Anaerobic treatment of groundwater co-contaminated by toluene and copper in a single chamber bioelectrochemical system
For library construction, PCR reactions were conducted in a total volume of 25 L, comprising Phusion Master Mix High Fidelity (Thermo Fisher Scientific, United States) and a final concentration of 0.5 M for the library adaptors along with 27F and 534R primers. All PCR reactions were performed in duplicate and subsequently pooled. The amplicon libraries were purified using Agencourt AMpureXP-beads (Beckman Coul-ter, United States), and their concentrations were measured using a Qubit 3.0 fluorom-eter (Thermo Fisher Scientific, United States). The purified libraries were equimolarly pooled and then diluted to 4 nM. A Phix control was added at a 10% ratio to the pooled libraries. Subsequently, the samples underwent paired-end sequencing (2  301 bp) on a MiSeq instrument (Illumina, United States) using a MiSeq Reagent kit v3, 600 cycles (Illumina, United States), following standard guidelines.