Fig. 2From: Meta-proteomic analysis of protein expression distinctive to electricity-generating biofilm communities in air-cathode microbial fuel cellsRepresentative current density of air–cathode MFCs that were compared with proteomics. Current density rose due to partial or complete replacement of medium. Dashed arrows represent full batch replacement of all medium in the MFC. Solid arrows indicate harvest point. Early anodes (red) were harvested 130.3 ± 9.1 h after inoculation, while intermediate anodes (blue) were harvested 523.7 ± 35.0 h after inoculation. Mature MFC performance data are shown in Additional file 2: Figure S3Back to article page