Long-term survival of Desulfovibrio vulgaris on carbon steel and associated pitting corrosion

Organic substrates may not be constantly available in the environments. It is important to know if and how sulfate reducing bacteria survive and corrode metal under organic electron donor starvation. In this study, biofilm structure of Desulfovibrio vulgaris on carbon steel and associated corrosion was examined over up to 55 days of organic starvation. Planktonic cell viability diminished rapidly but results of scanning electron microscopy and confocal laser scanning microscopy showed persistent pitting corrosion and high viability of the cells attached around or inside pits and in FeS crust. Results suggested the SRB cells survived with electrons from iron oxidation.