Prospecção de microrganismos e genes envolvidos na biodegradação de petróleo e derivados

Industrial activities carried out by oil exploration have generated a lot of waste. The waste generated represents a major environmental liability, which requires adequate treatment. In this way, the development of environmental bioremediation strategies has been increasing in recent years. In this context, the metagenomic approach was used in the present work to identify microorganisms and genes associated with hydrocarbon biodegradation and biosurfactant synthesis, from the functional screening of the metagenomic library and the isolation of bacteria. A metagenomic library using environmental DNA from the oil well drilling fluid residue was constructed and the clones obtained in plasmid (pBC) and expressed in E. coli (DH10B). The clones were functionally selected. For this, qualitative and quantitative tests were used, such as the colorimetric test based on the reduction of DCPIP (2,6-dichlorophenol indophenol), which allows the detection of hydrocarbon degradation. The DCPIP test revealed 60 clones positive for degradation activity, of which 25 were sequenced. The prediction of ORFs allowed the identification of genes involved in the degradation pathways of aliphatic and aromatic hydrocarbons. In addition, the growth of the clones in the presence of petroleum, corroborated with the results obtained in the DCPIP test, revealing ability of degradation by the clones. Six clones showed degradation estimates between 50 and 80% when compared to E.coli DH10BØ (host strain with empty vector). These six clones were selected for assembly of two consortia (C consortium and C + I consortium) which were used for bioremediation of the drilling fluid residue. In the assay that evaluated the dehydrogenase activity was observed a high metabolic activity during the period of 28 days. The degradation rates were 14 and 42% of n-alkanes for the consortia C and C + I, respectively, suggesting potential of application of the consortia in bioremediation processes. Sequencing of the consortium forming clones showed the presence of ...