Methanol improves methane uptake in starved methanotrophic microorganisms

Area of Science:

• Environmental microbiology
• Biogeochemical cycles

Background:

• Methanotrophs are microorganisms capable of oxidizing methane.
• Methane oxidation is a critical process in regulating atmospheric methane concentrations.
• The role of supplementary carbon sources, like methanol, in supporting methanotrophic activity requires further elucidation.

Purpose of the Study:

• To investigate the dependency of methanotrophs on methanol or formate for atmospheric methane oxidation.
• To examine the response of indigenous forest soil methanotrophs to methanol availability under varying methane conditions.

Main Methods:

• Enrichment cultures of methanotrophs were established and maintained.
• Methanol and formate were supplied or withheld to assess their impact on methane oxidation.
• Indigenous forest soil methanotrophs were exposed to different atmospheric conditions and methanol treatments.

Main Results:

• Enrichment cultures required methanol or formate to sustain atmospheric methane oxidation.
• Methane oxidation ceased without methanol or formate but was restored upon their reintroduction.
• Forest soil methanotrophs showed a dependence on methanol when methane was limited and in a methane-free atmosphere.
• Methanol addition initially inhibited, then reactivated, atmospheric methane oxidation in forest soil methanotrophs as methanol was consumed.

Conclusions:

• Methanol and formate are essential for sustained atmospheric methane oxidation by methanotrophs.
• Forest soil methanotrophs exhibit complex regulatory responses to methanol availability, impacting methane oxidation rates.