Estudo do metabolismo dos ramnolipídios produzidos por Pseudomonas aeruginosa
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Data
2018-11-21
Autores
Silva, Vinícius Luiz da [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Surfactantes são moléculas anfipáticas, que devido à presença de regiões com polaridades distintas apresentam propriedades únicas como a capacidade de reduzir a tensão interfacial e superficial. Os biossurfactantes são moléculas biológicas que podem ser sintetizados por uma ampla gama de seres vivos, no entanto os produtores mais estudados são os micro-organismos. Apesar das inúmeras vantagens dos tensoativos biológicos, como baixa toxicidade, biodegradabilidade e alta estabilidade, estes compostos não são amplamente utilizados, devido ao custo de produção. Por esse motivo, o presente estudo realizou a construção de linhagens mutantes, com a deleção de genes específicos, rhlG e rhlYZ e o mutante com a deleção dupla. Posteriormente foram realizados bioprocessos em biorreator, utilizando óleo de girassol e glicerol como fonte de carbono. Esses cultivos permitiram verificar a influência de cada um dos genes na biossíntese dos ramnolipídios. Os dados dos cultivos foram utilizados ainda para traçar os fluxos metabólicos das diferentes linhagens de P. aeruginosa MPAO1, a fim de entender melhor o metabolismo dos ramnolipídios e gerar dados para discussão de modificações genéticas dirigidas que visem o aumento da produção. Verificou-se ainda uma nova aplicação para esses glicolipídios, visando a remoção de azocorantes de soluções aquosas. Os cultivos permitiram inferir que o gene rhlG não é essencial para a produção dos ramnolipídios, pois sua deleção não resultou em queda na produção dos ramnolipídios, já o operon rhlYZ se mostrou necessário para a produção de ramnolipídios quando a fonte de carbono empregada foi hidrofóbica. As análises de fluxo levaram a inferir que a porção hidrofílica seja o gargalo na produção desses biotensoativos. Além disso estudou-se a adsorção do corante têxtil utilizando os ramnolipídios como adsorvente, demonstrou que essas biomoléculas apresentam potencial de biorremediação dos corantes em solução aquosa, a adsorção foi melhor em pHs ácidos
Surfactants are amphipathic molecules, which due to the presence of regions with distinct polarities present unique properties such as the ability to reduce surface and interfacial tension. Biosurfactants are biological molecules that can be synthesized by a wide range of living beings, however the most studied producers are microorganisms. Despite the numerous advantages of biological surfactants, such as low toxicity, biodegradability and high stability, these compounds are not widely used because of the cost of production. For this reason, the present study carried out the construction of mutant lines, with the deletion of specific genes, rhlG and rhlYZ and the mutant with the double deletion. Subsequently, bioprocesses were performed in bioreactor, using sunflower oil and glycerol as carbon source. These cultures allowed to verify the influence of each of the genes in the biosynthesis of the rhamnolipids. The culture data were also used to trace the metabolic fluxes of the different P. aeruginosa MPAO1 strains in order to better understand the metabolism of rhamnolipids and to generate data for the discussion of directed genetic modifications aimed at increasing production. A further application for these glycolipids has been found to remove azocorates from aqueous solutions. The cultures allowed to infer that the gene rhlG is not essential for the production of the rhamnolipids, since its deletion did not result in a decrease in the production of the rhamnolipids, whereas the rhlYZ operon was necessary for the production of rhamnolipids when the carbon source used was hydrophobic. Flow analyzes have led us to infer that the hydrophilic portion is the bottleneck in the production of these biotensoativos. In addition the adsorption of the textile dye was studied using the rhamnolipids as adsorbent, it was demonstrated that these biomolecules present bioremediation potential of the dyes in aqueous solution, the adsorption was better at acidic pHs
Surfactants are amphipathic molecules, which due to the presence of regions with distinct polarities present unique properties such as the ability to reduce surface and interfacial tension. Biosurfactants are biological molecules that can be synthesized by a wide range of living beings, however the most studied producers are microorganisms. Despite the numerous advantages of biological surfactants, such as low toxicity, biodegradability and high stability, these compounds are not widely used because of the cost of production. For this reason, the present study carried out the construction of mutant lines, with the deletion of specific genes, rhlG and rhlYZ and the mutant with the double deletion. Subsequently, bioprocesses were performed in bioreactor, using sunflower oil and glycerol as carbon source. These cultures allowed to verify the influence of each of the genes in the biosynthesis of the rhamnolipids. The culture data were also used to trace the metabolic fluxes of the different P. aeruginosa MPAO1 strains in order to better understand the metabolism of rhamnolipids and to generate data for the discussion of directed genetic modifications aimed at increasing production. A further application for these glycolipids has been found to remove azocorates from aqueous solutions. The cultures allowed to infer that the gene rhlG is not essential for the production of the rhamnolipids, since its deletion did not result in a decrease in the production of the rhamnolipids, whereas the rhlYZ operon was necessary for the production of rhamnolipids when the carbon source used was hydrophobic. Flow analyzes have led us to infer that the hydrophilic portion is the bottleneck in the production of these biotensoativos. In addition the adsorption of the textile dye was studied using the rhamnolipids as adsorbent, it was demonstrated that these biomolecules present bioremediation potential of the dyes in aqueous solution, the adsorption was better at acidic pHs
Descrição
Palavras-chave
Ramnolipídios, Corantes, Biorremediação, Analise de fluxo metabólico, Pseudomonas aeruginosa, Glicolipídios, Surfactantes, Biosurfactantes, Ramnolipids, Dyes, Bioremediation, Metabolic flow analysis, Glycolipids, Surfactants, Biosurfactants