At a Glance
- Researchers led by James Tiedje discovered a new group of microbes, CSP1-3, deep in the soil. These microbes help purify water and recycle essential nutrients for maintaining Earth’s “Critical Zone.”
- CSP1-3 microbes, found in soil samples from Iowa and China, are highly abundant and actively growing, making up to half of the microbial community in deep soils, contrary to previous assumptions of microbial dormancy.
- These microbes recycle carbon and nitrogen in deep soils, highlighting their role in ecosystem health. Their ancestors are believed to have lived in aquatic environments before transitioning to soil.
- CSP1-3 microbes act as “scavengers” in deep soils, purifying water by consuming carbon and nitrogen that trickle down from surface soil. This ensures cleaner groundwater and promotes water quality.
- Tiedje’s team plans to culture these microbes in a lab to study their biology and potential to address environmental challenges like pollution cleanup, offering hope for solving global environmental issues.
Researchers have uncovered a new group of microbes deep in the soil that are helping purify water and recycle essential nutrients. The discovery, whose results were published in the Proceedings of the National Academy of Sciences, was made in a study led by microbiologist James Tiedje from Michigan State University, and it highlights a previously unexplored ecosystem in Earth’s “Critical Zone.” This region is crucial in water quality, food production, and ecosystem health. These microbes, belonging to a newly identified group called CSP1-3, were found in soil samples from Iowa and China, stretching as deep as 70 feet underground.
CSP1-3 microbes are unlike typical soil organisms. Instead of being rare, they are highly abundant and actively growing, dominating up to half of the microbial community in deep soils. Traditionally, microbes in such environments were thought to be dormant or inactive. However, Tiedje’s team discovered that these microbes are busy recycling carbon and nitrogen, which is essential for maintaining the health of the soil ecosystem. Their findings suggest that CSP1-3’s ancestors lived in aquatic environments millions of years ago before transitioning to colonize the soil, adapting to the unique conditions of deep, energy-limited soils.
Soil is Earth’s largest natural water filter, and these microbes help clean water as it passes through the deep soil layers. They consume the carbon and nitrogen that trickles down from the surface soil, completing the purification process. In essence, CSP1-3 acts like a “scavenger” in deep soil, ensuring that the water reaching groundwater or being filtered through the Earth is cleaner and safer. This highlights how vital deep soil ecosystems are to maintaining water quality and supporting global environmental health.
Looking ahead, Tiedje and his team plan to culture these microbes in a lab to better understand their unique biology and discover how they thrive in such harsh conditions. By studying their physiology, researchers hope to uncover valuable genetic information that could help tackle environmental challenges, such as pollution cleanup. If these microbes can metabolize pollutants efficiently, they could be critical in addressing some of Earth’s most pressing environmental issues.
References
- Michigan State University. (2025, April 7). Scientists discover new microbes in Earth’s deep soil. Phys.Org; Michigan State University. https://phys.org/news/2025-04-scientists-microbes-earth-deep-soil.html
- Feng, W., Wan, X., Zhang, Y., Quensen, J., Williams, T. A., Thompson, M., Streeter, M., Zhang, Y., Jiao, S., Wei, G., Zhu, Y., Gu, J., Tiedje, J. M., & Qian, X. (2025). Diversification, niche adaptation, and evolution of a candidate phylum thriving in the deep Critical Zone. Proceedings of the National Academy of Sciences, 122(12), e2424463122. https://doi.org/10.1073/pnas.2424463122
