Biocorrosion is a serious problem affecting oil and gas industry facilities throughout the world.
Traditionally, the sulfate-reducing bacteria group has been considered the foremost
responsible for microbially-influenced corrosion (MIC). However, recent studies suggest that
other bacteria such as metal-reducing bacteria and methanogens may play a key role in
biocorrosion. Shewanella are facultative anaerobic iron-reducing bacteria that are well known
for their versatile metabolism. These bacteria have the ability to reduce ferric iron and sulfite,
oxidize hydrogen gas, and produce sulfide, and may be involved in biocorrosion. In the present
study, the corrosive activity of a strain of Shewanella sp isolated from a gas pipeline (black
powder) was investigated. An experiment was conducted to analyze the potential involvement
of Shewanella sp in MIC. The corrosion products were characterized by X-ray diffraction
identifying iron sulfides, iron oxides, and sulfur. Our results indicate that the strain isolated, S.
putrefaciens, plays a key role in corrosion problems in gas pipelines. Further studies related to
the interaction between D. desulfuricans and S. putrefaciens, and its implications to
biocorrosion are underway, as well as DGGE analysis from several gas pipeline samples.
Keywords: shewanella, desulfovibrio, blackpowder, gas pipeline, microbiologically influenced corrosion