Redox Interactions of Organohalide-Respiring Bacteria (OHRB) with Solid-State Electrodes: Principles and Perspectives of Microbial Electrochemical Remediation

Recent studies have revealed that a number of organohalide-respiring bacteria (OHRB) are capable to establish redox interactions with solid-state electrodes by using them as direct or indirect electron donors in their energy metabolism. Although the biochemical, ecological, and evolutionary significance of electron transfer capabilities in OHRB remain largely unknown, they are increasingly being considered for bioremediation applications. In principle, bioelectrochemical remediation systems which use insoluble electrodes to drive the microbial reduction of chlorinated compounds offer numerous advantages compared to conventional approaches, such as the possibility to fine-tune the rate of electron delivery and consumption, avoid injection of chemicals to the subsurface environment and ultimately gain a more direct control over the biodegradation reactions taking place at the electrodes. In spite of that, however, the technology is still in its infancy and further research and extensive field testing is needed to prove its actual potential for site remediation.