Fig. 4

Relative abundances of genera associated with OTUs from 16S rRNA gene sequencing or GhostKOALA protein categorization. Relative abundances are from OTUs of early anode biofilms (dark red), GhostKOALA of early anode biofilms (light red), OTUs of intermediate biofilms (dark blue), and GhostKOALA of intermediate anode biofilms (light blue). Error bars represent standard deviations across samples from three independent biological replicate MFC anode biofilms. Only genera with relative abundance greater than 0.5% for at least one sample type are shown; a table of full relative abundance values is available in Additional file 3: Table S6