查看文章

Interspecies electron transfer is common in methanogenic consortia. Syntrophic partners cooperate by transferring electrons from one species to the other using H₂, formate or other pathways, and maintaining H₂ at low levels, so that the overall reactions are thermodynamically more favorable. Here we reviewed the mechanisms of interspecies electron transfer involved in methanogenic consortia, i.e., interspecies H₂ transfer, interspecies formate transfer, and direct interspecies electron transfer (DIET) via pili, and/or outer membrane cytochromes. Although the relative importance of different mechanisms is uncertain, one mechanism may predominate under specific circumstances. Interspecies electron transfer is a probable mechanism in anaerobic granules formed in upflow anaerobic sludge bed (UASB) reactors, though direct evidence is limited. Studies of interspecies electron transfer without extracellular shuttles …