New Methane-Releasing Microbe Key Player in Climate Change

A new methane-releasing microbe, just recently discovered in Sweden, is a key player in climate change, according to new research.

Identified as Methanoflorens stordalenmirensis, it is just one of many species of soil microbes, known to be among the world's biggest potential amplifiers of human-caused climate change. Earlier this year, an international team of researchers discovered this previously unknown microbe living in permafrost soils in northern Sweden that have begun to thaw in our warming world.

So what makes this particular species of concern to scientists? Well, researchers suspect that it is a key player in global warming by releasing vast amount of carbon from permafrost soils in the form of methane, a powerful heat-trapping gas in the Earth's atmosphere.

"If you think of the African savanna as an analogy, you could say that both lions and elephants produce carbon dioxide, but they eat different things," senior author Scott Saleska said in a press release. "In Methanoflorens, we discovered the microbial equivalent of an elephant, an organism that plays an enormously important role in what happens to the whole ecosystem."

Their research also shows that not all soil microbes are created equal. Soil microbes can make methane two different ways: either from acetate, an organic molecule that comes from plants, or from carbon dioxide and hydrogen.

"Both processes produce energy for the microbe, and the microbe breathes out methane like we breathe out carbon dioxide," explained lead author Carmody McCalley said. "But we find that in thawing permafrost, most methane initially doesn't come from acetate as previously assumed, but the other pathway. This ratio then shifts towards previous estimates as the frozen soils are turned into wetlands and acetate becomes the preferred carbon source."

This leaves scientists wondering just how much of the soil's stored carbon eventually gets released into the atmosphere as methane. That's the million dollar question, but this research now shows that soils microbes, Methanoflorens especially, play a major role in the atmosphere's level of greenhouse gases, and further study could lead to more accurate climate models.

The findings were published in the journal Nature.