School of Medicine Researchers Uncover Blueprint for More Sustainable Agriculture
Rajnandani Kashyap, Ph.D., a postdoctoral fellow at Saint Louis University School of Medicine, is at the helm of a groundbreaking discovery that could revolutionize global food production.
The study, recently accepted for publication in the prestigious scientific journal Nature, reveals an entirely unexpected blueprint for how one of the oldest microbes on Earth processes nitrogen to create ammonia, the building block of fertilizer. The finding doesn’t just open up new biotech possibilities to reduce costs and pollution associated with industrial agriculture — it could also play a significant role in green energy and even supporting space travel to Mars.
“Looking at this, it’s the coolest discovery of my life,” said Kashyap, the study’s lead researcher and first author.
The achievement, funded by the Department of Energy, is the culmination of a multi-institution collaboration across SLU and the University of Arkansas. The U of A team spent several years engineering the oxygen-averse microbe to harvest a sample that was then sent to the laboratory of Edwin Antony, Ph.D., a SLU professor of biochemistry and molecular biology and the study’s principal investigator. The team isolated and purified the protein — a complex process with no room for error — before using a cryo-electron microscope (cryo-EM) to capture its native structure.
To picture how that imaging technology works, Kashyap said, imagine a freeze frame of someone dancing in the room, with thousands of different images taken from different angles, all capturing that single moment in the dance. Using this imaging technique, she was able to reconstruct a 3D model of the enzyme’s structure. She said the result was the discovery of a nitrogenase supercomplex, a structure that contradicts decades-old assumptions derived from how the enzyme works in common bacteria.
The cherry on top? Kashyap made the discovery on Christmas Day.
“It’s like a gift from Santa,” she said.
A Return on Investment
The team’s achievement underscores the transformative power of SLU’s investment in cryo-EM capabilities. As part of a 15-year agreement established in 2019 with Washington University in St. Louis, SLU contributed $2.5 million from the Doisy Fund for Biochemistry toward the purchase of a new $5 million cryo-EM. In turn, SLU researchers can access the cryo-EM and use the Washington University Center of Cellular Imaging (WUCCI) — one of the best of its kind in the nation.
Enrico Di Cera, M.D., chair of the Department of Biochemistry and Molecular Biology, said the investment has already generated more than $22 million in federal grant funding, dozens of publications in top-tier journals and key new hires for the department.
“This has been and continues to be an exemplary success story,” Di Cera said.
Beyond the funding, both Antony and Kashyap said the world-class infrastructure enriches the student experience at SLU, providing incoming undergraduate and graduate students with a level of personalized support and mentorship unlike anywhere else.
“As young investigators, we have the energy to carry on challenging projects and tackle those challenging questions,” Kashyap said. “It takes a lot of hard work and time and effort, but we should not get scared….they are going to reward you in the long run.”