MFC microbial communities profiles
DNA was isolated from the samples using FastDNA Spin Kit for Soil (MP Biomedicals, USA) including mechanical cell lysis using a FastPrep-24 5G homogenizer (MP Biomedicals, USA). Amplicon libraries were prepared using primers for the V4 region of 16S rRNA gene. PCR was performed on a StepOne Plus Real-Time instrument (Thermo Fisher Scientific, USA).