The risk of rapid pitting corrosion due to bacterial contamination has been studied by monitoring the natural coupling current flowing between two concentric electrodes. For sulfate reducing bacteria in general (SRB) and thiosulfate reducing bacteria in particular (TRB), the presence of thiosulfate and its utilization by the bacterial metabolism are shown to represent a major risk factor, leading to penetration rates greater than a centimeter per year,
Keywords : microbially induced corrosion, pitting corrosion, sulfate reducing bacteria, thiosulfate.