MICROBIAL REDOX REACTIONS MEDIATED BY HUMUS AND STRUCTURALLY RELATED QUINONES

摘要

Humic substances are natural organic compounds recalcitrant to biodegradation. Their structure is rich in quinone moieties that provides redox activity of humics. The evidence provided in this review indicates that quinonoid substructures of humics can play a number of significant roles in the anaerobic (bio)transformation of a wide variety of organic and inorganic compounds, including priority pollutants. Quinones can support the anaerobic microbial oxidation of different organic compounds by serving as terminal electron acceptors. Quinones, once being reduced, can also channel electrons to several distinct contaminants by acting as redox mediators. Reduced quinones can also serve as electron-donating substrates to bacteria supporting their growth.