Obtención y caracterización de un soporte sólido modelo para el estudio del metabolismo de hongos filamentosos degradadores de fenantreno
Si02 xerogels with an average pore size of 30 A and a surface area of 759 m2/g were prepared; Si02 xerogels were also prepared adding a solution of phenanthrene in dimethylformamide during the polymerization yielding xerogels with an average pore size of 89 A and a surface area of 429 m2/g, more phe...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2001 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:r781wg71j |
| Acceso en línea: | https://doi.org/10.24275/uami.r781wg71j |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Filamentous fungi info:eu-repo/classification/LEM/Hongos filamentosos info:eu-repo/classification/LEM/Fenantreno -- Biodegradación info:eu-repo/classification/LEM/Phenanthrene -- Biodegradation info:eu-repo/classification/cti/3 |
| Sumario: | Si02 xerogels with an average pore size of 30 A and a surface area of 759 m2/g were prepared; Si02 xerogels were also prepared adding a solution of phenanthrene in dimethylformamide during the polymerization yielding xerogels with an average pore size of 89 A and a surface area of 429 m2/g, more phenanthrene was added to these xerogels until a concentration of 250 ppm was reached. All xerogels prepared had an average water retention capacity of 4.2k1.3 g water/g xerogel. The xerogels were used as support for the growth of two filamentous fungi, Phanerochaete chrysosporium A594 and Aspergillus niger ATCC9642. In both xerogels the microorganisms had an average rate of reducing sugar consumption of 0.046 mg/g support h for P. chrysosporium A594 and of 0.106 mg/g support h for A. niger ATCC9642. These results show that, at an initial concentration of 250 ppm, phenathrene has no inhibiting effect neither in the growth of the fungi, nor in its sugar consumption. No significant changes on the morphology of the fungi were observed . using scanning electron microscopy. Despite the fact that neither the physiology nor the morphology of the fungi were affected, the phenantrene biotransformation was only 25% after ten days. Phenanthrene sorption and biotransformation kinetics in liquid culture showed that P. chrysosporium A594 and A. niger ATCC9642 sorb a maximum of 0.02 and 0.025 mg phenanthrene/mg biomass respectively. Both phenomena are closely related, which suggests hat an initial soption of the compound is necessary before its biotransformation. It is possible that the same phenomenon is present in the solid systems, which together with the classical mass transference models helps to explain the slow biotransformation of the pollutants by the indigenous microflora. |
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