Electromethanogenesis at medium-low temperatures: Impact on performance and sources of variability

In this study we aimed to understand the impact of medium–low temperatures on two main steps that usually comprise electromethanogenesis (EM) process: electrothrophic hydrogenesis and hydrogenothrophic methanogenesis. Results revealed pure CO2 could effectively be converted into a high-purity biogas (∼90:10 CH4/CO2) at 30 °C. However, when temperature was reduced 15 °C, methane richness greatly decreased (∼40:60 CH4/CO2). This deterioration in performance mostly attributed decline methanogenic activity (represented mainly by Methanobacterium Methanobrevibacter). contrast, hydrogenic (mostly Desulfomicrobium) did not suffer any significant decay. also seemed indicate methanogenesis, rather than hydrogenesis, is source variability EM. Increasing again °C restored previous performance, which highlights resilience EM wide fluctuations (from back °C).