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Microbial redox processes in deep subsurface environments and the potential application of (per)chlorate in oil reservoirs.

Liebensteiner MG, Tsesmetzis N, Stams AJ, Lomans BP - Front Microbiol (2014)

Bottom Line: Microbial reduction of (per)chlorate is a thermodynamically favorable redox process, also at high temperature.However, knowledge about (per)chlorate reduction at elevated temperatures is still scarce and restricted to members of the Firmicutes and the archaeon Archaeoglobus fulgidus.By analyzing the diversity and phylogenetic distribution of functional genes in (meta)genome databases and combining this knowledge with extrapolations to earlier-made physiological observations we speculate on the potential of (per)chlorate reduction in the subsurface and more precisely oil fields.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Microbiology, Wageningen University Wageningen, Netherlands.

ABSTRACT
The ability of microorganisms to thrive under oxygen-free conditions in subsurface environments relies on the enzymatic reduction of oxidized elements, such as sulfate, ferric iron, or CO2, coupled to the oxidation of inorganic or organic compounds. A broad phylogenetic and functional diversity of microorganisms from subsurface environments has been described using isolation-based and advanced molecular ecological techniques. The physiological groups reviewed here comprise iron-, manganese-, and nitrate-reducing microorganisms. In the context of recent findings also the potential of chlorate and perchlorate [jointly termed (per)chlorate] reduction in oil reservoirs will be discussed. Special attention is given to elevated temperatures that are predominant in the deep subsurface. Microbial reduction of (per)chlorate is a thermodynamically favorable redox process, also at high temperature. However, knowledge about (per)chlorate reduction at elevated temperatures is still scarce and restricted to members of the Firmicutes and the archaeon Archaeoglobus fulgidus. By analyzing the diversity and phylogenetic distribution of functional genes in (meta)genome databases and combining this knowledge with extrapolations to earlier-made physiological observations we speculate on the potential of (per)chlorate reduction in the subsurface and more precisely oil fields. In addition, the application of (per)chlorate for bioremediation, souring control, and microbial enhanced oil recovery are addressed.

No MeSH data available.


Related in: MedlinePlus

Complete (per)chlorate reduction by Archaeoglobus fulgidus VC-16 involving a biotic–abiotic reaction loop depending on sulfur. Biological processes are illustrated with green arrows indicating the direction of a respective reaction, whereas dashed red arrows stand for abiotic reactions. Chlorine and sulfur compounds relevant for the complete reduction of perchlorate are shown.
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Figure 1: Complete (per)chlorate reduction by Archaeoglobus fulgidus VC-16 involving a biotic–abiotic reaction loop depending on sulfur. Biological processes are illustrated with green arrows indicating the direction of a respective reaction, whereas dashed red arrows stand for abiotic reactions. Chlorine and sulfur compounds relevant for the complete reduction of perchlorate are shown.

Mentions: Archaeoglobus fulgidus appears to grow by (per)chlorate reduction without the involvement of a Cld. In the absence of a functional Cld an alternative mechanism may enable microorganisms to completely reduce (per)chlorate to chloride anions. In A. fulgidus the lack of a chlorite-disproportionating enzyme seems to be overcome by the abiotic scavenging of chlorite formed in the periplasm with naturally occurring or microbially generated sulfide (Liebensteiner et al., 2013). There is indirect evidence that this chemical reaction forms sulfur fractions of higher oxidation states and enables the continuous biological reduction of (per)chlorate. In turn oxidized sulfur compounds are partially reduced back and regenerate reducing power for an ongoing (per)chlorate reduction (Figure 1; Liebensteiner et al., 2013).


Microbial redox processes in deep subsurface environments and the potential application of (per)chlorate in oil reservoirs.

Liebensteiner MG, Tsesmetzis N, Stams AJ, Lomans BP - Front Microbiol (2014)

Complete (per)chlorate reduction by Archaeoglobus fulgidus VC-16 involving a biotic–abiotic reaction loop depending on sulfur. Biological processes are illustrated with green arrows indicating the direction of a respective reaction, whereas dashed red arrows stand for abiotic reactions. Chlorine and sulfur compounds relevant for the complete reduction of perchlorate are shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150442&req=5

Figure 1: Complete (per)chlorate reduction by Archaeoglobus fulgidus VC-16 involving a biotic–abiotic reaction loop depending on sulfur. Biological processes are illustrated with green arrows indicating the direction of a respective reaction, whereas dashed red arrows stand for abiotic reactions. Chlorine and sulfur compounds relevant for the complete reduction of perchlorate are shown.
Mentions: Archaeoglobus fulgidus appears to grow by (per)chlorate reduction without the involvement of a Cld. In the absence of a functional Cld an alternative mechanism may enable microorganisms to completely reduce (per)chlorate to chloride anions. In A. fulgidus the lack of a chlorite-disproportionating enzyme seems to be overcome by the abiotic scavenging of chlorite formed in the periplasm with naturally occurring or microbially generated sulfide (Liebensteiner et al., 2013). There is indirect evidence that this chemical reaction forms sulfur fractions of higher oxidation states and enables the continuous biological reduction of (per)chlorate. In turn oxidized sulfur compounds are partially reduced back and regenerate reducing power for an ongoing (per)chlorate reduction (Figure 1; Liebensteiner et al., 2013).

Bottom Line: Microbial reduction of (per)chlorate is a thermodynamically favorable redox process, also at high temperature.However, knowledge about (per)chlorate reduction at elevated temperatures is still scarce and restricted to members of the Firmicutes and the archaeon Archaeoglobus fulgidus.By analyzing the diversity and phylogenetic distribution of functional genes in (meta)genome databases and combining this knowledge with extrapolations to earlier-made physiological observations we speculate on the potential of (per)chlorate reduction in the subsurface and more precisely oil fields.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Microbiology, Wageningen University Wageningen, Netherlands.

ABSTRACT
The ability of microorganisms to thrive under oxygen-free conditions in subsurface environments relies on the enzymatic reduction of oxidized elements, such as sulfate, ferric iron, or CO2, coupled to the oxidation of inorganic or organic compounds. A broad phylogenetic and functional diversity of microorganisms from subsurface environments has been described using isolation-based and advanced molecular ecological techniques. The physiological groups reviewed here comprise iron-, manganese-, and nitrate-reducing microorganisms. In the context of recent findings also the potential of chlorate and perchlorate [jointly termed (per)chlorate] reduction in oil reservoirs will be discussed. Special attention is given to elevated temperatures that are predominant in the deep subsurface. Microbial reduction of (per)chlorate is a thermodynamically favorable redox process, also at high temperature. However, knowledge about (per)chlorate reduction at elevated temperatures is still scarce and restricted to members of the Firmicutes and the archaeon Archaeoglobus fulgidus. By analyzing the diversity and phylogenetic distribution of functional genes in (meta)genome databases and combining this knowledge with extrapolations to earlier-made physiological observations we speculate on the potential of (per)chlorate reduction in the subsurface and more precisely oil fields. In addition, the application of (per)chlorate for bioremediation, souring control, and microbial enhanced oil recovery are addressed.

No MeSH data available.


Related in: MedlinePlus