Aerobic methane production from organic matter

Abstract

Methane, together with H2O, CO2 and N2O, is an important greenhouse gas in the Earth’s atmosphere playing a key role in the radiative budget. It has been known for decades that the production of the reduced compound CH4 is possible almost exclusively in anoxic environments per opera of one of the most important class of microorganisms which form the Archaea reign. Methane can be produced also from incomplete combustion of organic material. The generation of CH4 in an oxygenated environment under near-ambient conditions is a new discovery made in 2006 by Keppler et. al where surprisingly they measured emissions of this greenhouse gas from plants incubated in chambers with air containing 20% of oxygen. Although the estimates on a global scale are still object of an intensive debate, the results presented in this thesis clearly show the existence of methane production under oxic conditions for non living plant material. Temperature and UV light are key factors that drive the generation of CH4 from plant matter in a well oxygenated environment.