Table 1: Basic characteristics of some common electricigens.

Electricigens	Aerobic/anaerobic	Gram staining	Electron transfer
E. coli	facultative anaerobic	negative	direct
Shewanella	anaerobic	negative	indirect
E. faecalis	facultative anaerobic	positive	direct
Geobacter	anaerobic	positive	direct
SRB	anaerobic	negative	direct
R. ferrireducens	facultative anaerobic	negative	direct
Saccharomyces cerevisiae	anaerobic	/	direct
Pseudomonas aeruginosa	aerobic	negative	direct