Biological nitrogen fixation (BNF) occurs when atmospheric nitrogen is converted to ammonia by an enzyme called nitrogenase. This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g. nucleotides for DNA and amino acids for proteins. Nitrogen fixation is utilized by numerous prokaryotes, which are called diazotrophs, and some of them form associations with higher plants (symbiosis). The development of processes for plant inoculation with dizotrophic bacteria have allowed drastic reductions in the use of nitrogen fertilizers in crops such as soybean, with substantial economic and environmental benefits.
Dr. Johanna Döbereiner, one of the greatest Brazilian scientists spent most of her career studying the role of nitrogen-fixing bacteria in plants. Of Czech origin, she graduated in agronomic engineering at the University of Munich, coming to Brazil after the Second World War. Her studies on nitrogen fixing bacteria had a huge impact in the expansion of soybean cultivation in Brazil, turning the country into one of the world’s biggest producer and exporter of this legume crop.
An article just published in the Seed Magazine points out that “the story of modern fertilizer is really the story of nitrogen, and how humans learned to make plant food out of air and energy”. The next challenge will be to unlock the secrets of the enzyme nitrogenase, a breakthrough that would have profound consequences for agriculture and the environment. Certainly a great challenge for 21st century biotechnology! If nitrogen fixation can be put to work in sugarcane, sorghum, maize and other crops as it does in soybeans, the impact will be tremendous. Click here to read the article.