When soil microbes eat plant matter, the digested food follows one of two pathways.
When soil microbes eat plant matter, the digested food follows one of two pathways. Either the microbe uses the food to build its own body, or it respires its meal as carbon dioxide (CO2) into the atmosphere.
Now, a Northwestern University-led research team has, for the first time, tracked the pathways of a mixture of plant waste as it moves through bacteria’s metabolism to contribute to atmospheric CO2. The researchers discovered that microbes respire three times as much CO2 from lignin carbons (non-sugar aromatic units) compared to cellulose carbons (glucose sugar units), which both add structure and support to plants’ cellular walls.
These findings help disentangle the role of microbes in soil carbon cycling — information that could help improve predictions of how carbon in soil will affect climate change.
The research was published today (June 11) in the journal Environmental Science & Technology.
Read more at Northwestern University
Image: Illustration of soil with a close-up of a bacterium and the cellular pathways involved in carbon dioxide production. Available substrates from soil organic matter are processed through specific pathways with different amounts of carbon dioxide output flux. (Credit: Aristilde Lab/Northwestern University)
