Abstract

Taxonomic Diversity and Biodegradation Potential of Bacteria Isolated from Oil Reservoirs of an Offshore Southern Brazilian Basin

Patrícia F. Lopes- Oliveira, Suzan P. Vasconcellos, Célio F. F. Angolini, Georgiana F. da Cruz, Anita J. Marsaioli, Eugênio V. Santos Neto and Valéria M. Oliveira

This study aimed at the taxonomic characterization of a collection with 98 bacteria isolated from oil and formation water samples from petroleum reservoirs of the Campos Basin (Brazil), as well as the evaluation of their degradation potential of petroleum biomarkers. The genomic DNA extracted from all isolates was employed in PCR reactions for amplification of the 16S rRNA gene and subsequent screening by ARDRA (Amplified Ribosomal DNA Restriction Analysis), in order to detect potentially distinct taxonomic groups. Further 16S rRNA gene sequencing and phylogenetic analysis of 39 isolates representing different ribotypes revealed that these isolates belonged to 10 different genera, encompassing Marinobacter, Halomonas, Citreicella, Stenotrophomonas, Achromobacter, Bacillus, Staphylococcus, Micrococcus, Kocuria and Streptomyces, affiliated to the three phyla Proteobacteria, Firmicutes and Actinobacteria. RAPD analysis enabled the discrimination of the isolates at the infraspecific level, allowing the identification of 45 distinct genetic band patterns. The chromatographic results showed the preference of all of bacteria to biodegrade nonadecanoic acid and squalane when grown in biomarker mixture. The results of this study provide further insight into the taxonomy of the cultivated fraction of microbial communities of Brazilian oil reservoirs and may offer potential tools for future application in bioremediation processes.