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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

Methane production (A) was monitored as field samples were incubated in the presence of carbon steel coupons and the associated corrosion rates (B) were determined using metal weight loss. Acetate production (C) was monitored in an independent incubation of these field samples in the presence of carbon steel coupons. Data represent results from separate incubations with two coupons each.
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Figure 2: Methane production (A) was monitored as field samples were incubated in the presence of carbon steel coupons and the associated corrosion rates (B) were determined using metal weight loss. Acetate production (C) was monitored in an independent incubation of these field samples in the presence of carbon steel coupons. Data represent results from separate incubations with two coupons each.

Mentions: Incubation of samples P0866, P0866S, and P0848S with carbon steel coupons and a headspace of N2-CO2 for 70 days gave formation of 2.3, 1.0, or 2.6 mM headspace methane, respectively (Figure 2A). No significant methane was formed in incubations with sample PW7 or the water-only control. Weight loss corrosion rates were higher (p < 0.00032) for incubations with samples P0866, P0866S, and P0848S (Figure 2B: average 0.018 ± 0.0040 mm/yr, n = 6) than with sample PW7 or the water-only control (Figure 2B: average 0.0060 ± 0.00091 mm/yr, n = 4). The formation of acetate was evaluated in a separate experiment indicating formation of 0.45 to 3.2 mM acetate in the aqueous phase of these incubations, whereas no acetate was formed in the water-only control (Figure 2C). Neither methane nor acetate were formed in the absence of steel coupons (results not shown).


The role of acetogens in microbially influenced corrosion of steel.

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

Methane production (A) was monitored as field samples were incubated in the presence of carbon steel coupons and the associated corrosion rates (B) were determined using metal weight loss. Acetate production (C) was monitored in an independent incubation of these field samples in the presence of carbon steel coupons. Data represent results from 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 2: Methane production (A) was monitored as field samples were incubated in the presence of carbon steel coupons and the associated corrosion rates (B) were determined using metal weight loss. Acetate production (C) was monitored in an independent incubation of these field samples in the presence of carbon steel coupons. Data represent results from separate incubations with two coupons each.
Mentions: Incubation of samples P0866, P0866S, and P0848S with carbon steel coupons and a headspace of N2-CO2 for 70 days gave formation of 2.3, 1.0, or 2.6 mM headspace methane, respectively (Figure 2A). No significant methane was formed in incubations with sample PW7 or the water-only control. Weight loss corrosion rates were higher (p < 0.00032) for incubations with samples P0866, P0866S, and P0848S (Figure 2B: average 0.018 ± 0.0040 mm/yr, n = 6) than with sample PW7 or the water-only control (Figure 2B: average 0.0060 ± 0.00091 mm/yr, n = 4). The formation of acetate was evaluated in a separate experiment indicating formation of 0.45 to 3.2 mM acetate in the aqueous phase of these incubations, whereas no acetate was formed in the water-only control (Figure 2C). Neither methane nor acetate were formed in the absence of steel coupons (results not shown).

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