Sulfate-reducing bacteria (SRB) can contribute to microbially-influenced corrosion (MIC) of
iron. Removal of hydrogen formed at the metal surface is often regarded as a critical step in the
progression of MIC. Hence SRB-mediated iron corrosion and hydrogen oxidation may be comparable
processes. Because the genome sequence of the model SRB Desulfovibrio vulgaris Hildenborough
(DvH) is now known, this theory can be tested by genomics technologies. D. vulgaris has four
periplasmic hydrogenases to oxidize molecular hydrogen, one iron-only (Hyd), two nickel-iron (Hyn1
and Hyn2) and one nickel-iron-selenium (Hys) hydrogenase. Total RNA was extracted from lactategrown
cells, from 5%- or 50%-hydrogen-grown cells and from cells grown under conditions of cathodic
protection. The lactate- and hydrogen-grown cells were planktonic, whereas the cathodic-protectiongrown
cells were attached to the iron electrode. Genome-wide gene expression profiles were obtained by
hybridizing labelled cDNA made from the extracted RNA preparations with microarrays containing a
70-mer oligonucleotide probe for each of the approximately 3000 genes from DvH.