Evaluation of the biological treatment of a real contaminated groundwater through reductive dechlorination biostimulation.
DNA was extracted from the filters using the DNeasy PowerSoil Pro Kit (Qiagen, Italy), following the manufacturers instructions. Purified DNA from each sample was eluted in 50 L of sterile Milli-Q water and used for microbial characterization through 16S rRNA gene amplicon sequencing. Amplicon libraries were prepared and sequenced on a MiSeq instrument (Illumina, San Diego, CA, USA) using the MiSeq Reagent Kit v3, 600 cycles (Illumina, USA), following standard protocols [Matturro et al., 2021]. Bioinformatic analysis included a read quality check with FastQC software (v 0.11.7), followed by quality filtering and analysis using QIIME2 version 2018.2 [Boylen et al., 2018]. The DADA2 algorithm was employed to denoise paired-end sequences, dereplicate them, filter chimeras using the consensus method, and resolve amplicon sequence variants (ASVs) [Callahan et al., 2016]. Taxonomy was assigned using the Silva 13299 database (release December 2017, https://www.arb-silva.de/documentation/release-132/) [Quast et al., 2013].