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| Author(s): |
Fabio Guimaro Dias
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos |
| Defense date: | 2007-11-07 |
| Examining board members: |
Lúcia Regina Durrant;
Maria Cristina Teixeira Duarte;
Fabiana Fantinatti Garboggini;
Ranulfo Monte Alegre;
Telma Teixeira Franco;
Andrea Roberta Clemente
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| Advisor: | Lúcia Regina Durrant |
| Abstract | |
In this work, a microbial consortium was evaluated regarding to its potential to degrade oil and derivatives, using microcosms in salt minimal medium. Forty three bacteria were tested in the first phase of this project to demonstrate some properties that could identify them as potentially degraders of hydrocarbons. The strains 1, 9, 22, 23 and 36 showed the best and homogeneous results in practically all the analyzed parameters, and five strains were selected to be part of the bacterial consortium. These strains had an average degradation of 62.65% for the strain 1; 61.12% for the strain 9; 53.77% for the strain 22; 57.87% for the strain 23; and 44.03% for the strain 36. Some PAHs were not completelly degraded by some strains, and this fact could be proven by the low values of EC50, with production of high values of acute toxicidade. In the microcosm experiments, the C-CO2 evolution was performed using statistical models, which could be concluded that the best condition for the maximization of this parameter was in the central point condition for the nitrogen source (0.10g/100g of soil), iron (0.0015g/100g of soil) and inoculum (0,6ml/100g of ground), using the condition of +2 for the phosphorus source (0.08g/100g of soil). In this experiments could be set an excellent condition for a better evolution of C-CO2 in contaminated soil. In the same experiment, analyzing the degradation of the hydrocarbons in GC-FID, a better degradation was obtained for the experiment 3 (urea 0,07g/100g of soil, potassium fosfate 0.065g/100g of soil, iron sulphate 0.001g/100g of ground, and inoculum of 0.4 ml/100g of soil), reaching hydrocarbons degradation of 70.74%. In the microcosms using the REPLAN (PAULINIA REFINARY/PETROBRAS) soil with previous contamination history, the best degradation of 75% was promoted when bioestimulating, and 51.7% when this soil was bioaugmented with the bacterial consortium and also bioestimulated. For the microcosms using the lyofilizated consortium, a degradation of 57.85% was verifyed without nutrient, and 67% with nutrient. The strains were identified through the RNA 16S sequencing as Bacillus genus, excepting to the strain 23, whose results of sequencing identification was not possible in this time. These results showed that the microbial consortium has a potential application in contaminated areas with oil and derivatives (AU) | |