Intérêt des champignons telluriques dans des processus de bioremédiation de sols pollués par des hydrocarbures aromatiques polycycliques
Résumé
Polycyclic aromatic hydrocarbons (PAH) are ubiquitous and persistent pollutants that cause great environmental and health concern, because of their genotoxic and carcinogenic properties. Among the processes whereby these compounds are removed from the environment, microbial degradation plays a major role in the remediation of contaminated sites. Numerous biodegradation studies have been done on fungi, especially on various white rot fungi such as Phanerochaete chrysosporium, under in vitro and in vivo conditions. The installation of these foreign fungi in non-sterile soils is quite hazardous due to intense negative interactions with indigenous soil microorganisms. Optimising the degradation of PAH by the indigenous microbial community that had already been adapted to the soil habitat would be probably more economical and equally efficient. In our studies, we focused therefore on the ability of telluric fungi for PAH field bioremediation processes. In particular, we isolated a Deuteromycete fungus Fusarium solani that was able to grow in liquid medium with benzo[a]pyrene as sole carbon source and to mineralise this PAH. In a batch fermentor, [7,10-14C]benz[a]pyrene mineralization occurred rapidly at early stages of fermentation (15 hr) during the germination of fungal spores and was not a continuous process as mineralization occurred in a biphasic pattern. Moreover, Fusarium solani showed an average rate of mineralization about 65 μg/g dry weight/day within 11 days of incubation, comparable as mineralization rate obtained with a white rot fungus Phanerochaete chrysosporium.
Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants ubiquistes et persistants dont certains posent de réels problèmes pour l'environnement et la santé publique. Parmi les différentes techniques de réhabilitation actuellement disponibles, la bioremédiation s'est développée lors de ces dernières décades comme une alternative rentable et prometteuse. De nombreuses études ont mis en évidence l'aptitude des champignons de type lignolytique à dégrader les HAP. Cependant, l'origine non tellurique de ces champignons les rend peu compétitifs par rapport à la microflore endogène du sol. Dans une optique de bioremédiation, nous avons conduit des travaux de recherche afin d'utiliser le potentiel biotechnologique de champignons telluriques et en particulier de Fusarium solani.
Domaines
Ingénierie de l'environnementOrigine | Fichiers produits par l'(les) auteur(s) |
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