Microbiologically influenced corrosion of CoCrFeMnNi high entropy alloy by sulfate-reducing bacterium Desulfovibrio vulgaris

Sulfate-reducing bacterium Desulfovibrio vulgaris promoted the microbiologically influenced corrosion (MIC) of CoCrFeMnNi high entropy alloy (HEA) and led to pitting corrosion. D. vulgaris caused the formation of metal sulfides and thinning of passive film. The corrosion resistance decreased, and pit depths increased when the carbon source reduced to 40%. The relative expression of hydrogenase genes hydA and hydB in the biofilms under 40% carbon source significantly increased, indicating that the indirect electron transfer mediated by 2H+/H2 might play an important role in promoting the HEA MIC by D. vulgaris under starvation.

Automated summary

The sulfate-reducing bacterium Desulfovibrio vulgaris promotes microbiologically influenced corrosion (MIC) of CoCrFeMnNi high entropy alloy (HEA) and leads to pitting corrosion. D. vulgaris causes the formation of metal sulfides and thinning of passive film. The relative expression of hydrogenase genes hydA and hydB in the biofilms significantly increases, indicating the importance of indirect electron transfer in promoting HEA MIC by D. vulgaris under starvation.