Ironing Out Early Microbial Metabolisms

Methane and nitrous oxide are potent greenhouse gases that contribute to modern climate change, and may have maintained habitable temperatures in ancient anoxic, iron-rich oceans when radiative heating was lower under the Faint Young Sun. 

I will present results from my Georgia Tech lab on the influence of iron speciation on methane production and microbial diversity in ferruginous sediments, and nitrous oxide production in ferruginous seawater (or "chemodenitrification"). 

These findings suggest that anoxic iron-rich seas emitted significantly higher atmospheric fluxes of these two greenhouse gases than modern anemic oceans, and that nitrous oxide, possibly arising from chemodenitrification, played a key role in the evolution of aerobic respiration.