Use of 2-D vibrating electrode technique in MIC studies
- Univ. of Tennessee, Knoxville, TN (United States). Center for Environmental Biotechnology
The role of bacteria in microbial-associated corrosion of steels has been well documented. Recently, bacteria have been shown to be involved in the freshwater pitting corrosion of copper pipes. However, there is still some controversy over how the pitting is actually initiated. This is due in part to the electrochemical methods traditionally employed in studying microbial corrosion. These methods are of very low resolution and provide information averaged over a relatively large area compared to the pits, that can be less than one millimeter in diameter. The scanning vibrating electrode technique (SVET) has been shown to be capable of detecting the localized anodic regions associated with microbial corrosion processes. The systems, as described previously, have not provided information on the localization of the microbes thought to be involved in the process. The inclusion of a microscope and a photon detecting camera to a two-dimensional scanning vibrating electrode has allowed the location and activity of genetically engineered ``reporter strains`` of bacteria to be mapped congruently with the localized current densities. These reporter strains have the luxB gene, which produces bacterial luminescence, inserted into specific pathways of interest for example alginate production, such, that the production of alginate is accompanied by the production of visible light. It has been observed that the anodic regions correspond to the location of the bacteria; providing further evidence that bacteria can be involved in the initiation of the pitting process. Similar results have been seen using a solution of purified exopolymers produced by some of the bacteria tested. This suggests that the anodic regions are a result of differential aeration cells being set up by the bacteria. Work is currently in hand to help determine possible mechanisms by which bacteria may be involved in pit initiation.
- OSTI ID:
- 80054
- Report Number(s):
- CONF-940222-; TRN: IM9532%%181
- Resource Relation:
- Conference: Corrosion 94: National Association of Corrosion Engineers (NACE) international annual conference, Baltimore, MD (United States), 28 Feb - 4 Mar 1994; Other Information: PBD: 1994; Related Information: Is Part Of Corrosion/94 conference papers; PB: 5005 p.
- Country of Publication:
- United States
- Language:
- English
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