Ancient Bacteria in Frozen Soil

Published September 25, 2020

Renaud Berlemont
As part of a collaboration with the USGS and CSUN, Dr. Renaud Berlemont, associate professor of Biological Sciences at CSULB, recently contributed to a research analyzing samples of ancient soil trapped in Arctic ice from roughly 33,000 years ago.

In this work, the team analyzed the soil chemistry and the bacteria that were able to survive the harsh frozen conditions of the Arctic. Among other discoveries, the team identified what remained of the plants and the bacteria, and how these microbes degraded the plant material under primitive conditions.

"We still do not understand the mechanisms that enable microbial survival and growth in permafrost(frozen soil in the arctic)," the authors said. "Nor how microbial communities respond to increasingly thermodynamically limited conditions given the closed nature of the system."

This research helps us understand how the soil was formed and preserved for so long. In addition, as the permafrost is melting due to climate change, it is essential to understand how the microbes will reactivate and degrade the remaining plant material. This could possibly increase the soil respiration and the release of CO2 in the atmosphere and thus accelerate the climate change.

Dr. Berlemont's work may also help people understand that these small organisms are affected by, and will contribute, to the climate change: "Most processes and fluxes (e.g., O2, CO2, N) in environments are driven by the many 'invisible' microbes. However, most people don't know that and focus on larger, easier to observe organisms." Berlemont said.

Explore more of Dr. Berlemont's work, including his research on microbes in the Arctic permafrost, on his faculty website.