According to a report published today in eVie.
The results have important implications for predicting the impact of global warming on ecosystems.
Microbes are an integral part of ecosystem functioning, due to their key role as pathogens, food sources and in nutrient recycling. To understand the profound impact of climate change on the functioning of different ecosystems, it is therefore necessary to study the microbial communities that make them up.
“Microbial communities can respond to short-term warming through acclimation — developing unique traits adapted to the environment — or in the longer term through adaptation, where they make evolutionary changes over multiple generations,” says lead author Thomas Smith, Research Associate at the Georgina Mace Center for the Living Planet, Imperial College London, UK. “But there is also a third mechanism, called species sorting, by which the composition of the overall community – i.e. what species are present – changes with changes in temperature. The importance of species sorting in relation to acclimation and adaptation has not been explored in the context of microbial community responses to temperature changes. »
To address this issue, the team performed a species sorting experiment, in which they grew replicated soil bacterial communities collected from a single site at different temperatures ranging from 4°C to 50°C. then measured the growth and metabolism of each isolated strain of bacteria at these different temperatures to determine their thermal performance, and studied the genetic sequences of the isolated bacteria to see how the temperature-response traits changed over time.
They found that evolutionarily and functionally distinct communities emerged at each of the temperature conditions, driven by the resuscitation of microbial strains that had been inactive under the previous environmental conditions. This suggests that – rather than new bacteria moving into a community to adapt to new conditions – the parent community harbors multiple bacterial strains that are pre-adapted to survive different temperatures and can activate when their preferred temperature is reached. . As a result, microbial communities in nature are likely to be able to respond quickly to temperature fluctuations.
“Understanding the relative importance of species acclimation, adaptation and sorting in the assembly and renewal of microbial communities is key to determining how quickly they can respond to temperature changes. Until now, a mechanistic basis for these community-level responses had not been discerned,” concludes lead author Thomas Bell, Professor of Microbial Ecology at the Georgina Mace Center for the Living Planet, Imperial College London. “We have discovered that resuscitating functional diversity within a microbial community can enable the entire community to survive in response to temperature changes. Further studies of other microbial communities – such as those residing in water – will support more accurate predictions of the effects of climate change on different ecosystems.