A resistência aos antibióticos é um problema de saúde pública global com sérias consequências para o tratamento de várias infecções bacterianas. Os fatores de transcrição da família MarR têm sido descritos controlando resistência a antibióticos e vários outros processos em bactérias. Neste trabalho, estudamos mecanismos de resistência a antibióticos em Chromobacterium violaceum, uma bactéria Gram-negativa ambiental que pode atuar como um patógeno oportunista em humanos. A estratégia envolveu a varredura de um painel de treze linhagens mutantes de fatores de transcrição da família MarR de C. violaceum disponíveis, por testes de susceptibilidade a 24 antibióticos. Estes ensaios revelaram que apenas o mutante ?emrR apresentou resistência aumentada ao antibiótico ácido nalidíxico em relação à linhagem selvagem. Esta resistência aumentada do mutante ?emrR ao ácido nalidíxico foi revertida em uma linhagem complementada deste mutante, conforme verificado por ensaios de viabilidade, ensaios de difusão em disco e concentração inibitória mínima (MIC). O fenótipo de diminuída produção de violaceína deste mutante, observado em meio líquido, também foi complementado. Além disso, foi realizado o isolamento de mutantes espontâneos de C. violaceum resistentes a ácido nalidíxico com mutação pontual em emrR. Os ensaios de microarranjo de DNA mostraram que EmrR reprime algumas dezenas de genes, incluindo o operon emrCAB, o qual codifica a bomba de efluxo EmrCAB. Os ensaios de Northern blot confirmaram que o EmrR reprime o operon emrCAB, e que a expressão desta bomba é induzida por salicilato, mas não outros compostos, como ácido nalidíxico ou brometo de etídeo. Os ensaios de alteração de mobilidade eletroforética (EMSA) mostraram que a proteína EmrR purificada se liga diretamente às 8 regiões promotoras de emrR, emrCAB e vários outros genes do regulon EmrR, para exercer uma regulação negativa direta sobre esses genes. Um mutante nulo ?emrCAB foi obtido, mas a ausência desta bomba de efluxo não tornou C. violaceum mais susceptível ao ácido nalidíxico, sugerindo que ela é importante somente em condições nas quais é induzida. Estas condições indutoras talvez incluam estresse oxidativo, uma vez que enzimas antioxidantes são parte do regulon de EmrR e a proteína EmrR formou dímeros covalentes na presença de agentes oxidantes in vitro. Portanto, nossos dados revelam que mutações pontuais ou moléculas como salicilato abolem a atividade repressora do fator de transcrição EmrR sobre o operon emrCAB, levando a superexpressão da bomba de efluxo EmrCAB e aumentando a resistência ao ácido nalidíxico em C. violaceum. / Antibiotic resistance is a global public health problem with serious consequences for the treatment of various bacterial infections. MarR family transcription factors have been described controlling antibiotic resistance and several other processes in bacteria. In this work, we studied mechanisms of antibiotic resistance in Chromobacterium violaceum, an environmental Gramnegative bacterium that can act as a human opportunistic pathogen. The strategy involved a screening of an available collection of thirteen C. violaceum mutant strains of MarR family transcription factors, by susceptibility testing for 24 antibiotics. These assays revealed that only the ?emrR mutant showed increased resistance to the antibiotic nalidixic acid in relation to the wild-type strain. This increased resistance of the ?emrR mutant to nalidixic acid was reversed in a complemented strain of this mutant, as verified by viability, disk diffusion, and minimal inhibitory concentration (MIC) assays. The phenotype of decreased violacein production of this mutant, observed in a liquid medium, was also complemented. In addition, it was performed the isolation of spontaneous mutants of C. violaceum resistant to nalidixic acid with a point mutation in emrR. DNA microarray assays showed that EmrR represses a few dozen of genes, including the emrCAB operon, which encodes the EmrCAB efflux pump. Northern blot assays confirmed that EmrR represses the emrCAB operon and that the expression of this pump is induced by salicylate, but not other compounds, such as nalidixic acid or ethidium bromide. Electrophoretic mobility shift assays (EMSA) showed that the purified EmrR protein binds directly to the promoter regions of emrR, emrCAB and several other genes of the EmrR regulon, to exert a direct negative regulation of these genes. A ?emrCAB null mutant strain was obtained, but the absence of this efflux pump did not make C. violaceum more susceptible to nalidixic acid, suggesting that it is important only under conditions in which it is induced. These inducing conditions may include 10 oxidative stress since antioxidant enzymes are part of the EmrR regulon and the EmrR protein has formed covalent dimers in the presence of oxidizing agents in vitro. Therefore, our data reveal that point mutations or molecules such as salicylate abolish the repressive activity of the EmrR transcription factor on the emrCAB operon, causing overexpression of the EmrCAB efflux pump and increasing the resistance to nalidixic acid in C. violaceum.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-06-03T19:13:32Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_AnaliseProteomicaResposta.pdf: 3111763 bytes, checksum: 3becf621a78134597cac267f54096574 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-06-04T13:26:11Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_AnaliseProteomicaResposta.pdf: 3111763 bytes, checksum: 3becf621a78134597cac267f54096574 (MD5) / Made available in DSpace on 2013-06-04T13:26:11Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_AnaliseProteomicaResposta.pdf: 3111763 bytes, checksum: 3becf621a78134597cac267f54096574 (MD5) Previous issue date: 2011 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Eletronorte - Centrais Elétricas do Norte do Brasil S/A / A Chromobacterium violaceum é uma beta-proteobactéria Gram-negativa comum da microbiota tropical e um patógeno oportunista para animais e humanos. A infecção causada pela C. violaceum apresenta alta taxa de mortalidade, mas os mecanismos da patogenicidade ainda não foram caracterizados. Como outros microorganismos ambientais, essa bactéria está exposta a condições externas muito variáveis, que exigem grande adaptabilidade e sistemas de proteção eficientes. Entre esses sistemas encontra-se um operon arsRBC de resistência ao arsênio, metaloide danoso à saúde humana associado a lesões de pele, doenças neurológicas e câncer. O objetivo deste trabalho foi investigar as alterações na expressão proteica de C. violaceum ATCC 12472 na presença do arsenito e caracterizar as diversas proteínas secretadas pela bactéria. As proteínas da C. violaceum foram analisadas por eletroforese bidimensional e espectrometria de massas. A análise proteômica revelou que o arsenito induz um aumento na quantidade das proteínas envolvidas na resposta ao estresse oxidativo, reparo do DNA e metabolismo energético. Entre as proteínas secretadas, foram identificados fatores de virulência (metalopeptidases, colagenase e toxinas), transportadores, proteínas de proteção contra estresses e com potencial aplicação biotecnológica. Os resultados mostraram que a C. violaceum possui um arsenal molecular de adaptação que a torna capaz de conservar suas atividades celulares e provocar lesões em outros organismos. / Chromobacterium violaceum is a Gram-negative beta-proteobacterium found in tropical ecosystems and it is an opportunistic pathogen for animals and humans. C. violaceum infection is associated with a high mortality rate, but little is known about the molecular basis of pathogenicity mechanisms. As an environmental microorganism, C. violaceum is exposed to diverse external conditions, which require great adaptability and effective protection systems. C. violaceum possesses an arsenic resistance operon arsRBC. Arsenic is a toxic metalloid associated with skin lesions, neurological diseases and cancer. The aim of this study was to investigate changes in protein pattern in presence of arsenite and characterize secreted proteins of C. violaceum ATCC 12472. The proteins from C. violaceum were analyzed by twodimensional electrophoresis and mass spectrometry. Proteomic analysis revealed that arsenite induces an increase of proteins involved in oxidative stress response, DNA repair and energetic metabolism. Among the secreted proteins were identified virulence factors (metallopeptidases, collagenase and toxins), transporters, and proteins involved in stress response and potentially useful. The results show novel insights into the adaptive response of C. violaceum.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-17T19:43:31Z No. of bitstreams: 1 DanielChavesDeLima_TESE.pdf: 22514409 bytes, checksum: 31f3c8faf388b52b979837aa634b9a04 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-20T18:50:56Z (GMT) No. of bitstreams: 1 DanielChavesDeLima_TESE.pdf: 22514409 bytes, checksum: 31f3c8faf388b52b979837aa634b9a04 (MD5) / Made available in DSpace on 2017-02-20T18:50:56Z (GMT). No. of bitstreams: 1 DanielChavesDeLima_TESE.pdf: 22514409 bytes, checksum: 31f3c8faf388b52b979837aa634b9a04 (MD5) Previous issue date: 2016-09-23 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Chromobacterium violaceum is a ?-proteobacteria commonly found around tropical and subtropical regions throughout the globe. It produces many metabolites with biotechnological properties such as antitumoral peptides, antibiotics and polymers that have potential to replace the oil-based ones. Although it has been extensively studied over the past 40 years, there are many aspects of C. violaceum that remains unclear until today. We have conducted a biochemical study on the homologous recombination (HR) machinery of C. violaceum, mainly in RecA and its paralog, RadA/Sms. We performed in vitro assays from initial and late steps of HR such as D-loop formation and branch migration, respectively, with their corresponding molecular actors and how RadA/Sms influenced each one. We observed cvRadA/Sms influences negatively D-loop formation promoted by cvRecA and through pull-down assay we have observed an interaction between these two proteins. We also observed the DNA-binding preference of cvRadA/Sms and cvRecA and observed that this protein binds preferentially to dsDNA instead ssDNA, unlike cvRecA. No involvement of cvRadA/Sms on branch migration reactions was detected. In this work, we also described, for the first time, the isolation, sequencing and annotation of a new plasmid from C. violaceum, which we named ChVi1 and has 44,236 base pairs, 39 predicted open reading frames (ORFs) and, possibly, two origins of replication. Most of the ORFs codes for hypothetical and structural bacteriophage proteins. By using restriction digestion and Next-generation sequencing (NGS) we also looked for the presence of a similar plasmid in other seven C. violaceum strains isolated from amazon region. Our analysis suggest the presence of a plasmid similar to ChVi1 in two of these strains. The present work describes for the first time a biochemical characterization of RadA/Sms and RecA from C. violaceum which have different roles in HR. Moreover, the discovery of ChVi1 opens a path to further explore C. violaceum?s biology.

No description available.

The dynamics of a plant-pathogen interaction vary both within and among species. Both spatial structuring and specific genetic and life-history characteristics will affect the interaction and the outcome of a potential co-evolution between the two organisms. In this thesis I have studied the interaction between the wild perennial herb Silene dioica and its automictic, obligate anther smut Microbotryum violaceum MvSd. From the plant perspective, I have examined different aspects of biochemical resistance in S. dioica to M. violaceum MvSd. From the pathogen perspective, I have focused on the breeding system of M. violaceum MvSd and its connection to fitness and distribution of genetic diversity. I have used varying methods; glasshouse trails involving inoculation of plants with the pathogen, classical Mendelian analysis involving controlled crosses between plants, microscopic studies of spores and molecular DNA-analysis. With the results I demonstrate that resistance to M. violaceum MvSd in S. dioica can be specific to the attacking pathogen strain and also spatially highly diverse both within and among populations within a metapopulation. Together, these factors are likely to delay the establishment of the disease within host populations and reduce the spread and amount of disease, once it has been established. The results also suggest that the specific resistance expressed against two different M. violaceum MvSd strains were determined by separate gene systems and that, in both cases, the resistance was simply inherited. This implies a potential for relatively rapid response to M. violaceum-induced selection in S. dioica populations variable for resistance. My results also show that automixis clearly is the predominating breeding system of M. violaceum MvSd, similarly to what earlier has been shown for M. violaceum MvSl. Furthermore, I found lower levels of neutral genetic diversity in M. violaceum MvSd in the northern parts of Sweden, compared to what has been found in populations in more southern Europe. This result is consistent with predictions that populations in the outer regions of a species distribution have lower levels of genetic variation. Moreover, populations were highly differentiated in northern Sweden, which could have been generated by high selfing rates, genetic drift and high population turnover rates, all factors that coincide with life-history and ecology of M. violaceum MvSd. However, despite the general low variability in neutral genetic markers, I did find variation in fitness related traits, both within and among populations, as well as differences in infection ability between strains, suggesting there is a potential for co-evolution between S. dioica and M. violaceum MvSd in the area. To summarize, this thesis reflect a plant-pathogen system that is highly influenced by constant colonisation-extinction dynamics, which is likely to have influenced both the genetics of resistance in the plant and the breeding system of the pathogen and thus also the interaction between the two organisms.

A diversidade genética dos isolados de Chromobacterium sp. foi avaliada por Multilocus sequence analysis com base nas análises dos genes conservados rpoA, lepA, gyrB, fusA e rRNA 16S. A análise do gene rRNA 16S e MLSA agrupou os isolados no gênero Chromobacterium, entretanto, cinco dos isolados estão distantes filogeneticamente das linhagens tipo, C. violaceum e C. subtsugae, sugerindo duas novas espécies. Os extratos brutos, obtidos por soxhlet, dos isolados de Chromobacterium sp., testados em ensaios in vitro em células tumorais humanas, apresentaram atividades antitumorais potenciais e seletivas para determinadas linhagens celulares. Os extratos brutos e frações foram analisados por HPLC-DAD para avaliação da presença ou ausência da violaceína. Além disso, outros metábólitos secundários que não a violaceína podem estar relacionados à atividade antitumoral. / The genetic diversity of strains of Chromobacterium sp was evaluated by Multilocus sequence analysis (MLSA) based on the analysis of conserved genes rpoA, recA, lepA, gyrB, fusA and rRNA 16S. The analysis of 16S ribosomal RNA gene grouped all isolates in the genus Chromobacterium, however, the five isolates are phylogenetically distant of type strain C. violaceum and C. subtsugae, suggesting new species. The crude extracts of the isolates from Chromobacterium sp., obtained by soxlhlet, evaluated in vitro tests on human tumor cells, showed potential and selective antitumor activities for certain cell lines. In addition, other secondary metabolites than violacein may be related with antitumor activity.

About 6% of all angiosperms are dioecious. This separation of sexual function to male and female individuals, and the fundamentally different patterns of reproductive resource allocation that follows that separation, are thought to have important ecological and evolutionary consequences for plant enemy interactions.  I have studied whether intersexual differences in susceptibility to natural enemies can be explained by intersexual differences in resource allocation. In cases when sexual dimorphic traits form the target resource of a particular enemy I expected the enemy to select the best resource. The study system is the perennial dioecious herb, Silene dioica (Caryophyllaceae) and three of its specialist natural enemies, two insect herbivores the fly Delia criniventris (Anthomyiidae) and the twirler moth Caryocolum viscariella (Gelechiidae) and one systemic anther smut fungus Microbotryum violaceum. All three share the same food recourse, the floral stems, of their host plant. I studied the interaction on nine islands in a rising Bothinan archipelago over seven consecutive years. Both herbivores attacked female plants more than male plants (D. criniventris, 32.8% females, 30.7% males; C. viscariella, 4% females, 2% males). This attack pattern was consistent over years and islands and also correlated with a number of sexually dimorphic traits suggesting that females offer the better resource. Herbivore attack had no effect on plant survival but a significant effect on re-flowering the following year. Non-attacked females had an estimated mean re-flowering rate of 30.2%, and non-attacked males of 31%. Herbivore-attacked females had an estimated re-flowering rate of 46% compared with 38.4% for males. Females showed a stronger compensatory response to attack and tended to re-flower more often than males. Attack rates differed markedly in the different stages of primary succession. They were consistently higher in the youngest zone and decreased in parallel to progressing succession. This zonal pattern of decreasing attack rates correlated with several plant attributes, a decrease in plant size and nitrogen content, and an increased content of secondary compounds, but not to host plant density. We failed to come up with a simple explanation for the spatial structure with chronic high attack rates in the younger zones. However, the consistent patterns in attack rate suggest that a suite of abiotic and biotic factors interact and reinforce the strength and direction of selection. In general females were more frequently diseased by the anther smut Microbotryum violaceum than males with two exceptions. Disease frequencies were male biased on islands with low disease levels and in one of the seven study years. The change in disease frequencies from male to female bias confirm earlier studies suggesting that the relative contribution of the two components of infection risk, disease encounter and per contact infection probability can vary with population disease level. The change in the proportions of diseased males and females that was observed in one of the study years, followed a year of extreme weather conditions (prolonged drought). Both sexes showed a similar decline in flowering but diseased females decreased more than diseased males. This difference in response can be explained if considering that disease is more resource demanding in females than in males. Except for resources needed for mycelial growth and spore production, in females resources are also needed to restructure their sex expression and produce anthers. My study shows (i) that in dioecious species traits that are sexually dimorphic are of great importance for understanding the outcome of interactions with natural enemies, (ii) that the strengths and directions of enemy-host plant interactions are strongly shaped by both biotic and abiotic conditions.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-27T00:18:43Z No. of bitstreams: 1 FelipheLacerdaSouzaDeAlencar_DISSERT.pdf: 4823530 bytes, checksum: b4a668d3c4f491b90de30b674816113d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-09-01T22:58:50Z (GMT) No. of bitstreams: 1 FelipheLacerdaSouzaDeAlencar_DISSERT.pdf: 4823530 bytes, checksum: b4a668d3c4f491b90de30b674816113d (MD5) / Made available in DSpace on 2016-09-01T22:58:50Z (GMT). No. of bitstreams: 1 FelipheLacerdaSouzaDeAlencar_DISSERT.pdf: 4823530 bytes, checksum: b4a668d3c4f491b90de30b674816113d (MD5) Previous issue date: 2016-01-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A baixa qualidade h?drica no semi?rido brasileiro, em grande parte associa-se a a??o antr?pica, tal como o lan?amento de res?duos met?licos oriundos da ind?stria minerada. O presente estudo objetiva comparar e discutir a evolu??o das pesquisas realizadas em ?mbito mundial, as quais fizeram uso do potencial biorremediador da Chromobacterium violaceum a metais pesados; compreender a capacidade biorremediadora e avaliar os padr?es fenot?picos de resist?ncia em cepas selvagens e padr?es (ATCC 12472) de C. violaceum diante dos metais pesados, Ferro, Zinco e Mangan?s, em diferentes concentra??es e intera??es met?licas; analisar os par?metros f?sico-qu?micos e microbiol?gicos do reservat?rio Engenheiro Armando Ribeiro Gon?alves, situado do munic?pio de Jucurutu (regi?o semi?rida do Rio Grande do Norte - RN); verificar a abordagem da tem?tica biorremedia??o em livros did?ticos do ensino fundamental e m?dio indicados pelo PNLD 2014 e 2012, respectivamente, assim como desenvolver um produto did?tico direcionado ? contextualiza??o da interface conhecimento t?cnico-cient?fico e meio ambiente. A revis?o sistem?tica foi limitada a trabalhos publicados entre 2001 e 2014, utilizando-se dos bancos de dados LILACS, PubMed e SciELO. A avalia??o da resist?ncia de C. violaceum aos metais pesados ocorreu em concentra??es decrescentes de Fe, Mn e Zn, durante intervalos de 24, 48 e 72 horas por planejamento fatorial completo 23; o isolamento e a identifica??o microbiol?gica foram realizados conforme metodologia preconizada pelo Standard Methods for Examinations of Water and Wastewater; a avalia??o da capacidade biorremediadora de C. violaceum por espectrofotometria de absor??o at?mica (EAA), enquanto que a an?lise das unidades de registro a partir da adapta??o da metodologia de an?lise de conte?do de Bardin (2004). A biolixivia??o foi a t?cnica mais discutida; o ouro o substrato biorremediado mais citado e a cianeta??o o mecanismo fenot?pico prevalente. Mecanismos gen?ticos foram citados em 29,4% das publica??es e entre as prote?nas transcritas por C. violaceum 18,3% eram ditas hipot?ticas. Ambas as cepas de C. violaceum apresentaram resist?ncia aos metais testes em diferentes escalas de concentra??es, intera??es e intervalos de exposi??o. No entanto aquelas selvagens apresentaram uma resposta de fase aguda mais eficiente comparadas ?s padr?es, sobretudo para as concentra??es de 80 a 480 g/100ml x 10-3. A an?lise f?sico-qu?mica da ?gua revelou par?metros aceit?veis, conforme a resolu??o vigente, exceto para o ponto 5, no que tange a an?lise do pH, nesse ponto ocorreu o isolamento da C. violaceum, cuja capacidade biorremediadora aos elementos Fe, Mn e Zn mostrou-se mais eficiente quanto ?s cepas ATCC. Todos os livros did?ticos analisados, embora tenham sido recomendados pelo PNLD, apresentaram car?ncias quanto ? tem?tica biorremedia??o, fazendo-se necess?rio o desenvolvimento de materiais did?ticos que visem suprir tal abordagem. Os dados avaliados demonstram a fundamental import?ncia da C. violaceum como microorganismo biorremediador de metais pesados e evidencia a import?ncia do monitoramento ambiental, desenvolvimento e aplica??o da biorremedia??o em ambientes impactados, bem como destaca a necessidade da reformula??o da interface educa??o ambiental e biotecnologia, com a finalidade de possibilitar ao docente e ao estudante de ensino m?dio e fundamental uma reflex?o mais cr?tica sobre as rela??es que envolvem a polui??o ambiental e as poss?veis ferramentas mitigadoras dessa problem?tica. / The low water quality in the Brazilian Semiarid, in the most of cases is associated to human activities, such as the release of metallic waste from the mined industry. This study aims to compare and discuss the research evolution performed worldwide, which made use of the potential of C. violaceum for bioremediation of heavy metals; understand the bioremediation and phenotypic resistance patterns in wild and Standard strains (ATCC 12472) of heavy metals, iron (Fe), zinc (Zn) and manganese (Mn), in differents responce time, concentrations and metal interactions; evaluate the physicochemical and microbiological parameters in Engenheiro Armando Ribeiro Gon?alves reservoir, located in the county of Jucurutu (semiarid region of Rio Grande do Norte - RN); analyze the approach of the subject bioremediation in textbooks from elementary and high school appointed by 2014 and 2012 PNLD, respectively, as well as developing an educational product targeted to approaching the technical and scientific knowledge and the environment interface. The systematic review was limited to research published between 2001 to 2015, using LILACS, PubMed, and SciELO databases. The evaluation of C. violaceum resistance for heavy metals occurred in decreasing concentrations of Fe, Zn and Mn, at intervals of 24, 48 and 72 hours by a full factorial design 23; the isolation and microbiological identification were performed according to the methodology recommended by the Standard Methods for Examinations of Water and Wastewater; the evaluation the use of the potential of C. violaceum for bioremediation of heavy metals was performed by atomic absorption spectrophotometry (AAS), while the analysis of the reporting units was carried out from the adaptation of Bardin content analysis methodology (2004). The systematic survey showed that bioleaching technique was further discussed; gold was the bioremediated substrate most mentioned, and cyanidation was the prevalent phenotypic mechanism. Genetic mechanisms were mentioned in 29.4% of the publications, and among proteins transcribed by C. violaceum 18.3% were hypothetical. Whereas experimental data indicated that both strains of C. violaceum showed resistance to the metals tests on different scales concentrations, interactions and exposure intervals (p<10-5). However that wild showed a more efficient acute phase response compared to the standard, especially for metal concentrations from 80 to 480 g/100 mL x 10-3. The physicochemical water analysis revealed acceptable parameters as the current resolution, except for point five, as regards the analysis of pH, on this point was the isolation of C. violaceum, whose the use in bioremediation of Fe, Zn and Mn showed more efficient as the ATCC strain (p<10-5). Finally, the educational axis directed to the analysis of the textbooks showed that all of them, although they were recommended by PNLD, showed shortcomings regarding the subject bioremediation, making it necessary to develop educational materials aiming at to supply such an approach. The evaluated data demonstrated the fundamental importance of C. violaceum in bioremediation of heavy metals and highlights the importance of environmental monitoring, development and application of bioremediation in impacted environments and emphasizes the need to reworking the environmental education and biotechnology interface, in order to enable the teacher and high school and fundamental students to a critical reflection about the relationships involving environmental pollution and possible mitigation tools of this problem.

A diversidade genética dos isolados de Chromobacterium sp. foi avaliada por Multilocus sequence analysis com base nas análises dos genes conservados rpoA, lepA, gyrB, fusA e rRNA 16S. A análise do gene rRNA 16S e MLSA agrupou os isolados no gênero Chromobacterium, entretanto, cinco dos isolados estão distantes filogeneticamente das linhagens tipo, C. violaceum e C. subtsugae, sugerindo duas novas espécies. Os extratos brutos, obtidos por soxhlet, dos isolados de Chromobacterium sp., testados em ensaios in vitro em células tumorais humanas, apresentaram atividades antitumorais potenciais e seletivas para determinadas linhagens celulares. Os extratos brutos e frações foram analisados por HPLC-DAD para avaliação da presença ou ausência da violaceína. Além disso, outros metábólitos secundários que não a violaceína podem estar relacionados à atividade antitumoral. / The genetic diversity of strains of Chromobacterium sp was evaluated by Multilocus sequence analysis (MLSA) based on the analysis of conserved genes rpoA, recA, lepA, gyrB, fusA and rRNA 16S. The analysis of 16S ribosomal RNA gene grouped all isolates in the genus Chromobacterium, however, the five isolates are phylogenetically distant of type strain C. violaceum and C. subtsugae, suggesting new species. The crude extracts of the isolates from Chromobacterium sp., obtained by soxlhlet, evaluated in vitro tests on human tumor cells, showed potential and selective antitumor activities for certain cell lines. In addition, other secondary metabolites than violacein may be related with antitumor activity.