In a refrigerated laboratory on the second floor of South Dakota State University's Edgar S. McFadden Biostress Laboratory, hundreds of petri dishes hold organisms that have already saved the world once—and may be about to do it again. Ruanbao Zhou and his team are cultivating cyanobacteria, ancient microbes that, roughly 4 billion years ago, performed the seemingly impossible: they transformed an oxygen-free atmosphere into one that could sustain life. Now, these same solar-powered bacteria may offer humanity a solution to one of agriculture's most pressing modern dilemmas.
The challenge is enormous and urgent. Globally, farmers depend on more than 130 million metric tons of ammonia each year to produce nitrogen fertilizer—a number that will only climb as the world's population grows and food demand increases. This ammonia production, however, relies on the Haber-Bosch process, a century-old method that consumes vast amounts of fossil fuels. The toll is staggering: approximately 1.8 tons of carbon dioxide are released for every single ton of ammonia produced, making ammonia production responsible for around 1.2% of global emissions. The environmental damage extends beyond climate impact. When excess fertilizer runs off into waterways, it triggers eutrophication—a process that sparks toxic algal blooms and kills aquatic ecosystems. Meanwhile, farmers themselves face another crisis: the cost of synthetic fertilizers has skyrocketed in recent years, with the American Farm Bureau Federation projecting prices will continue climbing due to export restrictions, rising natural gas costs, and geopolitical instability.
Zhou, who directs the National Science Foundation-backed BioNitrogen Economy Research Center, is pursuing a radically different path. Rather than refining the energy-intensive Haber-Bosch process as other researchers are doing, his team aims to genetically engineer cyanobacteria to produce nitrogen-rich fertilizer directly. "More than 2.8 billion years ago, tiny cyanobacteria did something truly extraordinary," Zhou explains. "They used sunlight to split water and release oxygen. In doing so, they turned a lifeless planet into one that could breathe. Today, these same solar-powered, nitrogen-fixing microbes may once again help us reshape our world."
The research is a collaborative effort spanning South Dakota State University, South Dakota Mines, University of South Dakota, and Oglala Lakota College—drawing together the region's leading biologists and scientists. Three years ago, Zhou and co-professors Lan Xu and Liping Gu ventured into Badlands National Park searching for cyanobacteria samples in the wild, beginning the work that now fills those petri dishes in Brookings. The bacteria possess what amounts to a biological superpower: they can convert atmospheric nitrogen into usable forms like ammonia through a process called biological nitrogen fixation, all powered by sunlight rather than fossil fuels.
If successful, this approach would bypass the Haber-Bosch process entirely, slashing both carbon emissions and production costs while eliminating the fertilizer runoff that poisons waterways. The stakes could hardly be higher. The original cyanobacteria made complex life on Earth possible; Zhou's team believes their descendants might help preserve it. In laboratories in South Dakota, ancient microbes are being positioned to solve one of modern agriculture's most stubborn challenges—not through brute industrial force, but through the elegant, renewable power they've wielded for billions of years.