Microbiology: A new source of methane in terrestrial ecosystems

The discovery that fungi are a biological source of the greenhouse gas methane is reported in Nature Communications this week. This finding may advance our understanding of global methane cycles and could help improving climate models.

Methane is the second most important greenhouse gas after carbon dioxide. Apart from industrial processes, methane is produced by animals, plants and certain microbes called archaea. Katharina Lenhart and colleagues now add fungi to this list, which are found in almost all terrestrial ecosystems. The team demonstrates that eight different species of wood and soil degrading Basidomycetes produce methane from the amino acid methionine.

The discovery suggests that aerobic methane formation is more widespread in nature than previously thought. How much methane emissions from these or other fungi contribute to the global methane budget remains to be established.