Accelerated cathodic reaction in microbial corrosion of iron due to direct electron uptake by sulfate-reducing bacteria

► Corrosive SRB strain accelerates cathodic reaction of iron by direct electron uptake. ► Hydrogenotrophic control strain does not influence the cathodic reaction. ► Deposited ferrous sulfides do not stimulate the cathodic reaction. ► Deposited ferrous sulfides mediate electrical contact between metal and cells.