Recent dynamics and uncertainties in global methane budgets
necessitate research of controls of sources and sinks of
atmospheric methane. Production of methane by
methanogenic archaea in wetlands is a major source while
consumption by methane oxidizing bacteria in upland soils is a
major sink. Methane formation as well as consumption is
affected by nitrogenous fertilizers as has been studied
intensively. This review synthesizes the results of these studies
which are contradictory and await mechanistic explanations.
These can be found in the community composition and the
traits of the microbes involved in methane cycling. Molecular
microbial investigations, use of stable isotope labeling
techniques, discoveries and isolation of new species and
pathways offer new insight into interactions between nitrogen
and methane cycling.