Networks of Dissolved Organic Matter and Organo-Mineral Associations Stimulate Electron Transfer over Centimeter Distances

• DOI: 10.1021/acs.estlett.3c00172
• Publication Date: 2023-05-22T12:15:41Z
• Authors: Yuge Bai; Tianran Sun; Muammar Mansor; Prachi Joshi; Yiling Zhuang; Stefan B. Haderlein; Stefan Fischer; Kurt O. Konhauser; Daniel S. Alessi; Andreas Kappler
• Keywords: Biogeochemical Cycle; Carbon fibers

Natural organic matter (NOM) dominated electron transfer has been widely studied in wetlands, freshwater sediments, and peatlands, which a diffusion-electron hopping mechanism consisting of dissolved (DOM) particulate (POM) was found to mediate over centimeter (cm) distances. However, it remains unclear whether such long-distance also occurs when NOM is associated with minerals, form organo-mineral associations (OMAs) thus are less mobile accessible. In this study, we investigated the roles DOM OMAs transferring electrons by performing series microbial Fe(III)-mineral reduction experiments 2 cm distance. We that significant only occurred both were present. Generally, observed positive correlation between relative proportion extent Fe(III) mineral reduction. varying showed stronger effect on compared OMAs, indicating played more critical role network. Our findings shed new light how carbon facilitates iron transformation biogeochemical cycling nutrients contaminants forest soil systems.