Metagenome
The DNA samples, obtained from the wastewater influent and those purified from the plant rhizospheres, were used to study the microbial communities. In particular, the hypervariable region V3-V4 of the bacterial 16S rRNA gene was amplified, in triplicate, with 341F (5-CCTACGGGRSGCAGCAG-3) and 909R (5-TTTCAGYCTTGCGRCCGTAC-3) specific primers. The thermal profile consisted in: an initial step of denaturation at 95C for 3 min, followed by 40 cycles of denaturation at 95C for 1 min, annealing at 58 C for 1 min and elongation at 72C for 1 min, with an additional final elongation step at 72C for 5 min. The fungal ITS2 region was amplified using the ITS3 (5-GCATCGATGAAGAACGCAGC) and ITS4 (5-TCCTCCGCTTATTGATATGC-3) primers adopting the same thermal profile as described above, but with an annealing temperature of 55 C. The amplicon libraries were set up and sequenced by means NGS (Genomics4life company, Baronissi, SA, Italy).