Consumption of NO by methanotrophic bacteria in pure culture and in soil

The methanotrophs Methylomonas angile (type I) and Methylosinus trichosporium (type II) produced nitrite, nitrate and N2O during growth on methane, apparently by heterotrophic nitrification of ammonium. The methanotrophs were also able to consume NO but did not produce it. After incubation of soil from a drained paddy field in the presence of CH4 the numbers of methanotrophs increased from 105 to 107 per gram dry weigth. The thus enriched soil showed increased rates of NO consumption while rates of NO production did not change.