Tiny Amazon microbes could hold key to global climate impact

Scientists have discovered a family of microscopic organisms deep in puddle soil in the Peruvian Amazon that could play a crucial role in determining how tropical peatlands respond to climate change. Thousands of times smaller than a grain of sand, these newly discovered microorganisms have developed the unique ability to lock away carbon or release it as a greenhouse gas.

The discovery comes at a critical time for Amazon peatlands, which currently store an estimated 3.1 billion tonnes of carbon, roughly twice the amount contained in forests worldwide. Researchers warn that the destruction of these ecosystems could release up to 500 million tons of carbon by the end of the century, equivalent to 5% of global annual fossil fuel emissions.

“The microbial universe of the Amazon peatland is extensive in space and time, hidden by its remoteness, and heavily studied in local and global contributions.” Biodesign Swette Center for Environmental Biotechnology at State University.

The study, published in the journal Microbiology Spectrum, reveals how these microorganisms adapt to the challenging conditions of tropical peatlands. Unlike most organisms, they can survive in environments with little oxygen, exhibiting remarkable metabolic flexibility.

These microorganisms perform a dual function in the carbon cycle. Under stable conditions, they help peatlands act as carbon sinks, capturing and storing carbon that would otherwise enter the atmosphere. But when environmental conditions change due to factors such as drought or warming, these same organisms can accelerate the release of greenhouse gases.

Nature’s carbon dome is under threat

The study focused on Peru’s pie-maranan foran basin, a vital peatland region that spans approximately 100,000 square kilometers of the northwestern Amazon rainforest. The area includes extensive flooded forests and swamps.

What makes these microorganisms particularly interesting is their ability to consume carbon monoxide (a poisonous gas to many organisms) and convert it into energy. In this way, they simultaneously reduce carbon toxicity in the environment and produce compounds that other microorganisms can use to produce methane.

“Our job is to find incredible organisms that are adapted to this environment, some of which provide unique and important services – from carbon stabilization or recycling to carbon monoxide detoxification and more,” explains Cadillo-Quiroz.

Impact of climate change

Although tropical peatlands currently act as carbon sinks, absorbing more carbon than they release, scientists warn they are increasingly vulnerable to the impacts of climate change. Rising temperatures and changing rainfall patterns could deplete these peatlands, converting them from carbon storage systems to carbon sources.

The researchers emphasize the urgent need to protect these ecosystems from human activities such as deforestation, drainage and mining. They advocate for sustainable land management practices and continue to investigate microbial communities to better understand their role in the carbon cycle.

“Working to understand the microorganisms and ecosystems in the lush and majestic Amazon rainforest has been the privilege of my life, and my goal is to use it to protect the region in the fight against climate change,” Cadillo-Quiroz said.

The research, supported by the National Science Foundation, represents a major advance in understanding how Earth’s smallest organisms have an outsized impact on the global climate system. As climate change continues to reshape our planet, these hidden ecosystems may hold vital lessons to protect our future.