Methylocystis dominates methane oxidation in glacier foreland soil at elevated temperature

Area of Science:

• Microbiology
• Environmental Science
• Geosciences

Background:

• Methane-oxidizing bacteria (methanotrophs) are crucial for mitigating methane emissions in cold environments.
• The response of these microbes to temperatures exceeding in-situ conditions in glacial regions remains understudied.

Purpose of the Study:

• To investigate the activity and community structure of methanotrophs in glacier foreland soils under elevated temperatures (35°C).
• To assess the impact of soil water content on methane oxidation potential at higher temperatures.

Main Methods:

• Soil samples were collected from Longxiazailongba (LXZ) and Qiangyong (QY) glacier forelands.
• Microcosm incubations with 13CH4 at 35°C under varying soil water conditions.
• DNA stable isotope probing (DNA-SIP) coupled with high-throughput sequencing to identify active methanotrophs.

Main Results:

• Methane oxidation potential significantly increased at 35°C in both LXZ and QY soils, particularly with abundant methane and oxygen.
• Soil water content influenced methane oxidation rates.
• The mesophilic methanotroph Methylocystis, previously undetected in active roles, became dominant at 35°C.

Conclusions:

• Methylocystis can survive prolonged low temperatures and become metabolically active under favorable conditions.
• The presence and activity of mesophilic methanotrophs in cold habitats have significant implications for greenhouse gas regulation in warming glacial environments.