Trained to corrode: Cultivation in the presence of Fe(III) increases the electrochemical activity of iron reducing bacteria – An in situ electrochemical XANES study

• Published in: Electrochemistry communications Vol. 112; p. 106673
• Main Authors: Wurzler, Nina, Schutter, Jan David, Wagner, Ralph, Dimper, Matthias, Lützenkirchen-Hecht, Dirk, Ozcan, Ozlem
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-2020; Elsevier
• Subjects: In situ electrochemical XANES; Iron reducing bacteria; MIC; Microbiologically influenced corrosion; Shewacnella putrefaciens CN32; XANES; Iron reducing bacteria; Microbiologically influenced corrosion; Shewacnella putrefaciens CN32; XANES; In situ electrochemical XANES; MIC
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2020.106673

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•Application of electrochemical XANES to microbially influenced corrosion (MIC).•In situ electrochemical XANES allows the analysis of the biofilm-metal interface.•Shewanella spp. grown in abundance of Fe(III) show higher electrochemical activity.•Cultivation conditions can play an important role in MIC processes.
This paper reports results from in situ electrochemical X-ray absorption near-edge spectroscopy (XANES) studies of the corrosion processes on model thin iron films in the presence of iron reducing bacteria Shewanella putrefaciens. Here we investigate the electrochemical activity of two cultures grown in the presence and absence of Fe(III) citrate in the culture medium. The XANES spectra and the OCP data of the Fe sample incubated with the culture grown in absence of Fe(III) did not show any significant changes during twenty hours of monitoring. In the case of the culture grown in Fe(III) containing medium, an accelerated dissolution of the iron film was observed together with the formation of a mixed Fe(II)-Fe(III) hydroxide surface layer. The open circuit potential (OCP) steadily approached the free corrosion potential of iron in neutral chloride containing electrolytes, indicating a continuous dissolution process without passivation.