The U.S. Department of Energy awarded a three-year, $3.4 million grant to the University of Hawaii at Mānoa to study the effect of fungal-bacterial interactions on nutrients such as carbon and nitrogen in the soil.
The study is being conducted by an interdisciplinary team led by Associate Professor Nhu Nguyen from the university’s Department of Tropical Plant and Soil Sciences. The team hopes to find out if fungal-bacterial interactions can change if carbon and nitrogen molecules are kept sequestered underground or if they are released into the atmosphere, contributing to climate change.
Scientists now know that a single teaspoon of soil contains billions of bacteria from thousands of bacterial species, interacting with miles of fungal hyphae, which are the long, threadlike branches that make up a fungus’ body.
Fungal hyphae release digestive enzymes in order to absorb nutrients from food sources. These microorganisms are the machinery that drives important elemental cycles such as carbon and nitrogen on the planet. Researchers are unclear about how these microbial interactions behave in different soils.
Hawaii’s great soil diversity represents more than 80% of soil types on the planet, making it the perfect environment to study these dominant members of the soil microbiome.
“Due to our island topology and small landmass, we can control environmental factors, including climate and host plants, that can influence the soil microbiome,” Nguyen said. “The diversity of soils in Hawaii plays a central role. In other words, this work can only be done in Hawaiʻi, and because each of our soils is representative of those found in larger landmasses, our findings would be transferable to other soils around the world.
Nguyen and UH Mānoa soil scientists Jonathan Deenik and Tai Maaz teamed up with Maggie Yuan of the University of California at Berkeley, Jizhong Zhou of the University of Oklahoma and Jennifer Pett-Ridge of the Lawrence Livermore National Laboratory.
The team knows that soil contains more carbon than all above-ground biomass and the atmosphere combined, and that soil microbes recycle available nitrogen that sustains much of Earth’s life.
“The question of whether these molecules contribute to climate change is likely related to the interactions between the millions of species of fungi and bacteria that live there,” Nguyen said.
The team is trying to understand how interactions between members of the soil microbiome can determine the fate of molecules that warm the planet.
“As these molecules pass through soil microbes, they can be taken up by plants and thus help open pathways to sustainable agriculture – a system that both provides food and prevents carbon molecules and nitrogen from leaving the soil,” Nguyen said.
Due to the extremely complex nature of the soil, the researchers will exploit the tools they have developed over the past decade, using stable isotopes to track carbon and nitrogen molecules as they move from atmosphere, in plants, in microbial cells and possibly on soil mineral surfaces. , where they can be stabilized or released into the atmosphere.
The strength of the project lies in combining stable isotopes with multi-omics tools and bringing all of these data streams together into a microbial-informed ecosystem model.
The multi-omics tools are:
- metagenomics – the study of genetic material recovered directly from environmental samples
- metatranscriptomics – the science that studies the gene expression of microbes in natural environments
- metabolomics – the large-scale study of small molecules
This systems biology approach, from molecule to organism to ecosystem, is fundamental to understanding the complexity of the processes that occur in soils and translating them into meaningful outcomes, such as climate change mitigation. and support for sustainable agriculture.
This work will contribute to an ongoing initiative at UH to study the microbiome of natural and human environments.
Watch a one minute video about Nguyen, Deenik and Maaz.