"

From 2011.igem.org

Revision as of 09:02, 6 July 2011 (view source) July (Talk | contribs) ← Older edit		Revision as of 09:24, 6 July 2011 (view source) Ahaag (Talk | contribs) Newer edit →
Line 51:		Line 51:
	<p class="contenu">		<p class="contenu">
	<span style="line-height : 2em">		<span style="line-height : 2em">
-	Environment and risks prevention issues are a major stake in our society. The Rhône-Alpes region has	+
-	understood that very early, especially through the importance of its chemical and nuclear activities.	+	The activity of modern nuclear power plants with pressurized water reactors generates
-	Industrial wastewater treatment permits their reuse in industrial use and improve their quality, enabling	+	radioactive effluents that contain among other things radioactive cobalt. The tubing of
-	compliance with discharge standards. Various processes are currently implemented to clear the wastewater	+	the cooling circuit is made of a steel alloy rich in stable cobalt (59Co). Undergoing neutron
-	from its contaminants (e.g. biological, membrane liquid-solid separation, physical, chemical and thermal	+	bombardment coming from the reactor, this stable cobalt changes into its radioactive isotope,
-	processes). One of them is bioremediation.	+	cobalt 60 (60Co).
-	It embraces processes that use microorganism metabolism to remove pollutants from a contaminated	+
-	environment. This rather new approach, the less expensive to put in place, is especially interesting in the	+
-	treatment of poorly contaminated effluents.	+
	<br/> <br/>		<br/> <br/>
-	However, these microorganisms must respect a few criteria: <br/>
-	- harmlessness towards the environment and human nature,  <br/>
-	- easiness of cultivation, <br/>
-	- tolerance to treated pollutant(s), <br/>
-	- ability to be separated from the treated effluent. <br/>
-	<br/>	+	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.
-	It is in compliance with this latter requirement that lies our project. In fact, the immobilization of bacteria on	+	<br/> <br/>
-	a solid support makes it possible to retrieve more easily the residue in treated wastewater.	+
-	The activity of modern nuclear power plants with pressurized water reactors generates radioactive	+	Controlled immobilization of radioactive cobalt is both an important sanitary and environmental
-	effluents that contain among other things radioactive cobalt.	+	issue, which we intend to solve with an innovative and economical response. A researcher
-	The tubing of the cooling circuit is made of a steel alloy rich in stable cobalt (59Co).	+	from the Lyon INSA-ENS team, Agnès Rodrigues, has recently constructed a E.coli strain able
-	Undergoing neutron bombardment coming from the reactor, this stable cobalt	+	to eliminate 85% of radioactive cobalt (60Co), initially present as traces in a simulated nuclear
-	changes into its radioactive isotope, cobalt 60 (60Co).	+	effluent made up of a mix of heavy metals, in only twice one-hour incubation (Appl Microbio
-	The capture of this metal is interesting on a sanitary point of view, because it	+	Biotechnol 2009 81:571- 578).
-	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.	+
	<br/> <br/>		<br/> <br/>
-	Controlled immobilization of radioactive cobalt is both an important sanitary and environmental issue, which	+
-	we intend to solve with an innovative and economical response.	+	The process that was developed by Agnès Rodrigues’ 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.
		+
		+	<br/> <br/>
		+
		+	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.
		+
		+	<br/> <br/>
		+
		+	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.
		+
		+	<br/>
	</span>		</span>

---

Revision as of 09:24, 6 July 2011

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 Rodrigues’ 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.