2026/05/29 by Zhengyu Wu, Mengqi Li, C Liu +5 · 1 voice
Earth and Planetary Sciences · Environmental Science · #Arsenic contamination and mitigation #CO2 Sequestration and Geologic Interactions #Coal and Its By-products
paper · pdf · doi:10.3389/fmicb.2026.1818899
openalex publication_date 2026/05/29 · openalex created_date 2026/05/30 · openalex updated_date 2026/07/23
Microorganisms play a pivotal role in driving both arsenic (As) biogeochemical cycling and the significantly anomalous greenhouse gas (GHG) levels frequently observed in naturally high-As environments; however, the mechanistic coupling between these two processes remains insufficiently characterized. This review presents a comprehensive synthesis of the interplay between microbial transformations of As (oxidation, reduction, and methylation/demethylation) and three major greenhouse gases—CH 4 , N 2 O, and CO 2 . We first summarize the key microbial taxa and molecular mechanisms governing As redox transformation, CH 4 oxidation and methanogenesis, autotrophic CO 2 fixation, and denitrification-driven N 2 O production. Building on this mechanistic foundation, we elucidate four experimentally and environmentally validated linkages, including (1) direct methane oxidation coupled with As(V) reduction (AOM-AsR), highlighting the molecular mechanisms that drive arsenic mobilization during anaerobic/aerobic methane oxidation and their environmental implications; (2) direct As(III) oxidation coupled with denitrification, linking the As and nitrogen cycles, wherein incomplete denitrification acts as a significant biological source of N 2 O; (3) direct As(III) oxidation driving autotrophic carbon fixation, offering a potential regional net carbon sink across diverse environments; and (4) indirect feedbacks mediated by As methylation/demethylation and geochemical mobilization, where detoxification-driven shifts in As speciation and local toxicity indirectly regulate downstream methanogenic communities and CH 4 fluxes. Finally, we identify critical knowledge gaps regarding specific molecular pathways and multi-element interactions underlying these microbially driven couplings, and propose future research directions centered on deeper mechanistic elucidation. Overall, this review provides a robust scientific foundation for understanding the complex interplay between As biogeochemistry and GHG dynamics in specific environmental niches.