Isolation of Cultivable Bacteria Associated with the Root of Typha latifolia in a Constructed Wetland for the Removal of Diclofenac or Naproxen

In this work, we designed at the level of microscale, subsurface flow wetlands planted with Typha latifolia , and used to remove diclofenac and naproxen from solutions that contained them. The wetlands were operated for 105 days with a hydraulic residence time (TRH) of 5 days. In these conditions, the removal efficiencies for diclofenac and naproxen were 98.4% and 97.7%, respectively. Moreover, we identified cultivable bacteria associated with the roots of plants exposed to either diclofenac or naproxen. We obtained 898 isolates that clustered in 9 morphotypes from the roots of Typha latifolia exposed to diclofenac, and 563 isolates grouped in 7 morphotypes, in the case of naproxen. All isolates were identified by 16S ribosomal sequencing. The BLASTn analysis indicated that 16 morphotypes showed an identity higher than 95% with the 16S rDNA gene of bacteria belonging to the genus Pseudomonas . Biochemical characterization based on plant growth-promoting activities suggests that bacteria contribute to plant growth in the wetland conditions. The results indicate that Typha latifolia and bacteria associated with their roots removed diclofenac and naproxen in subsurface flow wetlands.