关键词: 微生物电化学反应器, 厌氧生物还原, 环境污染物, 生物阴极, 电驱动

Abstract: The ability of some microorganisms to accept electrons from an electrode for the reduction of terminal electron acceptors in anaerobic environments has attracted growing interest on the electric field-stimulated biological reduction technology, which may open new possibility for the sustainable wastewater treatment and bioremediation in the field of environmental engineering. Here, we reviewed the extracellular electron transfer mechanism which is thought to play a key role in determining the feasibility and efficiency for the anaerobic biotransformation of environmental pollutants. Possible mechanisms that may be involved in bioelectrochemical reactors (BERs) with biocathodes include indirect electron transfer via hydrogen generated from water electrolysis or via a soluble mediator that can be artificial or secreted from bacteria, and direct transfer from the cathode to the microorganism. Direct electron transfer has many advantages over indirect electron transfer because it avoids the loss of electrons to unused mediators and planktonic cells, and thus allows significant reduction in power requirements. In addition, potential application examples of anaerobic biotransformation of environmental pollutants, known as autotrophic denitrification, microbial reductive dechlorination, heavy-metal bioreduction, CO2 bioreduction, sulfate bioreduction stimulated by an applied electric field were also reviewed. Finally, we proposed that more efforts should be made on developing new strategies for growing cathode biofilms and further disclosing biochemical mechanisms for the cathode extracellular electron transfer, in order to achieve the promising applications of this biotechnology.

Key words: bioelectrochemical reactors, anaerobic bioreduction, environmental pollutants, biocathode, electric filed stimulation