934 resultados para Fungos - Biotecnologia


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Agronomia (Proteção de Plantas) - FCA

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O Brasil apresenta regiões com grande diversidade geográfica proporcionando o desenvolvimento de diferentes espécies vegetais, favorecendo a busca por bioativos com fins terapêuticos. Nos últimos anos, fungos endofíticos vêm sendo considerados fontes importantes de produtos naturais, demonstrando atividades biológicas de interesses terapêuticos. Pesquisas apontam que extratos brutos oriundos de fungos endofíticos da Eugenia jambolana demonstram atividades antineoplásicas e antimicrobianas. No presente estudo verificou-se a atividade citotóxica e genotóxica de extratos brutos provenientes do metabolismo secundários dos fungos endofíticos isolados de partes da planta da Eugenia jambolana, como caule (Ej- c), folhas (Ej-f), fruto verde (Ej-fv) e fruto maduro (Ej-fm) por meio de experimentos in vitro, utilizando células de hepatocarcinoma murino selvagem (Hepa-1c1c7). Para avaliar a citotoxicidade dos extratos brutos foi realizado o teste do MTT, podendo ser observados diferentes perfis citotóxicos de acordo com a parte da planta e o tempo de exposição de 24 e 48 horas. No tempo de exposição de 24 horas as amostras de Ej-fv(1) e Ej-fv(3) apresentaram CI50 de 65,57 μg/ml e 85,75 μg/ml, respectivamente. Já para amostra Ej-fm(1) houve CI50= 46,53 μg/ml . Nas análises que correspondem o tempo de exposição de 48 horas os extratos brutos do caule Ej-c ( Ej-c(3) e Ej-c(5)) apresentaram CI50 nas concentrações de 84,65 μg/ml e 95,35 μg/ml, respectivamente. O composto Ej-c(1) também foi observado uma menor citotoxicidade na concentração de 100,0 μg/ml. A atividade citotóxica também foi observada nas amostras da folha Ej-f (Ej-f(1), Ej-f(2), Ej-f(3)) atingindo o CI50 nas concentrações de 95,54 μg/ml, 90,8, μg/ml e 26,91 μg/ml, respectivamente. O composto Ej-f(3) também apresentou atividade citotóxica de menor na concentração de 33,3 μg/ml. As amostras do fruto verde Ej-fv(1), Ej-fv(2), Ej-fv(3), Ej-fv(4) e ...

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Brazil is a major world producer and exporter of agricultural products like soybeans, sugar, coffee, orange and tobacoo. However, the action of phytopathogenic fungi has been one of the largest challenges encountered in the field as they are responsible for approximately 25 to 50 per cent of losses in crops of fruits and vegetables. The presence of these pathogens is always a problem, because the damage on the tissues and organs promote lesions which decreses growth vegetation and often leads the individual (host) to death. Therefore, it is crucial to understand the process of spreading of these pathogens in the field to develop strategies which prevent the epidemics caused by them. In this study, the dispersal of fungi phytopathogenic in the field was modeled using the automata cellular formalism. The growth rate of infected plants population was measured by the radius of gyration and the influence of host different susceptibility degrees into the disease spread was assessed. The spatial anisotropy related to the plant-to-plant space and the system’s response to distinct seasonal patterns were also evaluated. The results obtained by a mean field model (spatially implicit models) emphasized the importance of the spatial structure on the spreading process, and dispersal patterns obtained by simulation (using a cellular automata) were in agreement with thse observed in data. All computational implementation was held in language Cl

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Microbiologia - IBILCE

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Photodynamic Therapy (PDT) is a therapeutic method which employs a photosensitizer and light to cause cellular death. The chemical compounds have low or none toxicity for hosts cells. Under the incidence of light, in an appropriated wavelength, these chemical compounds produce reactive oxygen which affects the biomolecules of the target-cells. The specific illumination of the affected area increases the selectivity of the therapy, since the photodynamic process occurs only in the irradiated area. Pythiosis, for instance, is a life-threatening emerging disease caused by a fungus-like organism called Pythium insidiosum. The disease occurs in man and other animals, being mostly observed in horses. Human pythiosis may present as ophthalmic, cutaneous-subcutaneous and systemic forms of lesions. Due to the fact that P. insidiosum is not a true fungus, it is refractory to most antifungal drugs and the treatment of the disease is difficult. Extensive surgery procedures, such as limb amputation, are the treatment of choice, however relapses may occur frequently. Although not totally effective, the use of immunotherapy associated to surgery have shown some results. Considering that pythiosis is an emerging disease few explored in its etiological and therapeutic aspects, which are limited and few effective, it is of great importance to encourage the development of researches for new strategies of treatment. In this sense, it was evaluated the effect of PDT on in vitro growth of the pathogen employing two chemical compounds as photosensitizer, porphyrin and chlorine, at different concentrations in combination with several energetic dosages. Porphyrin showed inhibition of growth at 25mg/mL with 100J/cm2 of energetic dosage and chlorine showed similar results employing low concentrations (0,7, 1,0 and 1,3mg/mL) with 70J/cm2 of energetic dosage... (Complete abstract click electronic access below)

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Dissertação mest., Biologia e Geologia, Universidade do Algarve, 2007

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O filoplano do Hibiscus rosa-sinensis abriga uma enorme biodiversidade de leveduras e fungos semelhantes a leveduras cujo potencial biotecnológico ainda é desconhecido. Foram isoladas 84 cepas de leveduras de filoplano desta planta, sendo identificadas pela metodologia clássica. Do total de isolados 37% são de afinidade ascomicética, 36% de afinidade basidiomicética e 27% de fungos semelhantes a leveduras.