A recent report in "Cell" shows that Shewanella oneidensis can be converted into little generators. Researchers fed a chemical additive (DSFO+), that contains iron in its core, to modify the cell membrane of Shewanella oneidensis to be able to efficiently conduct electricity. While the amount of electricity produced is minimal, the thought is to give bacteria at waste water treatment plants multiple jobs: produce electricity while cleaning wastewater. The electricity produced might offset some of the costs of wastewater treatment.
Source: Kirchhofer and Rengert et al.: "A Ferrocene-Based Conjugated Oligoelectrolyte Catalyzes Bacterial Electrode Respiration" Chem. Vol 2 Issue 2, March 2017