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Team:Lyon-INSA-ENS/Project/Context
From 2011.igem.org
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The activity of modern nuclear power plants with pressurized water reactors generates | The activity of modern nuclear power plants with pressurized water reactors generates | ||
| - | radioactive effluents that contain among other things radioactive cobalt. The tubing of | + | radioactive effluents that contain among other things <b> radioactive cobalt </b>. The tubing of |
| - | the cooling circuit is made of a steel alloy rich in stable cobalt (<sup>59</sup>Co). Undergoing neutron | + | the cooling circuit is made of <b> a steel alloy rich in stable cobalt (<sup>59</sup>Co)</b>. Undergoing neutron |
| - | bombardment coming from the reactor, this stable cobalt changes into its radioactive isotope, | + | bombardment coming from the reactor, <b>this stable cobalt changes into its radioactive isotope</b>, |
cobalt 60 (<sup>60</sup>Co). | cobalt 60 (<sup>60</sup>Co). | ||
<br/><br/> | <br/><br/> | ||
| - | The capture of this metal is interesting on a sanitary point of view, because it represents | + | The capture of this metal is interesting on a <b>sanitary</b> point of view, because it represents |
| - | a danger under both its radioactive and stable forms (carcinogenic). It also represents an | + | <b>a danger under both its radioactive and stable forms (carcinogenic)</b>. It also represents an |
| - | advantage on an environmental point of view, in order to avoid contamination of waters, soil | + | advantage on an <b>environmental</b> point of view, in order to avoid contamination of waters, soil |
| - | and groundwater. Even with a short half life, cobalt 60 emits high intensity gamma rays, and | + | and groundwater. Even with a short half life, cobalt 60 emits <b>high intensity gamma rays</b>, and |
decays to nickel, which is stable but polluting. | decays to nickel, which is stable but polluting. | ||
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Controlled immobilization of radioactive cobalt is both an important sanitary and environmental | Controlled immobilization of radioactive cobalt is both an important sanitary and environmental | ||
| - | issue, which we intend to solve with an innovative and economical response. A researcher | + | issue, which we intend to solve with <b>an innovative and economical response</b>. A researcher |
from the Lyon INSA-ENS team, Agnès Rodrigues, has recently constructed a E.coli strain able | from the Lyon INSA-ENS team, Agnès Rodrigues, has recently constructed a E.coli strain able | ||
| - | to eliminate 85% of radioactive cobalt (<sup>60</sup>Co), initially present as traces in a simulated nuclear | + | to <b>eliminate 85% of radioactive cobalt (<sup>60</sup>Co)</b>, initially present as traces in a simulated nuclear |
effluent made up of a mix of heavy metals, in only twice one-hour incubation (Appl Microbio | effluent made up of a mix of heavy metals, in only twice one-hour incubation (Appl Microbio | ||
Biotechnol 2009 81:571- 578). | Biotechnol 2009 81:571- 578). | ||
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The process that was developed by Agnès Rodrigue’s team ensures the decontamination | The process that was developed by Agnès Rodrigue’s team ensures the decontamination | ||
| - | of cobalt up to 0,5 ppm (8 nM in 100 000L) with only 4kg of bacteria as against 50kg with | + | of cobalt <b>up to 0,5 ppm</b> (8 nM in 100 000L) with <b>only 4kg of bacteria</b> as against 50kg with |
an unmodified bacterium or 8,000kg of an ion-exchange polymer. This kind of process with | an unmodified bacterium or 8,000kg of an ion-exchange polymer. This kind of process with | ||
modified bacteria will be a good value because the production of bacteria in a bioreactor is | modified bacteria will be a good value because the production of bacteria in a bioreactor is | ||
rather economical. However, one issue remained unsolved at the end of this study, that is the | rather economical. However, one issue remained unsolved at the end of this study, that is the | ||
| - | separation of cobalt-fixing bacteria. | + | <b>separation of cobalt-fixing bacteria</b>. |
<br/><br/> | <br/><br/> | ||
The first objective of our project is, with the most recent genetic engineering techniques, to | The first objective of our project is, with the most recent genetic engineering techniques, to | ||
| - | induce the fixation of optimized bacteria for the cobalt capture and retention in response to the | + | <b>induce the fixation </b> of optimized bacteria for the cobalt capture and retention in response to the |
presence of contaminants in the effluent to be treated. | presence of contaminants in the effluent to be treated. | ||
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A second objective aims to develop a system to construct custom-built “biofilm inducible” | A second objective aims to develop a system to construct custom-built “biofilm inducible” | ||
| - | strains. Our goal is to construct captors able to launch the formation of biofilm in response to | + | strains. Our goal is to construct <b>captors able to launch the formation of biofilm in response to |
| - | the presence of various radioactive or not pollutants, and to offer more efficient and cheaper | + | the presence of various radioactive or not pollutants</b>, and to offer <b>more efficient</b> and <b>cheaper</b> |
bioremediation processes. | bioremediation processes. | ||
<br/><br/> | <br/><br/> | ||
| - | To conclude, our objective is to deposit a part able to make any strains inducible to cobalt. In presence of this element, strains will become adherent and will form biofilm thanks to their curli. | + | To conclude, our objective is to deposit <b>a part able to make any strains inducible to cobalt</b>. In presence of this element, strains will become adherent and will form biofilm thanks to their curli. |
<br/><br/><br/> | <br/><br/><br/> | ||
Revision as of 09:44, 13 September 2011
A project anchored at the heart of current concerns
The activity of modern nuclear power plants with pressurized water reactors generates
radioactive effluents that contain among other things radioactive cobalt . The tubing of
the cooling circuit is made of a steel alloy rich in stable cobalt (59Co). Undergoing neutron
bombardment coming from the reactor, this stable cobalt changes into its radioactive isotope,
cobalt 60 (60Co).
The capture of this metal is interesting on a sanitary point of view, because it represents
a danger under both its radioactive and stable forms (carcinogenic). It also represents an
advantage on an environmental point of view, in order to avoid contamination of waters, soil
and groundwater. Even with a short half life, cobalt 60 emits high intensity gamma rays, and
decays to nickel, which is stable but polluting.
Controlled immobilization of radioactive cobalt is both an important sanitary and environmental
issue, which we intend to solve with an innovative and economical response. A researcher
from the Lyon INSA-ENS team, Agnès Rodrigues, has recently constructed a E.coli strain able
to eliminate 85% of radioactive cobalt (60Co), initially present as traces in a simulated nuclear
effluent made up of a mix of heavy metals, in only twice one-hour incubation (Appl Microbio
Biotechnol 2009 81:571- 578).
The process that was developed by Agnès Rodrigue’s team ensures the decontamination
of cobalt up to 0,5 ppm (8 nM in 100 000L) with only 4kg of bacteria as against 50kg with
an unmodified bacterium or 8,000kg of an ion-exchange polymer. This kind of process with
modified bacteria will be a good value because the production of bacteria in a bioreactor is
rather economical. However, one issue remained unsolved at the end of this study, that is the
separation of cobalt-fixing bacteria.
The first objective of our project is, with the most recent genetic engineering techniques, to
induce the fixation of optimized bacteria for the cobalt capture and retention in response to the
presence of contaminants in the effluent to be treated.
A second objective aims to develop a system to construct custom-built “biofilm inducible”
strains. Our goal is to construct captors able to launch the formation of biofilm in response to
the presence of various radioactive or not pollutants, and to offer more efficient and cheaper
bioremediation processes.
To conclude, our objective is to deposit a part able to make any strains inducible to cobalt. In presence of this element, strains will become adherent and will form biofilm thanks to their curli.
