Biofilm grown in sulfate medium
After Microbial Fuel Cells were operated for 7 days post inoculation plus 7 days of stability, anodic biofilm and supernatant DNA were sampled for genomic DNA extraction by using Powersoil DNA Isolation Kit (MO BIO Laboratories inc.), and DNA concentration was determined fluorometrically (Qubit 3.0). The V4 region of bacterial 16S rRNA gene was amplified  and submitted to MiSeq sequencing. The QIIME version 1.9.1 software package was used to filter readings and determine Operating Taxonomic Units (OTUs) and diversity anaylis.