Impacts of Organic Molecule Chemistry on Microbial Metabolism
Anaerobic respiration in peatland soils
Peatland ecosystems are one of the largest natural sources of methane to the atmosphere. The production of methane in anaerobic, waterlogged peatland soils depends on the availability of electron acceptors that promote carbon dioxide as a by-product during respiration instead of methane. Dissolved organic molecules are used as electron donors during these pathways, but the impact of organic molecule chemistry on anaerobic respiration is not well understood.
To address this gap, our group is investigating the impact of organic molecule chemistry on carbon dioxide and methane production in boreal and tropical peatlands.
Collaboration with: Clarice Perryman (Stanford), PanAm Tropical Peat Project, Jessica Rush (PNNL), and Jason Keller (CMC)
Rush, Bowen et al (2026). Organic matter redox status predicts methane production in boreal peatland ecosystems. Ecosystems, 29 (85).
Rousseau* et al (2026). Microbial degradation of dissolved organic matter in anaerobic peatland soils with depth and redox potential. Georgia Tech School of Chemistry and Biochemistry Retreat, Atlanta GA.
Bog in boreal Alaska. Photo credit: J. Bowen
Mountain stream in Costa Rica. Photo credit: J. Bowen
Aerobic respiration in headwaters
Headwater streams and canals are known hotspots for carbon emissions to the atmosphere. The dissolved organic molecules exported from soils also undergo substantial degradation and respiration in these waters, but the impact of organic molecule chemistry on this respiration remains uncertain.
Ongoing work in our group focuses on the impact of organic molecule chemistry, characterized through high resolution and ultra-high resolution mass spectrometry, on aerobic respiration in headwater streams and canals in the tropics.
Sullivan, Bowen et al (2025). Seasonal and longitudinal dynamics of DOM within headwater streams of a tropical evergreen forest. Water Research, 281: 123668.
Bowen et al (2024). Canal networks regulate aquatic losses of carbon from degraded tropical peatlands. Nature Geoscience, 7, 213-218.