Gene Expression by the Sulfate-Reducing Bacterium Desulfovibrio vulgaris Hildenborough Grown on an Iron Electrode under Cathodic Protection Conditions

Abstract

The genome sequence of the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough was reanalyzed to design unique 70-mer oligonucleotide probes against 2,824 probable protein-coding regions. These included three genes not previously annotated, including one that encodes a c-type cytochrome. Using microarrays printed with these 70-mer probes, we analyzed the gene expression profile of wild-type D. vulgaris grown on cathodic hydrogen, generated at an iron electrode surface with an imposed negative potential of ؊1.1 V (cathodic protection conditions). The gene expression profile of cells grown on cathodic hydrogen was compared to that of cells grown with gaseous hydrogen bubbling through the culture. Relative to the latter, the electrode-grown cells overexpressed two hydrogenases, the hyn-1 genes for [NiFe] hydrogenase 1 and the hyd genes, encoding [Fe] hydrogenase. The hmc genes for the high-molecular-weight cytochrome complex, which allows electron flow from the hydrogenases across the cytoplasmic membrane, were also overexpressed. In contrast, cells grown on gaseous hydrogen overexpressed the hys genes for [NiFeSe] hydrogenase. Cells growing on the electrode also overexpressed genes encoding proteins which promote biofilm formation. Although the gene expression profiles for these two modes of growth were distinct, they were more closely related to each other than to that for cells grown in a lactate-and sulfate-containing medium. Electrochemically measured corrosion rates were lower for iron electrodes covered with hyn-1, hyd, and hmc mutant biofilms than for wild-type biofilms. This confirms the importance, suggested by the gene expression studies, of the corresponding gene products in D. vulgaris-mediated iron corrosion.

A Molybdopterin Oxidoreductase Is Involved in H 2 Oxidation in Desulfovibrio desulfuricans G20

“…These include a molybdopterinbinding subunit, an Fe-S cluster-containing subunit, and an integral membrane component that is thought to interact directly with menaquinone or menaquinone derivatives (3,9,16). The mop operon was compared to existing Desulfovibrio genomic data and appears to be conserved in all the available genomes of Desulfovibrio (7). The Mop complex is definitely produced at reasonable levels, as proteomic analyses have detected MopB and MopC in cell extracts of D. vulgaris (41) and MopC in D. desulfuricans G20 (22).…”

Effect of sulfide on growth physiology and gene expression of Desulfovibrio vulgaris Hildenborough

“…Full genome D. vulgaris microarrays (Caffrey et al 2008) were used to compare the gene expression patterns for mid-log-phase wild-type D. vulgaris cells grown in serum bottles (high sulfide) and the batch flow system (low sulfide). A survey of all results obtained is provided in Table S1 and the microarray data has been deposited into NCBI GEO under the accession number GSE15073 (Edgar et al 2002).…”

Low temperature acclimation with electrical stimulation enhance the biocathode functioning stability for antibiotics detoxification

“…Hydrogenases have been involved in electron flow for reductive metabolism in biocathode (Aulenta et al, 2008;Caffrey et al, 2008;Deutzmann et al, 2015). In the current study, a total of 65 hydrogenase genes from 8 genera and 2 uncultured microorganisms were detected, 23 of which came from Desulfovibrio species that with bifunctional features of nitroaromatics reduction and electrochemical activity.…”