34 investigation has properties in fuel cells that are signiﬁcantly different than previously studied organisms (Bond et al., 2002; Bond & Lovley, 2003, 2005; Chaudhuri & Lovley, 2003; Holmes et al., 2004a, b; Bifﬁnger et al., 2007). The ﬁnding that S. oneidensis offers yet another variation on growth on electrodes emphasizes the need to further evaluate the diversity of microorganisms capable of respiration with electrodes in order to realize the full range of microbial strategies that can be potentially exploited for the optimiza- tion of microbial fuel cells. Acknowledgement This research was supported by the Ofﬁce of Naval Research Award No. N00014-06-1-0802 and the Ofﬁce of Science (BER), US Department of Energy, Grant No. DE-FC02- 02ER63446. 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