The role of iron oxides and natural organic matter in interspecies electron transfer during methanogenesis
Article
Wang, S, Guo, Y, Yang, P et al. (2025). The role of iron oxides and natural organic matter in interspecies electron transfer during methanogenesis
. 44(9), 3149-3159. 10.7524/j.issn.0254-6108.2024120502
Wang, S, Guo, Y, Yang, P et al. (2025). The role of iron oxides and natural organic matter in interspecies electron transfer during methanogenesis
. 44(9), 3149-3159. 10.7524/j.issn.0254-6108.2024120502
Methane (CH4) is a major greenhouse gas contributing to global warming. Approximate 60% of global CH4 emissions originate from anaerobic methanogens, which primarily produce CH4 through interspecies electron transfer (IET) in cooperation with other microorganisms. Iron oxides and natural organic matter (NOM) are crucial environmental mediators regulating microbial IET, but their roles in CH4 production remain controversial. This study investigated the effects of different types of iron oxides (magnetite and hematite) and NOM (peat soil organic matter and anthraquinone-2,6-disulfonate, AQDS) on IET and CH4 production by constructing a co-culture system of Geobacter sulfurreducens and Methanosarcina barkeri. The results demonstrated that iron oxides could enhance CH4 production through both electron shuttling and conductive properties. Although the model quinone molecule AQDS inhibited CH4 production via an electron competition mechanism, peat soil organic matter (with equivalent quinone content) significantly promoted CH4 production, suggesting that NOM may have additional mechanisms that facilitate CH4 production during IET. This provides new insights into understanding and controlling methane emissions in anoxic environments.
