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The role of acetogens in microbially influenced corrosion of steel.

Mand J, Park HS, Jack TR, Voordouw G - Front Microbiol (2014)

Bottom Line: Through a mechanism, that is still poorly understood, electrons or hydrogen (H2) molecules are removed from the metal surface and used as electron donor for sulfate reduction.The resulting ferrous ions precipitate in part with the sulfide produced, forming characteristic black iron sulfide.An extended MIC model capturing these results is presented.

View Article: PubMed Central - PubMed

Affiliation: Petroleum Microbiology Research Group, Department of Biological Sciences, University of Calgary Calgary, AB, Canada.

ABSTRACT
Microbially influenced corrosion (MIC) of iron (Fe(0)) by sulfate-reducing bacteria (SRB) has been studied extensively. Through a mechanism, that is still poorly understood, electrons or hydrogen (H2) molecules are removed from the metal surface and used as electron donor for sulfate reduction. The resulting ferrous ions precipitate in part with the sulfide produced, forming characteristic black iron sulfide. Hydrogenotrophic methanogens can also contribute to MIC. Incubation of pipeline water samples, containing bicarbonate and some sulfate, in serum bottles with steel coupons and a headspace of 10% (vol/vol) CO2 and 90% N2, indicated formation of acetate and methane. Incubation of these samples in serum bottles, containing medium with coupons and bicarbonate but no sulfate, also indicated that formation of acetate preceded the formation of methane. Microbial community analyses of these enrichments indicated the presence of Acetobacterium, as well as of hydrogenotrophic and acetotrophic methanogens. The formation of acetate by homoacetogens, such as Acetobacterium woodii from H2 (or Fe(0)) and CO2, is potentially important, because acetate is a required carbon source for many SRB growing with H2 and sulfate. A consortium of the SRB Desulfovibrio vulgaris Hildenborough and A. woodii was able to grow in defined medium with H2, CO2, and sulfate, because A. woodii provides the acetate, needed by D. vulgaris under these conditions. Likewise, general corrosion rates of metal coupons incubated with D. vulgaris in the presence of acetate or in the presence of A. woodii were higher than in the absence of acetate or A. woodii, respectively. An extended MIC model capturing these results is presented.

No MeSH data available.


Related in: MedlinePlus

Field samples were incubated in CSB-K medium with carbon steel coupons. Acetate (A) and methane (B) concentrations were monitored during incubation. Corrosion rates (C) were determined from metal weight loss. Data represent average results from two separate incubations with two coupons each.
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Figure 5: Field samples were incubated in CSB-K medium with carbon steel coupons. Acetate (A) and methane (B) concentrations were monitored during incubation. Corrosion rates (C) were determined from metal weight loss. Data represent average results from two separate incubations with two coupons each.

Mentions: Similar results were obtained with samples PW8, PW8-PAW, and PW8-PAS, the latter representing pipe-associated solids suspended in microfiltered pipe-associated water (PW8-PAW). Incubation of metal coupons in these samples gave up to 0.38 mM acetate in the aqueous phase and 1 to 2 mM headspace methane (Figures 4A,B). The highest concentrations of acetate and methane were produced in incubations with PW8-PAS, which also had the highest corrosion rate (p < 0.0026) at 0.020 mm/yr (Figure 4C). When these field samples were inoculated in CSB-K medium, production of up to 1.2 mM acetate was seen to precede production of up to 2 mM of headspace methane (Figures 5A,B). Acetate and methane production were observed in incubations with PW8, PW8-PAW, and PW8-PAS, which had higher corrosion rates (p < 0.12) (average 0.0099 ± 0.0049 mm/yr, n = 12) than the uninoculated control (0.0058 ± 0.00042 mm/yr, n = 4) (Figure 5C).


The role of acetogens in microbially influenced corrosion of steel.

Mand J, Park HS, Jack TR, Voordouw G - Front Microbiol (2014)

Field samples were incubated in CSB-K medium with carbon steel coupons. Acetate (A) and methane (B) concentrations were monitored during incubation. Corrosion rates (C) were determined from metal weight loss. Data represent average results from two separate incubations with two coupons each.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4043135&req=5

Figure 5: Field samples were incubated in CSB-K medium with carbon steel coupons. Acetate (A) and methane (B) concentrations were monitored during incubation. Corrosion rates (C) were determined from metal weight loss. Data represent average results from two separate incubations with two coupons each.
Mentions: Similar results were obtained with samples PW8, PW8-PAW, and PW8-PAS, the latter representing pipe-associated solids suspended in microfiltered pipe-associated water (PW8-PAW). Incubation of metal coupons in these samples gave up to 0.38 mM acetate in the aqueous phase and 1 to 2 mM headspace methane (Figures 4A,B). The highest concentrations of acetate and methane were produced in incubations with PW8-PAS, which also had the highest corrosion rate (p < 0.0026) at 0.020 mm/yr (Figure 4C). When these field samples were inoculated in CSB-K medium, production of up to 1.2 mM acetate was seen to precede production of up to 2 mM of headspace methane (Figures 5A,B). Acetate and methane production were observed in incubations with PW8, PW8-PAW, and PW8-PAS, which had higher corrosion rates (p < 0.12) (average 0.0099 ± 0.0049 mm/yr, n = 12) than the uninoculated control (0.0058 ± 0.00042 mm/yr, n = 4) (Figure 5C).

Bottom Line: Through a mechanism, that is still poorly understood, electrons or hydrogen (H2) molecules are removed from the metal surface and used as electron donor for sulfate reduction.The resulting ferrous ions precipitate in part with the sulfide produced, forming characteristic black iron sulfide.An extended MIC model capturing these results is presented.

View Article: PubMed Central - PubMed

Affiliation: Petroleum Microbiology Research Group, Department of Biological Sciences, University of Calgary Calgary, AB, Canada.

ABSTRACT
Microbially influenced corrosion (MIC) of iron (Fe(0)) by sulfate-reducing bacteria (SRB) has been studied extensively. Through a mechanism, that is still poorly understood, electrons or hydrogen (H2) molecules are removed from the metal surface and used as electron donor for sulfate reduction. The resulting ferrous ions precipitate in part with the sulfide produced, forming characteristic black iron sulfide. Hydrogenotrophic methanogens can also contribute to MIC. Incubation of pipeline water samples, containing bicarbonate and some sulfate, in serum bottles with steel coupons and a headspace of 10% (vol/vol) CO2 and 90% N2, indicated formation of acetate and methane. Incubation of these samples in serum bottles, containing medium with coupons and bicarbonate but no sulfate, also indicated that formation of acetate preceded the formation of methane. Microbial community analyses of these enrichments indicated the presence of Acetobacterium, as well as of hydrogenotrophic and acetotrophic methanogens. The formation of acetate by homoacetogens, such as Acetobacterium woodii from H2 (or Fe(0)) and CO2, is potentially important, because acetate is a required carbon source for many SRB growing with H2 and sulfate. A consortium of the SRB Desulfovibrio vulgaris Hildenborough and A. woodii was able to grow in defined medium with H2, CO2, and sulfate, because A. woodii provides the acetate, needed by D. vulgaris under these conditions. Likewise, general corrosion rates of metal coupons incubated with D. vulgaris in the presence of acetate or in the presence of A. woodii were higher than in the absence of acetate or A. woodii, respectively. An extended MIC model capturing these results is presented.

No MeSH data available.


Related in: MedlinePlus