Bioelectrochemical systems have been shown to treat low-value biorefinery streams while recovering energy, however, low current densities and anode conversion efficiencies (ACE) limit their application. A bioanode was developed via enrichment of electroactive biofilm under fed-batch and continuous feeding conditions using corn stover-derived waste stream. The continuously-fed MFC exhibited a current density of 5.8 � 0.06 A/m<
sup>
2<
/sup>
and an ACE of 39% � 4. The fed-batch MFC achieved a similar current density and an ACE of 19.2%, however, its performance dropped after 36 days of operation to 1.1 A/m<
sup>
2<
/sup>
and 0.5%, respectively. In comparison, the ACE of the continuously-fed MFC remained stable achieving an ACE of 30% � 3 after 48 days of operation. An MFC treating a biorefinery stream post fuel separation achieved a current density of 10.7 � 0.1 A/m<
sup>
2<
/sup>
and an ACE of 57% � 9 at an organic loading of 12.5 g COD/L-day. Characterization of the microbial communities indicate higher abundance of <
i>
Firmicutes<
/i>
and <
i>
Proteobacteria<
/i>
and lower abundance of <
i>
Bacteriodetes<
/i>
and a higher level of Geobacter spp. (1.4% vs. 0.2%) in continuously-fed MFC vs. fed-batch MFC. Finally, the results demonstrate that limiting substrate to the equivalent maximum current that the anode can generate, maintains MFC performance over a long term for high strength wastewaters, such as those generated in the biorefinery.