Methane-eating microbes turn greenhouse gas into fuel, food, and bioplastics

Methane is one of the most powerful greenhouse gases, warming the planet far faster than carbon dioxide over the short term. Yet much of the world’s methane escapes into the air from landfills, farms, mines, and wastewater systems. Scientists are now uncovering a surprising ally in the fight against climate change: tiny microbes that eat methane and can turn it into useful products.

A new review of fast-moving research shows that these microbes, called methanotrophs, could help reduce methane emissions while creating fuels, animal feed, and biodegradable plastics. By harnessing these unusual bacteria, researchers hope to turn one of the planet’s climate threats into a resource for industry and society.

Methanotrophs are bacteria that consume methane for both energy and carbon. They thrive in many environments, from wetlands, rice paddies, and forest soils to lakes, sediments, and even hot springs.

In the lab, scientists have shown that these microbes can oxidize methane step by step into methanol, formaldehyde, formate, and finally carbon dioxide. These reactions occur at mild temperatures and low energy, making them highly efficient compared with conventional chemical processes.

“Our work shows that methanotrophs are no longer just a curiosity of environmental microbiology; they are a strategic biological tool for a low carbon future,” said Jingrui Deng of Shandong University, lead author of the review. “If we can understand and control these microbial communities, we can simultaneously cut greenhouse gases and manufacture useful products from the same processes.”

These microbes don’t just eliminate methane—they transform it. By channeling carbon through different metabolic pathways, methanotrophs can produce methanol for fuel or chemical feedstock, single-cell protein (SCP) for animal or human nutrition, and polyhydroxyalkanoates (PHAs), a type of biodegradable plastic. In this way, methane becomes not a waste gas but a feedstock for sustainable products.

Researchers are developing engineering solutions to put methanotrophs to work in the real world. Landfill surfaces can be covered with biofilms seeded with these bacteria, while biofilters strip methane from exhaust streams at biogas plants and mines.

Spraying ultrafine water mists containing methane-eating microbes in mining operations has reduced methane levels in the air and lowered explosion risks. In wastewater treatment, methanotrophs can remove both dissolved methane and nitrite simultaneously, cutting greenhouse gas emissions and water pollutants.

Scientists are also exploring how to boost the microbes’ productivity. Immobilizing methanotrophs on materials such as coconut coir, ion exchange resins, or modified chitosan has multiplied methanol yields. Mixed microbial cultures can transform biogas into protein rich in essential amino acids, providing a new path for sustainable feed ingredients.

Certain Type II methanotrophs, such as Methylocystis, can store over half of their cell mass as bioplastics under carefully controlled conditions, creating renewable materials that could reduce reliance on petroleum-based plastics.

Not all methanotrophs are equally beneficial. Some strains compete with other microbes for key metals, which can unintentionally increase nitrous oxide, another potent greenhouse gas. Other strains, however, can fully reduce nitrate to harmless nitrogen gas, avoiding this problem entirely. “Designing future systems means choosing the right microbial partners so that we reduce both methane and nitrous oxide rather than trading one gas for another,” Deng said.

Scientists classify methanotrophs into types I, II, and X, each with different metabolic pathways. Type I microbes efficiently convert methane into biomass or targeted compounds, Type II are flexible under nutrient-limited conditions, and Type X combine features of both. Understanding these differences is critical for engineering systems that both remove methane and produce valuable products.

Methanotrophs often work best in communities rather than alone. In mixed cultures, methanotrophs can feed byproducts to other microbes, known as methylotrophs, improving efficiency and avoiding toxic buildups of intermediates such as formaldehyde.

By cooperating, microbial communities process methane faster and more completely. This cross-feeding behavior is vital for scaling production in industrial applications.

Scientists are also learning how to fine-tune microbial metabolism.

Recent advances in technology are helping scientists design microbial communities rather than simply observing them. High-throughput Raman-activated cell sorting allows researchers to select the best-performing strains from complex environmental samples.

Synthetic biology enables precise rerouting or deletion of metabolic steps. These tools bring researchers closer to building microbial systems for targeted climate mitigation and sustainable manufacturing.

Senior author Qigui Niu said, “Methanotrophs sit at the crossroads of climate mitigation, waste management, and green manufacturing. By integrating strain engineering, smart bioreactor design, and rigorous life cycle assessment, we can turn methane from a liability into a cornerstone of sustainable biomanufacturing.”

Despite their promise, methanotrophs are not yet widely used industrially. Scaling up requires careful control of growth conditions, gas composition, and microbial interactions. Intermediate compounds such as formaldehyde must be managed to prevent toxicity.

Bioreactors must be designed to handle gas flow safely, maintain stability over long periods, and remain cost-effective compared with traditional chemical processes.

Researchers are also investigating which strains work best in which environments. The ultimate goal is systems that capture methane emissions from livestock, landfills, oil and gas operations, and wastewater treatment, converting it into useful products efficiently and safely. If successful, this approach could reduce greenhouse gas emissions while producing sustainable fuels, protein, and materials.

This research offers a dual benefit: mitigating climate change and creating economic value from waste gases. Methanotroph-based systems could turn methane from a potent greenhouse gas into fuels, animal feed, and bioplastics.

Industries could integrate these microbes into landfill covers, wastewater treatment plants, or mining operations. Over time, such strategies may help achieve negative carbon goals, reduce dependence on fossil fuels, and provide sustainable protein and materials.

By learning to control microbial metabolism and community interactions, scientists can scale these approaches for widespread environmental and industrial impact.

Research findings are available online in the journal Maximum Academic Press.

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