Chloride Enhances Corrosion Associated with Sulfate-Reducing Bacteria

Desulfovibrio vulgaris and Desulfovibrio ferrophilus were previously proposed to have distinct iron corrosion mechanisms because D. ferrophilus corroded faster. However, the chloride concentration in the D. ferrophilus ‘marine’ medium was much higher than in the D. vulgaris ‘freshwater’ medium. D. vulgaris corrosion rates accelerated with increasing chloride and were faster than D. ferrophilus in the same marine medium. Differences in D. ferrophilus corrosion rates in two different media with the same chloride concentration suggested that minor differences in other medium constituents also impact on microbial corrosion. These results demonstrate the importance of considering medium composition in microbial corrosion studies.