title: OMW_End 800_Bristle_Microbial Community
design: DNA extraction was performed from (i) the MEC electrolyte and the biofilm grown on the anode bristles after the acclimation, before the start of the H2 production experiment, and (ii) from the biofilms grown on the anode bristles at the end of the two experimental phases at different cell voltages (800 and 600 mV). The microbial community grown on the cathode was sampled only after the 600 mV polarization phase to avoid potential cathode damage, as the 600 mV polarization had been applied immediately after 800 mV voltage application as described in Section 2.2.DNA was extracted using the DNeasy PowerSoil Kit (Qiagen, Germany) according to manufacturer instructions after an initial step of thermal treatment (5 cycles of 10 min at -20C and 10 min at 65C). The yield and purity (A260/A280 and A260/A230) of the extracted DNA was quantified on a Nanodrop 1000 spectrophotometer (Thermo Fisher Scientific) while eventual fragmentation was determined through gel electrophoresis 0.8% (w/v) 1TAE agarose gels. DNA was stored at -80C until analyses.Multi-Amplicon Sequencing and bioinformatics was performed as per Maretto et al. (2022).