Project description:Identification of putative proteins of interest that are involved in cathodic electron uptake by the novel iron-corroding strain D. ferrophilus IS5
Project description:Microbial extracellular electron uptake (EEU) is central to bioelectrochemical processes and biocorrosion, yet its molecular mechanisms remain incompletely understood. Here, we investigate how excess Fe2+ modulates EEU in Desulfovibrio ferrophilus IS5, a strain that causes severe anaerobic iron corrosion via outer-membrane cytochromes (OMCs)-mediated electron uptake. We show that IS5 grown with elevated Fe2+ exhibits substantially enhanced EEU. This enhancement arises through two complementary mechanisms: (i) increased abundance of functional OMCs via upregulation of a cytochrome assembly protein, and (ii) an additional electron transfer route mediated by FeS nanoparticles precipitated on the IS5 outer membrane. Remarkably, IS5 with low OMCs expression but biosynthesized FeS can rapidly shift to EEU before OMCs induction. These findings suggest that during iron corrosion, when IS5 cells are embedded within thick corrosion crusts and biofilms and face both high Fe2+ concentrations and organic limitation, they exploit OMCs and FeS nanoparticles in parallel to sustain high-rate EEU from iron. This study advances the mechanistic understanding of EEU-driven iron corrosion and highlights a potential avenue for manipulating bioelectrochemical systems.
Project description:Desulfovibrio ferrophilus IS5 was incubated on indium-tin oxide (ITO) electrodes poised at −0.4 V and −0.5 V (versus standard hydrogen electrode) in H-type reactors for 10 days. Total RNA was extracted from cells after incubation, and RNA fragments were purified and transcribed into cDNA. cDNA was sequenced by NovaSeq 6000 System.
Project description:Microbiologically influenced corrosion (MIC) is recognized as a considerable threat to carbon steel asset integrity in the oil and gas industry. There is an immediate need for reliable and broadly applicable methods for detection and monitoring of MIC. Proteins associated with microbial metabolisms involved in MIC could serve as useful biomarkers for MIC diagnosis and monitoring. A proteomic study was conducted using a lithotrophically-grown bacteria Desulfovibrio ferrophilus strain IS5, which is known to cause severe electric MIC in seawater environments. Unique proteins, which are differentially and uniquely expressed during severe microbial corrosion by strain IS5, were identified. This includes the detection of a multi-heme cytochrome protein predicted to be involved in extracellular electron transfer in the presence of the carbon steel. Thus, we conclude that newly identified protein biomarker for MIC could be used to generate easy-to-implement immunoassays for reliable detection of microbiological corrosion in the field.
Project description:RNA-sequencing (transcriptome analysis) of Desulfovibrio ferrophilus IS5 conducting electron uptake from electrodes at different potentials
| PRJNA553153 | ENA
Project description:Transcriptomic analysis of Desulfovibrio ferrophilus strain IS5
Project description:The marine bacterial strain Desulfovibrio ferrophilus IS5, known for its lithotrophic growth ability to use metallic iron as a sole electron donor and for causing corrosion of steel, was used in the current study. Four commonly used biocides in the oil and gas industry, namely tetrakis(hydroxymethyl) phosphonium sulfate (THPS), glutaraldehyde (GLUT), benzalkonium chloride (BAC), and GLUT/BAC were selected to study their efficacy in controlling carbon steel corrosion in the presence of this strain. Incubations containing strain IS5 and low carbon steel coupons were prepared in the presence and absence of the four biocides, and these were monitored using both electrochemical methods (electrochemical impedance spectroscopy, linear polarization resistance and potentiodynamic polarization) and surface analyses (scanning electron microscopy, confocal measurements, optical microscopy, and profilometry) to assess the biofilm/metal interactions. When THPS, BAC, and GLUT/BAC treatments were applied, minimal corrosion was measured by all methods. In contrast, severe pitting was observed in the presence of 50 ppm GLUT, similar to what was observed when D. ferrophilus IS5 was incubated in the absence of biocide, suggesting that GLUT alone may not be effective in controlling MIC in marine environments. This study also showed that the use of non-destructive electrochemical methods is effective for screening for real time biocide selection and monitoring of the impact of chemicals post-dosage in oil and gas operations.
Project description:Microbiologically influenced corrosion (MIC) is recognized as a considerable threat to carbon steel asset integrity in the oil and gas industry. There is an immediate need for reliable and broadly applicable methods for detection and monitoring of MIC. Proteins associated with microbial metabolisms involved in MIC could serve as useful biomarkers for MIC diagnosis and monitoring. A proteomic study was conducted using a lithotrophically-grown bacterium Desulfovibrio ferrophilus strain IS5, which is known to cause severe MIC in seawater environments. Unique proteins, which are differentially and uniquely expressed during severe microbial corrosion by strain IS5, were identified. This includes the detection of a multi-heme cytochrome protein possibly involved in extracellular electron transfer in the presence of the carbon steel. Thus, we conclude that this newly identified protein associated closely with severe MIC could be used to generate easy-to-implement immunoassays for reliable detection of microbiological corrosion in the field.
