Caracterização da comunidade microbiana de reservatório de petróleo

Abstract

The bacterial is metabolically diverse and represents a huge source of molecules with new biotechnological applications. Although this kingdom it is very rich, microbiological techniques of cultivation and identification are limited to access and identify this favorable source. Soon metagenomics stands out as an innovative tool to study bacterial communities independently of cultivation, and in addition, to extract new proteins and organisms with biotechnological application. The present study aimed to identify, both taxonomically and functionally, microorganisms residing in the bacterial community of petroleum wells involved in the degradation of oil and the production of surfactant molecules. To do so, samples of production water and well rocks are subjected to DNA extraction, as well as the preparation of cultures subjected to selection of petroleum degrading organisms and surfactant producers. Subsequently, all samples were sequenced through new generation sequencing platforms. The bioinformatics results show that the communities living in the rocks and in the production water were predominantly belonging to the Halomonas and Marinobacter genera, respectively. While the results of the consortia classification show a predominance of degrading and biosurfactant producers of genera Microbacterium, Ochrobactrum, Devosia and Paenibacillus in the R2 consortium, and Sphingobacterium, Bacillus and Lysinibacillus in the R1 consortium. Functional tests show that such bacteria are producers of biosurfactants to stabilize an emulsion as well as reduce interfacial tension between oil and water. Using homology comparisons with a protein custom database, it was possible to identify that such surfactant molecules were synthesized in Lichenysin, Plipastatin and Pultisolvin operons. This data refers to the degradation tests by means of the oxy-redox indicator, showing that there was predominance of degradation routes of linear as well as polycycloaromatic alkanes. These results indicate that isolated reservoir consortia have potential to increase the fluidity of the oil by degrading it, as well as the production of surfactants that significantly reduce the interfacial tension between water and oil, therefore showing potential for biotechnological application.