The global production of chemical fertilizers contributes significantly to the world’s greenhouse gas emissions, accounting for about 1.5 percent. In a bid to combat this environmental challenge, researchers at the Massachusetts Institute of Technology (MIT) are exploring the integration of bacteria as a more sustainable alternative to traditional chemical fertilizers.
Ariel Furst, an assistant professor of chemical engineering at MIT, led the study with support from the Army Research Office, a National Institutes of Health New Innovator Award, a National Institute for Environmental Health Sciences Core Center Grant, the MIT Climate and Sustainability Consortium, and the MIT Deshpande Center. Benjamin Burke, Gang Fan, Pris Wasuwanich, and Evan Moore are also the authors of the study.
Reducing Carbon Footprint through Bacterial Fertilizers
The researchers developed a novel metal-organic coating to shield bacterial cells from damage while preserving their growth and functionality. In the study, these coated bacteria demonstrated an improved germination rate for various seeds, including crops like corn and bok choy. This breakthrough could revolutionize the deployment of microbes as fertilizers.
Ariel Furst highlights the coating’s ability to protect bacteria during the drying process, enabling cost-effective distribution in dried powder form rather than liquid. Additionally, the coated microbes exhibit resilience to temperatures up to 132 degrees Fahrenheit, eliminating the need for cold storage during transportation.
“We can protect them from the drying process, which would allow us to distribute them much more easily and with less cost because they’re a dried powder instead of in liquid,” she says. “They can also withstand heat up to 132 degrees Fahrenheit, which means that you wouldn’t have to use cold storage for these microbes.”
To shield bacteria from heat and freeze-drying, the researchers applied a metal-phenol network (MPN) coating. Comprising metals such as iron, manganese, aluminum, and zinc, along with polyphenols found in plants, these coatings form a protective shell. The FDA classifies these compounds as generally regarded as safe (GRAS), ensuring the safety of the coated microbes.
Additionally, the study also created 12 different MPNs to encapsulate nitrogen-fixing bacteria. These coatings proved effective in protecting the bacteria from temperatures up to 50 degrees Celsius and relative humidity up to 48 percent. The coated microbes also survived the freeze-drying process, addressing critical hurdles in transportation.
The most effective MPN, a combination of manganese and the polyphenol EGCG, showcased promising results in aiding seed germination. This development holds the potential to democratize regenerative agriculture by offering an inexpensive and accessible solution.
“When we think about developing technology, we need to intentionally design it to be inexpensive and accessible, and that’s what this technology is. It would help democratize regenerative agriculture,” she added.
Ariel Furst, assistant professor of chemical engineering at MIT
