Evaluation of methyl fluoride and dimethyl ether as inhibitors of aerobic methane oxidation
Methyl fluoride (MF) and dimethyl ether (DME) were effective inhibitors of aerobic methanotrophy in a variety of soils. MF and DME blocked consumption of CH 4 as well as the oxidation of 14 CH 4 to 14 CO 2 , but neither MF nor DME affected the oxidation of [ 14 C]methanol or [ 14 C]formate to 14 CO 2 . Cooxidation of ethane and propane by methane-oxidizing soils was also inhibited by MF. Nitrification (ammonia oxidation) in soils was inhibited by both MF and DME. Production of N 2 O via nitrification was inhibited by MF; however, MF did not affect N 2 O production associated with denitrification. Methanogenesis was partially inhibited by MF but not by DME. Methane oxidation was ∼100-fold more sensitive to MF than was methanogenesis, indicating that an optimum concentration could be employed to selectively block methanotrophy. MF inhibited methane oxidation by cell suspensions of Methylococcus capsulatus ; however, DME was a much less effective inhibitor.