Nitrous oxide emissions from fertilizer application found to disrupt vital plant growth supporting soil bacteria

MIT study shows nitrous oxide from fertilizer is toxic to B12-dependent soil bacteria, potentially damaging microbial ecosystems that support plant growth.

By: AXL Media

Published: Mar 4, 2026, 9:21 AM EST

Source: The information in this article was sourced from Massachusetts Institute of Technology

The unrecognized biological impact of nitrous oxide

Nitrous oxide (N2O) has long been categorized primarily as a potent greenhouse gas and ozone-depleting substance. While its environmental impact is well-documented, its interaction with living organisms in the soil has been largely overlooked by the scientific community. However, new research from the Massachusetts Institute of Technology (MIT) published in the journal mBio reveals that N2O is far from biologically inert. Researchers found that the gas can actively shape microbial communities in the rhizosphere—the critical area of soil surrounding plant roots—by inhibiting the growth of specific bacterial strains that support plant development and pathogen protection.

Disruption of vitamin B12 dependent processes

The toxic nature of nitrous oxide stems from its ability to deactivate vitamin B12, a nutrient essential for many living organisms. The MIT team focused on methionine biosynthesis, a fundamental process cells use to grow. While some bacteria possess enzymes that can synthesize methionine without B12, others are entirely dependent on the vitamin. By utilizing the microbe Pseudomonas aeruginosa, researchers demonstrated that when B12-independent enzymes were removed, the bacteria became highly sensitive to N2O. Remarkably, the growth of these microbes was hindered even by the nitrous oxide they produced as a byproduct of their own metabolism.

Implications for microbial community distribution

To test how these findings apply to more complex systems, the researchers examined a synthetic microbial community associated with the plant Arabidopsis thaliana. The experiments showed that many root-based microbes are susceptible to N2O toxicity. When sensitive microbes were placed in proximity to N2O-producing bacteria, their growth was significantly hampered. This suggests that nitrous oxide does not merely dissipate into the atmosphere; it serves as a selective pressure that determines which bacteria survive and thrive near plant roots, potentially favoring less beneficial or more resilient strains over those that actively promote crop health.