Fungal biodegradation of the N-nitrosodimethylamine precursors venlafaxine and O-desmethylvenlafaxine in water

Antidepressant drugs such as Venlafaxine (VFX) and O-desmethylvenlafaxine (ODMVFX) are emerging contaminants that are commonly detected in aquatic environments, since conventional wastewater treatment plants are unable to completely remove them. They can be precursors of hazardous by-products, such as the carcinogenic N-nitrosodimethylamine (NDMA), generated upon water chlorination, as they contain the dimethylamino moiety, necessary for the formation of NDMA. In this study, the capability of three white rot fungi (Trametes versicolor, Ganoderma lucidum and Pleurotus ostreatus) to remove both antidepressants from water and to decrease NDMA formation potential was investigated. Furthermore, transformation by-products (TPs) generated along the treatment process were elucidated and also correlated with their NDMA formation potential. Very promising results were obtained for T. versicolor and G. lucidum, both being able to remove up to 100% of ODMVFX. In the case of VFX, which is very recalcitrant to conventional wastewater treatment, a 70% of removal was achieved by T. versicolor, along with a reduction in NDMA formation potential, thus decreasing the associated problems for human health and the environment. However, the NDMA formation potential remained practically constant during treatment with G. lucidum despite of the equally high VFX removal (70%). This difference was attributed to the generation of different TPs during both fungal treatments. For example, G. lucidum generated more ODMVFX, which actually has a higher NDMA formation potential than the parent compound itself. © 2018 Elsevier Ltd

This work was supported by the Spanish Ministry of Economy, Industry and Competitiveness (project CTQ2010-21776-C02 and CTM2013-48545-C2), co-financed by the European Union through the European Regional Development Fund (ERDF) and supported by the Generalitat de Catalunya (Consolidated Research Groups: Catalan Institute for water Research 2014 SGR 291 and 2014 SGR 476). The Department of Chemical, Biological and Environmental Engineering of the Autonomous University of Barcelona (UAB) is member of the Xarxa de Referència en Biotecnologia de la Generalitat de Catalunya. Castellet-Rovira, F. acknowledges a predoctoral grant from UAB. Dr. SRM acknowledges her Ramón y Cajal fellowship (RyC-2014-16707) and Dr. MJF acknowledges her Ramón y Cajal fellowship (RyC-2015-17108) from the Spanish Ministry of Economy, Industry and Competitiveness. Dr. MJF acknowledges the European Commission for funding project 623711 under the FP7-PEOPLE-2013-IIF - Marie Curie Action: “International Incoming Fellowships”. Adrián Jaén-Gil acknowledge their PhD scholarship from AGAUR (2017FI_B 00778). Pleurotus ostreatus (NCBI KJ020935) cultures were kindly provided by Laura Palli.

Peer reviewed