Biodechlord search for evidence for microbial degradation of chlordecone in French West Indies contaminated soils
Biodechlord : à la recherche de traces de dégradation microbienne du chlordécone dans les sols contaminés des Antilles
Résumé
Objectives: Chlordecone was intensively used in the French West Indies (FWI) to control the banana weewil. Recent surveys showed that arable soils cropped with banana, representing up to 20,000 ha, are contaminated this insecticide with concentrations ranging between 0.2 and 37.4 mg kg−1. Chlordecone was classified as a persistent organic pollutant in May 2009. It is not only contaminating soil resources but also water resources where it is often detected. This insecticide is bioaccumulated in different plant and animals thereby contaminating the food chain causing an important human health. This contaminant is recalcitrant to biodegradation and very few information is available on microbial degradation of chlordecone in soils and almost nothing in the soil of the French West Indies. In this context, the program of research Biodechlord funded by the INRA (National Institute of Agronomical Research) in the framework the National Plan for Chlordecone (PNAC), was aiming at searching for traces of chlordecone microbial degradation in FWI soils. This project relied on a multidisciplinary approach developed by a broad scientific consortium involving researchers from CEA, Ecole Centrale Lyon, INRA, Irstea, Strasbourg and Lyon Universities. This program was made of several approaches consisting in (i) in silico analyses aiming at (ia) classifying chlordecone and its known metabolites using the QSAR Typol in order to define hypotheses on possible degradation pathways (ib) searching for microbial genes coding deshalogenases in genomic databank that could be used to dechlorinate chlordecone; (ii) chemical analyses aiming at (iia) optimizing approaches to quantify chlordecone and its main metabolites in soils, (iib) identify chemical processes (photodegradation and photocatalysis) that can be used to transform chlordecone; (iii) search for microbes tolerant to chlordecone able to grow on it under aerobic or anaerobic conditions; (iv) characterize the impact of chlordecone on soil microbial communities using soil metagenomics. A synthesis of the work carried out in the framework of Biodechlord will be presented. Innovative nature of the proposed topic: Very little information is available on the processes involved in the transformation of chlordecone in the contaminated soils of the French West Indies. Regarding to the environmental and the human health problems caused by the pollutant there is an urgent to document this question. The Biodechlord project proposed to search for chemical and microbial processes possibly involved in chlordecone transformation in the contaminated soils of the French West Indies. Among the results accumulated by the Biodechlord project, results about the isolation of microbial cultures tolerant to chlordecone will be highlighted.
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers produits par l'(les) auteur(s)