Electrical Interplay between Microorganisms and Iron-bearing Minerals

Iron-bearing minerals are widespread in soil and subsurface environment where they support microbial growth and metabolisms by serving as the terminal electron acceptors for microbial anaerobic respiration; the electron donors and energy sources for microbial autotrophic growth; the conductors for mediating electron transfer between microbial cells and the electron storage materials. Because microbial cell envelope is neither permeable to iron-bearing minerals nor electrical conductive, microorganisms have evolved capabilities to exchange electrons between the microbial cytoplasmic membrane and the minerals external to the microbial cells (i.e., microbial extracellular electron transfer). Microbial extracellular electron transfer differs fundamentally from the microbial electron transport chain for aerobic respiration. In this review, we discussed the molecular underpinnings of microbial extracellular electron transfer with iron-bearing minerals and applications of the related microorganisms in remediation of environmental contaminants, production of novel nano-materials, biomining and bioenergy production.