The contribution of biofilms to corrosion of metals and alloys, termed microbially influenced corrosion
(MIC), is still a challenge for research in the field of corrosion protection. In order to inhibit or prevent
MIC, one promising route can be to inhibit the adhesion of single cells. The processes of adhesion and
desorption of microorganisms are known to be induced and mediated by various (bio-)molecules. The
aim of this project is to identify and to investigate substances appropriate to inhibit the formation of
biofilms of sulphate reducing bacteria (SRB). For this purpose, so-called extracellular polymeric
substances (EPS) of various bacteria have been harvested from biofilms and purified. These
substances have been analyzed with focus on chemical groups like proteins, carbohydrates or
glucuronic acids. The EPS have been adsorbed on metal substrates in order to form layers probably
protecting against adhesion of Desulfovibrio vulgaris. Layer formation and adhesion of bacteria were
studied by epi-fluorescence microscopy (EFM) and atomic force microscopy (AFM). It was observed
that the number of attached cells was significantly lower on the covered surfaces when compared to
pure substrates. Additionally, most of the EPS were found to be resistant against degradation by
Desulfovibrio vulgaris.
Keywords: microbially influenced corrosion, corrosion inhibition, biofilms, extracellular polymeric
substances