Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-04-27T18:09:30Z No. of bitstreams: 1 2015 - Jessica Coelho Melo.pdf: 1651769 bytes, checksum: 37df9227b9a25c24297ba5364064be27 (MD5) / Made available in DSpace on 2018-04-27T18:09:30Z (GMT). No. of bitstreams: 1 2015 - Jessica Coelho Melo.pdf: 1651769 bytes, checksum: 37df9227b9a25c24297ba5364064be27 (MD5) Previous issue date: 2015-08-21 / CNPq / The gray leaf spot caused by Stemphylium solani, has occasioned losses in the tomato crop (Solanum lycopersicum L.) in several regions of Brazil. Although there are resistant cultivars, the control has been made, essentially, with application of fungicides. These, despite the practicality and efficiency can lead to the accumulation of polluting substances in the air and in the fruits. This study aimed to evaluate: 1) the chemical control efficiency of the disease with commercial fungicides registered for crop and with alternative products such as syrups and plant extracts; 2) the influence of these treatments on the development and production of tomato; 3) the contribution of metals in the system and its contents in leaves and fruits; 4) to compare the contents of metals in the fresh mass of the fruits with the limits allowed by the legislation. Three trials were carried out, one in the greenhouse and two in the field, and different products were compared: mancozebe, tebuconazole, copper oxychloride, vi?osa mixture, bordeaux mixture, lime sulfur, garlic extract and water. Were evaluated the progress of the disease, the production and the supply of metals in the soil, plants and fruits (Cd, Co, Cr, Cu, Fe, Mn, Pb, Ni and Zn). The disease occurred on average at low intensity and did not affect the fruit production, which did not allow an adequate evaluation of the efficiency of the treatments. Among all the products tested, bordeaux and vi?osa mixtures and mancozebe were the most efficient in controlling the disease, however, without affecting the accumulation of fresh and dry mass of the plants and productivity. Bordeaux and vi?osa mixtures were the products that contributed the most to the incorporation of metals to the agrosystem followed by mancozebe and copper oxychloride. The concentration of metals in the fruits was below the maximum limit allowed by the MERCOSUL Technical Regulation, however, it deserves attention in view of fact that the Cd values found in the fruits are very close to the allowed limit, especially in the treatments with vi?osa mixture, oxychloride copper and bordeaux mixture. The continuous use of fungicides and vi?osa and bordeaux mixtures can contribute to the accumulation of heavy metals in the agrosystem. New studies addressing this topic should be made. / A mancha-de-estenf?lio, causada por Stemphylium solani, tem ocasionado perdas na cultura do tomateiro (Solanum lycopersicum L.) em v?rias regi?es do Brasil. Apesar de existirem cultivares resistentes, o controle tem sido feito, essencialmente, com aplica??o de fungicidas. Estes, apesar da praticidade e efici?ncia podem levar ao ac?mulo de subst?ncias poluentes no ar e nos frutos. O presente trabalho teve como objetivos avaliar: 1) a efici?ncia do controle qu?mico da doen?a com fungicidas comerciais registrados para a cultura e com produtos alternativos como caldas e extratos de plantas; 2) a influ?ncia destes tratamentos no desenvolvimento e produ??o do tomateiro; 3) o aporte de metais no sistema e os seus teores nas folhas e frutos; 4) comparar os teores de metais na massa fresca dos frutos com os limites permitidos pela legisla??o. Realizaram-se tr?s ensaios, um em casa-de-vegeta??o e dois no campo e compararam-se diferentes produtos: mancozebe, tebuconazole, oxicloreto de cobre, calda vi?osa, calda bordalesa, calda sulfoc?lcica, extrato de alho e ?gua. Avaliaram-se o progresso da doen?a, a produ??o e o aporte de metais no solo, plantas e frutos (Cd, Co, Cr, Cu, Fe, Mn, Pb, Ni e Zn). A doen?a ocorreu em m?dia a baixa intensidade e n?o afetou a produ??o de frutos, o que n?o permitiu uma adequada avalia??o da efici?ncia dos tratamentos. Dentre todos os produtos testados, as caldas bordalesa e vi?osa e o mancozebe foram os mais eficientes no controle da doen?a, por?m, sem afetar o ac?mulo de massa fresca e seca das plantas e a produtividade. As caldas bordalesa e vi?osa foram os produtos que mais contribu?ram para a incorpora??o de metais ao agrossistema seguido do mancozebe e do oxicloreto de cobre. A concentra??o de metais nos frutos esteve abaixo do limite m?ximo permitido pelo Regulamento T?cnico MERCOSUL, no entanto, merece aten??o tendo em vista o fato dos valores de Cd encontrados nos frutos estarem muio pr?ximo do limite permitido, especialmente nos tratamentos com calda vi?osa, oxicloreto de cobre e calda bordalesa. O uso cont?nuo de fungicidas e das caldas vi?osa e bordalesa podem contribuir para o ac?mulo de metais pesados no agrossistema. Novos estudos abordando este tema devem ser feitos.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-12-15T17:45:11Z No. of bitstreams: 1 HenriqueCesarDeJesusFerreira_DISSERT.pdf: 3079036 bytes, checksum: 669ef1f5f7345e06f0db2159cfbc3fcd (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2015-12-29T20:46:40Z (GMT) No. of bitstreams: 1 HenriqueCesarDeJesusFerreira_DISSERT.pdf: 3079036 bytes, checksum: 669ef1f5f7345e06f0db2159cfbc3fcd (MD5) / Made available in DSpace on 2015-12-29T20:46:40Z (GMT). No. of bitstreams: 1 HenriqueCesarDeJesusFerreira_DISSERT.pdf: 3079036 bytes, checksum: 669ef1f5f7345e06f0db2159cfbc3fcd (MD5) Previous issue date: 2014-09-25 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Muitas esp?cies se especializaram em viver nos mais variados ambientes existentes demonstrando a not?vel capacidade de adapta??o do mundo microbiano as mais diversas condi??es f?sico-qu?micas. Ambientes expostos ? radia??o natural e a metais s?o escassos ao redor do mundo, apresentando uma microbiota ainda desconhecida. Com um n?mero total estimado entre 4 e 6 x 1030 microrganismos na terra, estes constituem um enorme pool biol?gico e gen?tico a ser explorado. Abordagens metagen?micas, independentes de cultivo, proporcionam uma nova forma de acesso ao potencial gen?mico de amostras ambientais tornando-se uma importante ferramenta para elucida??o de fun??es ecol?gicas, bem como para identifica??o de novas esp?cies e biomol?culas. Neste trabalho, o material gen?tico ambiental de amostras de solo e ?gua do A?ude Boqueir?o de Parelhas-RN, sob influ?ncia de radia??o natural e da presen?a de metais, foi extra?do, pirosequenciado, e as sequ?ncias geradas foram analisadas atrav?s de programas de bioinform?tica (MG-RAST e STAMP). Perfis taxon?micos comparativos de ambas as amostras mostraram alta abund?ncia do Dom?nio Bacteria, seguida por uma pequena parcela atribu?da aos Dom?nios Eucaryota, Archaea e V?rus. Proteobacteria, Actinobacteria e Bacterioidetes foram os filos que mostraram maior domin?ncia em ambas as amostras. Importantes g?neros e esp?cies associados ? resist?ncia aos agentes estressores encontrados na regi?o foram observados. Sequ?ncias relacionadas ? replica??o e reparo do DNA, ao estresse oxidativo e estresse pelo calor e a resist?ncia a compostos t?xicos foram observadas, mostrando uma importante rela??o entre a microbiota e seu perfil metab?lico, influenciada pelas vari?veis ambientais regionais. Os resultados encontrados neste estudo adicionam valiosos e in?ditos dados sobre a composi??o de comunidades microbianas nestas regi?es. / Many species have specialized to live in the most varied existing environments showing the remarkable adaptability of the microbial world the most diverse physicochemical conditions. Environments exposed to natural radiation and metals are scarce around the world, presenting a microbiota still unknown. With a total number estimated between 4 and 6 x 1030 microrganisms on earth, they constitute an enormous biological and genetic pool to be explored. Metagenomic approach independent of cultivation, provides a new form to access to the potential genomic environmental samples becoming a powerful tool for the elucidation of ecological functions, metabolic profiles, as well as to identify new biomolecules. In this context, the genetic material of environmental soil and water samples from A?ude Boqueirao Parelhas-RN, under the influence of natural radiation and the presence of metals, was extracted, pirosequencing and the generated sequences were analyzed by bioinformatics programs (MG-RAST and STAMP). Taxonomic comparative profiles of both samples showed high abundance of Domain Bacteria, followed by a small portion attributable to Eucaryota Domains, Archaea and Viruses. Proteobacteria, Actinobacteria and Bacterioidetes phyla showed the greater dominance in both samples. Important genera and species associated with resistance to various stressors found in region were observed. Sequences related to oxidative and heat stress, DNA replication and repair, and resistance to toxic compounds were observed, suggesting a significant relationship between the microbiota and their metabolic profile, influenced by regional environmental variables. The results of this study add valuable and unpublished data on the composition of microbial communities in these regions

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-01T21:27:08Z No. of bitstreams: 1 MariaMaesiaSoaresGomesEiband_TESE.pdf: 3538406 bytes, checksum: e5d34715daa7cb202b6908f42f0b111d (MD5) / Approved for entry into archive by Elisangela Moura (lilaalves@gmail.com) on 2016-02-02T22:08:17Z (GMT) No. of bitstreams: 1 MariaMaesiaSoaresGomesEiband_TESE.pdf: 3538406 bytes, checksum: e5d34715daa7cb202b6908f42f0b111d (MD5) / Made available in DSpace on 2016-02-02T22:08:17Z (GMT). No. of bitstreams: 1 MariaMaesiaSoaresGomesEiband_TESE.pdf: 3538406 bytes, checksum: e5d34715daa7cb202b6908f42f0b111d (MD5) Previous issue date: 2015-01-28 / Os metais pesados est?o presentes em res?duos industriais. Estes metais podem gerar um grande impacto ambiental contaminado ?gua, solos e plantas. A a??o qu?mica de metais pesados tem despertado grande interesse ambiental. Neste contexto, esta pesquisa teve como objetivo principal testar o desempenho de tecnologias eletroqu?micas para a remo??o e quantifica??o de metais pesados. Primeiramente, a t?cnica eletroanal?tica de esgotamento ou redissolu??o (Adsortion stripping voltammetry, em ingl?s) com eletrodo de carbono v?treo (GC) foi padronizada a fim de usar essa metodologia para a quantifica??o dos metais durante sua elimina??o mediante o processo de eletrocoagula??o (EC). As curvas anal?ticas necess?rias foram avaliadas visando obter confiabilidade na determina??o e quantifica??o de Cd2+ e Pb2+ separadamente ou em uma mistura (solu??es sint?ticas contendo Cd2+ e Pb2+). Entretanto, o processo de remo??o mediante a EC foi desenvolvida empregando uma c?lula eletroqu?mica em fluxo cont?nuo (EFC) para a remo??o de Cd2+ e Pb2+. Os experimentos foram realizados utilizando eletrodos em placas paralelas de Al com 10 cm de di?metro e ?rea de 63,5 cm2. A otimiza??o das condi??es para a remo??o de Cd2+ e Pb2+ no tratamento de 2 L de solu??o, com fluxo de 151 L h-1 foram estudadas em fun??o de diferentes valores de corrente aplicada durante 30 min. A remo??o dos ?ons de Cd2+ e Pb2+ da solu??o foram monitoradas durante a eletr?lise utilizando a voltametria de redissolu??o empregando o GC como sensor. Os resultados mostraram que a elimina??o de Pb2+? eficiente quando o processo de EC ? utilizado, obtendo valores de remo??o de 98% em 30 min. Este comportamento ? dependente da corrente aplicada, o que implica num aumento do consumo de energia. A partir dos resultados tamb?m verificou-se que a voltametria de redissolu??o (AdSV) ? bastante confi?vel na determina??o da concentra??o de Pb2+, quando comprada com a t?cnica de absor??o at?mica (AA). Diante disto, como segundo objetivo deste trabalho foi avaliar a remo??o de Cd2+ e Pb2+ mediante a EC, acoplando esta tecnologia eletroqu?mica com a metodologia eletroanal?tica para a quantifica??o destes metais durante sua remo??o de efluentes sint?ticos. A efici?ncia de remo??o, com o aumento da corrente foi confirmada, obteve-se remo??o 93% e 100% de Cd2+ e Pb2+ respectivamente, ap?s 30 min de EC. O aumento da corrente promove a oxida??o dos eletrodos de sacrif?cio, e consequentemente o aumento da quantidade de coagulantes, que influencia a elimina??o dos metais em solu??o. A AdSV ? uma maneira r?pida, confi?vel, econ?mica e simples para determinar ?ons de Cd2+ e Pb2+ durante suas remo??es, o m?todo eletroanal?tico pode ser utilizado com confian?a aceit?vel, assegurando a precis?o da quantifica??o e uma boa sensibilidade e, al?m disso, ? mais barato do que os normalmente usados, que requerem a utiliza??o de reagentes t?xicos e mais caros. Os nossos resultados demonstraram o potencial de t?cnicas eletroanal?ticas para monitorar o curso de interven??es ambientais. Assim, a aplica??o das duas t?cnicas associadas pode ser um caminho confi?vel para monitoramento de impactos ambientais devido ? contamina??o de ecossistemas aqu?ticos por metais pesados. / Heavy metals are present in industrial waste. These metals can generate a large environmental impact contaminating water, soil and plants. The chemical action of heavy metals has attracted environmental interest. In this context, this study aimed to test t he performance of electrochemical technologies for removing and quantifying heavy metals. First ly , the electroanalytical technique of stripping voltammetry with glassy carbon electrode (GC) was standardized in order to use this method for the quantificatio n of metals during their removal by electrocoagulation process (EC). A nalytical curves were evaluated to obtain reliability of the determin ation and quantification of Cd 2+ and Pb 2+ separately or in a mixture. Meanwhile , EC process was developed using an el ectrochemical cell in a continuous flow (EFC) for removing Pb 2+ and Cd 2+ . The se experiments were performed using Al parallel plates with 10 cm of diameter ( ? 63.5 cm 2 ) . The optimization of conditions for removing Pb 2+ and Cd 2+ , dissolved in 2 L of solution at 151 L h - 1 , were studied by applying different values of current for 30 min. Cd 2+ and Pb 2+ concentrations were monitored during electrolysis using stripping voltammetry. The results showed that the removal of Pb 2 + was effective when the EC pro cess is used, obtaining removals of 98% in 30 min. This behavior is dependent on the applied current, which implies an increase in power consumption. From the results also verified that the stripping voltammetry technique is quite reliable deter mining Pb 2+ concentration , when compared with the measurements obtained by atomic absorption method (AA). In view of this, t he second objective of this study was to evaluate the removal of Cd 2+ and Pb 2+ (mixture solution) by EC . Removal efficiency increasing current was confirmed when 93% and 100% of Cd 2+ and Pb 2+ was removed after 30 min . The increase in the current promotes the oxidation of sacrificial electrodes, and consequently increased amount of coagulant, which influences the removal of heavy metals in solution. Adsortive voltammetry is a fast, reliable, economical and simple way to determine Cd 2+ and Pb 2+ during their removal. I t is more economical than those normally used, which require the use of toxic and expensive reagents. Our results demonstrated the potential use of electroanalytical techniques to monitor the course of environmental interventions. Thus, the application of the two techniques associated can be a reliable way to monitor environmental impacts due to the pollution of aquatic ecosystems by heavy metals.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-06-13T19:15:42Z No. of bitstreams: 1 AlcioneOlintoGalvao_TESE.pdf: 2924664 bytes, checksum: f8011e637681ba38a8a5c55b07dc7de6 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-06-14T21:19:34Z (GMT) No. of bitstreams: 1 AlcioneOlintoGalvao_TESE.pdf: 2924664 bytes, checksum: f8011e637681ba38a8a5c55b07dc7de6 (MD5) / Made available in DSpace on 2017-06-14T21:19:35Z (GMT). No. of bitstreams: 1 AlcioneOlintoGalvao_TESE.pdf: 2924664 bytes, checksum: f8011e637681ba38a8a5c55b07dc7de6 (MD5) Previous issue date: 2017-01-20 / A remo??o de metais t?xicos das ?guas residuais ? de grande interesse no estudo da polui??o da ?gua. Entre os v?rios metais conhecidos por serem altamente t?xico destaca-se o c?dmio, que ? considerado como uma das subst?ncias mais perigosas podendo causar s?rios danos aos rins e ossos. O processo de adsor??o vem sendo utilizado como um m?todo eficaz para a remo??o de ?ons met?licos. Uma alternativa para utiliza??o de adsorventes em forma de p? ? sua utiliza??o em conjunto com outros materiais. Com esse intuito, o presente estudo teve como objetivo desenvolver blendas polim?ricas (PVA/Amido), tendo a hidroxiapatita (HAP) e o biovidro (BV) dispersos no meio para a remo??o dos ?ons de c?dmio. Realizou-se, inicialmente, a caracteriza??o dos p?s e das blendas polim?ricas por diferentes t?cnicas: An?lise Termogravim?trica (TGA), Espectroscopia de Infravermelho Transformada de Fourier (FTIR), Difra??o de Raios X (DRX), Espectrometria de fluoresc?ncia de raios-X (FRX), Microscopia Eletr?nica de Varredura (MEV), Microscopia de For?a At?mica (AFM), Determina??o do Potencial Zeta. Foram realizados os ensaios de adsor??o a fim de estudar a cin?tica e o equil?brio na adsor??o dos ?ons met?licos, bem como um planejamento fatorial atrav?s do software Design Expert. As an?lises de caracteriza??o mostram que os materiais adsorventes s?o adequados para utiliza??o na remo??o de metais pesados. Os dados cin?ticos mostraram melhor correla??o com a equa??o de velocidade de pseudo-segunda ordem e os pontos experimentais se ajustaram ao modelo da isot?rmica de Freundlich. O planejamento experimental apresentou um coeficiente de determina??o (R?) de 0,9826 e 0,9991 para as blendas polim?ricas PVA/Amido/HAP e PVA/Amido/BV, respectivamente, com um n?vel de confian?a de 95%. Com isso, a adsor??o do c?dmio pelas blendas polim?ricas com HAP e BV em solu??o aquosa mostraram-se eficientes, tornando o processo vi?vel para a remo??o de metais pesados. / The removal of toxic metals from wastewater is of great interest in the study of water pollution. Among the various metals known to be highly toxic is cadmium, which is considered one of the most dangerous substances and can cause serious damage to the kidneys and bones. The adsorption process has been used as an effective method for the removal of metallic ions. An alternative to the use of adsorbents in powder form is their use in conjunction with other materials. The aim of the present study was to develop polymer blends (PVA/Starch), with hydroxyapatite (HAP) and bioglass (BV) dispersed in the medium for the removal of cadmium ions. The characterization of the powders and the polymer blends was carried out by different techniques: Thermogravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), X-ray Fluorescence Spectrometry FRX), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Determination of Zeta Potential. The adsorption tests were carried out in order to study the kinetics and the equilibrium in the adsorption of the metallic ions, as well as a factorial planning through the software Design Expert. Characterization analyzes show that the adsorbent materials are suitable for use in the removal of heavy metals. The kinetic data showed better correlation with the pseudo-second order velocity equation and the experimental points conformed to the Freundlich isothermal model. The experimental design presented a coefficient of determination (R?) of 0.9826 and 0.9999 for the polymer blends PVA/Starch/HAP and PVA/Starch/BV, respectively, with a confidence level of 95%. Thus, the adsorption of the cadmium by the polymer blends with HAP and BV in aqueous solution proved to be efficient, making the process viable for the removal of heavy metals.

Made available in DSpace on 2014-12-17T15:42:03Z (GMT). No. of bitstreams: 1 MariaFPV.pdf: 6083202 bytes, checksum: 8b9199df5753800b615ab0a90bae3e8e (MD5) Previous issue date: 2007-12-10 / Heavy metals can cause problems of human poisoning by ingestion of contaminated food, and the environment, a negative impact on the aquatic fauna and flora. And for the presence of these metals have been used for aquatic animals biomonitoramento environment. This research was done in order to assess the environmental impact of industrial and domestic sewage dumped in estuaries potiguares, from measures of heavy metals in mullet. The methods used for these determinations are those in the literature for analysis of food and water. Collections were 20 samples of mullet in several municipality of the state of Rio Grande do Norte, from the estuaries potiguares. Were analyzed the content of humidity, ash and heavy metals. The data were subjected to two methods of exploratory analysis: analysis of the main components (PCA), which provided a multivariate interpretation, showing that the samples are grouped according to similarities in the levels of metals and analysis of hierarchical groupings (HCA), producing similar results. These tests have proved useful for the treatment of the data producing information that would hardly viewed directly in the matrix of data. The analysis of the results shows the high levels of metallic species in samples Mugil brasiliensis collected in Estuaries /Potengi, Piranhas/A?u, Guara?ra / Papeba / Ar?s and Curimata? / Os metais pesados podem provocar problemas de intoxica??o humana pela ingest?o de alimentos contaminados e para o meio ambiente, uma repercuss?o negativa ? fauna e flora aqu?ticas. E para detectar a presen?a destes metais t?m-se utilizado animais aqu?ticos para o biomonitoramento ambiental. Esta pesquisa foi feita com o intuito de se avaliar o impacto ambiental de esgotos dom?sticos e industriais despejados nos estu?rios potiguares, a partir das medidas de metais pesados em tainha. Os m?todos utilizados para estas determina??es s?o aqueles constantes da literatura para an?lise de alimentos e de ?gua. Foram coletas 20 amostras de tainha em diversos munic?pios do Estado do Rio Grande do Norte, oriundas dos estu?rios potiguares. Foram analisados os teores de umidade, cinzas e metais pesados. Os dados foram submetidos a dois m?todos de an?lises explorat?rios: an?lise de componentes principais (PCA), que proporcionou uma interpreta??o multivariada, mostrando que as amostras s?o agrupadas de acordo com as similaridades de teores de metais e an?lise hier?rquica de agrupamentos (HCA), produzindo resultados semelhantes. Estas an?lises mostraram-se ?teis para o tratamento dos dados produzindo informa??es que dificilmente seriam visualizados diretamente na matriz de dados. A an?lise dos resultados mostra os altos teores de esp?cies met?licas em amostras coletadas em tainhas nos Estu?rios Potengi, Piranhas/A?u, Guara?ra/Papeba/Ares e Curimata?

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2015-11-12T01:11:08Z No. of bitstreams: 1 Disserta??o Adriana Fidelis - Vers?o Definitiva.pdf: 9437752 bytes, checksum: f708082e56eba193c45496d67cab5993 (MD5) / Made available in DSpace on 2015-11-12T01:11:08Z (GMT). No. of bitstreams: 1 Disserta??o Adriana Fidelis - Vers?o Definitiva.pdf: 9437752 bytes, checksum: f708082e56eba193c45496d67cab5993 (MD5) Previous issue date: 2013-03-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / In the 1960? the mining company Plumbum Mineradora was installed in the Satate of Bahia, Brazil. This company, which produced lead ingots for 33 years, left over 400,000 tons of slag, which contained, among other pollutants, cadmium and lead. These metals are currently found in the soil surrounding the old factory, in concentrations considered highly toxic. A study was started to investigate possible bioremediation in the area with the isolation of bacteria from the rhizosphere of local plants, followed by the test in their performance in metals contaminant tolerance. Finally, identification of the bacteria was made based on molecular marker 16S rRNA. The isolation protocol was carry out using Nutrient Agar and after obtaining a pure culture. The isolates were then subjected to tests of Minimum Inhibitory Concentration (CIM). Each isolate served as a source for extraction of DNA for molecular analysis with 16S rRNA region. Among the rhizospheres collected, those from which the greatest number of species were isolated from plants with a perennial habit, among them the castor bean (Ricinus communis L.) and emba?ba (Cecropia pachystachya Tr?cul) which together comprised approximately 38% of all species of bacteria obtained. Interestingly, from the castor bean (an exotic plant in Brazil), 2/3 of the bacteria were Gram negative, while from the emba?ba (a native plant of Brazil), ? of the bacteria isolated were of Gram positive. Regardless of the classification of Gram, the bacteria studied showed higher tolerance to lead; 70% of Gram negative bacteria showed conspicuous morphological changes, whereas of those that were Gram positive, only 13% demonstrated. In addition, these bacteria have been identified by molecular analysis using the 16S rRNA marker. The used methodology based on analysis of parsimony and distance trees. As a result, the region 16S was able to identify only 22% of species while the remain species could only be identified to genus or to infra-generic groups. Therefore, the data suggest that the Gram negative and Gram positive bacteria have distinct mechanisms of adaptation in environments polluted by lead and cadmium and that the 16S region is not an efficient universal barcode marker, which should be used only as the first step on the identification of bacteria. Although this study does not provide a final parameter for ecological factors under consideration here, it provides an insight into the influence of the plant habitat on bacterial communites, and the role of Gram in the mechanisms of tolerance. It is hope to explore these aspects in the further studies. / Na d?cada de 60, a empresa de minera??o Plumbum Mineradora foi instalada no Estado da Bahia, Brasil. Esta empresa, a qual produziu lingotes de chumbo por 33 anos, deixou mais de 400.000 toneladas de esc?ria, a qual continha, dentre outros poluentes, c?dmio e chumbo. Estes metais s?o, atualmente, encontrados no solo do entorno das antigas instala??es da f?brica, em concentra??es consideradas altamente t?xicas. Este estudo come?ou a investigar a biorremedia??o da ?rea com o isolamento de bact?rias das rizosferas de plantas locais, seguido por testar a toler?ncia das bact?rias a esses metais. Finalmente, a identifica??o de bact?rias foi feita baseada no marcador molecular 16S rRNA. O protocolo de isolamento foi realizado em meio de Agar Nutriente e ap?s a obten??o de cultura pura, os isolados foram submetidos a testes de Concentra??o Inibit?ria M?nima (CIM). Cada isolado serviu de fonte para extra??es de DNA para an?lise molecular com a regi?o 16S rRNA. Dentre as rizosferas coletadas, as que mais se destacaram em rela??o a quantidade de esp?cies isoladas foram as plantas de h?bito perene, dentre elas, a mamona (Ricinus comunis L.) e a emba?ba (Cecropia pachystachya Tr?cul), que abrigaram juntas aproximadamente 38% de todas as esp?cies de bact?rias obtidas. Interessante notar que da mamona (uma planta ex?tica no Brasil), 2/3 das bact?rias foram Gram negativas, enquanto que da emba?ba (uma planta nativa do Brasil), 3/4 das bact?rias isoladas foram Gram positivas. Independentemente da classifica??o do Gram, as bact?rias apresentaram maior resist?ncia ao chumbo; 70% das Gram negativas apresentaram mudan?as morfol?gicas acentuadas, enquanto que estas, nas Gram positivas, manifestaram-se em apenas 13%. Al?m disso, estas bact?rias foram identificadas por meio de an?lise molecular, com o uso do marcador 16S rRNA. A metodologia usada foi baseada em an?lise de ?rvores de parcim?nia e dist?ncia. Como resultado, a regi?o 16S foi capaz de identificar 22% das esp?cies, enquanto que para o restante mostrou-se eficiente para classifica??o at? g?nero ou para agrupamentos infragen?ricos. Portanto, os dados sugerem que as bact?rias Gram negativas e Gram positivas possuem mecanismos de adapta??es distintos em ambientes polu?dos por chumbo e c?dmio e que a regi?o 16S n?o ? eficiente como marcador universal tipo ?c?digo de barras?, o qual deve ser utilizado apenas como a primeira ferramenta de identifica??o de bact?rias isoladas. Apesar deste estudo n?o servir como par?metro definitivo para considera??es ecol?gicas, ele fornece conhecimento sobre a influ?ncia do h?bito da planta sobre a comunidade bacteriana e o papel da estrutura morfol?gica das bact?rias (Gram) nos mecanismos de toler?ncia. Espera-se que estes dados possam ser explorados em estudos posteriores.