Perchlorate is commonly used in industrial processes, fireworks, fertilizers, and the military and aerospace industries. Environmental perchlorate contamination can impact groundwater and soil. Perchlorate is highly mobile when released into the environment as it binds weakly to soil and is water soluble. Exposure to perchlorate has been associated with thyroid inhibition and impacts on fetal and infant health.
Perchlorate reductase catalyzes the initial, rate-limiting step in the anaerobic biodegradation of perchlorate. In some organisms, perchlorate reductase also catalyzes the reduction of chlorate to chlorite.
For more information on the molecular biological tools that can be used to assess the biodegradation of perchlorate, click the section of interest in the dropdown menu below. For guidance tailored to your current needs, contact our project success team at 865-573-8188 or [email protected].
Perchlorate binds weakly to soil, is extremely water soluble, and therefore is highly mobile when released into the environment. Fortunately, some bacteria are capable of using perchlorate as a growth supporting electron acceptor producing chloride ion as an end product. Biodegradation of perchlorate is dependent upon three main factors: availability of an electron donor (carbon and energy source), in situ redox conditions/competing electron acceptors, and the presence of organisms capable of perchlorate reduction. A CENSUS® qPCR assay is available to quantify perchlorate reductase genes to evaluate the potential for perchlorate biodegradation during MNA or in response to electron donor addition.
| TARGET | CODE | RELEVANCE / DATA INTERPRETATION |
|---|---|---|
| Perchlorate Reductase | pcrA | Quantifies the gene encoding perchlorate reductase which catalyzes the initial, rate-limiting step in the biodegradation of perchlorate. In some organisms, perchlorate reductase also catalyzes the reduction of chlorate to chlorite. |
| Perchlorate Reductase Sedimenticola spp. | pcrAS | Quantifies the gene encoding perchlorate reductase in Sedimenticola spp. which catalyzes the initial, rate-limiting step in the biodegradation of perchlorate as well as the reduction of chlorate to chlorite. |
| Denitrifying Bacteria | DNF | The DNF assay quantifies the two types of nitrite reductase genes (nirS and nirK, respectively) encoding the second key step in denitrification. While important in any situation where nitrate is serving as the dominant electron acceptor, quantification of denitrifying bacteria can be critical at perchlorate impacted sites. Many, but not all, perchlorate reducing bacteria will utilize nitrate as an electron acceptor potentially limiting perchlorate reduction. |
| REFERENCE |
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| Bender KS, Shang C, Chakraborty R, Belchik SM, Coates JD, Achenbach LA. Identification, characterization, and classification of genes encoding perchlorate reductase. Journal of Bacteriology. 2005;187:5090-6. https://doi.org/10.1128/jb.187.15.5090-5096.2005. |
| Braker G, Fesefeldt A, Witzel K. Development of PCR primer systems for amplification of nitrite reductase genes (nirK and nirS) To detect denitrifying bacteria in environmental samples. Applied and Environmental Microbiology. 1998;64:3769-75. https://doi.org/10.1128/AEM.64.10.3769-3775.1998. |
| Carlström CI, Loutey DE, Wang O, Engelbrektson A, Clark I, Lucas LN, Somasekhar PY, Coates JD. Phenotypic and genotypic description of Sedimenticola selenatireducens Strain CUZ, a marine (per)chlorate-respiring gammaproteobacterium, and its close relative the chlorate-respiring Sedimenticola Strain NSS. Applied and Environmental Microbiology. 2015;81:2717-26. https://doi.org/10.1128/AEM.03606-14. |
| Nozawa-Inoue M, Jien M, Yang K, Rolston DE, Hristova KR, Scow KM. Effect of nitrate, acetate, and hydrogen on native perchlorate-reducing microbial communities and their activity in vadose soil. FEMS Microbiology Ecology. 2011;76:278–288. https://doi.org/10.1111/j.1574-6941.2011.01045.x. |