Extracellular electron transfer

Results from several laboratories indicate that extracellular electron tran sfer may be a general mechanism whereby microoorganisms generate energy for cell growth and/or maintenance. Specifically, bacteria can use redox-activ e organic small molecules, generated outside or inside the cells, to shuttl e electrons between reduced and oxidized compounds. Electron shuttling has now been reported for several different bacterial species, and exchanges of shuttling compounds may even syntrophically link diverse organisms in natu re. Biofilm systems in both geological and clinical settings are likely to be important environments for metabolisms that employ extracellular electro n transfer. Both structural and functional analyses suggest that electron s huttles and some virulence factors may be related to one another.