Enhancement of exogenous riboflavin on microbiologically influenced corrosion of nickel by electroactive Desulfovibrio vulgaris biofilm

Abstract Riboflavin, a soluble redox mediator for electron transfer, is involved in various processes biogeochemical systems. This work gives some insights into the MIC mechanism of pure nickel (Ni) caused by Desulfovibrio vulgaris . Compared with copper (Cu) metabolite (M)-MIC, Ni D. exhibits distinctly different corrosion behavior. 20 ppm (w/w) riboflavin dramatically enhances rate (59% increase weight loss), while it has no impact on Cu MIC. Furthermore, headspace H 2 detection reveals that neither proton nor S occurs (Cu biogenic produces large amounts , whereas does not). The thermodynamic analysis and experimental results indicate trapping extracellular electrons from oxidation energy, which belongs to transfer (EET)-MIC.