Methanotroph Ecology, Environmental Distribution and Functioning

The dynamics of methane concentrations in the atmosphere in recent decades has demonstrated many anomalies which are poorly understood. The only biological way of degrading this potent greenhouse gas is by microbial oxidation. Aerobic methanotrophic bacteria (MB) play an important role in many ecosystems worldwide degrading methane before it can escape to the atmosphere. This group of bacteria has intensively been studied as a model microbial functional guild because there is a strong link between the consumption of methane and the composition of MB communities, facilitating the study of microbial “behavior” in the environment. These studies have revealed a strong biogeography of MB which is displayed in their phylogeny not only on the basis of single functional marker genes but also on genome sequence basis. Novel environmental controlling factors have been revealed (e.g. rare earth metals) as well as novel organisms with as yet unknown traits for MB. The resistance and resilience of methane consumption and methane consuming communities have been shown to depend on specific community members. The current knowledge on environmental distribution and of MB has led to propose a life-history scheme, classifying MB communities on their collective traits rather than singly on their capacity the oxidise methane alone.