Iron corrosion induced by the hyperthermophilic sulfate-reducing archaeon Archaeoglobus fulgidus at 70 °C

Abstract

This work assessed the role of the hyperthermophilic sulfate-reducing archaeon, Archaeoglobus fulgidus in anaerobic iron corrosion, at 70 °C, in the presence and the absence of lactate as energy source. Experiments performed with A. fulgidus planktonic cells, displayed their capacity to form a biofilm on an iron coupon and exhibited their biocorrosive activity. A. fulgidus was shown to cause indirect corrosion by producing sulfide while oxidizing lactate. Furthermore, the archaeon could grow lithotrophically by using elemental iron as a mineral energy source. Under these latter conditions, A. fulgidus formed chimneys enhancing the direct corrosion process. Moreover, physiological modifications occurred under these conditions notably highlighting the probable use of CO2 instead of sulfate as a terminal electron acceptor to produce acetate similarly to homoacetogens. All together, these results illustrate the metabolic versatility and hence the importance of this hyperthermophilic archaeon in microbial induced corrosion (MIC).