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Identification of endophytic bacterial communities associated with South African crops: sorghum bicolor (L. Moench), pennisetum glaucum and arachis villosulicarpaMaropola, Mapula Kgomotso Annah January 2014 (has links)
>Magister Scientiae - MSc / In this study, the diversity of endophytic bacteria associated with food crops, sorghum (Sorghum bicolor L. Moench), pearl millet (Pennisetum glaucum L.) and groundnut (Arachis villosulicarpa) is investigated using culture-independent techniques: terminal retriction fragment length polymorphism (t- RFLP) and next generation sequencing (NGS). The first objective of this study was to investigate the effect of different DNA extraction protocols on mDNA yield and quality, as well as the diversity of endophytic bacteria retrieved from root and stem tissues (0.1g or 0.3g) of sorghum, pearl millet and groundnut. Protocols used include two classical methods (CTAB- and SDS-based) and five commercial kits: MoBio PowerPlant Pro® DNA Isolation Kit, Qiagen DNeasyR Plant Mini Kit, Fermentas GeneJET Plant Genomic DNA Purification Kit, MoBio PowerSoilTM DNA Purification Kit and MoBio UltraClean® Soil DNA Isolation Kit. Eletrophoresis and the Nanodrop were used to determine DNA yield and purity
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The effect of endophytic bacteria on the alfalfa-<i>sinorhizobium</i> symbiosisAl Otaibi, Fahad Nasser 23 July 2010
Although plant growth-promoting rhizobacteria (PGPR) have shown tremendous potential to be used as inoculants for many agricultural crops, they may not survive severe environmental conditions in the field which could limit their large scale applications. Endophytic bacteria, which can be recovered from inside plant tissues such as roots, stems and leaves, might overcome this limitation due to their unique ecological niche inside plant roots where they are sheltered from external environmental disturbances. Some of these bacterial endophytes have beneficial effects on their host plants and stimulate plant growth or reduce disease symptoms, apparently through mechanisms that are similar to those proposed for PGPR. The objective of this study was to assess a collection of endophytic bacteria for PGPR traits and potential use to enhance the rhizobial-legume symbiosis. Forty isolates obtained from the roots of various plants were identified by fatty acid methyl ester (FAME) analysis, and 16S RNA gene sequencing analysis. The majority (i.e., 75%) were identified as Pseudomonas species. Many of these isolates were able to solubilize phosphate, produce indole-3-acetic acid (IAA), produce aminocyclopropane-1-carboxylic acid (ACC) deaminase, synthesize siderophores and show antagonistic activities against several soil-borne plant pathogenic fungi under in vitro conditions. Selected isolates were further evaluated for the ability to enhance plant growth and nodulation of alfalfa when co-inoculated with Sinorhizobium meliloti under growth chamber conditions using growth pouch and potted soil assays. Results revealed that P. putida strain EB EE 4-25, P. syringae strain EB XDE 4-48, and P. fluorescens strain EB EE 2-23 significantly increased shoot length, root length, enhanced nodulation and increased lateral root formation of alfalfa plants in growth pouch and potted soil assays when co-inoculated with S. meliloti strain P102 compared to plants inoculated with S. meliloti strain P102 alone. Results also suggested that expression of one or more of the mechanisms, such as solubilization of phosphate, production of IAA, production of siderophores, and ACC deaminase production might have played a role in the enhancement of the alfalfa- Sinorhizobium symbiosis. These results suggest that some endophytic bacterial strains may be useful as biofertilizers and/or biocontrol agents in sustainable agricultural practices.
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The effect of endophytic bacteria on the alfalfa-<i>sinorhizobium</i> symbiosisAl Otaibi, Fahad Nasser 23 July 2010 (has links)
Although plant growth-promoting rhizobacteria (PGPR) have shown tremendous potential to be used as inoculants for many agricultural crops, they may not survive severe environmental conditions in the field which could limit their large scale applications. Endophytic bacteria, which can be recovered from inside plant tissues such as roots, stems and leaves, might overcome this limitation due to their unique ecological niche inside plant roots where they are sheltered from external environmental disturbances. Some of these bacterial endophytes have beneficial effects on their host plants and stimulate plant growth or reduce disease symptoms, apparently through mechanisms that are similar to those proposed for PGPR. The objective of this study was to assess a collection of endophytic bacteria for PGPR traits and potential use to enhance the rhizobial-legume symbiosis. Forty isolates obtained from the roots of various plants were identified by fatty acid methyl ester (FAME) analysis, and 16S RNA gene sequencing analysis. The majority (i.e., 75%) were identified as Pseudomonas species. Many of these isolates were able to solubilize phosphate, produce indole-3-acetic acid (IAA), produce aminocyclopropane-1-carboxylic acid (ACC) deaminase, synthesize siderophores and show antagonistic activities against several soil-borne plant pathogenic fungi under in vitro conditions. Selected isolates were further evaluated for the ability to enhance plant growth and nodulation of alfalfa when co-inoculated with Sinorhizobium meliloti under growth chamber conditions using growth pouch and potted soil assays. Results revealed that P. putida strain EB EE 4-25, P. syringae strain EB XDE 4-48, and P. fluorescens strain EB EE 2-23 significantly increased shoot length, root length, enhanced nodulation and increased lateral root formation of alfalfa plants in growth pouch and potted soil assays when co-inoculated with S. meliloti strain P102 compared to plants inoculated with S. meliloti strain P102 alone. Results also suggested that expression of one or more of the mechanisms, such as solubilization of phosphate, production of IAA, production of siderophores, and ACC deaminase production might have played a role in the enhancement of the alfalfa- Sinorhizobium symbiosis. These results suggest that some endophytic bacterial strains may be useful as biofertilizers and/or biocontrol agents in sustainable agricultural practices.
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Prospecção de substâncias com atividade antagonista á Candida albicans produzida por bactéria endofítica da região amazônicaSouza, Ivanete Ferreira de 16 February 2016 (has links)
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Previous issue date: 2016-02-16 / The Amazon Biodiversity symbolize Is a great potential to Discovery of new bacterial straight producer of active biomolecules with importance biotechnological as antimycotics that can be producing by endophytic microorganisms whose the object may be the yeast Candida albicans. This yeast is present in the human body as commensally, being able to cause serious infections, especially in individual immune depressed by diseases as cancer, AIDS and diabetes. It is resistant to antifungal available actually. This way, the object this study was find, from the Amazon bacteria, a bacteria able of produce actives molecules against the C. Albicans yeast, with a purpose to make the production of a active extract that make possible to fractionate and purify the active substance. In the search this anti-candida substance after a analysis of bacteria from different habitats as Waters of the Rio Negro and Solimões and strains derived from endophytic bacteria work collection of Applied Genetics Laboratory Health and Biotechnology of UEA, initially had their potential antimicrobial tested against different pathogenic organisms (Mycobacterium smegmatis, Pseudomlmonasae ruginosa and Staphylococcus aureaus) by cross streaking. The potentials microorganisms were selected and identified by morphology and for sequences of the 16S rDNA region. The growth was made in two different culture media to production of crud extract. The verification the anti-candida action was by diffusion tests in Agar and the quantification was through the Minimum Inhibitory Concentration (MIC). The extract produced was pré-purified by chromatography in open column and was applied thin layer chromatography (TLC) to check the fractions obtained. In total six endopthytic bacteria were selected because they had antimicrobial activity against at least one of pathogens tested, but only the bacteria 229 presented active against C. albicans being cultivate to produce of extract and possibility of identified of anti-candida substance. The culture media that showed better production of biomolecules was the ISP2, according to analysis of size of the halos from of the extract produced. The colony growth was identified as B. amyloliquefaciens and morphologically characterized as Gram positive bacilli The pré-purification resulted in two actives fractions as MIC of 0,25 and 0,5 ug.mL-1 . This way, conclude that in Amazon is possible the identify of bacteria with pharmacological activities from which can be produce antimycotic molecules. / A Biodiversidade Amazônica representa um grande potencial para descoberta de novas linhagens bacterianas produtoras de biomoléculas ativas de importância biotecnológica, como os antimicóticos que podem ser produzidos por microrganismos endofíticos cujo o alvo pode ser a levedura Candida albicans. Esta levedura está presente no corpo humano de forma comensal, sendo capaz de ocasionar graves infecções, principalmente em individuos com o sistema imunológico debilitado por doenças como câncer, AIDS e diabetes. Ela apresenta resistência aos antifúngicos disponíveis na atualidade. Desta forma, o objetivo deste trabalho foi encontrar, a partir de bactérias da Amazônia, uma bactéria capaz de produzir moléculas ativa contra a levedura C. albicans afim de fazer a produção de um extrato ativo que fosse possível fracionar e purificar a substância ativa. Na busca desta substância anti-candida, após a análise de bactérias de diversos habitats como águas dos Rios Negro e Solimões e de cepas oriundas de coleção de trabalho de bactérias endofiticas do Laboratório de Genética Aplicada a Sáude e a Biotecnologia da UEA tiveram inicialmente seu potencial antimicrobiano testado frente a diferentes microrganismos patogênicos (Micobacterium smegmatis, Pseudomonas aeruginosa e Staphylococcus aureus) por estrias cruzadas. Os microrganismos com potencial foram selecionados e identificados por morfológia e pelas sequências da região 16S do rDNA. Fez-se o cultivo em dois meios de cultura diferentes para produção do extrato bruto. A verificação da ação anti-candida foi por testes de difusão em ágar e a quantificação desta através da Concentração Mínima Inibitória (CIM). O extrato produzido foi pré-purificado por cromatografia em coluna aberta e aplicou-se cromatografia em camada delgada (CCD) para acompanhamento das frações obtidas. Ao total seis bactérias endofíticas foram selecionadas por apresentarem atividade antimicrobiana contra ao menos um dos patógenos testados, porém, somente a bactéria 229 apresentou-se ativa contra C. albicans sendo cultivada para produção do extrato e tentativa de identificação da substância anti-candida. O meio de cultura que apresentou melhor produção da biomolécula foi o ISP2, conforme avaliação do tamanho dos halos a partir do extrato produzido. A colônia cultivada foi identificada como Bacillus amyloliquefaciens e caracterizada morfologicamente como bacilos Gram positivo. A pre-purificação resultou em duas frações ativas com CIM de 0,25 e 0,5 ug.mL-1. Conclui-se desta maneira que na Amazônia é possível a identificação de bactérias com atividades farmacológicas a partir das quais pode-se produzir moléculas antimicóticas
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Estabelecimento de protocolo para controlar a manifestação de bactérias endofíticas no processo de multiplicação in vitro de eucalipto / Protocol establishment to control the manifestation of endophytic bacteria in the process of Eucalyptus in vitro multiplicationLeone, Gabriela Ferraz 27 August 2013 (has links)
A presença de bactérias no cultivo in vitro de plantas é normalmente relacionada à contaminação, acarretando o descarte de microplantas de alto valor comercial. No entanto, essa presença pode ser caracterizada como \"manifestações\", decorrentes de possíveis estresses físicos ou nutricionais, da microbiota endofítica, que coloniza ativamente os tecidos vegetais, e que não necessariamente, afeta o desenvolvimento da planta. Sendo assim, o objetivo deste trabalho foi controlar a manifestação bacteriana, preservando as microcepas de Eucalyptus cloeziana em desenvolvimento in vitro, adicionando-se ao meio de cultura, os antibióticos gentamicina, ciprofloxacina, rifampicina, timentin (isolados ou combinados entre si) e o biocida clorometil-isotiazolinona + metil-isotiazolinona. O monitoramento do trabalho foi realizado por meio de avaliações semanais, visando verificar possíveis influências dos agentes antimicrobianos na morfofisiologia do vegetal e a eficiência no controle das manifestações bacterianas. Para tanto, foram avaliados parâmetros referentes ao incremento de massa seca, número de brotações, teor de acúmulo de nutrientes, análises histológicas e histoquímicas das microcepas. Para verificar possíveis flutuações das comunidades bacterianas endofíticas nas microcepas, utilizou-se a técnica de DGGE. Todas as análises foram realizadas aos 15 e 30 dias após a adição dos agentes antimicrobianos no meio de cultura, exceto a avaliação nutricional que foi feita apenas no final do experimento (30 dias). Os resultados obtidos permitiram inferir que ao longo dos 30 dias de cultivo, o antibiótico gentamicina, ocasionou queda no desenvolvimento das microcepas e não foi eficiente no controle das manifestações bacterianas. Os antibióticos rifampicina e ciprofloxacina apesar de não serem efetivos no controle da manifestação bacteriana, não afetaram o desenvolvimento das microcepas. Conclui-se que, o biocida clorometil-isotiazolinona + metil-isotiazolinona efetivamente controlou as manifestações bacterianas, sem alterar a morfofisiologia das microcepas, bem como o timentin, que além de controlar as manifestações, proporcionou maior vigor das microcepas em função da melhor assimilação dos nutrientes. / The in vitro bacterial presence in plant cultivation, usually is related to contamination, resulting in the elimination of the microplants with high commercial value. However, this presence can be characterized as \"manifestations\" arising from possible physical or nutritional stresses, from microbial endophytic that actively colonize plant tissues, and do not necessarily affect plant development. Therefore, the purpose of this study was to control the bacterial manifestation, preserving in vitro developing of Eucalyptus cloeziana microstumps, by adding to the culture medium, the antibiotics gentamicin, ciprofloxacin, rifampicin, timentin (alone or combined) and biocide + chloromethyl isothiazolinone methyl-isothiazolinone. The monitoring work was conducted through weekly evaluations, to verify the possible influence of antimicrobial agents in the plant morphophysiology and the efficient control of bacterial manifestations. Therefore, were evaluated parameters related to the increase in dry weight, number of buds, content of nutrient accumulation, histological and histochemical the microstumps. DGGE technique was used to check possible fluctuations of endophytic bacterial communities in microstumps. All analyzes were performed at 15 and 30 days after the addition of antimicrobial agents in the culture medium, except for the nutritional assessment that was made only at the end of the experiment (30 days). The results allow to infer that over the 30 days of culture, the antibiotic gentamicin, resulted in the microstumps development decrease and was not effective in controlling bacterial manifestations. The antibiotics rifampicin and ciprofloxacin although were not effective in controlling the bacterial manifestation, affected the development of microstumps. It was concluded that the biocide chloromethyl-methyl-Isothiazolinone + Isothiazolinone effectively controlled the bacterial manifestations without modifying the morphophysiology of the microstumps, well as the timentin, which besides controlling the manifestations, provided greater vigor of microstumps due to better assimilation of nutrients.
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Efeito de bactérias endofíticas do cafeeiro no controle da ferrugem /Shiomi, Humberto Franco, 1970- January 2004 (has links)
Orientador: Wagner Bettiol / Banca: Antonio carlos Maringoni / Banca: Itamar Soares de Melo / Resumo: Experimentos sob condições controladas e testes de campo com bactérias endofíticas isoladas de folhas e caules de Coffea arabica e Coffea robusta, provenientes das cidades de Pedreira-SP, Mococa-SP e Pindorama-SP, foram realizadas com o objetivo de avaliar a inibição da germinação de urediniosporos de Hemileia vastatrix, raça II e o controle do desenvolvimento da ferrugem alaranjada do cafeeiro, em testes em discos de folhas, folhas destacadas e em plantas da cv. Mundo Novo, pela aplicação de suspensões de bectérias endofíticas 72 e 24 horas antes e após à inoculação de H. vastatrix e concomitantemente à inoculação com o patógeno. Isolados de bactérias endofíticas testados demonstraram eficácia na inibiação da germinação de urediniosporos e/ou no desenvolvimento da ferrugem, com valores acima de 50%, embora os resultados obtidos nos testes de germinação de urediniosporos tenham sido inferiores ao tratamento com o propiconazole. Nos testes em discos de folhas, folhas destacadas e em plantas de cafeeiro, os isolados endofíticos T G4-Ia, T F2-IIc, T F7-Ib e T F9-Ia, demonstraram melhor controle da ferrugem do cafeeiro. Os isolados endofíticos T G4-Ia e T F9-Ia foram identificados como Bacillus lentimorbus e Bacillus cereus, respectivamente. Os resultados indicam a ocorrência de isolados endofíticos eficientes em controlar a ferrugem alaranjada do cafeeiro. Alguns isolados de bactérias edonfíticas podem aumentar a severidade da doença. / Abstract: Experiments under controlled conditions and field tests with endophytic bacteria from leaves and stem of Coffea arabica and Coffea robusta plants from Pedreira-SP, Mococa-SP and Pindorama-SP, were carried out with th objective to evaluate the inhibition of germination of urediniospores of Hemileia vastatrix, race II and control the development of coffea leaf rust cv. Mundo Novo leaf disk, datached-leaf and coffee plants, by dripping of bacterial suspensions 72 e 24 hours prior and after the H. Vastatrix and also concomitant the aplication of the pathogen. Endophytes tested demonstrated inhibition efficacy of urediniospores germination and/or the development of leaf rust over 50%, althought the results obtained in urediniospores germination was below of propiconazole treatment. In leaf dsk and datached-leaf inoculations, the endophytes strains T G4-Ia, T F2-IIc, T F7-Ib and T F9-Ia demonstrated better control of coffee leaf rust disease. The endophytic strains T G4-Ia and T F9-Ia was identified as Bacillus lentimorbus and Bacillus cereus. The results the ocorrence of efficiente endophytes controlling the coffee leaf rust. Some endophytes can partially improve severity of coffee leaf rust. / Mestre
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Efeito de bactérias endofíticas do cafeeiro no controle da ferrugemShiomi, Humberto Franco [UNESP] 15 April 2004 (has links) (PDF)
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shiomi_hf_me_botfca.pdf: 1002815 bytes, checksum: aa3a55c9b04258872a970f0e010f3cdf (MD5) / Universidade Estadual Paulista (UNESP) / Experimentos sob condições controladas e testes de campo com bactérias endofíticas isoladas de folhas e caules de Coffea arabica e Coffea robusta, provenientes das cidades de Pedreira-SP, Mococa-SP e Pindorama-SP, foram realizadas com o objetivo de avaliar a inibição da germinação de urediniosporos de Hemileia vastatrix, raça II e o controle do desenvolvimento da ferrugem alaranjada do cafeeiro, em testes em discos de folhas, folhas destacadas e em plantas da cv. Mundo Novo, pela aplicação de suspensões de bectérias endofíticas 72 e 24 horas antes e após à inoculação de H. vastatrix e concomitantemente à inoculação com o patógeno. Isolados de bactérias endofíticas testados demonstraram eficácia na inibiação da germinação de urediniosporos e/ou no desenvolvimento da ferrugem, com valores acima de 50%, embora os resultados obtidos nos testes de germinação de urediniosporos tenham sido inferiores ao tratamento com o propiconazole. Nos testes em discos de folhas, folhas destacadas e em plantas de cafeeiro, os isolados endofíticos T G4-Ia, T F2-IIc, T F7-Ib e T F9-Ia, demonstraram melhor controle da ferrugem do cafeeiro. Os isolados endofíticos T G4-Ia e T F9-Ia foram identificados como Bacillus lentimorbus e Bacillus cereus, respectivamente. Os resultados indicam a ocorrência de isolados endofíticos eficientes em controlar a ferrugem alaranjada do cafeeiro. Alguns isolados de bactérias edonfíticas podem aumentar a severidade da doença. / Experiments under controlled conditions and field tests with endophytic bacteria from leaves and stem of Coffea arabica and Coffea robusta plants from Pedreira-SP, Mococa-SP and Pindorama-SP, were carried out with th objective to evaluate the inhibition of germination of urediniospores of Hemileia vastatrix, race II and control the development of coffea leaf rust cv. Mundo Novo leaf disk, datached-leaf and coffee plants, by dripping of bacterial suspensions 72 e 24 hours prior and after the H. Vastatrix and also concomitant the aplication of the pathogen. Endophytes tested demonstrated inhibition efficacy of urediniospores germination and/or the development of leaf rust over 50%, althought the results obtained in urediniospores germination was below of propiconazole treatment. In leaf dsk and datached-leaf inoculations, the endophytes strains T G4-Ia, T F2-IIc, T F7-Ib and T F9-Ia demonstrated better control of coffee leaf rust disease. The endophytic strains T G4-Ia and T F9-Ia was identified as Bacillus lentimorbus and Bacillus cereus. The results the ocorrence of efficiente endophytes controlling the coffee leaf rust. Some endophytes can partially improve severity of coffee leaf rust.
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Avaliação do crescimento inicial da cana-de-açúcar, variedade RB867515, sob o efeito de bactérias endofíticas / Evaluation of sugarcane initial, RB867515 variety, growth unde effect of endophytic bacteriaGonzaga, Giordano Bruno Medeiros 06 March 2012 (has links)
This present research aimed to evaluate the effects of different endophytic bacteria species regarding the tolerance of sugarcane water stress in the initial growth phase. With that purpose, an experiment was installed, in the greenhouse at the Centro de Ciências Agrárias of Universidade Federal de Alagoas, located in the city of Rio Largo, in the state of Alagoas (9° 28 S, 35° 49 W, altitude 127 m), completely ramdomized on a factorial arrengement 4x2 (endophytic bacteria and levels of water stress in this order), with 8 replications. The levels of the first factor were composed of: non-inoculated plants; inoculated plants with complete inoculant (mix of Gluconacetobacter diazotrophicus, Burkholderia tropica, Herbaspirillum seropedicae, Herbaspirillum rubrisubalbicans e Azospirillum amazonense); inoculated plants with G. diazotrophicus; inoculated plants with B. tropica. The levels of the second factor were: plants kept on the soil with moisture next to field capacity (without stress); plants under water deficit due to irrigation suspension. The morphological and physiological variables analyzed were plant height, stalk diameter, number of green leaves, leaf area, dry mass analyze, leaf water potential (ψwf), potential and effective quantic efficiency and chlorophyll content. The bacteria application didn t interfer in stalk diameter, plants height and estimated leaf area. When the plants average growth was evaluated, it was verified that plants treated without bacteria (control) and with inoculum B. tropica presented showed greater aerial part mass, whereas the bacteria application G. diazotrophicus and the control treatment presented greater root mass. The water stress has significantly affected the potential quantic efficiency (Fv/Fm) on the irrigated plants (control) which the Fv/Fm values were above 0,79 statistically differing of water stress (draught) and rehydratation, wherein the values were below 0,79. Apparently, the damages presented on the photosystem II at midday were recovered during nighttime, showing higher Fv/Fm values at predawn. The presence of bacteria hasn t significantly affected the biometric characteristics of sugarcane plants grown in vases at 114 days after planting (DAP). The leaf area ratio (LAR) utilized the measured leaf area, being greater on control and complete inoculant treatments. On these, the plant developed more leaves and was less efficient on carbon fixation, which refleced on dry mass increase. / A presente pesquisa teve como objetivo avaliar os efeitos de diferentes espécies de bactérias endofíticas sobre a tolerância ao déficit hídrico de cana-de-açúcar em sua fase inicial de crescimento. Para tanto, instalou-se um experimento, em casa de vegetação no Centro de Ciências Agrárias da Universidade Federal de Alagoas, localizado no município de Rio Largo - AL (9° 28 S, 35° 49 W, a 127 m de altitude), em delineamento inteiramente ao acaso em arranjo fatorial, 4 x 2 (tipos de bactérias endofíticas e níveis de déficit hídrico respectivamente), com oito repetições. Os níveis do primeiro fator foram compostos por: plantas não inoculadas; plantas inoculadas com inoculante completo (mistura das Gluconacetobacter diazotrophicus, Burkholderia tropica, Herbaspirillum seropedicae, Herbaspirillum rubrisubalbicans e Azospirillum amazonense); plantas inoculadas com a G. diazotrophicus; plantas inoculadas com a B. tropica. Os níveis do segundo fator foram: plantas mantidas em solo com umidade a próxima da capacidade de campo (sem estresse); plantas submetidas ao déficit hídrico pela suspensão da rega. As variáveis morfológicas e fisiológicas analisadas foram: altura, diâmetro do colmo, número de folhas verdes, área foliar, análise da massa seca, potencial hídrico foliar (ψwf), eficiência quântica potencial e efetiva e estimativa do teor de clorofila. A aplicação de bactéria não afetou o diâmetro do colmo, altura de plantas e área foliar estimada. Quando avaliado o crescimento médio das plantas, verificou-se que plantas tratadas sem bactérias (controle) e com o inoculado B. tropica apresentavam maior massa de parte aérea, enquanto que a aplicação da bactéria G. diazotrophicus e o tratamento controle apresentaram maior massa de raiz. O estresse hídrico afetou significativamente a eficiência quântica potencial (Fv/Fm), nas plantas irrigadas (controle) os valores Fv/Fm estavam acima de 0,79 diferindo estatisticamente do estresse hídrico (seca) e reidratação, em que os valores estavam abaixo de 0,79. Aparentemente os danos apresentados no fotossistema II ao meio-dia foram recuperados durante o período noturno, mostrando valores de Fv/Fm mais elevados na antemanhã. A presença de bactérias não efetou significativamente as características biométricas das plantas de cana-de-açúcar crescidas em vasos aos 114 DAP. A Razão da Área Foliar (RAF) utilizou a AF mensurada, sendo maior nos tratamentos controle e inoculante completo. Nestes, a planta desenvolveu mais folhas e foi menos eficiente na fixação de carbono, refletido no aumento de massa seca.
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Eficiência de Gluconacetobacter diazotrophicus no aumento da tolerância de arroz vermelho à deficiência hídrica na fase inicial de desenvolvimento / Efficiency Gluconacetobacter diazotrophicus in increased red rice tolerance to water stress in the early stage of developmentSilva, Renata Priscila Almeida 21 March 2016 (has links)
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Previous issue date: 2016-03-21 / Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq / Drought is an of the main constraints to food production worldwide, as well as in the cultivation of red rice, which in Brazil is currently restricted to small areas of the northeastern semiarid. The water stress affects virtually all aspects of plants growth and development, with consequent reduced productivity. In this sense, the use of cultivars resistant to water stress is required, and the plant-microbe interaction, beneficial to plant growth and promote increased tolerance to biotic and abiotic stresses. According to the above, this study aimed to evaluate the agro nomic and ecophysiological aspects of red rice plants inoculated with Gluconacetobacter diazotrophicus under water stress in vegetative stage of development. The experiment was conducted under controlled conditions, with a completely randomized design in a factorial 2x4, with two conditions of inoculation, four water restriction levels (100, 70, 50 and 30% of field capacity), a rice genotype red (405 Embrapa Meio Norte), totaling eight treatments with four replications each. Each experimental plot consisted of a drainage lysimeter, which were planted 70 seeds, which after thinning was a total of 60 plants per plot. Water stress was imposed in the vegetative stage of development between stages V3 and V5, in a period of 15 days. The evaluations were performed after 15 days of water stress, growth variables were evaluated (leaf area, biomass), ecophysiological (gas exchange and chlorophyll a fluorescence) and productive (1000-grain weight and total mass of production). It was found that there was interaction between plants and G. diazotrophicus with positive responses, where possibly the endophytic bacteria used their growth promoting mechanisms and induction of tolerance to drought, as shown by increases in biomass and shoot as well as higher rates of photosynthesis and photochemical efficiency and increases in total productivity of plants inoculated with the bacteria. The results indicate that the inoculation was beneficial plants, and that the plant inoculation with G. diazotrophicus suppressed various water stress deleterious effects. / A seca é uma das principais limitações para a produção de alimentos no mundo inteiro, assim como, no cultivo do arroz vermelho, que no Brasil, atualmente está restrito à pequenas áreas do semiárido nordestino. O déficit hídrico afeta praticamente todos os aspectos do crescimento e desenvolvimento das plantas, com consequente redução da produtividade. Neste sentido, se faz necessário o uso de cultivares resistentes ao déficit hídrico, bem como, a interação planta-microrganismos, benéficas para o crescimento das plantas e por promover aumento da tolerância à estresses bióticos e abióticos. De acordo com o exposto, este estudo teve como objetivo, avaliar os aspectos agronômicos e ecofisiológicos em plantas de arroz vermelho inoculadas com Gluconacetobacter diazotrophicus sob deficiência hídrica na fase vegetativa de desenvolvimento. O experimento foi conduzido em condições controladas, com um delineamento experimental inteiramente casualizado, em um fatorial 2x4, sendo duas condições de inoculação (I1= sementes não inoculadas e I2= sementes inoculadas), quatro níveis de restrição hídrica (100, 70, 50 e 30% da capacidade de campo), um genótipo de arroz vermelho (405 Embrapa Meio Norte), totalizando oito tratamentos com quatro repetições cada. Cada parcela constou de um lisímetro de drenagem, no qual foram semeadas 70 sementes, que após desbastes ficou um total de 60 plantas por parcela. O estresse hídrico foi imposto na fase vegetativa do desenvolvimento entre os estádios V3 e V5, em um período de 15 dias. As avaliações foram realizadas ao 15º dia do estresse, foram avaliadas variáveis de crescimento (área foliar, fitomassa), ecofisiológicos (trocas gasosas e fluorescência da clorofila a), e produtivas (massa seca de 1000 grãos e massa da produção total). Foi possível constatar que plantas e G. diazotrophicus houve interação entre as com respostas positivas, onde possivelmente a bactéria endofítica utilizou de seus mecanismos de promoção do crescimento bem como de indução à tolerância ao déficit hídrico, como pode ser observado por meio de incrementos da fitomassa e parte aérea, bem como maiores taxas de fotossíntese e eficiência fotoquímica e incrementos na produtividade total de plantas inoculadas com a bactéria. Os resultados indicam que a inoculação foi benéfica para as plantas, e que a inoculação das plantas com G. diazotrophicus suprimiu vários efeitos deletérios do estresse hídrico.
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Seleção de bactérias endofíticas amazônicas produtoras de lipopeptídeos bioativosMesquita, Adriana Spirotto Stein 15 September 2015 (has links)
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Previous issue date: 2015-09-15 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The endophytic microrganisms, particularly bacteria and fungi live in the plants, including thein roots apparently cause no harm. Bacteria and fungi are potentially useful in agriculture and industry, particularly in the food and pharmaceutical industries, as they produce different chemical classes and can participate in various industrial biotechnological processes. Among the compounds produced by bacteria, lipopeptides belong to a class that has attracted great interest for its antifungal, antibiotic and surfactant among others. In this stud 50 strains were selected of Amazonian endophytic bacteria for antimicrobial evoluction and the production of lipopeptides by ESI-ITMS2. Of these, 25 strains produced lipopeptides, six plant isolated from Gustavia genus, nine Macrophyte, five Duguetia, one Pothomorpha, two Rollina and one Bryophyllum. The fragmentation analysis by ESI-MS2 in negative mode identified eight extracts the lipopeptide surfactin homologs of C11 - C18, including C11, C17 and C18 not been reported in the literature. In biological assays paired cultures, 48 strains showed mycoparasitism antimicrobial activity against Gram-negative bacteria P. aeruginosa and E. coli, 27 strains against Gram-positive bacteria S. aureus, E. faecalis, 29 strains against and 28 against C. albicans, also presenting competition activity against E. faecalis 21 strains and C. albicans strains against 23 S. aureus strains and 2 against P.aeruginosas and E. coli. No strain with antibiotic activity observed. In assessing the bioactivity of lipopeptide extracts, 13 of the extracts strains showed antibiosis against S. aureus, P. aeruginosa and C.albicans. / Os microrganismos endofíticos, especialmente bactérias e fungos, são assim denominados por viverem no interior das plantas, habitando inclusive suas raízes, sem lhes causar aparentemente nenhum dano. As bactérias e os fungos são potencialmente úteis na agricultura e na indústria, particularmente na alimentícia e farmacêutica, pois produzem inúmeras classes de substâncias e podem participar de processos biotecnológicos industriais diversos. Entre as substâncias produzidas por bactérias, os lipopeptídeos são uma classe que tem atraído grande interesse por suas atividades antifúngica, antibiótica e surfactante entre outras. No presente trabalho foram selecionadas 50 linhagens de bactérias endofíticas amazônicas para serem avaliadas por ensaios antimicrobianos e quanto à produção de lipopeptídeos por ESI-ITMS2. Destas, 25 linhagens produziram lipopeptídeos, sendo seis isoladas de planta do gênero Gustavia, nove de Macrofita, cinco de Duguetia, uma de Pothomorpha, duas de Rollina e uma de Bryophyllum. As análises de fragmentação por ESI-MS2 no modo negativo dos extratos lipopeptídicos identificaram oito homólogos da surfactina de C11 - C18, entre os quais o C11, C17 e C18 ainda não foram relatados na literatura. Em ensaios biológicos de culturas pareadas, 48 linhagens apresentaram atividade antimicrobiana de microparasitismo contra as bactérias Gram-negativas P. aeruginosa e E. coli, 27 linhagens contra as bactérias Gram-positiva S. aureus, 29 linhagens contra E. faecalis e 28 contra C. albicans, apresentando também atividade de competição frente a 21 linhagens contra E. faecalis e C. albicans, 23 linhagens contra S. aureus e 2 linhagens contra P.aeruginosa e E. coli. Não foi observada nenhuma linhagem com atividade antibiótica. Na avaliação da bioatividade dos extratos lipopeptídicos, 13 extratos destas linhagens apresentaram antibiose frente a S. aureus, P. aeruginosa e C. albicans.
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