World’s first soil atlas reveals most common bacteria in dirt

The world’s first atlas that maps the most common types of soil bacteria in environments around the world has been compiled by an international team of scientists.

The research narrows down the immense diversity of bacteria living in soils from a list of more than 25,000 to the most common 500 species that are found in many environments around the world.

The study by scientists from Australia, the US, Spain and the UK is published in the journal Science.

“Our study narrows down the immense number of bacteria to a “most wanted” list that we can study to improve our understanding of soil microbes and their contributions to the functioning of many different kinds of ecosystems,” says team member and UNSW scientist Professor David Eldridge.

The team collected soil samples from 237 different locations across six continents and 18 countries, spanning an entire range of climates from deserts to grasslands to wetlands. Processing the samples through DNA analysis, the researchers not only discovered which soil species were common, but also uncovered new species previously unknown to science.

Team member Professor Brajesh Singh, from Western Sydney University’s Hawkesbury Institute for the Environment, says understanding the distribution of soil bacteria is essential as it has a significant impact on our world, including producing food, making use of fertiliser nutrients and restoring native forests.

However, despite soil microorganisms being studied for decades, Professor Singh says little was known about their dominance, distribution and functional roles identity until now.

“Now that scientists have been able to narrow down the most common bacteria it gives us a starting point from which we can better understand how soil bacteria function in most of the world’s environments – everything from deserts and farmland, to forests and alpine regions,” he says.

“With the world’s soils home to common bacterial species, we can more closely predict how those dominant bacteria are influencing the way that those soils function.”

The research team says further studies could potential lead to agricultural and industrial applications in the future.

“Eventually, knowing more about these common bacteria might allow us to better connecting specific soil bacteria species to large-scale ecosystem functions such as carbon cycling, crop and plant production and greenhouse gas emissions, all processes that are fundamentally driven by soil bacteria and other microbial organisms,” says lead author Dr Manuel Delgado-Baquerizo, of University of Colorado Boulder’s Cooperative Institute for Research in Environmental Sciences in the United States and honorary collaborator at the Western Sydney University.