Researchers say resurrected ancient enzyme could explain early life on Earth and beyond

LOGAN, UTAH, USA -- Nitrogen, upon which all life on Earth depends, may hold the key for explaining how early life on the planet evolved and how it could evolve on other planets.

“All living organisms need nitrogen to survive and, though it’s all around us, we can’t access it directly,” says Utah State University biochemist Lance Seefeldt. “Enzymes called nitrogenases enable nitrogen fixation, which converts nitrogen to a form plants, animals, humans and other life forms can access. And we’re just beginning to understand the extent to which, over the Earth’s four-billion-year history, these nitrogenases have evolved.”

Seefeldt, with USU senior scientist Derek Harris and fellow colleagues with the NASA-funded Metal Utilization and Selection across Eons (MUSE) project at the University of Wisconsin-Madison, report findings from a study using synthetic biology to reverse-engineer modern nitrogenases and rebuild their possible ancestors in the Jan. 22, 2026 issue of Nature Communications.

“Our role in the study was to characterize a library of the synthetically reconstructed ancestral nitrogenase genes,” says Harris. “Under controlled lab conditions, we measured the nitrogen isotope fractionation in the cell biomass of the engineered strains.”

Seefeldt, professor and head of USU’s Department of Chemistry and Biochemistry, has studied the structure and function of nitrogenases for more than three decades, says being able to reconstruct ancient nitrogenases represents a breakthrough in understanding the origins of life on Earth, as well as on other planets.

“Until now, science has relied on ancient rock and fossils to study early life,” he says. “Our planet was vastly different billions of years ago. Modern microbes access atmospheric sources of nitrogen through nitrogenases, which are just one family of enzymes. Study of fossilized enzymes assumes ancient enzymes produced the same isotopic signatures as modern enzymes.”

Reconstructed nitrogenases, Seefeldt says, offer researchers a new window into what Earth and its atmosphere was like eons ago.

“Understanding nitrogenases, both ancient and modern, is critical to helping us tackle current agricultural challenges in a changing climate, including areas at risk of famine due to drought and lack of access to commercial fertilizers,” he says.

Additionally, Seefeldt, who has collaborated on other NASA-funded projects, says the research fuels efforts to explore how to grow food in space and on Mars.

Betül Kaçar, professor of bacteriology at the UW-Madison, director of the MUSE project and corresponding author on the paper, says study findings offer a sharper picture of how life persisted and evolved before oxygen-dependent organisms began reshaping the Earth.

“The search for life starts here at home, and our home is four billion years old,” she says. “So, we need to understand our own past. We need to understand life before us, if we want to understand life ahead of us and life elsewhere.”

###