The Nitrate-Dependent Impact of Carbon Source Starvation on EH40 Steel Corrosion Induced by the Coexistence of Desulfovibrio vulgaris and Pseudomonas aeruginosa

Abstract

Carbon source starvation can promote steel corrosion in the presence of a pure culture through extracellular electron transfer (EET). However, the impact of carbon source starvation on corrosion induced by mixed strains is still unknown. This work investigated the impact of carbon source starvation on EH40 steel corrosion in the presence of Desulfovibrio vulgaris and Pseudomonas aeruginosa, typical species of sulfate- and nitrate-reducing bacteria. It was found that the impact of carbon source starvation on corrosion depended on nitrate addition. When nitrate (5 g∙L−1 NaNO3) was not added, the corrosion was promoted by carbon source starvation. However, the corrosion was initially promoted by carbon source starvation, but later inhibited with nitrate addition. The corrosion behaviors in different systems were closely related to different numbers of the strains in biofilms and their metabolic activities, and the mechanisms were revealed.