A methanotrophic bacterium to enable methane removal for climate mitigation.

Area of Science:

• Environmental microbiology
• Biotechnology for climate change mitigation

Background:

• Atmospheric methane is a potent greenhouse gas, necessitating urgent mitigation strategies.
• Methanotrophs, bacteria that consume methane, offer a biological approach to methane removal.
• Current methanotrophs typically require high methane concentrations (5,000-10,000 ppm), limiting their application in ambient air (1.9 ppm) or emission sites (approx. 500 ppm).

Purpose of the Study:

• To identify methanotrophic bacteria capable of efficient methane consumption at low concentrations (≤500 ppm).
• To evaluate the potential of these bacteria for developing methane removal technologies at emission sources.

Main Methods:

• Screening of existing methanotrophic strains for growth and methane consumption at 500 ppm methane.
• Bioreactor performance analysis.
• RNAseq-based transcriptomics to understand the metabolic basis for low-methane utilization.

Main Results:

• Several methanotrophic strains demonstrated effective growth at 500 ppm methane.
• *Methylotuvimicrobium buryatense* 5GB1C exhibited enhanced low-methane consumption rates compared to previously reported values.
• Transcriptomic and metabolic analyses indicated low maintenance energy requirements and high methane affinity contribute to its efficiency.

Conclusions:

• *Methylotuvimicrobium buryatense* 5GB1C is a strong candidate for developing biological methane removal technology.
• This technology, if scaled, could significantly contribute to slowing global warming by targeting methane emissions from various industrial and natural sources.