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000826291.pdf: 818795 bytes, checksum: 47d05f49fd9ee2c1e61968aa35f0ab40 (MD5) / A biocatálise consiste no uso de enzimas (microbianas, vegetais ou animais) para catalisar transformações químicas, principalmente em compostos orgânicos. Em geral, as reações enzimáticas apresentam muitos atrativos quando comparadas às respectivas versões químicas clássicas, por utilizarem catalisadores potencialmente quimio-, regio- e estereosseletivos, biodegradáveis, oriundos de fontes renováveis que requerem condições brandas de reação (pH, temperatura e pressão) e solventes ambientalmente amigáveis (água, fluidos supercríticos, líquidos iônicos). Por isso, e associado às pressões de cunho sócio-econômico-ambiental sofridas pelas indústrias para a utilização de processos sustentáveis e mais eficientes, a busca por novos biocatalisadores tem aumentado consideravelmente. As enzimas envolvidas na conversão de nitrilas estão entre as mais utilizadas industrialmente. Além de seu valor sintético, estas enzimas exercem um papel fundamental em termos de proteção ambiental, pois têm sido empregadas com sucesso na biodegradação e biorremediação de áreas contaminadas com organonitrilas de origem antropogênica. Assim, neste trabalho realizou-se a prospecção de micro-organismos da biodiversidade brasileira quanto à presença de enzimas envolvidas no metabolismo de nitrilas, mais especificamente nitrilases (Nase), nitrila-hidratases (NHase), amidases e as hidroxinitrila liases (HNLase) através de ensaios colorimétricos. Nesse estudo foram encontrados 1 hit positivo para nitrila-hidratase/amidase, 8 para nitrilases e 3 micro-organismos com sistema enzimático indefinido dentre 29 micro-organismos analisados. Para a enzima hidroxinitrila liase, foram avaliados 76 micro-organismos e foram encontrados 27 hits positivos. Estes resultados foram confirmados por técnicas cromatográficas e espectrométricas. Os micro-organismos positivos das triagens colorimétricas foram... / Biocatalysis is the use of enzymes (microbial, plant or animal) to catalyze chemical transformations, primarily of organic compounds. Generally, enzymatic reactions are much more attractive than the classical chemical alternatives, as they use catalysts that are potentially chemo-, region- and stereoselective, biodegradable, which come from renewable sources and that require mild reaction conditions in terms of pH, temperature and pressure and the use of environmentally friendly solvents (water, supercritical fluids, ionic liquids). Therefore and associated to the socioeconomic and environmental pressures exerted on industries to use sustainable and more efficient processes, the search for new biocatalysts has increased considerably. Nitriles converting enzymes are among the most widely ones used industrially. In addition to their synthetic value, these enzymes play a key role in protecting the environmental as they have been successfully used in the biodegradation and bioremediation of areas contaminated by man-made organic nitriles. Thus, herein we intend to investigate microorganisms from Brazilian biodiversity in terms of enzymes involved in the metabolism of nitriles, more specifically nitrilases (Nase), nitrile hydratase (NHase), amidases and hydroxynitrile lyase (HNLase) through colorimetric assays. It was found 1 positive hit for nitrile hydratase/amidase, 8 for nitrilases and 3 microorganisms with undefined enzymatic system within the 29 evaluated microorganisms. Regarding the enzyme hydroxinitrile lyase, 76 microorganisms were evaluated and 27 positive hits were found. Those colorimetric assays were confirmed through chromatographic and spectrometrically techniques. The positive hits found in the colorimetric assay were applied in the study of biodegradation of Totril® herbicide. These reactions were monitored by HPLC-MS/MS and there were found 5 biodegradation products...
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.unesp.br:11449/124420 |
| Date | 26 February 2015 |
| Creators | Oliveira, Karina Ota [UNESP] |
| Contributors | Universidade Estadual Paulista (UNESP), Milagre, Cíntia Duarte de Freitas [UNESP] |
| Publisher | Universidade Estadual Paulista (UNESP) |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | Portuguese |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | 81 f. : il. - |
| Source | Aleph, reponame:Repositório Institucional da UNESP, instname:Universidade Estadual Paulista, instacron:UNESP |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | -1, -1 |
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