Diversity of sulfate-reducing prokaryotes in petroleum production water and oil samples

Microorganisms from oil reservoirs are associated with negative impacts on the oilfield, such as oil biodeterioration and biocorrosion of steel structures used for exploration, transportation and storage. The objectives of this study were to analyze the taxonomic and functional diversity in the production water and oil of two oil reservoirs, with emphasis on H2S producing bacteria. Total DNA from the microbial community was extracted, and the taxonomic and functional diversity was evaluated. The phyla Proteobacteria, Firmicutes and Euryarchaeota were the most abundant among the samples and contain the main sulfate-reducing species, such as Desulfovibrio alaskensis and Archeoglobus fulgidus. The production water and the oil were found to have taxonomic and functionally different microbial communities in the three communities, however correlation networks showed basically the same types of interconnected metabolism between the sulfidogenic microorganisms. This indicates the importance of understanding the microbial diversity and metabolic capacity of communities in these environments and trying to control harmful processes that may result in huge economic damage to the oil industry.