Dear Maria,

Bioremediation is a branch of biotechnology that uses natural or diverted biological mechanisms to address environmental problems. The biological agents can be simple organic molecules, such as DNA or antibodies, or live or dead organisms (bacteria, microalgae, fungi, higher algae and plants). Phytoremediation refers more specifically to using plants to decontaminate polluted soil, water, or air. Unlike organic pollutants such as PCBs, TNT, TCE, which can be metabolized by soil microorganisms and plant roots, radionuclides ─ like most heavy metals ─ cannot be degraded. Thus, bioremediation strategies for radionuclides will consist into: - stabilization/mineralization to reduce their bioavailability through a change in their redox state; - for soil, their extraction using the plant nutrition mechanisms; - for polluted solutions, their extraction using the “cation traps” properties of plant cell walls. Compared to physicochemical methods conventionally used to decontaminate soils but which lead to a sharp decline in fertility and productivity, bioremediation is considered a friendly environmental technology. An important advantage of this technique is its cost, much lower than traditional remediation techniques. By cons, bioremediation cannot be applied in an emergency, because processing times are spread over several years ─ even decades ─ depending on the degree of pollution. Therefore current research focuses on optimizing the processing time.

The challenges for bioremediation are: - Treatment times need to be improved; - Contamination must be moderate and not multiple; - Each case is specific, with many parameters (climate, soil ...); - The exploitation of biomass offers interesting potential; - Better co-ordination of research is desired (creation of databases); - It is necessary to develop spaces to demonstrate the potential of this technology.

In the nuclear context: these techniques are unattractive at the commercial level due to the uncertain nature of demand; They therefore require development on public funds. It is true that in France, in the present state Oof the legislation and the state of mind of the company regarding transgenesis, it is not possible to use genetically modified plants to decontaminate soil. Already, it is possible to make genetic modifications, using non-GM techniques, so that certain genes no longer express themselves, in particular those involved in the transfer of Cs into the plant. However, in the medium term, opinions may evolve through better information on what a GMO is, showing that plants intended for phytoremediation can be designed sterile and do not enter the food chain.

With my best regards

Prof. Bachir ACHOUR

Dear Bachir,

I thank you for the extended and effective contribution, I fully agree on your considerations on bioremediation. I just would like to specify that my question was not on bioremediation in general, but  on the new platform/technology for bioremediation proposed in the project.

With my best regards,

M.C. Tomei