderia foi confirmada pelos experimentos de hibridiza??o DNA:DNA, com apenas 30% de similaridade com a esp?cie mais pr?xima. B. silvatlantica fixou nitrog?nio em condi??es microaerof?licas, n?o apresentou capacidade de solubiliza??o de fosfato inorg?nico, n?o produziu horm?nios vegetais e n?o apresentou capacidade de nodula??o em leguminosas. Estes resultados confirmaram que o g?nero Burkholderia ? rico em esp?cies diazotr?ficas e est?o presentes em diferentes habitats.
27

Biorredu??o de acetofenona por microrganismos do estado da Bahia

Miranda, Joseneide Alves de 31 August 2009 (has links)
Submitted by Carolina Neves (carolinapon@uefs.br) on 2017-02-17T23:59:52Z No. of bitstreams: 1 Disserta??oJoseneideAlves.pdf: 3612959 bytes, checksum: a4ba8033510286e66a0d4453ad52d71d (MD5) / Made available in DSpace on 2017-02-17T23:59:53Z (GMT). No. of bitstreams: 1 Disserta??oJoseneideAlves.pdf: 3612959 bytes, checksum: a4ba8033510286e66a0d4453ad52d71d (MD5) Previous issue date: 2009-08-31 / The biorreduction has great importance in the production of optically pure substances and is widely used for asymmetric synthesis. Bioconversions occur with high specificity and efficiency because they are catalyzed by enzymes, forming one of the isomers from a pro-chiral substrate. This work had as main objective to evaluate the potential reduction of micro-organisms (yeasts, bacteria and fungi) isolated in the state of Bahia using as carbonyl substrate the acetophenone, analyzing its conversion into alcohol and identifying the enantiomeric excess produced. Strains of Saccharomyces cerevisiae isolated from sugar cane brandy distilleries of Bahia state, rhizobacteria isolated from Arachis pintoi (forage peanut) in southern Bahia and endophytic fungi isolated Hevea brasiliensis. The products were analyzed by gas chromatography coupled to mass spectrometry to verify the conversion of the substrate in alcohol and enantiomeric excess was determined by gas chromatography with chiral stationary phase. Of the 28 microorganisms evaluated 18 acted as biocatalysts. Products of reduction of acetophenone were obtained with yields between 6 and 79% and enantiomeric excess from 41 to 100%. Fungi CDC026, CDC086 and MDF077 converted acetophenone into (R)-alcohol, with ee of 54, 56, and 84%, while the other strains that showed positive results for acetophenone yielded the (S)-alcohol. Whereas 64% of test organisms were able to act as catalysts in the enantioseletive reduction of acetophenone, it was observed that the microbial diversity of the state of Bahia is a source of new catalysts for the production of enantiomeric pure compounds. / A Biorredu??o tem grande import?ncia na produ??o de subst?ncias opticamente puras, sendo amplamente utilizada para s?nteses assim?tricas. As bioconvers?es ocorrem com alta especificidade e efici?ncia por serem catalisadas por enzimas, formando um dos is?meros a partir de um substrato pr?-quiral. O presente trabalho teve como objetivo principal avaliar o potencial redutor dos microrganismos (leveduras, bact?rias e fungos) isolados no territ?rio baiano frente ao substrato carbon?lico acetofenona; verificando a convers?o do substrato (acetofenona) em ?lcool quiral e identificando o excesso enantiom?rico com que as rea??es biocatal?ticas ocorreram. Foram utilizadas culturas de Saccharomyces cerevisiae isoladas em cacha?arias do estado da Bahia, rizobact?rias isoladas no sul da Bahia e fungos endof?ticos. Foi testada a a??o desses microrganismos sobre o substrato acetofenona. Os produtos foram analisados por Cromatografia gasosa acoplada a espetrometria de massa, para verificar a convers?o do substrato em ?lcool; o excesso enantiom?rico foi obtido em cromat?grafo gasoso equipado com coluna quiral obtendo-se separa??o para os is?meros da acetofenona com um excesso enantiom?rico de at? 100%, para a cepa bacteriana I68. Os fungos CDC026 e CDC086 converteram a acetofenona em (R)-?lcool, as demais cepas que apresentaram resultados positivos para aceofenona produziram o (S)-?lcool em excesso. Conclui-se que em geral os microrganismos testados apresentaram boa capacidade de redu??o da acetofenona em experimentos de biotransforma??o, constituindo-se fontes de compostos enantiomericamente puros.
28

Sele??o de bact?rias diazotr?ficas solubilizadoras de f?sforo e seu efeito no desenvolvimento de plantas de arroz

Bonilla, German Andres Estrada 09 June 2011 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-17T14:23:26Z No. of bitstreams: 1 2011- German Andres Estrada Bonilla.pdf: 1652819 bytes, checksum: 24a4d4664a65dfad88ccdfe17b4a0c02 (MD5) / Made available in DSpace on 2016-08-17T14:23:26Z (GMT). No. of bitstreams: 1 2011- German Andres Estrada Bonilla.pdf: 1652819 bytes, checksum: 24a4d4664a65dfad88ccdfe17b4a0c02 (MD5) Previous issue date: 2011-06-09 / Rice (Oryza sativa L.) is one of the major world crops, being widely consumed among people from five continents. In recent years research have increased in relation to the use of plant growth promoting diazotrophic bacteria (PGPB) as a possible solution to reduce the use of chemical nitrogen and phosphate fertilizers. Thus, this study aimed to evaluate the physiological potential and inorganic phosphate (IP) solubilization capacity of different diazotrophic strains isolated from rice plants grown in different regions of Brazil as well as to evaluate their role in the development of rice plants. Firstly, the culture media employed to test the phosphate solubilization in petri dishes were standardized. In this study 49 strains were tested for their capability of solibilizing tricalcium phosphate in NBRIP and GL solid media. Afterwards, the soluble P, pH, population and the index of solubilization (IS) were quantified for 7 IP solubilizing strains grown in the NBRIP liquid medium. The IP solubilizing isolates were also tested for the production of indolic compounds (IAA) and the nitrogen fixation capacity through the acetylene reduction activity (ARA). The isolates were taxonomical identified through the amplification and partial sequencing of 16S RNAr and nifH genes. Three of these strains and the controls H. seropedicae ZAE94, G diazotrophicus PAL5 and A.chroochoccum AC1 were tested in greenhouse conditions in association with rice plants. All strains that solubilized IP in NBRIP liquid medium decreased the medium pH while the bacterial population remained around 108 cfu ml-1 for up to 15 days. All strains were capable to produce indole compounds and reduced acetylene. The partial analysis of 16S RNAr and nifH gene indicated the identification of the species Herbaspirillum seropedicae, Burkholderia vietnamiensis and B. kururiensis species. All strains showed an increase in the range of 33 and 47% in grain yield when tricalcium phosphate (PTC) was applied and between 18 and 44% when PSS (simple superphosphate) was used. In general, all of the strains stimulated an increase of total P in the grain and a greater harvest index. The use of these strains as bioinculant is promising and therefore it is necessary to test in the field conditions / O arroz (Oryza sativa L.) ? uma das principais culturas cultivadas, sendo amplamente consumida nos cinco continentes. Nos ?ltimos anos as pesquisas t?m aumentado em rela??o ao uso de bact?rias diazotr?ficas e promotoras de crescimento vegetal (BPCV), como uma poss?vel solu??o para diminuir o uso de fertilizantes qu?micos nitrogenados e fosfatados. Desta forma, este trabalho teve por objetivo avaliar o potencial fisiol?gico e a capacidade de solubiliza??o de fosfato inorg?nico (PI) de diferentes estirpes de bact?rias diazotr?ficas oriundas de plantas de arroz cultivadas em diferentes regi?es do Brasil e seu papel no desenvolvimento de plantas de arroz. Primeiramente foi padronizado o meio de cultura a ser empregado nos ensaios de solubiliza??o de fosfato inorg?nico em placas de petri. Neste estudo foram testadas 49 estirpes em quanto sua capacidade de solubilizar fosfato tric?lcico (PTC) nos meios s?lidos NBRIP e GL. Em seguida foi quantificado o P sol?vel, pH, a popula??o de bact?rias e ?ndice de solubiliza??o (IS) das 7 estirpes solubilizadoras de PI em meio l?quido NBRIP. As estirpes solubilizadoras de PI tamb?m foram testadas quanto ? produ??o de compostos ind?licos (AIA) e capacidade de fixar nitrog?nio atrav?s da atividade de redu??o e acetileno (ARA). As estirpes foram identificadas atrav?s da amplifica??o e do sequenciamento parcial dos genes 16S RNAr e gene nifH. Tr?s destas estirpes foram testadas em condi??es de casa de vegeta??o junto com os controles Herbaspirillum seropedicae BR11417 (ZAE94), Gluconacetobacter diazotophicus BR11281 (PAL5) e Azotobacter Chroochoccum AC1 quanto ? capacidade de aumentar o desenvolvimento e produ??o de plantas de arroz. Todas as estirpes que solubilizaram PI no meio de cultura NBRIP l?quido influenciaram na diminui??o do pH do meio enquanto que a popula??o se manteve em torno de 108 ufc.ml-1 por at? 15 dias. Todas as estirpes apresentaram capacidade de produzir compostos ind?licos e foram capazes de reduzir acetileno. A an?lise parcial do gene 16S RNAr e do gene nifH das sete estirpes possibilitou a identifica??o das esp?cies Herbaspirillum seropedicae, Burkholderia vietnamiensis e B. kururiensis. Todas as estirpes promoveram um aumento na produ??o de massa seca nos gr?os entre 33 e 47% quando foi utilizado o PTC e de 18 a 44% quando foi utilizado o fosfato super simples (PSS). Em geral, todas as estirpes estimularam um maior acumulo de N e P total no gr?o e um maior ?ndice de colheita. O uso dessas estirpes como bioinoculante ? bastante promissor e portanto torna-se necess?rio test?-las em condi??es de campo.
29

Doen?as de Veicula??o H?drica em Trechos da Bacia do Rio Piranhas-Assu: ocorr?ncia de bact?rias oportunistas, caracteriza??o epidemiol?gica e concep??es de professores e agentes de sa?de

Nascimento, Viviane Silva F?lix 07 February 2012 (has links)
Made available in DSpace on 2014-12-17T15:55:00Z (GMT). No. of bitstreams: 1 VivianeSFN_DISSERT.pdf: 1830875 bytes, checksum: cab92fad26402f8ffafa1b30a4f983b4 (MD5) Previous issue date: 2012-02-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Water is essential to life and all living organisms and their supply is necessary for economic development and quality of life of human populations, but their quality has been altered by human actions. In semi-arid northeast, the water is an issue of concern, especially its quality. This region is common to the construction of reservoirs that capture rain water, streams and temporary rivers in search of ease this situation, being intended for various purposes. Water scarcity is a limiting factor for the economic and social development of the region and contributes to the maintenance of waterborne diseases. About 80% of diseases that occur in developing countries are infected by waterborne pathogens. Therefore, this study aimed to determine in two environments that are part of semil?nticos Armando Ribeiro Gon?alves reservoir, and a stretch of the river Assu, all located in the semiarid RN, the occurrence of opportunistic pathogenic bacteria; check the conceptions of teachers and health workers about the issues "waterborne diseases" and "bacteria" and a diagnosis of diarrheal diseases that affect the population in some municipalities of the semi-arid region of RN from a survey of epidemiological data. For identification of bacteria using commercial kits and the diagnosis of diarrheal disease was based on information from databases. The previous conceptions of teachers and health workers were obtained through questionnaires. The results confirmed the presence of opportunistic bacteria in the studied area, showing the importance of monitoring water quality. There was an under-reporting of cases of diarrhea pointing out flaws in the monitoring of Diarrheal Diseases and indicating the need to improve it. It was felt also the need to implement educational activities on topics dealt with both with teachers and health workers, since they were identified misconceptions on the subject / A ?gua ? essencial ? vida e a todos os organismos vivos e o seu suprimento ? necess?rio para o desenvolvimento econ?mico e para a qualidade de vida das popula??es humanas, mas sua qualidade vem sendo alterada pelas a??es antr?picas. No semi?rido nordestino, a ?gua ? uma quest?o preocupante, especialmente a sua qualidade. Nessa regi?o ? comum a constru??o de reservat?rios, que captam ?guas de chuvas, c?rregos e rios tempor?rios, na busca de amenizar essa situa??o, sendo destinados para diversas finalidades. A escassez de ?gua ? limitante para o desenvolvimento econ?mico e social da regi?o e contribui com a manuten??o das doen?as de veicula??o h?drica. Cerca de 80% das doen?as que ocorrem em pa?ses em desenvolvimento s?o veiculadas pela ?gua contaminada por microrganismos patog?nicos. Nesse contexto, este trabalho objetivou determinar, em dois ambientes semil?nticos que fazem parte do reservat?rio Armando Ribeiro Gon?alves, e em um trecho do rio Assu, todos localizados no semi-?rido potiguar, a ocorr?ncia de bact?rias patog?nicas oportunistas; verificar as concep??es de professores e agentes de sa?de a respeito dos temas doen?as de veicula??o h?drica e bact?rias , e realizar um diagn?stico das doen?as diarr?icas que acometem a popula??o de alguns munic?pios do semi-?rido do RN a partir do levantamento de dados epidemiol?gicos. Para identifica??o das bact?rias utilizaram-se kits comerciais, e o diagn?stico das doen?as diarr?icas foi realizado com base em informa??es de bancos de dados. As concep??es pr?vias de professores e agentes de sa?de foram obtidas por meio da aplica??o de question?rios. Os resultados confirmaram a presen?a de bact?rias oportunistas nos ambientes estudados, evidenciando a import?ncia de vigil?ncia da qualidade da ?gua. Verificou-se uma sub-notifica?ao de casos de diarr?ias apontando falhas no Monitoramento das Doen?as Diarr?icas, e indicando a necessidade de aprimor?-lo. Percebeu-se, ainda, a necessidade de implementa??o de atividades educativas sobre os temas abordados, tanto com os professores como com os agentes de sa?de, uma vez que foram identificadas concep??es equivocadas sobre o tema
30

Efic?cia do bochecho de quitosana a 0,4% sobre o biofilme e bact?rias orais

Vieira, Liza Barreto 19 May 2006 (has links)
Made available in DSpace on 2014-12-17T15:30:48Z (GMT). No. of bitstreams: 1 LizaBV.pdf: 651863 bytes, checksum: 861130b51ad28ee890a75755594ddae3 (MD5) Previous issue date: 2006-05-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The purpose of this study was evaluate the effectiveness of the chitosan at 0.4 with high molecular weight and high deacetylation degree mouthrinse over the total decrease of the streptococci, Streptococcus mutans, lactobaci/li and over the perceptible bacterial film and gingival bleeding indices. For that, a total of 68 healthy students between 11 and 13 years old, not allergic to crustacean and not users of antibiotics or antimicrobial agent for the last three months or during the treatment, was selected. From those, thirty two individuaIs used the mouthrinse test, and thirty six, the control one. The participants rinsed 10 mL of the solutions twice a day, one during the moming (which was supervised), and another one during the aftemoon (which was not supervised), for fifteen days. The saliva collect for the microbiological analysis, as well as the perceptible bacterial film and gingival bleeding indices check, were made before the use ofthe mouthrinses (base line), immediately after the last mouthrinse on the day (zero time) and fifteen days after (fifteen time). These data were collected at school and the saliva was carried inside the ice to the laboratory. The samples were diluted, and 0.1 mL ofthe 10 -1 dilution was seeded in Rogosa SL agar, for further analysis of the total of lactobaci/lus~ 0.1 mL of the 10-4 dilution in Mitis Salivarius with bacitracin, for S. mutans analysis; and 0.1 mL of the 10-6 dilution in Mitis Salivarius for the analysis ofthe total of streptococcus. The Rogosa SL agar plates were incubated in aerobic at 37?C for 72 hours and the MSB and the MS were incubated in anaerobic in Gaspak@ jars at 37?C for 48 hours for further count ofColonies Former Units (CFUs). The assay was made in duplicate for each bacterial group analyzed. The number of CFUs transformed in LOGlO was analyzed according to the following tests: ANOV A, t of Paired and Not Paired Student, Friedman, Man-Whitney and square-qui test. On the base line, alI the variables analyzed were similar on both tested groups. On both groups, for the total of streptococcus there was no significant difference along the time and for S. mutans there was a statistic significant increase of the CFUs from the base line to the zero time. For the total of lactobaccilus there was no significant difference on the test group along the time, and on the control there was a significant increase ofthe CFUs ITom the base line to the zero time. For both groups, there was significant decrease ofthe perceptible bacterial film index along the time, and that can be explained by the mechanic effect of the mouthrinse over the bacterial film and by the participation of the students on the research which could have motivated him to a better toothbrushing (Hawthome effect). The gingival bleeding index also showed a decrease along the time, even though it was not significant. Therefore, the conclusion of this study was that the chitosan at 0.4 % mouthrinse was not effective on the CFUs reduction of the three bacterial groups analyzed, as well as on the reduction of the perceptible bacterial film and gingival bleeding indices / O objetivo deste estudo foi avaliar a efic?cia do bochecho de quitosana a 0,4% com alto peso molecular e alto grau de desacetiliza??o sobre a redu??o do total de estreptococcus, Streptococcus mutans, total de lactobacilos e sobre os ?ndices de placa vis?vel e sangramento gengival. Para tanto, foram selecionados 68 estudantes saud?veis, com idade entre 11 e 13 anos, n?o al?rgicos a crust?ceos e que n?o tivessem usado antibi?tico ou antimicrobiano nos ?ltimos tr?s meses ou durante o tratamento. Trinta e dois indiv?duos utilizaram o bochecho teste e trinta e seis o controle. Os participantes bochecho 10 ML das solu??es duas vezes ao dia, um pela manh? (supervisionado) e outro ? tarde (n?o supervisionado, durante quinza dias. A coleta de saliva para an?lise microbiol?gica, bem como a aferi??o dos ?ndices de placa vis?vel e de sangramento gengival, deu-se antes do uso dos bochechos (linha base),no dia imediatamento ap?s o ?ltimo bochecho (tempo zero) e quinze dias ap?s (tempo quinze). Esses dados foram coletados na escola e a saliva transportada em gelo at? o laborat?rio. As amostras de saliva foram diluidas e 0,1ML da dilui??o 10 elevado a menos 1 foi semeada em Rogosa SL ?gar para a posterior an?lise do total de lactobacilos; 0,1mL da dilui??o 10 elevado a menos 4 em Mitis Salivarus com bacitracina, para an?lise de S mutans, e 0,1mL da dilui??o 10 elevado a menos 6 em Mitis Salivarius para an?lise do total de estreptococous. As placas de Rogosa SL ?gar foram incubadas em aerobiose a 37 grau cent?grado por 72 horas e as de MSB e MS foram incubadas em anaeribiose em jarras Gaspak a 337 grau cent?grado, por 48 horas, para posterior contagem das unidades formadoras de col?nias (UFCs). O ensaio foi feito em duplicadta para cada grupo bacteriano analisado. O n?mero de UFCs transformados em LOG10 foi analisado mediante os seguintes testes: ANOVA, t de Student emparelhado e n?o emparelhado, Friedman, Man-Whitney e teste do qui-quadrado. Na linha base, todas as vari?veis analisadas no estudo foram semelhantes nos dois grupos testados. Em ambos os grupos, para o total de estreptococcus n?o houve diferen?a significativa ao longo do tempo; para o S. mutans, houve aumento estatisticamente significativo das UFCs da linha base para o T0. Para o total de lactobacilos, n?o houve diferen?a no grupo teste ao longo do tempo e, no controle, houve aumento significativo das UFCs da linha base para o T0. Em ambos os grupos, houve diminui??o significativa do IPV ao longo do tempo. O ISG tamb?m apresentou redu??o ao longo do tempo, por?m n?o foi significativa. Portanto, este estudo concluiu que o bochecho de quitosana a 0,4% n?o foi eficaz na redu??o das UFCs dos tr?s grupos bacterianos analisados, assim como, na redu??o do IPV e ISG

Page generated in 0.0428 seconds