Capture of methane by fungi: Evidence from laboratory-scale biofilter and chromatographic isotherm studies

Livestock production accounts for a third of total U.S. anthropogenic methane (CH₄) emissions. Mitigating these greenhouse gas (GHG) emissions is central to efforts aimed at curbing near-term climate change, but low-cost, practical technologies are needed to reduce fugitive CH₄ from farms. Biofilters have mitigation potential, but current designs for odor are limited in their ability to capture CH₄. Fungi have been shown to improve capture of hard-to-target gases in other biofilter applications and were investigated here for their ability to capture CH₄. Using a lab-scale biofilter, several fungal species were shown to improve CH₄ capture compared to a bacterial system and sterile control. A subsequent experiment with Pleurotus ostreatus found capture to increase with increasing levels of fungal biomass. Using a chromatographic isotherm, the ability of fungal materials to sorb CH₄ was confirmed, and again greater sorption of CH₄ was possible when fungal biomass was increased. These results demonstrate the ability of fungi to capture CH₄ and warrant their investigation as a way to improve the CH4 mitigation capacity of livestock emission biofilters.