13 Feb. () –
Communities of microbes that work together release more carbon dioxide than competing communities, which contributes the most to climate change.
New research from scientists at Imperial College London and the University of Exeter has shown that when heated, bacterial communities that have matured to cooperate release more carbon dioxide (CO2) than competing communities. The results are published in Nature Microbiology.
Despite being small, microbes, and especially bacteria, contribute a lot to the global carbon cycle: the movement of carbon in various forms through nature. Its level in the atmosphere, and therefore its influence on climate change, is controlled by a series of sources and sinks, such as respiration and photosynthesis respectively.
Co-author of the new study, Dr Tom Clegg, who led development of the theory from Imperial’s Department of Life Sciences, said: “Our findings have far-reaching implications given the important contributions that bacterial communities make to the cycle. We show that changes in the interactions of bacterial species can rapidly and substantially increase carbon emissions from natural ecosystems around the world.”
Bacteria -like humans- respire, take in oxygen and release CO2. Of the many factors that control your level of respiration, temperature is especially important.
Bacteria form communities of different species in all habitable environments, including soil, puddles, and our intestines. When communities first form, bacterial species are often “competitive,” each trying to get the best resources.
However, over time these communities mature to cooperate in facilitating each other’s use of resources. In this scenario, each species plays a role in the community that ensures its overall “health”; for example, several species work together to break down litter and access nutrients.
Previously, researchers had hypothesized that the response of bacterial communities to rising temperatures was governed primarily by changes in the metabolism of individual species: as the environment warms, individual cells have to breathe faster to survive. . However, as these species interact, the new article team wanted to see if the level of cooperation in the community changed this picture.
They created a mathematical model showing that cooperative communities are more sensitive to warming, which means that as the temperature rises, they release CO2 at an accelerated rate. The team tested their model in lab experiments with Icelandic geothermal stream communities, which showed that a switch from competition to facilitation caused a 60% increase in the community’s respiration sensitivity to warming.
Dr Francisca Garcia, from the University of Exeter’s Institute for Environment and Sustainability, said: “Researchers should incorporate this phenomenon into models as it has the potential to substantially improve the accuracy of predictions about the effects of climate change. current and future in the global carbon cycle.”
“Indeed, new bacterial communities are assembling on melting glaciers and permafrost driven by climate change as we speak, and as they become more cooperative, this will likely amplify carbon emissions from these rapidly changing environments.”
