Reservoir souring, the production of hydrogen sulfide in oil wells as a result of downhole activity by a specialized group of microorganisms called sulfate-reducing bacteria (SRB), is a detrimental process of great concern to the oil industry. As petroleum reserves age and water injection is implemented for pressure maintenance, there is an inherent risk of reservoir souring due to the co-mingling of injection waters and formation waters.
Scanning electron micrograph of D. acetiphilus strain N2460T. (Image from H. Kiss et al, doi.org/10.4056/sigs.892105)
Denitrovibrio acetiphilus was isolated as a representative of a population reducing nitrate to ammonia in a laboratory column simulating the conditions in off-shore oil recovery fields. When nitrate was added to this column, undesirable hydrogen sulfide production was stopped because the sulfate reducing populations were superseded by these nitrate reducing bacteria.
Published in the current issue of Standards in Genomic Sciences (SIGS) (May 20, 2010 – June 30, 2010;(2):270-279) are the features of this marine, obligately anaerobic organism respiring by nitrate reduction, together with the complete genome sequence, and annotation. The 3.2-megabase genome with its 3,034 protein-coding and 51 RNA genes was sequenced by DOE JGI as part of the Genomic Encyclopedia of Bacteria and Archaea (GEBA) project.