In the recent article by Chaudhuri and Lovley, a fuel cell is described in which a microorganism, Rhodoferax ferrireducens, is used to oxidize glucose to carbon dioxide at neutral pH. This reaction occurs via direct bioelectrocatalysis: the microorganism uses the anode itself as the terminal oxidant to which liberated electrons are transferred, and does so with 83% efficiency. These findings are significant because they demonstrate a new approach for harvesting energy from the environment using microorganisms.