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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

Growth physiology of D. vulgaris (Dv) and A. woodii (Aw) monocultures and a co-culture in closed serum bottles under an atmosphere of 80% H2, 20% CO2. Cell density (A), acetate concentrations (B), sulfate concentrations (C), and sulfide concentrations (D). Data represent results from separate incubations without coupons present.
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Figure 7: Growth physiology of D. vulgaris (Dv) and A. woodii (Aw) monocultures and a co-culture in closed serum bottles under an atmosphere of 80% H2, 20% CO2. Cell density (A), acetate concentrations (B), sulfate concentrations (C), and sulfide concentrations (D). Data represent results from separate incubations without coupons present.

Mentions: SRB of the genus Desulfovibrio or Desulfomicrobium need acetate as a carbon source when deriving energy for growth from reduction of sulfate with H2 or Fe0 (Badziong et al., 1979; Dinh et al., 2004; Caffrey et al., 2007; Enning et al., 2012). When acetate is absent or limiting, this can in principle be provided by acetogens from H2 (or Fe0) and CO2. In order to test this hypothesis we studied the growth of the model SRB Desulfovibrio vulgaris Hildenborough and the model acetogen Acetobacterium woodii in WP medium, containing bicarbonate and sulfate and a headspace of 80% H2 and 20% CO2. A monoculture of A. woodii grew poorly in this medium as judged by turbidity (Figure 7A) and produced up to 1.6 mM acetate after 10 days (Figure 7B). A monoculture of D. vulgaris did not grow (Figure 7A), did not have detectable acetate (Figure 7B) and reduced only 2 mM sulfate to sulfide (Figures 7C,D). Addition of 3 mM acetate to the monoculture of D. vulgaris gave strong growth, sulfate reduction, and sulfide production, while using 1.5 mM of added acetate. Following a lag phase of 2 days needed for the production of 1.3 mM acetate (Figure 7B), the co-culture of D. vulgaris and A. woodii exhibited similar growth, sulfate reduction and sulfide production as the monoculture of D. vulgaris with added acetate. No sulfate reduction or acetate production was seen in the inoculum-free control. Hence, A. woodii can provide the acetate needed by D. vulgaris for growth under chemolithotrophic conditions.


The role of acetogens in microbially influenced corrosion of steel.

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

Growth physiology of D. vulgaris (Dv) and A. woodii (Aw) monocultures and a co-culture in closed serum bottles under an atmosphere of 80% H2, 20% CO2. Cell density (A), acetate concentrations (B), sulfate concentrations (C), and sulfide concentrations (D). Data represent results from separate incubations without coupons present.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 7: Growth physiology of D. vulgaris (Dv) and A. woodii (Aw) monocultures and a co-culture in closed serum bottles under an atmosphere of 80% H2, 20% CO2. Cell density (A), acetate concentrations (B), sulfate concentrations (C), and sulfide concentrations (D). Data represent results from separate incubations without coupons present.
Mentions: SRB of the genus Desulfovibrio or Desulfomicrobium need acetate as a carbon source when deriving energy for growth from reduction of sulfate with H2 or Fe0 (Badziong et al., 1979; Dinh et al., 2004; Caffrey et al., 2007; Enning et al., 2012). When acetate is absent or limiting, this can in principle be provided by acetogens from H2 (or Fe0) and CO2. In order to test this hypothesis we studied the growth of the model SRB Desulfovibrio vulgaris Hildenborough and the model acetogen Acetobacterium woodii in WP medium, containing bicarbonate and sulfate and a headspace of 80% H2 and 20% CO2. A monoculture of A. woodii grew poorly in this medium as judged by turbidity (Figure 7A) and produced up to 1.6 mM acetate after 10 days (Figure 7B). A monoculture of D. vulgaris did not grow (Figure 7A), did not have detectable acetate (Figure 7B) and reduced only 2 mM sulfate to sulfide (Figures 7C,D). Addition of 3 mM acetate to the monoculture of D. vulgaris gave strong growth, sulfate reduction, and sulfide production, while using 1.5 mM of added acetate. Following a lag phase of 2 days needed for the production of 1.3 mM acetate (Figure 7B), the co-culture of D. vulgaris and A. woodii exhibited similar growth, sulfate reduction and sulfide production as the monoculture of D. vulgaris with added acetate. No sulfate reduction or acetate production was seen in the inoculum-free control. Hence, A. woodii can provide the acetate needed by D. vulgaris for growth under chemolithotrophic conditions.

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